World of Ham Radio 1997/WOHR97_AmSoft_(1997-02-01).iso/usenets/1996_03/_homebre.txt

Text File | 1997-02-01 | 584KB | 15,734 lines

The World of Ham Radio CD-ROM



From [e-mail] Thu Mar 07 10:10:29 1996
From: A J Jeffreys <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: !!!! Also wanted HF SSB Transmitter schematic !!!!!!!!!!!!!!!!!!!!
Date: 5 Mar 1996 20:01:13 GMT
Message-ID: <4hi6i9$[e-mail]>

Hi again!
         I don't suppose anybody has a schematic for an HF SSB transmitter?
If so please could you post a message, or Email me direct.   Thank you!


A J Jeffreys

[e-mail]




From [e-mail] Thu Mar 07 10:10:30 1996
From: A J Jeffreys <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: !!!!!!!!!!!!!!!!!! WANTED  2 meter transmitter schematic or kit info !!!!!!!!!!!!!!!!!!!!!!!
Date: 5 Mar 1996 19:59:33 GMT
Message-ID: <4hi6f5$[e-mail]>

Hi,
   Just wondering if anyone knows of/has a schematic, or knows of a suitable k
it
for a 144-146mhz FM trasmitter/transciever.

If so, please could you post a message, or Email me direct.   Thanks

A J Jeffreys

[e-mail]



From [e-mail] Thu Mar 07 10:10:31 1996
From: [e-mail] (Ed Ganger)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 567 Tone Decoder Help Needed
Date: Wed, 6 Mar 1996 23:58:03 -0400
Message-ID: <[e-mail]>
References: <[e-mail]>

In article <[e-mail]> [e-mail]
(Jason Goldring) writes:
>this is where my problem starts. I have the earphone jack from my scanner
>plugged into
>the 567 circuit, and decoupled with a .01uf capacitor. The output of the 567
is
>simply a

Often, the audio output from a radio is filtered to 300-3000Hz ...
and the tone is not even getting there.


Regards,
Ed


From [e-mail] Thu Mar 07 10:10:32 1996
From: [e-mail] (Wes Stewart)
Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada
Subject: Re: Announsing: Technology Patent Available For Purchase
Date: Mon, 4 Mar 1996 20:50:45 LOCAL
Message-ID: <[e-mail]>
References: <[e-mail]>   <4hdlvj$[e-mail]> <[e-mail]> <4hfqtn$[e-mail]>

In article <4hfqtn$[e-mail]> [e-mail] (Jim Fell
ows) writes:

>In article <[e-mail]>,
>[e-mail] writes:
>|> Paul,
>|>
>|> That's a very blatent claim you make. This patent went through with only
>|> one need for clarification from the PTO. Obviously know one else sought
>|> such a patent which is evidence by the PTO issuing me patent # 5457342.
>|>
>|> Those companies you mention have devices that are similar with respect to
>|> cooling only if you care to follow the patents mentioned on my abstract.
>|> However, NONE have developed the device I have NOR do they have a patent
>|> on such a device. As such, I am the sole owner to pursue development of
>|> this product or companies under infringement.
>|>
>|> Gaerhardt G. Herbst
>|>


>What I am wondering is what this has anything to do with amateur radio antenn
as,
>homebrew, space, etc.?  The point is that this, and the preceding posts were
>made to the amateur radio news groups.

>Cooling of microprocessors, and your grandstanding of being awarded a patent
are
>of no interest to me or in any way pertinent to my interest in amateur radio.

>And that is why the newsgroup(s) have those titles.

>If you are looking for invetors, get a clue and do it somewhere else.

>If you are simply so proud of yourself for being awarded a patent for what
>appears to be anothers work, then HIP HIP HOORAY for you!  Now grow up and go
>away.

>Jim



Amen, Jim.  If this thing works like this guy spells, he's got a tough sell.

"Announsing", "blatent" and "know one else" indeed. I don't know what his
device is,  because searching for the number didn't work for me. Sounds like a

Peltier device, but I guess it could be cold fusion.

73, Wes -- N7WS



From [e-mail] Thu Mar 07 10:10:34 1996
From: [e-mail] (Paul Laughton)
Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada
Subject: Re: Announsing: Technology Patent Available For Purchase
Date: Tue, 05 Mar 1996 07:42:56 GMT
Message-ID: <4hgr8o$[e-mail]>
References: <[e-mail]>  <4hdlvj$[e-mail]> <[e-mail]>
Reply-To: [e-mail]

[e-mail] wrote:

>Paul,

>That's a very blatent claim you make. This patent went through with only
>one need for clarification from the PTO. Obviously know one else sought
>such a patent which is evidence by the PTO issuing me patent # 5457342.

>Those companies you mention have devices that are similar with respect to
>cooling only if you care to follow the patents mentioned on my abstract.
>However, NONE have developed the device I have NOR do they have a patent
>on such a device. As such, I am the sole owner to pursue development of
>this product or companies under infringement.

>Gaerhardt G. Herbst

Having too much time on my hands, I went and looked at your patent.
The first part of the patent describes the exact CCD cooling method
used for years by Santa Barbara Instruments (and others) for cooling
CCDs. Your novel claim seems to be an IC cooler that is retrofitted to
an existing, uncooled IC.

<Yawn>



From [e-mail] Thu Mar 07 10:10:35 1996
From: "Thomas C. J. Sefranek" <[e-mail]>
Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada
Subject: Re: Announsing: Technology Patent Available For Purchase
Date: 5 Mar 1996 12:31:07 GMT
Message-ID: <4hhc6u$[e-mail]>
References: <[e-mail]> <1996Mar5.000656.1@ssrl01>

Westinghouse Semiconductor DOES indeed have a patent on TE coolers.
(I don't know if they even exist anymore...)
I have a large (4"-4" plate) made by them and it has a patent number on
it.  It has a nice fan on the back for moving the heat and embedded
thermocouples for reading the two sides of the junction.

I have used these devices at MIT for over 20 years now, and I'm curious
as to the patent system that is being used by this guy who obviously had
NO interest in the origional development of the device.  Clearly a case
of opportunism.  Ah well Bill Gates can do it, why not this turkey?

Tom
WA1RHP




From [e-mail] Thu Mar 07 10:10:36 1996
From: [e-mail] (Wes Stewart)
Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada
Subject: Re: Announsing: Technology Patent Available For Purchase
Date: Tue, 5 Mar 1996 22:06:25 LOCAL
Message-ID: <[e-mail]>
References: <[e-mail]> <4hdlvj$[e-mail]>

In article <4hdlvj$[e-mail]> [e-mail] (Paul Laughton) write
s:
>From: [e-mail] (Paul Laughton)
>Subject: Re: Announsing: Technology Patent Available For Purchase
>Date: Mon, 04 Mar 1996 02:54:14 GMT

>[e-mail] wrote:


[blah,blah... deleted]

>I wonder how Mr Herbst slipped this one past the prior art
>investigation? This technology has been around since the early 70's -
>at least. For example, IBM and Amdahl main frames made extensive use
>of it.

Simple. He reinvented it first!






From [e-mail] Thu Mar 07 10:10:38 1996
Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada
Subject: Re: Announsing: Technology Patent Available For Purchase
Message-ID: <[e-mail]>
From: [e-mail]
Date: Mon, 04 Mar 96 08:44:20 PDT
References: <[e-mail]>

Paul,

That's a very blatent claim you make. This patent went through with only
one need for clarification from the PTO. Obviously know one else sought
such a patent which is evidence by the PTO issuing me patent # 5457342.

Those companies you mention have devices that are similar with respect to
cooling only if you care to follow the patents mentioned on my abstract.
However, NONE have developed the device I have NOR do they have a patent
on such a device. As such, I am the sole owner to pursue development of
this product or companies under infringement.

Gaerhardt G. Herbst



From [e-mail] Thu Mar 07 10:10:39 1996
From: [e-mail]
Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada
Subject: Re: Announsing: Technology Patent Available For Purchase
Date: Wed, 06 Mar 96 14:52:01 PDT
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]>  <4hg97g$[e-mail]>


> I believe your final statement is too broad.  You may "preclude others
> from practicing your invention" is closer to the correct formulation.
>
Correct you Charles.

Gerhardt G. Herbst



From [e-mail] Thu Mar 07 10:10:40 1996
From: [e-mail]
Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada
Subject: Re: Announsing: Technology Patent Available For Purchase
Date: Wed, 06 Mar 96 15:00:58 PDT
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]> <4hg97g$[e-mail]>  <[e-mail]>


> Correct you Charles.
>
> Gerhardt G. Herbst
>
Whoops...I mean correct you are Charles...

Gerhardt



From [e-mail] Thu Mar 07 10:10:41 1996
From: [e-mail] (WB3U)
Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada
Subject: Re: Announsing: Technology Patent Available For Purchase
Date: Thu, 07 Mar 96 13:37:23 GMT
Message-ID: <4hmp0u$[e-mail]>
References: <[e-mail]> <1996Mar5.000656.1@ssrl01> <4hhc6u$[e-mail]>

   "Thomas C. J. Sefranek" <[e-mail]> wrote:

>Clearly a case of opportunism.  Ah well Bill Gates can do it, why not
>this turkey?

Bill Gates' success year after year is NOT the result of taking undue
advantage of some helpless victim.

Perhaps opportunism is just another catch-all phrase coined so the
have-nots could better antagonize the haves?

73,
Jack WB3U


From [e-mail] Thu Mar 07 10:10:43 1996
From: Leon Heller <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Can anyone ID these IF amps?
Date: Sat, 02 Mar 96 07:47:37 GMT
Message-ID: <[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]

In article <[e-mail]>
           [e-mail] "Bob Applegate" writes:

> Last night I picked up some IF amps at our club's White Elephant sale.  They
> have RCA part numbers, but none of the retired RCA guys at the meeting had
> any idea what they were for.  Markings are:
>
>    LOG IF AMPLIFIER
>    RHG ELECTRONICS LAB (15286)
>    MODEL NO. ICL60G23EA
>    RCA CORP P/N 5616449-5
>
> The connectors are labeled: IF IN, -15V, RET, +15V, TP1, VID 1, VID 2, TP2.

Logarithmic IF amplifiers are used in RADAR receivers as logarithmic
detectors. Plessey (now GPS) is one maker of the special IF amp chips
that are used, like their SL521, which is described as a 140 MHz
wideband logarithmic amplifier. I don't think that they are much use for
anything else, apart from a spectrum analyser, perhaps. According to the
Plessey data, several of the chips are cascaded, and the outputs of each
chip tied together. Interestingly, the chips are DC coupled, with as
many as seven stages, and no other components, apart from some
decoupling. The chips in your amplifiers are probably similar ones made
by RCA (a long time ago).

Leon
--
Leon Heller, G1HSM                | "Do not adjust your mind, there is
E-mail [e-mail]  |  a fault in reality": on a wall
Phone: [phone]         |  many years ago in Oxford.


From [e-mail] Thu Mar 07 10:10:44 1996
From: [e-mail] (T Dunn)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Can anyone ID these IF amps?
Date: Fri, 01 Mar 1996 17:37:02 -0800
Message-ID: <[e-mail]>
References: <[e-mail]>



> Last night I picked up some IF amps at our club's White Elephant sale.  They
> have RCA part numbers, but none of the retired RCA guys at the meeting had
> any idea what they were for.  Markings are:
>
>    LOG IF AMPLIFIER
>    RHG ELECTRONICS LAB (15286)
>    MODEL NO. ICL60G23EA
>    RCA CORP P/N 5616449-5
>
> The connectors are labeled: IF IN, -15V, RET, +15V, TP1, VID 1, VID 2, TP2.
>
> The price was right (25 cents each), so it was worth the gamble that they
> might be something interesting.
>
> Any info about specifications would be appreciated!
>
> Tnx
> Bob - WA2ZZX
>
>Well: I checked my RHG catalog and they don't list the ICL60G23EA.
Thier part numbers usually show the first two digits being IF freq.(ie
60=60MHz) and second two digits(23) are the band width in MHz. The part
number start at ICLL. No ICL. Typical number would be ICLL6020. The
outputs are shown as IF in, IF out, and video1. They also have a Pot. for
offset adjustment. You can give RHG a call at 516 242-1100. This info is
from thier 1988 Catalog. They are a division of Adams Russell.
Hope this helps.  73 WB6IQD  Tom  [e-mail]


From [e-mail] Thu Mar 07 10:10:45 1996
From: [e-mail] (Jim Weir)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Can anyone ID these IF amps?
Date: Thu, 07 Mar 1996 04:33:43 GMT
Message-ID: <4hloro$[e-mail]>
References: <[e-mail]> <[e-mail]>

Leon Heller <[e-mail]> shared the following priceless
pearls of wisdom:
>>
>> The connectors are labeled: IF IN, -15V, RET, +15V, TP1, VID 1, VID 2, TP2.

And that is exactly what you will get out.  Put a -15 volt power
supply (I'd guess somewhere around 50 mA or so) to the -15 port, +15
to the +15 port, the common of both power supplies to RET (return, or
ground), an RF signal (*) to the IF IN port and look at the detected
video at VID 1 or VID 2.  As I roughly remember this device, VID 1 and
VID 2 were mirror images of each other reflected about ground -- an
output of 1 volt at one would be an output of -1 volt at the other,
and any video information is inverted in phase.  The output is
logarithmic -- you put in some level that gives you a volt out.
You've gotta put in ten times that level to get two volts out, 100
times the level to get three volts out, and so forth.

(*)  Most of the RHG stuff was good from fairly low frequency up
through about 150 MHz. or so.  I'd get a good signal generator and
just put in a constant level and see where the output drops to the
point where the generator has to be increased 3 dB to keep a constant
level output.  That should well define the amplifier corner.

>Logarithmic IF amplifiers are used in RADAR receivers as logarithmic
>detectors. Plessey (now GPS) is one maker of the special IF amp chips
>that are used

And by the grace of God you can hope that RHG had the good sense not
to use a Plessey chip.

Jim

Jim Weir VP Engineering | You bet your sweet patootie I speak for the
RST Engineering         | company.  I OWN the cotton-pickin' company.
Grass Valley CA 95945   |
http://www.rst-engr.com | AR Adv WB6BHI--FCC 1/C phone--Cessna 182A N73CQ
[e-mail]        | Commercial/CFI-Airplane/Glider-----A&P Mechanic



From [e-mail] Thu Mar 07 10:10:47 1996
Newsgroups: rec.radio.amateur.homebrew,rec.radio.amateur.misc
From: [e-mail] (Robert E. Garland)
Subject: Re: CB conversion for HAM use?
Message-ID: <[e-mail]>
References: <[e-mail]>
Date: Sun, 3 Mar 1996 01:14:41 GMT

[e-mail] (SARUMAN) writes:

>Howdy folks, I was just going thru some of my stuff and found my old Walkie T
's
>Both are 3 channel 3 watt units. one Lafayette one Radio Shack. Is it possabl
e
>to get Crystals for Frequencies other thatn the 40 CB Channels for use with
>these units? Any other Mod's needed? Thanx for the help folks.
>The Crystals in these are socketed if that matters. I've been out of this for
>Years.


><tsb>
>                               Midgard Graphics
>           3D Animation and Special FX for the hobbyist videographer
>                          Email: [e-mail]

>--
>          Drop into #amigacafe on IRC's undernet for a chat sometime

>--

><tsb>

>                     A man of many hobby's master of none.


For what it is worth, you can legally convert the 49 MHz units to 50 MHz
ham band units.  I can't say how useful they would be since I don't work
50 MHz myself.  I suspect that you will have to retune as well as
recrystal, but if you have some technical skill, that should not be a
problem.

--
     Robert Garland                            NX3S @ N3ACL.PA.USA.NOAM
     Hilltown Township Bucks County               [e-mail]
     Pennsylvania USA                                       Grid FN20ii
                   Hams do it bouncing off the "F" layer


From [e-mail] Thu Mar 07 10:10:48 1996
Newsgroups: sci.astro.amateur,rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna,misc.invest.technical,misc.invest.stocks,misc.invest.funds,misc.invest.canada
From: [e-mail] (James D. Cronin)
Subject: Cold fusion superconducting antennas (was: Announsing...)
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]> <4hfqtn$[e-mail]> <[e-mail]>
Date: Wed, 6 Mar 1996 17:27:42 GMT

In article <[e-mail]>,
Wes Stewart <[e-mail]> wrote:
>...
>"Announsing", "blatent" and "know one else" indeed. I don't know what his
>device is,  because searching for the number didn't work for me. Sounds like
a
>Peltier device, but I guess it could be cold fusion.
>
>73, Wes -- N7WS

Isn't it obvious:

Homebrew superconducting cold fusion ham radio astronomy antenna
equipment with investment potential for insider stock trader Canadians.
(Apoligies in advance to our friends in VE land...)

Ten points to the first person who cross-posts all this stuff to the
alt.sex hierarchy.  April 1 is closer than you think.

73...Jim  N2VNO


From [e-mail] Thu Mar 07 10:10:49 1996
From: Zack Lau <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Comb and interdigital filters for diplexers
Date: Sat, 02 Mar 1996 11:12:12 -0500
Message-ID: <[e-mail]>
References: <4gho2f$[e-mail]> <[e-mail]> <[e-mail]>

Zack Lau wrote:
>
> But, with such a narrow bandwidth, you need to space the rods
> really far apart, or shield them from each other. Of course,
> if the rods are shielded from each other you really have coaxial
> cavity resonators.

However, since you need as much Q as possible, you probably
want to use waveguide filters, dispensing with most of the
resonator rods.  You might want to save one rod to feed the
input of the FET preamp.  A rather challenging project, but
certainly possible--Zack.
> Zack KH6CP/1


From [e-mail] Thu Mar 07 10:10:50 1996
From: Gareth Edwards <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Comb and interdigital filters for diplexers
Date: Sat, 02 Mar 96 19:15:39 GMT
Message-ID: <[e-mail]>
References: <4gho2f$[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
Reply-To: [e-mail]

In article <[e-mail]> [e-mail] "Zack Lau" writes:

> Zack Lau wrote:
> >
> > But, with such a narrow bandwidth, you need to space the rods
> > really far apart, or shield them from each other. Of course,
> > if the rods are shielded from each other you really have coaxial
> > cavity resonators.
>
> However, since you need as much Q as possible, you probably
> want to use waveguide filters, dispensing with most of the
> resonator rods.  You might want to save one rod to feed the
> input of the FET preamp.  A rather challenging project, but
> certainly possible--Zack.
> > Zack KH6CP/1
>

At these frequecies the waveguide is going to have to be pretty big
to allow a TE or TM mode to propagate.

Gareth
GM7WFT

--
I don't want the world; I just want your half. - TMBG
------------------------------------------------------------------
|  Gareth Edwards       |  [e-mail]           |
|  Edinburgh,           |  Home of Edinburgh Beige Cricket Club  |
|  Scotland             |  PGP public key available on request   |
------------------------------------------------------------------


From [e-mail] Thu Mar 07 10:10:52 1996
From: [e-mail] (Elendir)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Comb and interdigital filters for diplexers
Date: 4 Mar 1996 10:14:13 GMT
Message-ID: <4hefpl$[e-mail]>
References: <4gho2f$[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>

Gareth Edwards ([e-mail]) wrote:
: In article <[e-mail]> [e-mail] "Zack Lau" writes:
: > Zack Lau wrote:
: > However, since you need as much Q as possible, you probably
: > want to use waveguide filters, dispensing with most of the

: At these frequecies the waveguide is going to have to be pretty big
: to allow a TE or TM mode to propagate.

Indeed.
We'll use standard coaxial cable (low loss though).

TEM, TEM, TEM :-)

Vince
--
Fox 5 RCS - Round the world and beyond through amateur radio.
VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.


From [e-mail] Thu Mar 07 10:10:53 1996
From: "Paul N. Nix" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: DigiBrain Spur/Noise Elimination?
Date: 5 Mar 1996 23:08:40 GMT
Message-ID: <4hihho$[e-mail]>
References: <rohrwerk-2302962250450001@10.0.2.15>


Previously, John Seboldt (K0JD) said:

Quote:
-------------------------------------------------------------------------
March QST's refinement of the DigiVFO (adding a microprocessor and "knob"
tuning with display) looks wonderful.  It raises, of course, the same
question I had about the original:  additional circuitry needed to "clean
up" the output to avoid spurs on receive.  (Spurs at only 70 dB down can
mean lots of receive birdies!)  I'd love to apply it to my R2 setup, but
not at the price of tons of spurs and noise!

A good PLL is of course the obvious solution... but I wonder... I am using
a 74HC240 buffer to generate square wave drive for my system... similar to
the buffer of the "remote VFO" project a while back.  Would this tend to
take care of those spurs and noise, the chips responding only to the main
(strongest) signal in shaping the square wave?
-------------------------------------------------------------------------

John, you've probably already gotten lots of replies, but just in case ...
last year I got all fired-up over DDS, called suppliers to get Spec Sheets,
started reading catalogs to find out where the chips were available, etc.
(I'm a little reluctant to try and 'wheedle' chips out of a salesman when
my job has nothing to do with DDS design, and therefore my after-hours
tinkering won't resultant in the salesman increasing his company's
business)

It seems to me that, in either a Qualcomm or Harris Spec Sheet, they
discussed the very idea you're asking about ... ie. running the output of
the D/A converter to a flip-flop, to 'square-up' the signal, and by doing
so you effectively limit the spectral output to the fundamental frequency
and the odd harmonics.

Regards;

Paul Nix (WB5AGF)        e-mail: [e-mail]

PS

I've already downloaded the "digibrain" source code, as I just 'happen'
to have the Motorola 68HC05 Developer's Kit sitting in the closet at
home. I'm hoping that the DigiBrain project will make me learn some
Assembly code, and at the same time I'll be able to customize the DDS
to meet my needs (want to 'lock' the 9 MHz local oscillator in my
Tentec Paragon to a 'master reference').

----------------------------- END ---------------------------------





From [e-mail] Thu Mar 07 10:10:54 1996
From: William Kresl <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Direct conversion
Date: 2 Mar 1996 14:42:45 GMT
Message-ID: <4h9mp5$[e-mail]>
References: <[e-mail]>

A little off your topic, but an alternative to
the lousy DIRECT CONVERSION designs that suffer
from AC hum and LO leakage is the HARMONIC MIXER
based receivers. They utilize the same base as
the DIRECT CONVERSION types (i.e MIXER/DETECTOR
to a HI gain AF amp), but the LO operates at HALF
the desired received frequeny. Allowing a more
stable LO source, and simple mixer configuration
(full-wave diodes). Good performance and simple
construction.

With the availabilty of NE602(A), good superhets
are very easy to make and transceivers are not
much more complicated to construct. And
multi-mode systems can be inexpensively made. The
homebrewer has a lot of choices!

I believe you want a cheap TRF design. Consult
your local library for the ARRL handbook for
some radio designs. Cheerio...

Wm Kresl
WB9BBBC

Delavan, WI





From [e-mail] Thu Mar 07 10:10:55 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Clifton T. Sharp)
Subject: Re: Direct conversion
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]> <[e-mail]>
Date: Mon, 4 Mar 1996 17:51:30 GMT

In article <[e-mail]> Robert Bissett <[e-mail]>
 writes:
>It is called Tuned Radio Frequency (TRF)  and the superheterodyne
> was developed to overcome all its' shortcomings.

True, but I thought those shortcomings were related to tube design
and to the cost of multigang variable capacitors; neither is a problem
with semiconductors (though coils are a consideration). Are there any
shortcomings I've missed?

Another question arises: is it practical to use gyrators in RF tuned
circuits? In all these years, I've found about four pages (literally)
of reading about gyrators, two in a magazine and two in a datasheet.
The applications shown were audio low-pass filtering.

--
   Cliff Sharp                  Whatever it is that hits the fan,
     WA9PDM                      it will not be evenly distributed.
  [e-mail]       --The Third Law of Reality


From [e-mail] Thu Mar 07 10:10:56 1996
From: [e-mail] (Jerry Flanders)
Newsgroups: rec.radio.amateur.homebrew
Subject: EIMAC 5CX3000A tube
Date: Tue, 05 Mar 1996 03:42:55 GMT
Message-ID: <4hgd7v$[e-mail]>

I recently picked up a piece of surplus gear with a big EIMAC 5CX3000A
tube. I have written to EIMAC to get operating voltages for this
monster, but they may not respond in time for shopping for a plate
transformer at this weekend's hamfest.

Can somebody please post or e-mail the operating voltages / limiting
specs for it?

Thanks

Jerry Flanders   W4UKU   South Carolina     [e-mail]



From [e-mail] Thu Mar 07 10:10:57 1996
From: Gordon Walker <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: EIMAC 5CX3000A tube
Date: Tue, 05 Mar 1996 23:14:15 -0500
Message-ID: <[e-mail]>
References: <4hgd7v$[e-mail]>

Jerry Flanders wrote:
>
> I recently picked up a piece of surplus gear with a big EIMAC 5CX3000A
> tube. I have written to EIMAC to get operating voltages for this
> monster, but they may not respond in time for shopping for a plate
> transformer at this weekend's hamfest.
>
> Can somebody please post or e-mail the operating voltages / limiting
> specs for it?
>
> Thanks
>
> Jerry Flanders   W4UKU   South Carolina     [e-mail]

Jerry,
        Just looked in my Eimac ref manual.
For the 5cx3000a maximum ratings:
        Plate Voltage: 7000 volts
        Plate Current 2.0 amps.

Typical Operation

Class C - plate voltage 6800 volts
         Screen voltage 500 volts
         Plate Current 1.6 amps
         Drive power 52 watts
        Output power 8,500 watts
Class AB1 - Plate voltage 6000 volts
            Screen Voltage 850 volts
            Plate Current 1.4 volts
            Output power 5,500 watts

Filament voltage - 9.0 volts
         current - 41.5 amps
Hope this helps,

Gord
VE3LUM


From [e-mail] Thu Mar 07 10:10:59 1996
Newsgroups: rec.radio.amateur.homebrew
From: Tom Skelton <[e-mail]>
Subject: Re: EIMAC 5CX3000A tube
Message-ID: <[e-mail]>
Reply-To: [e-mail] (skeltt)
References: <4hgd7v$[e-mail]>
Date: Wed, 6 Mar 1996 18:01:30 GMT


>==========Jerry Flanders, 3/4/96==========
>
>I recently picked up a piece of surplus gear with a big EIMAC 5CX3000A
>tube. I have written to EIMAC to get operating voltages for this
>monster, but they may not respond in time for shopping for a plate
>transformer at this weekend's hamfest.
>
>Can somebody please post or e-mail the operating voltages / limiting
>specs for it?
>
>Thanks
>
>Jerry Flanders   W4UKU   South Carolina     [e-mail]
>

Hey Jerry!  Warn me when you fire it up so I can make sure I'm not on the
same band, or even the same county here in S.C.! hi    ... ;-))

73, Tom WB4iUX (Clemson, SC)
[e-mail] or [e-mail]



From [e-mail] Thu Mar 07 10:11:01 1996
From: [e-mail] (Dennis Ashworth)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Ham-Homebrew Digest V96 #95
Date: 5 Mar 96 17:53:01 GMT
Message-ID: <9603051746.AA20982@adphdw20>


>Date: Sun, 03 Mar 1996 19:04:58 -0800
>>From: Svein Henriksen <[e-mail]>
>Subject: QRO design using 4-1000
>
>Anyone out there with a good design for a linear using the 4-1000. I have
>one but little practical experience in amplifier design although I am an
>electronics engineer.
>Any help would be apresiated.

Svein:

I earned money for college in the 1970's by building 4-1000A amplifiers from
surplus components. A year or two ago, I thought I would build another to
replace my pair of 3-500Z's. Afetr careful consideration, I moved away from
the 4-1000A to the 8877 ceramic tube. One of the significant contributors to
my decision is the high drive power requirements of the 4-1000A. Even with
high plate voltages (eg 6KV) they require more drive than most of the solid
state transceivers deliver. In the 70's, we had mostly tube radios,
delivering 125-180W, which drove the 4-1000A fine. Now about the only radio
in this output range is the FT1000D at 200W.

If you plan to use a tube radio as a driver, then the 4-1000A will work
well. However, if you plan to drive it with one of the modern transceivers,
you may be dissapointed in the results.

If you do elect to build a 4-1000 amplifier, and have specific questions,
please feel free to contact me. I would be pleased to help.

Vy 73's
Dennis, K7FL
_________________________________________________________________

Dennis H. Ashworth                      [e-mail]
Director, Quality Assurance

ADP Dealer Services Group            Phone: [phone]
2525 SW First Avenue                    Fax:   [phone]
Portland, OR  97201-4792
_________________________________________________________________



From [e-mail] Thu Mar 07 10:11:02 1996
From: "Mr. Brooke Clarke" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Help needed
Date: Fri, 01 Mar 1996 20:30:00 -0800
Message-ID: <[e-mail]>
References: <[e-mail]>
To: James Blaney <[e-mail]>

James Blaney wrote:
>
> Hi folks,

> Does anyone have details on how to build a ô very basic ô Short-wave Reviver
> ( Crystal set type of thing ). Any details on WWW sites, KitÆs, any informat
ion
> at all would be appreciated. Try:
"The Crystal Set Handbook and Volume III of the Xtal Set Society
Newsletter"  by Philip N. Anderson
The Crystal Set Society
P.O. Box 3026
St. Louis, MO 63130

Brooke




From [e-mail] Thu Mar 07 10:11:02 1996
From: "Mr. Brooke Clarke" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Info on Canidian GPS receiver R-5133/URN-502
Date: Fri, 01 Mar 1996 20:26:25 -0800
Message-ID: <[e-mail]>

Can anyone give a clue as to how to get documents from the Canadian
Government that would relate to the now obsolete GPS receiver?  Or if you
have anything let me know.

Thanks very much,
Brooke




From [e-mail] Thu Mar 07 10:11:03 1996
From: [e-mail] (Prowler)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Linear Amp Modifications?
Date: Sat, 02 Mar 1996 23:07:01 GMT
Message-ID: <4hak6q$[e-mail]>
References: <[e-mail]> <[e-mail]>

Totally impossible project...  KN2Y

[e-mail] (Wes Stewart) scribed:

xxIn article <[e-mail]> [e-mail]
(Douglas R Davis) writes:
xx>From: [e-mail] (Douglas R Davis)
xx>Subject: Linear Amp Modifications?
xx>Date: 29 Feb 96 14:14:55 GMT

xx>How much trouble would it be to modify an amp made for use between
3-30 MHz,
xx>for use on, say...75 meters? Is it possible or economically
feasible?

xx>Thanks.

xxNope, don't even consider it.




From [e-mail] Thu Mar 07 10:11:04 1996
From: [e-mail] (Jeff Benedict)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Linear Amp Modifications?
Date: 1 Mar 1996 21:36:48 GMT
Message-ID: <4h7qlg$[e-mail]>
References: <[e-mail]> <[e-mail]>

Wes Stewart ([e-mail]) wrote:
: In article <[e-mail]> [e-mail] (Douglas R Davi
s) writes:
: >From: [e-mail] (Douglas R Davis)
: >Subject: Linear Amp Modifications?
: >Date: 29 Feb 96 14:14:55 GMT

: >How much trouble would it be to modify an amp made for use between 3-30 MHz
,
: >for use on, say...75 meters? Is it possible or economically feasible?

: >Thanks.

: Nope, don't even consider it.


Are you joking or how do you figure?

there are/were wide band amps for 3-30 mHz although the CB boom just
about wiped them out.  There are plans in various places for such
wideband amps.

75 meters is right in the low end of the range for the amp mentioned
(3.8-40 mHz)

Jeff


From [e-mail] Thu Mar 07 10:11:06 1996
Distribution: world
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Brian Carling)
References: <4hj5vp$[e-mail]>
Date: Thu, 07 Mar 1996 06:25:00 -0500
Subject: looking for kit companies
Message-ID: <[e-mail]>

From: [e-mail]
"mail sometimes bounces here, please resend if needed!"

N9>As a scout merit badge counselor, I am in need of kit addresses for the
N9>kids.

N9>Seems many of them are gone. Rainbow too expensive, and ramsey somewhat
N9>limited. Looking for the older stuff, such as receivers, strobelites, etc.
N9>any ideas?

You need to look at MEGALIST! It is a huge list of kit suppliers!

Updated copies downloadable from BBSes at:
[phone], [phone], [phone], [phone]
[phone], [phone], [phone], [phone]

FTP site is at ftp.Lehigh.EDU.  Login as anonymous, and use your
e-mail address as the password.
FTP:  ftp://ftp.lehigh.edu/pub/listserv/qrp-l/misc/megalist.txt
WWW: http://qrp.cc.nd.edu/QRP-L/index.html
WWW: http://www.nd.edu/~shideg/

DOWNLOAD as MEGALIST.ZIP or individually as:
megalist.txt
manuals.txt
dealers.txt
tubes.txt
xtals.txt
========

 * SLMR 2.1a * James 1:20



From [e-mail] Thu Mar 07 10:11:07 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Philip A Zimmermann)
Subject: Re: looking for RE article
Message-ID: <[e-mail]>
Date: Mon, 4 Mar 1996 23:21:43 GMT



I'm looking for a reprint of an article which appeared in a
Radio-Electronics issue somewhere between 1979 - 1983. It was a project to
build a frequency counter based on the Intersil 7207 & 7208 ic's, if
memory serves. It was basically the same as an Optoelectronics brand
frequency counter at the time, but schematic and foil circuit board
pattern for DIY.


Send email if you can get the article to me somehow...


tnx.

=paz=

philip zimmermann, WA2JTH

[e-mail]


From [e-mail] Thu Mar 07 10:11:08 1996
From: [e-mail] (Ed Ganger)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Need 1n78 point contact mixer diodes
Date: Fri, 1 Mar 1996 19:55:24 -0400
Message-ID: <[e-mail]>
References: <4h22f2$[e-mail]>

In article <4h22f2$[e-mail]> [e-mail] (VINY N1VC) wri
tes:
>For my old HP-8551 spectrum analyzer. If you have any I could sure use
>them.

>Thanks beforehand

>-Viny Coppola

Wouldn't Hot-Carrier Diodes do as well or better?
The point-contact were an early (and un-named) implementation
of schottky diodes (metal-semiconductor junctions)

Regards,
Ed


From [e-mail] Thu Mar 07 10:11:09 1996
From: [e-mail] (RH)
Newsgroups: rec.radio.amateur.homebrew
Subject: Need mods for Uniden HR2600
Date: Wed, 06 Mar 1996 23:13:22
Message-ID: <4hlr9u$[e-mail]>

Looking for mod for Uniden HR2600 that opens up to 11m band.
                 Thanks....Ron



From [e-mail] Thu Mar 07 10:11:09 1996
From: Neal McEwen <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Need Old Telegraph Key parts for restorations
Date: Sat, 02 Mar 1996 16:24:20 -0800
Message-ID: <[e-mail]>

I am restoring some old telegraph keys and bugs.  Need some parts to
finish them off.  Do you have any old keys and bugs that I could part
out.  Or do you have an old key or bug that I could add to my collection?
--
73 de K5RW     - Neal McEwen                    - Richardson, TX (Dallas)
  ******** I collect old telgraph and wireless telegraph keys  *********
HomeNet        - [e-mail]           - OS/2 tcp/ip SLIP
HomePage       - http://fohnix.metronet.com/~nmcewen/k5rw.html



From [e-mail] Thu Mar 07 10:11:11 1996
From: [e-mail] (Filip M Gieszczykiewicz)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: PCB design software
Date: 6 Mar 1996 22:33:06 GMT
Message-ID: <4hl3r2$[e-mail]>
References: <3139888f.382937@194.72.192.4> <[e-mail]>
Summary: correction

In Article '<[e-mail]>', through puissant locution, 'v
[e-mail]' soliloquized:
>[e-mail] (Steve Drury) wrote:
>>Can anyone tell me of a good P.D. or inexpensive shareware PCB cad
>>software which will do block fill or ground plane generation? Output
>>to laser printer is also required!
>
>There is a free X11 pcb program for ftp from
>pluto.medizin.uni-ulm.de/pub/pcb
>I had no trouble getting it to work on Linux.

Greetings. Correction, it's now at:

ftp://ftp.uni-ulm.de/pub/pcb/current

and all you need is the pcb-xxxx.tar.gz file... it has all the
samples, packages, and READMEs in it (I mention this because
they are also provided in the above directory and want to save
people extra downloads). I too have had no problems running it.
It's not as "spiffy" as some of the limited-demos that some
firms put out for DOS/Windoze but it does the deed.

I'm fiddling with a free PCB list (like my free spcie list, see URL:
http://www.paranoia.com/~filipg/HTML/FAQ/BODY/F_Free_Spice.html) but
I only have a few listed now... Please let me know if you know of
any other PCB packages that are demo or Free.

Take care.

--
+-->Filip "I'll buy a vowel" Gieszczykiewicz | E-mail: [e-mail]
| http://www.paranoia.com/~filipg/| Sci.Electronics, RC, Misc FAQs + MORE!
| Enjoy your job, work within the law, make lots of money : Choose any two.
| I think for myself. I listen. I make decisions. I speak what I believe.


From [e-mail] Thu Mar 07 10:11:12 1996
From: Vance Campbell <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: PCB design software
References: <3139888f.382937@194.72.192.4>
Message-ID: <[e-mail]>
Date: 6 Mar 96 01:03:20 GMT

[e-mail] (Steve Drury) wrote:
>Can anyone tell me of a good P.D. or inexpensive shareware PCB cad
>software which will do block fill or ground plane generation? Output
>to laser printer is also required!

There is a free X11 pcb program for ftp from
pluto.medizin.uni-ulm.de/pub/pcb

I had no trouble getting it to work on Linux.

-VC




From [e-mail] Thu Mar 07 10:11:13 1996
Newsgroups: rec.radio.amateur.homebrew
From: Jean-marc BORD <[e-mail]>
Subject: Serious 144 PowerAmps designs
Date: Mon, 4 Mar 1996 10:48:07 GMT
Message-ID: <[e-mail]>

Hi there,

I'm looking for serious tested designs using either one QBL5/3500
tetrode or a 3CX3000A7 triode for the 144MHz band.
For Moonbounce operation, I'm already using a 3CX1500A7 but need more
'fruitjuce' !.

Regards
Jean-marc

P.S.
Please reply direct to
[e-mail]




From [e-mail] Thu Mar 07 10:11:14 1996
Newsgroups: rec.radio.amateur.homebrew
From: Jean-marc BORD <[e-mail]>
Subject: Serious 144 PowerAmps designs
Date: Mon, 4 Mar 1996 10:48:31 GMT
Message-ID: <[e-mail]>

Hi there,

I'm looking for serious tested designs using either one QBL5/3500
tetrode or a 3CX3000A7 triode for the 144MHz band.
For Moonbounce operation, I'm already using a 3CX1500A7 but need more
'fruitjuce' !.

Regards
Jean-marc

P.S.
Please reply direct to
[e-mail]




From [e-mail] Thu Mar 07 10:11:15 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Gary Coffman)
Subject: Re: Silver Plating ?
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
References: <[e-mail]> <4heg2m$[e-mail]>
Date: Mon, 4 Mar 1996 17:28:32 GMT

In article <4heg2m$[e-mail]> [e-mail] (Elendir) writes:
>Brad Duffield ([e-mail]) wrote:
>: I am bulding a set of Duplexers and want to silver plate the inside
>: parts.. Anyone have any info on homebrew silver plating???
>
>I'm planning the same job (on 23 cm, though).
>The point is :
>Do you really think it is necessary ?
>The increase in the Q is about 10 %.
>
>I really don't know if it's worth it. I'd rather build another cavity.

Vincent, silver plating allows you to lower the *insertion* loss of
the system while adding another cavity will *increase* the insertion
loss of the system. They aren't alternative paths to the same solution.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Thu Mar 07 10:11:16 1996
From: [e-mail] (Elendir)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: 4 Mar 1996 10:19:02 GMT
Message-ID: <4heg2m$[e-mail]>
References: <[e-mail]>

Brad Duffield ([e-mail]) wrote:
: I am bulding a set of Duplexers and want to silver plate the inside
: parts.. Anyone have any info on homebrew silver plating???

I'm planning the same job (on 23 cm, though).
The point is :
Do you really think it is necessary ?
The increase in the Q is about 10 %.

I really don't know if it's worth it. I'd rather build another cavity.

Vincent

--
Fox 5 RCS - Round the world and beyond through amateur radio.
VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.


From [e-mail] Thu Mar 07 10:11:17 1996
From: [e-mail] (Drew Diamond)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: Wed, 6 Mar 1996 11:46:48
Message-ID: <[e-mail]>
References: <[e-mail]> <4heg2m$[e-mail]> <[e-mail]> <4hh27g$[e-mail]>
Keywords: silver plating

In article <4hh27g$[e-mail]> [e-mail] (Elendir) writes:
>From: [e-mail] (Elendir)
>Subject: Re: Silver Plating ?
>Date: 5 Mar 1996 09:41:04 GMT
>Gary,>: Vincent, silver plating allows you to lower the *insertion* loss of
>: the system while adding another cavity will *increase* the insertion
>: loss of the system. They aren't alternative paths to the same solution.
>I agree.>Is it really that significant ?>What is the improvement in the
insertion loss between a normal copper>cavity and a sliver-plated one ?
>VIncent-->Fox 5 RCS - Round the world and beyond through amateur radio.
>VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.

Where copper has a resistivity of 1.0, silver is 0.9. Therefore,Unless it is
done properly (and regular plater's- used only  to doing ornamental plating
may well not know); silver plating copper coils and cavities may actually
increase their loss.

Reference: Fowler; Specifying Elecrtoplated Finishes For Radio Frequency
Applications; Elec. Eng. Trans. I.E Aust. Vol EE8, No. 2 Sept. 1972. and

Fowler; Radio Frequency Performance of Electroplated Finishes, Proc IREE Vol
31 No 5 May 1970 pp 148-64. and

Von Bayer; The Effect of Silver Plating on Attenuation at Microwave
Frequencies; Microwave Journal Vol 3, No 4 Apr 1960 pp 47-50.

73, Drew Diamond, VK3XU.    Telstra Research Laboratories.


From [e-mail] Thu Mar 07 10:11:19 1996
From: [e-mail] (Elendir)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: 6 Mar 1996 11:36:50 GMT
Message-ID: <4hjtci$[e-mail]>
References: <[e-mail]> <rohrwerk-0303962308180001@10.0.2.15> <[e-mail]>

Mark Pettigrew ([e-mail]) wrote:

: layer, and I have no reason not to believe that the layer is actually
: silver. However, it's obviously not very thick.

This leads to another (important) point :

At 145 MHz, how thick must the plating be ? More than 10 microns, I guess.
The skin effect is not that important.
Next, what about silver oxydation ?

Vincent

--
Fox 5 RCS - Round the world and beyond through amateur radio.
VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.


From [e-mail] Thu Mar 07 10:11:20 1996
From: "Ian White, G3SEK" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: Sat, 2 Mar 1996 16:03:37 +0000
Distribution: world
Message-ID: <[e-mail]>
References: <[e-mail]> <4h9fm7$[e-mail]>

In article <4h9fm7$[e-mail]>, Kevin Shea wrote:
>In article <[e-mail]>,
>   Brad Duffield <[e-mail]> wrote:
>>I am bulding a set of Duplexers and want to silver plate the inside
>>parts.. Anyone have any info on homebrew silver plating???
>>
>>Brad Duffield WB8MZI
>>
>Brad,
>
>There was an article written by Stu Gurske K9EYY in _Ham Radio_ several years

>ago.  I don't have a copy of it, perhaps someone else does.
>
>Stu's homepage is http://www.execpc.com/~swagur
>
>73,
>Kevin N9JKP

"Safe, Sensible Silverplating", February 1985, page 29.

Simple electrolytic method using spent photographic fixer, which is
loaded with silver dissolved out of the emulsion. No highly toxic
chemicals involved.

Clever technique for bringing the solution to the work using a sponge on
a carbon rod, so you don't need buckets of solution.

Very highly recommended!


73 from Ian G3SEK          Editor, 'The VHF/UHF DX Book'
                          'In Practice' columnist for RadCom (RSGB)
Professionally:
IFW Technical Services     Clear technical English - anywhere.


From [e-mail] Thu Mar 07 10:11:21 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (John Seboldt)
Subject: Re: Silver Plating ?
Message-ID: <rohrwerk-0303962308180001@10.0.2.15>
References: <[e-mail]>
Date: Mon, 4 Mar 1996 05:08:17 GMT

In article <[e-mail]>, Brad Duffield
<[e-mail]> wrote:

> I am bulding a set of Duplexers and want to silver plate the inside
> parts.. Anyone have any info on homebrew silver plating???
>
> Brad Duffield WB8MZI

I have info from a company I saw in a broadcast trade publication that
makes a silver plating powder.  Just apply with a damp rag!  Of course,
it's $120 per pound (well, it's silver after all :-) ), but you can
request a sample on a business letterhead, and maybe get smaller vials.

Cool-Amp Conducto-Lube Company
15834 Upper Boones Ferry Rd
Lake Oswego, OR   97035
503 624-6426

: John Seboldt  [e-mail]  / CW:  It don't mean a thing
:      K0JD... Minneapolis, MN      /  if it ain't got that swing!
:   My R2/T2 station described in  / Di dah, di dah, di dah, di dah...
> http://www.lehigh.edu/lists/qrp-l/k0jd/index.html <


From [e-mail] Thu Mar 07 10:11:22 1996
From: Neal McEwen <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew,uk.radio.amateur
Subject: Re: Simulating old valves/tubes with FETs
Date: Sat, 02 Mar 1996 16:22:43 -0800
Message-ID: <[e-mail]>
References: <4gias8$[e-mail]> <[e-mail]>

>
> > I am looking for advice on FET based equivalent circuits to replace
> > old valves/tubes. In particular I have a National HRO-M which uses
> > several 6C6. What are the most important characteristics that need
> > to be reproduced?
>

At the Dallas AWA convention in October, there was a demonstration of FETs
and other transistors to replace tubes.  Contact K5RB, Dick Bauer.  He was
one of the presentors.
--
73 de K5RW     - Neal McEwen                    - Richardson, TX (Dallas)
  ******** I collect old telgraph and wireless telegraph keys  *********
HomeNet        - [e-mail]           - OS/2 tcp/ip SLIP
HomePage       - http://fohnix.metronet.com/~nmcewen/k5rw.html




From [e-mail] Thu Mar 07 10:11:23 1996
From: Charles Bolland <[e-mail]>
Newsgroups: rec.radio.shortwave,rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.policy,rec.radio.amateur.space,rec.radio.noncomm,rec.radio.scanner,rec.radio.swap
Subject: Re: Stand Alone Broadcast Radio Station Database - LW,MW,SW
Date: 2 Mar 1996 21:35:10 GMT
Message-ID: <4haeue$[e-mail]>
References: <4gttsh$[e-mail]> <4gvda8$[e-mail]>
To: [e-mail]

Friends,

I'm still sending out the Stand Alone Broadcast Radio Station Database to
whomever wants it.  I would like your mailing address and Email address
for registration and possibly a future letter describing a more
comprehensive database program for radio.  All information will be kept
confidential..

Just answer this posting to "[e-mail]".

The database has more than 4,000 records already and can be edited and
updated.

Hope to hear from you.

Chuck
KA4PRF




From [e-mail] Thu Mar 07 10:11:24 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Clifton T. Sharp)
Subject: TRF etc.
Message-ID: <[e-mail]>
Date: Mon, 4 Mar 1996 17:46:16 GMT

Okay, maybe the TRF wasn't such a good idea. However, the idea came
about because I've heard so much over the years about LO noise,
LO distortion, excessive or insufficient LO injection, mixer noise,
mixer distortion (as far as I understand it, a mixer won't work
without distortion, although I suppose the PC term is "nonlinearity"
:-), etc.

Yes, it's easy to put together a receiver using something like an NE602,
or any one of the nifty chips out there. A TDA1072 has a sensitivity
of 15 uV for 26 dB S/N. But I won't LEARN anything by doing it, as
I've done enough home projects and kits over the years to make it
little more than an afternoon's busywork.

So, what about local oscillators and mixers, and the problems inherent
in them, and how to solve them? (I'm reading up; but experiences are
good to hear, and I don't have access to the very latest stuff, either.)

--
   Cliff Sharp                  Whatever it is that hits the fan,
     WA9PDM                      it will not be evenly distributed.
  [e-mail]       --The Third Law of Reality


From [e-mail] Thu Mar 07 10:11:26 1996
From: [e-mail] ()
Newsgroups: rec.radio.amateur.homebrew
Subject: Vacuum Tubes, Canadian Suppliers
Date: 5 Mar 1996 18:44:01 GMT
Message-ID: <4hi21h$[e-mail]>

   I am interested in experimenting with a number of antique regenerative
   receiver circuits and also, in future, simple transmitters.  Although
   I have located several excellent sources of RF parts and several
   sources of vacuum tubes, none are inside Canada.  Does anyone out
   there know of any vacuum tube suppliers here, preferably close to
   Edmonton?

   If so, or if you have insights to offer, please post to this article
   or e-mail me your reply.

   Thanks,
   Shane

--












From [e-mail] Thu Mar 07 10:11:26 1996
From: [e-mail] (Paul Temple )
Newsgroups: rec.radio.amateur.homebrew
Subject: VOX switch
Date: 2 Mar 1996 17:08:37 GMT
Message-ID: <4h9val$[e-mail]>

Hello,
I am in need of a cheap easy to build VOX switch.  Does anyone have any
plans for makeing one I could have?  If so could you tell me where I
can find them please email me.
TNX
73 DE KF4GDH
email me at:
[e-mail]


From [e-mail] Thu Mar 07 10:11:27 1996
From: [e-mail] (DAVE M . SCHERTZER)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: WANTED: ICOM T21A & IC-2000H mods
Date: 4 Mar 1996 14:26:29 GMT
Message-ID: <4heuil$[e-mail]>
References: <4h49m5$[e-mail]>

IC-2000 Mod: Locate and cut diode D8

 IC T21 Mod: Locate + remove diode D15 (RX)
               "        "      "   D14 (TX)

Install chip jumper in position W2 on the UHF PLL
board next to IC2. Near board edge # B39218

Press + hold (B) + (#) turn power on -reset CPU


[e-mail]





From [e-mail] Thu Mar 07 10:11:28 1996
From: "Ian White, G3SEK" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: What does GaAs-FET cost?
Date: Fri, 1 Mar 1996 16:37:55 +0000
Distribution: world
Message-ID: <[e-mail]>
References: <4h58ff$[e-mail]>

In article <4h58ff$[e-mail]>, Michael Petzold wrote:
>I've got a circuit diagram of a LNC, and its input stage is fitted with a
>Mitsubishi MGF1502, a single-gate GaAs-FET. I couldn't find any GaAs
>components in my catalogs (RS, Farnell), so my question is: What
>(approx.) does such a device (or a similar one) cost? The text said it
>was a cost-effective device, but I got no clue what the usual prices are.

Try Aspen Electronics (0181 868 1311), or for small quantities try
Mainline Electronics (0116 277 7648).

The RSGB Microwave Components Service (G3WDG and G4KGC) might be able to
recommend a good equivalent, and probably supply it too.

>(The same circuit uses a CF300 dual-gate GaAs tetrode. How much does this
>cost?)

Same circuit as which? Surely not an LNC?

CF300s are "priceless" - becoming very hard to get!

73 from Ian G3SEK          Editor, 'The VHF/UHF DX Book'
                          'In Practice' columnist for RadCom (RSGB)
Professionally:
IFW Technical Services     Clear technical English - anywhere.


From [e-mail] Thu Mar 07 10:11:30 1996
From: Mike Gathergood <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew,rec.radio.amateur.misc
Subject: Re: Whatever happened to AC-SSB ??
Date: Fri, 01 Mar 96 09:55:38 GMT
Distribution: world
Message-ID: <[e-mail]>
References: <4h1tmr$[e-mail]>
Reply-To: [e-mail]

In article <4h1tmr$[e-mail]>
           [e-mail] "Ken Edwards" writes:

> A few years ago ther was alot of talk about Amplitude Compandored Single-Sid
e
> Band communications.
>
> Haven't heard much about it lately.
>
> Any pointers on info ?

It's being marketed (very successfully) in the UK by Securicor as
'LINEAR MODULATION'

I toured the factory (near Bath, UK) last year and saw a large number
of radios being soak tested - these were badged with another vendor's
name, and were destined for Chicago.

73
Mike                  * QRV around 0800 and 1800 most weekdays on GB3HL *
G4KFK                 * (Hillingdon 433.075/434.675) and also 51.83 MHz *


From [e-mail] Mon Mar 11 13:55:39 1996
From: tnbiesheuvel <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: 11 to 6 meters!
Date: 8 Mar 1996 22:42:03 GMT
Message-ID: <4hqd3r$[e-mail]>

From pe1pdc, evert verduin, The netherlands:

Some while ago, I found an article on the packet network,
which was about modifying 11 meter cybernet radio's to 6 meters.
The article was written by .. an australian amateur.

if someone can use this article, just leave a note in this newsgroup.
ax25: pe1pdc
e:mail ; [e-mail]




From [e-mail] Mon Mar 11 13:55:40 1996
From: [e-mail] (Elendir)
Newsgroups: rec.radio.amateur.homebrew
Subject: 50 MHz FET, low noise
Date: 6 Mar 1996 11:41:29 GMT
Message-ID: <4hjtl9$[e-mail]>

Hello once more,
meanwhile I was working on the 23 cm repeater project, I received my
6 meter authorization (Yes, yes, 50 MHz is alloted to BROADCASTING in
Region 1, and we're not as lucky as English people, we get only
50.2 to 51.2 with 10 to 100 W e.r.p) - so I'm planning to design a
transverter 50 to H.F. (Whatever).
Therefore : According to you, what is the best FET (or best small-
signal device) that can be used at that frequency ?
J310 ? 2N4416 ? BF998 ?
I know this is B.F, but...

THX, Vincent

--
Fox 5 RCS - Round the world and beyond through amateur radio.
VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.


From [e-mail] Mon Mar 11 13:55:41 1996
From: [e-mail] (Dana Myers)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 50 MHz FET, low noise
Date: 9 Mar 1996 18:12:37 GMT
Message-ID: <4hshml$[e-mail]>
References: <4hjtl9$[e-mail]> <4hs9q1$[e-mail]>

In article <4hs9q1$[e-mail]>,
WB3U <[e-mail]> wrote:
>   [e-mail] (Elendir) wrote:
>
>>Therefore : According to you, what is the best FET (or best small-
>>signal device) that can be used at that frequency ?
>
>The MPF102 and 2SK19 will work very well at 50 MHz.

I'd pick the J310 over the MPF102, hands down.

--
 * Dana H. Myers KK6JQ, DoD#: j | Views expressed here are      *
 * [phone]               | mine and do not necessarily   *
 * [e-mail]      | reflect those of my employer  *


From [e-mail] Mon Mar 11 13:55:42 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 50 MHz FET, low noise
Date: Sat, 09 Mar 96 15:54:12 GMT
Message-ID: <4hs9q1$[e-mail]>
References: <4hjtl9$[e-mail]>

   [e-mail] (Elendir) wrote:

>Therefore : According to you, what is the best FET (or best small-
>signal device) that can be used at that frequency ?

The MPF102 and 2SK19 will work very well at 50 MHz.

73,
Jack  WB3U


From [e-mail] Mon Mar 11 13:55:43 1996
Distribution: world
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Brian Carling)
References: <4hjtl9$[e-mail]>
Date: Thu, 07 Mar 1996 21:43:00 -0500
Subject: 50 MHz FET, low noise
Message-ID: <[e-mail]>

From: [e-mail]
"mail sometimes bounces here, please resend if needed!"

Bonjour!

EL>Hello once more,
EL>meanwhile I was working on the 23 cm repeater project, I received my
EL>6 meter authorization (Yes, yes, 50 MHz is alloted to BROADCASTING in
EL>Region 1, and we're not as lucky as English people, we get only
EL>50.2 to 51.2 with 10 to 100 W e.r.p) - so I'm planning to design a
EL>transverter 50 to H.F. (Whatever).
EL>Therefore : According to you, what is the best FET (or best small-
EL>signal device) that can be used at that frequency ?
EL>J310 ? 2N4416 ? BF998 ?

You can BUY a transverter KIT or ready-made from TEN-TEC in Tennessee
USA for USD $100 or 150 for ready made. It puts out 10 watts on 50 MHz
and the i.f. is 14 MHz

Bon chance!

EL>I know this is B.F, but...

B.F. ? Qu'est que c'est?

EL>THX, Vincent

TKS - Bry, Radio AF4K in Gaithersburg, MD USA

 * SLMR 2.1a * Fairchild and Honeywell merged; "Farewell honeychild!"



From [e-mail] Mon Mar 11 13:55:44 1996
From: Leon Heller <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: AD7008 DDS Chip
Date: Sun, 10 Mar 96 17:20:20 GMT
Message-ID: <[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]

In article <[e-mail]>
           [e-mail] "Robert A. French" writes:

> Anyone know how much the Analog Devices AD7008 direct digitial synthesis
> chip costs in single unit quantities? Also, where would I get it from?
> Thanks.

It was a few months ago, and the distributor I asked (Polar Electronics
here in the UK) said they were on allocation, but I was quoted about #25
(UK). Someone who got a couple of free samples from Analog gave me one
of them - thanks, Colin. 8-)

Leon
--
Leon Heller, G1HSM                | "Do not adjust your mind, there is
E-mail [e-mail]  |  a fault in reality": on a wall
Phone: [phone]         |  many years ago in Oxford.


From [e-mail] Mon Mar 11 13:55:45 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail]
Subject: AD7008 Supplies
Message-ID: <[e-mail]>
Date: Sat, 09 Mar 96 12:04:31 EDT


To the person (people?) interested in AD7008 supplies, I have AD7008 chips
available in single quantites as well as a prototyping board. Contact me by
e-mail if you are interested. Thanks,

-Chris WA3LDI
e-mail [e-mail]




From [e-mail] Mon Mar 11 13:55:45 1996
From: [e-mail] (Nan Gwa)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: ARRGH ! I need help!!
Date: 7 Mar 1996 11:31:49 -0500
Message-ID: <4hn31l$[e-mail]>
References: <4hlemk$[e-mail]>

In article <4hlemk$[e-mail]>, [e-mail]
(Praetorian) writes:

>... but from then on I dont get shit.
>

You don't need electronics for this.  Ask your doctor to
recommend a good laxative.

Tom


From [e-mail] Mon Mar 11 13:55:46 1996
From: [e-mail] (Praetorian)
Newsgroups: rec.radio.amateur.homebrew
Subject: ARRGH ! I need help!!
Date: Thu, 07 Mar 1996 01:38:57 GMT
Message-ID: <4hlemk$[e-mail]>
Reply-To: [e-mail]

Ok, here goes, I have been taking apart various Cheap radio shack
walkie talkies, and attaching them with different connections, eg. CB
antenna, one time I heard somebody on a cell phone but from then on I
dont get shit. I want to fix the litter bugger up to transmit &
recieve more than 100ft. any suggestions???

Andrew



From [e-mail] Mon Mar 11 13:55:47 1996
From: [e-mail] (Curtis, Charles)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re:  Can anyone ID these IF amps?
Date: 5 Mar 96 18:30:00 GMT
Message-ID: <[e-mail]>


Bob,

These IF log amps (detectors) cost around $700 back when there were new.
 The part you mention is a "special" made for RCA by RHG.  One video output
is a DC level proportional to the log of the amplitude of the IF input.  The
output approximately ranges from about 100 mV to 2 volts with input
amplitudes of -60 dbm to +10 dbm.  The output is a linear function of the
input power in dBm.  The unit responds to signals 60 Mhz +/- 23 Mhz in
frequency.   The other video output is a 'limited video' output for use in
detecting the simple absence or presence of on input (think of it as a logic
level output).

You could make a nice, sensitive power meter for the 6 meter band with one
of these units.  Just apply DC power to the unit and connect a DC voltmeter
to the video output.   Apply a low level, 60 Mhz +/- 23 Mhz signal to the IF
input.  The voltmeter will indicate the power level of the applied IF.   You
could calibrate it against a known
power meter for use as a stable, wide dynamic range, accurate power
measuring
device.

Chuck Curtis, N2UCN
[e-mail]
[e-mail]
n2ucn@wa2soc.#nnj.nj.usa.noam
 ------------------------------

Date: 29 Feb 96 20:38:08 GMT
From: [e-mail] (Bob Applegate)
Subject: Can anyone ID these IF amps?

Last night I picked up some IF amps at our club's White Elephant sale.  They
have RCA part numbers, but none of the retired RCA guys at the meeting had
any idea what they were for.  Markings are:

   LOG IF AMPLIFIER
   RHG ELECTRONICS LAB (15286)
   MODEL NO. ICL60G23EA
   RCA CORP P/N 5616449-5

The connectors are labeled: IF IN, -15V, RET, +15V, TP1, VID 1, VID 2, TP2.

The price was right (25 cents each), so it was worth the gamble that they
might be something interesting.

Any info about specifications would be appreciated!

Tnx
Bob - WA2ZZX

Bob Applegate, [e-mail]
Water Wheel Systems
35A East Main Street, Suite 10
Marlton, NJ  08053
609-596-0032


From [e-mail] Mon Mar 11 13:55:49 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (SARUMAN)
Subject: Re: CB conversion for HAM use?
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]> <[e-mail]>
Date: Wed, 6 Mar 1996 03:31:35 GMT

>[e-mail] (Robert E. Garland) writes:

>>[e-mail] (SARUMAN) writes:

>>>Howdy folks, I was just going thru some of my stuff and found my old Walkie
>>>T's Both are 3 channel 3 watt units. one Lafayette one Radio Shack. Is it
>>>possable to get Crystals for Frequencies other thatn the 40 CB Channels for
>>>use with these units? Any other Mod's needed? Thanx for the help folks. The
>>>Crystals in these are socketed if that matters. I've been out of this for
>>>Years.


>>For what it is worth, you can legally convert the 49 MHz units to 50 MHz
>>ham band units.  I can't say how useful they would be since I don't work
>>50 MHz myself.  I suspect that you will have to retune as well as
>>recrystal, but if you have some technical skill, that should not be a
>>problem.

>>--
>>     Robert Garland                            NX3S @ N3ACL.PA.USA.NOAM
>>     Hilltown Township Bucks County               [e-mail]
>>     Pennsylvania USA                                       Grid FN20ii
>>                   Hams do it bouncing off the "F" layer

>In reading this again, I see that I picked the wrong band, mistakenly
>thinking he was talking about the 49 MHz stuff.

>Indeed, it is possible, and legal for hams, to convert a CB to a 10-meter
>ham rig.  Check old issues of 73 magazine, to be found on microfilm at
>your local university library, for the many conversion articles published
>over the years.


>--
>     Robert Garland                            NX3S @ N3ACL.PA.USA.NOAM
>     Hilltown Township Bucks County               [e-mail]
>     Pennsylvania USA                                       Grid FN20ii
>                   Hams do it bouncing off the "F" layer
Thank ya kindly

<tsb>
                               Midgard Graphics
           3D Animation and Special FX for the hobbyist videographer
                          Email: [e-mail]

--
          Drop into #amigacafe on IRC's undernet for a chat sometime

--

<tsb>

                     A man of many hobby's master of none.




From [e-mail] Mon Mar 11 13:55:50 1996
From: Zack Lau <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Comb and interdigital filters for diplexers
Date: Tue, 05 Mar 1996 17:48:40 -0500
Message-ID: <[e-mail]>
References: <4gho2f$[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]> <4hefpl$[e-mail]>

> Gareth Edwards ([e-mail]) wrote:
> : In article <[e-mail]> [e-mail] "Zack Lau" writes:
> : > Zack Lau wrote:
> : > However, since you need as much Q as possible, you probably
> : > want to use waveguide filters, dispensing with most of the
>
> : At these frequecies the waveguide is going to have to be pretty big
> : to allow a TE or TM mode to propagate.

Actually, if you just want to make a filter, the
signal merely needs to get from one resonator to
another, which doesn't necessarily require a
propagating mode.  Thus, you can in fact make
filters for 1296 out of WR-90, though the loss
isn't low enough for this application.

Yes, WR-650 is pretty big, till you compare it
against a 2M duplexer cavity...

Zack KH6CP/1  [e-mail]


From [e-mail] Mon Mar 11 13:55:51 1996
From: [e-mail] (Art Blair)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: DigiBrain Spur/Noise Elimination?
Date: 7 Mar 1996 01:16:39 GMT
Message-ID: <4hlddn$[e-mail]>
References: <rohrwerk-2302962250450001@10.0.2.15> <4hihho$[e-mail]>

Paul N. Nix ([e-mail]) wrote:
: It seems to me that, in either a Qualcomm or Harris Spec Sheet, they
: discussed the very idea you're asking about ... ie. running the output of
: the D/A converter to a flip-flop, to 'square-up' the signal, and by doing
: so you effectively limit the spectral output to the fundamental frequency
: and the odd harmonics.

This doesn't make sense to me. Alot of the spurs from a DDS come about
because of periodic errors in the phase accumulation (which ends up
looking like a periodicly varying duty cycle). I can see a flip flop
smoothing over the amplitude quantization errors but not the phase errors.

And if you're just going to pipe that sine wave into a flip flop why not
use a 1 bit DAC to start with. Nothing is more linear than a 1 bit DAC.
(except anything analog of course ;-) )
Art.


From [e-mail] Mon Mar 11 13:55:52 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Gary Coffman)
Subject: Re: Direct conversion
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
References: <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
Date: Fri, 8 Mar 1996 19:52:22 GMT

In article <[e-mail]> [e-mail] (Clifton T. Sh
arp) writes:
>In article <[e-mail]> Robert Bissett <[e-mail]
> writes:
>>It is called Tuned Radio Frequency (TRF)  and the superheterodyne
>> was developed to overcome all its' shortcomings.
>
>True, but I thought those shortcomings were related to tube design
>and to the cost of multigang variable capacitors; neither is a problem
>with semiconductors (though coils are a consideration). Are there any
>shortcomings I've missed?

Several. Aside from the tracking problem (not really solved by varactors
unless they are hand matched), and aside from the percentage bandwidth
problem, there is the old bugaboo of TRF receivers, uncontrolled oscillation.
It is very easy to build an unintended regenerative receiver when trying
to build a TRF receiver, and the regeneration won't be under your control.

>Another question arises: is it practical to use gyrators in RF tuned
>circuits? In all these years, I've found about four pages (literally)
>of reading about gyrators, two in a magazine and two in a datasheet.
>The applications shown were audio low-pass filtering.

It's not usually *practical*, though it is possible. Above LF, real
inductors are small enough and cheap enough not to warrant the complication
of a gyrator circuit. The usual gain block for a gyrator is an opamp.
It allows the perfect 180 degree phase shift of the capacitor characteristic
needed to form the synthetic inductor, but only when working well below
the limits imposed by its gain bandwidth product. Opamps with the required
gain bandwidth for HF and above are still rare and expensive. Of course
you could just use a 1/2-wave transmission line section to get the phase
shift (at least over a narrow band of frequencies), but that hardly seems
worthwhile when the line section would be larger than the inductor it is
helping synthesize.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Mon Mar 11 13:55:54 1996
From: Adriano Sgarbi <[e-mail]>
Newsgroups: rec.radio.amateur.digital.misc,rec.radio.amateur.homebrew
Subject: ELECTRONIC TESTING EQUIPMENTS
Date: Fri, 08 Mar 1996 10:52:19 +0100
Message-ID: <[e-mail]>

ELECTRONIC TESTING EQUIPMENTS at

http://www.datas.it/~aea/


From [e-mail] Mon Mar 11 13:55:56 1996
Newsgroups: rec.radio.amateur.homebrew
Subject: FS   --   HAMMARLUND  VARIABLE  CAPACITORS
Message-ID: <[e-mail]>
From: Bill <[e-mail]>
Date: 7 Mar 96 16:24:41 CST

                      HAMMARLUND AIR VARIABLE CAPACITORS

                           ::::::::::::::::::::::

TYPE APC

        Compact, hi-quality variables. Isolantite base. Screwdriver
        or hex-wrench adjust.

        APC-25          3.0 - 25 mmf             9 available
        APC-140         6.7 - 140 mmf            2    "


TYPE MAPC

        Midget padding, trimming and general purpose capacitors similar
        type APC but smaller. Ideal for small space applications. Gap
        .0135 inch.  Rotors and stators are nickle-plated brass.
        Nickle-plated beryllium copper wiper contact. Tapped (4-40
        thread) brass studs in Steatite base permit mounting without
        grounding rotor.  Tested at 600 volts rms, 60 cps.  Slotted
        shafts for screwdriver or hex wrench.

        MAPC-75         3.9 - 75 mmf            6 available
        MAPC-25         2.6 - 25 mmf           17    "


TYPE ???

        Identical in size and shape to the type APC, but have military
        part number. Rotors and stators are silver plated (tarnished).
        Please note that capacitance ranges and values for this
        particular group are APPROXIMATE, subject to the accuracy
        of my RLC tester.

        922-0004-00     2.5 - 30 mmf              9 available
        CA-290          3.5 - 60 mmf              7    "

                          :::::::::::::::::::::::

The are all NOS units and are in excellent condition (mil types are silver
tarnished).

$45 + shipping  for the entire group (50 caps)

73s

Bill
AA4FM / 0




From [e-mail] Mon Mar 11 13:55:57 1996
From: AC6V <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Help needed
Date: 3 Mar 1996 17:16:11 GMT
Message-ID: <4hck4r$[e-mail]>
References: <[e-mail]>
To: [e-mail]

Hello James.

From Antique Radio Classified Magazine, (P.O. Box 2, Carlisle, MA 01741),
there is an ad from Midco for crystal set parts, plans, kits and books.
Catalog is $1.00. Address is P.O. Box 2288, Hollywood, Fla, 33022.

I used to build the coils on oatmeal boxes. Also fun to experiment with
razor blade edges as a detector.

Good Luck with the projects.

Rod
PS. Really like the universe quote --- outstanding.

--
*****************************************************************
Hark! I Have Hurled My Words To The Far Reaches Of The Earth!
What King Of Old Could Do Thus ?  --- AC6V
*****************************************************************
A Man May Know Of The World Without Leaving The Shelter Of His
Own Home!
Loa-Tsze
*****************************************************************




From [e-mail] Mon Mar 11 13:55:58 1996
From: joe2tpd <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: hi all
Date: 7 Mar 1996 19:20:02 GMT
Message-ID: <4hnct2$[e-mail]>

i'm looking for homemade item's
like antenna's, liner's, etc
e-mail me
i'm looking for easy made antenna's


From [e-mail] Mon Mar 11 13:55:59 1996
From: AC6V <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: hi all
Date: 8 Mar 1996 14:20:35 GMT
Message-ID: <4hpfnj$[e-mail]>
References: <4hnct2$[e-mail]>
To: [e-mail]

joe2tpd <[e-mail]> wrote:
>i'm looking for homemade item's
>like antenna's, liner's, etc
>e-mail me
>i'm looking for easy made antenna's

Hi Joe. I've had a lot of success and fun building antennas from the
following book, They are practical and inexpensive.

"Easy-Up Antennas for Radio Listeners and Hams" by Edward M. Knoll, Howard
Sams & Co. ISBN 0-672-22495-X.

Good DX
73
AC6V


--
*****************************************************************
Hark! I Have Hurled My Words To The Far Reaches Of The Earth!
What King Of Old Could Do Thus ?  --- AC6V
*****************************************************************
A Man May Know Of The World Without Leaving The Shelter Of His
Own Home!
Loa-Tsze
*****************************************************************




From [e-mail] Mon Mar 11 13:55:59 1996
From: Mark Mansfield <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Interdigital filter design info?
Date: Fri, 08 Mar 1996 10:18:08 -0600
Message-ID: <[e-mail]>

Speaking of interdigital filters, is there a ftp site on the WWW that
helps one design interdigital filters. I'd like to build a bandpass
filter in the 400-500MHz range and another for 800-900MHz. Maybe a
interdigital filter is what I need. Any ideas on this one?

Thanks,
Mark


From [e-mail] Mon Mar 11 13:56:00 1996
From: [e-mail] (Kris Cordova)
Newsgroups: rec.radio.amateur.homebrew
Subject: Looking for Information about Dentron Linear
Date: 6 Mar 1996 20:17:54 GMT
Message-ID: <4hkrti$[e-mail]>



--

Kris Cordova
[e-mail]



From [e-mail] Mon Mar 11 13:56:01 1996
From: [e-mail] (Kris Cordova)
Newsgroups: rec.radio.amateur.homebrew
Subject: Looking for Information about Dentron Linear
Date: 6 Mar 1996 20:22:20 GMT
Message-ID: <4hks5s$[e-mail]>



--

Kris Cordova
[e-mail]



From [e-mail] Mon Mar 11 13:56:02 1996
From: [e-mail] (Ed Ganger)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: looking for kit companies
Date: Wed, 6 Mar 1996 19:17:20 -0400
Message-ID: <[e-mail]>
References: <4hj5vp$[e-mail]>

In article <4hj5vp$[e-mail]> n9ifg <[e-mail]> writes:


>As a scout merit badge counselor, I am in need of kit addresses for the
>kids.

>Seems many of them are gone. Rainbow too expensive, and ramsey somewhat
>limited. Looking for the older stuff, such as receivers, strobelites, etc.

>any ideas?

>thanks

>[e-mail]


I just got a ten-tec kit catalog in the mail ...
One of their kits is a regenerative SW receiver for $29.95 ---
4 bands, optional case for $19.95, but the base kit comes with
a front panel/dashboard for tuning and controls ...

T-Kits
A division of Ten-Tec
1185 Dolly Parton Parkway
Sevierville, Tenn 37862
Inf0- 1-423-453-7172

Regards,
Ed



From [e-mail] Mon Mar 11 13:56:03 1996
From: n9ifg <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: looking for kit companies
Date: 6 Mar 1996 04:57:29 GMT
Message-ID: <4hj5vp$[e-mail]>

As a scout merit badge counselor, I am in need of kit addresses for the
kids.

Seems many of them are gone. Rainbow too expensive, and ramsey somewhat
limited. Looking for the older stuff, such as receivers, strobelites, etc.

any ideas?

thanks

[e-mail]




From [e-mail] Mon Mar 11 13:56:04 1996
From: [e-mail] (K2EK)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: looking for kit companies
Date: 6 Mar 1996 01:41:54 -0500
Message-ID: <4hjc3i$[e-mail]>
References: <4hj5vp$[e-mail]>

Send an E-mail to [e-mail]

with:

SEND KITS.TXT
QUIT


as the message text.

de Bill  K2EK


From [e-mail] Mon Mar 11 13:56:04 1996
From: [e-mail] (VINY N1VC)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: looking for RE article
Date: 9 Mar 1996 14:38:17 -0500
Message-ID: <4hsmn9$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail] (VINY N1VC)

Give your local library a shot. If they don't have the orig magazine, a
lot of times they reproduce them and store in microfiche. You can make a
hardcopy at $.XX
per page, with some degradation. If they never had the original mag,
sometimes there computer system can point you to a library that does. I
use this technique alot.

Regards,
Vin Coppola N1VC



From [e-mail] Mon Mar 11 13:56:05 1996
From: Norm Hammar <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Need books on repairing/building tube radios
Date: Thu, 07 Mar 1996 06:54:00 -0700
Message-ID: <[e-mail]>

I am looking for resources to help in repairing my old tube equipment as
well as help in building homebrew equipment. Does anyone know of a good
resource that could help teach me basic repairing techniques and/or help
in understanding schematics to aid in homebrew constructin? Any help
would be greatly appreciated.
Thanks, Norm  N0DHO   [e-mail]


From [e-mail] Mon Mar 11 13:56:06 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Need books on repairing/building tube radios
Date: 8 Mar 1996 01:30:14 GMT
Message-ID: <4ho2j6$[e-mail]>
References: <[e-mail]> <4hml3k$[e-mail]> <4hngvd$[e-mail]>
Reply-To: [e-mail]


> [e-mail] wrote:
>
>>I am looking for resources to help in repairing my old tube equipment
>>as well as help in building homebrew equipment. Does anyone know of a
>>good resource that could help teach me basic repairing techniques
>>and/or help in understanding schematics to aid in homebrew
>>constructin?
>

A good "generic" tube radio restoration and repair book is:

  "Old Time Radios! Restoration and Repair" by Joseph J. Carr,
   McGraw-Hill, ISBN 0-8306-7342-3 OR 0-8306-3342-1


P.J. "Josh" Rovero                            work:  [e-mail]
Ocean Surveys, Inc.                           play:   [e-mail]
Old Saybrook, CT 06475 USA               Amateur Radio:  KK1D



From [e-mail] Mon Mar 11 13:56:07 1996
From: Jay Wicklund <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Need books on repairing/building tube radios
Date: Thu, 07 Mar 96 16:56:46 PDT
Message-ID: <[e-mail]>
References: <[e-mail]>


In article <[e-mail]>, <[e-mail]> writes:

> I am looking for resources to help in repairing my old tube
equipment as
> well as help in building homebrew equipment. Does anyone know of a
good
> resource that could help teach me basic repairing techniques and/or
help
> in understanding schematics to aid in homebrew constructin? Any help

> would be greatly appreciated.
> Thanks, Norm  N0DHO   [e-mail]
>
You could start with Antique Electronic Supply in Arizona
phone #[phone].  They have a number of books on radio
restoration, also a large selection of tubes, and other parts.  Email
me if you want more info.

73 de KI7RH (Jay) [e-mail]




From [e-mail] Mon Mar 11 13:56:08 1996
From: [e-mail] (Jeff Duntemann)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Need books on repairing/building tube radios
Date: Sat, 09 Mar 1996 01:12:05 GMT
Message-ID: <4hqm0d$[e-mail]>
References: <[e-mail]>

Norm Hammar <[e-mail]> wrote:

>I am looking for resources to help in repairing my old tube equipment as
>well as help in building homebrew equipment. Does anyone know of a good
>resource that could help teach me basic repairing techniques and/or help
>in understanding schematics to aid in homebrew constructin? Any help
>would be greatly appreciated.
>Thanks, Norm  N0DHO   [e-mail]

I have several books by Abraham Marcus on servicing tube-era radios.
They are superb, and are relatively common on the used book market,
since every radio repair shop had one on the shelf in the back room up
through the Sixties.  I want to say the title is something like RADIO
SERVICING although the book isn't here at the office and I may not be
recalling it perfectly.  It went through numerous revisions and I have
three of them.

RCA's RADIOTRON DESIGNERS MANUAL (or something close to that) is
another standard worth snagging when you see it on the used market.
It was published from the Thirties through the Fifties. I have two
editions of that as well, and there's nothing like it for
tube-oriented design.

As for tube homebrewing, hit the hamfest circuit and start
accumulating QSTs from the Fifties and Sixties.  You can't do better
than that for good projects.

You might also subscribe to ELECTRIC RADIO magazine, which has been
publishing nice tube projects in the last year or two.

Good luck with it and let us know how you do.

--73--

--Jeff Duntemann KG7JF
  Scottsdale, Arizona





From [e-mail] Mon Mar 11 13:56:09 1996
Newsgroups: sci.electronics.components,rec.radio.amateur.homebrew
From: [e-mail] (Alan M. Horowitz)
Subject: need ferrite beads to pass 6-khz, suppress 25-khz
Message-ID: <[e-mail]>
Date: Tue, 5 Mar 1996 21:22:40 GMT

I shouldn't throw away my QST's after reading them, I guess!

I need a ferrite bead that will keep a 25-khz spurious square-wave (it's
a legitimate clock signal in another board) from entering my receiver's
a-to-d.  The wanted analog signal is a voice channel centered around 6 khz.

Which is the proper formulation of ferrite?  Who are the vendors who will
sell small quantities?


From [e-mail] Mon Mar 11 13:56:10 1996
From: Paul Mathews <[e-mail]>
Newsgroups: sci.electronics.components,rec.radio.amateur.homebrew
Subject: Re: need ferrite beads to pass 6-khz, suppress 25-khz
Date: Fri, 08 Mar 1996 16:04:09 -0800
Message-ID: <[e-mail]>
References: <[e-mail]>

Alan M. Horowitz wrote:
>
> I shouldn't throw away my QST's after reading them, I guess!
>
> I need a ferrite bead that will keep a 25-khz spurious square-wave (it's
> a legitimate clock signal in another board) from entering my receiver's
> a-to-d.

You are unlikely to find any beads that are effective at such low
frequencies.  However, regular multi-turn inductors and bypass caps
should do the job for you if the interference is, in fact, being
conducted as opposed to radiated.

--
Paul Mathews, consulting engineer
AEngineering Co.
[e-mail]
non-contact sensing and optoelectronics specialists


From [e-mail] Mon Mar 11 13:56:14 1996
From: [e-mail] (John Lundgren)
Newsgroups: sci.electronics.components,rec.radio.amateur.homebrew
Subject: Re: need ferrite beads to pass 6-khz, suppress 25-khz
Date: 6 Mar 1996 13:55:59 GMT
Message-ID: <4hk5hf$[e-mail]>
References: <[e-mail]>

Alan M. Horowitz ([e-mail]) penned:
: I shouldn't throw away my QST's after reading them, I guess!

: I need a ferrite bead that will keep a 25-khz spurious square-wave (it's
: a legitimate clock signal in another board) from entering my receiver's
: a-to-d.  The wanted analog signal is a voice channel centered around 6 khz.

: Which is the proper formulation of ferrite?  Who are the vendors who will
: sell small quantities?

Those freqs seem a bit low for ferrites.  For audio freqs I would guess
that some big electrolytics across the power busses would help.  And the
grounding of the different circuits has to be checked to see if there
might be ground loops.  If you can detect a sq wave with a scope across
the opposite ends of a ground then there is current in the ground that
should be rerouted to another point.

--
#======P=G=P==k=e=y==a=v=a=i=l=a=b=l=e==u=p=o=n==r=e=q=u=e=s=t======#
|    John Lundgren - Elec Tech - Info Tech Svcs. | jlundgre@delta1  |
|    Rancho Santiago Community College District  | .deltanet.com    |
|     17th St at Bristol \ Santa Ana, CA 92706   | http://rsc.rancho|
| My opinions are my own, and not my employer's. |    .cc.ca.us     |
|   Most FAQs are available through Thomas Fine's WWW FAQ archive:  |
|http://www.cis.ohio-state.edu:80/hypertext/faq/usenet/FAQ-List.html|
|      "You can flame your brains out -- it won't take long."       |
#===T=u=z=l=a==C=o=m=p=a=n=y=.=.===t=h=r=e=e='=s==L=e==C=r=o=w=d=!==#


From [e-mail] Mon Mar 11 13:56:15 1996
From: [e-mail] (Bob T.)
Newsgroups: sci.electronics.components,rec.radio.amateur.homebrew
Subject: Re: need ferrite beads to pass 6-khz, suppress 25-khz
Date: Wed, 06 Mar 1996 06:18:02 -0800
Message-ID: <[e-mail]>
References: <[e-mail]>

In article <[e-mail]>, [e-mail] (Alan M.
Horowitz) wrote:
> I need a ferrite bead that will keep a 25-khz spurious square-wave (it's
> a legitimate clock signal in another board) from entering my receiver's
> a-to-d.  The wanted analog signal is a voice channel centered around 6 khz.
>
> Which is the proper formulation of ferrite?  Who are the vendors who will
> sell small quantities?

Ferrite beads act only as a lossy inductor, and therefore their single
pole "filter" response curve probably won't give you the attenuation you
need for a spurious signal only 2 octaves away, depending on relative
amplitudes.

Typically, one would use an active or passive elliptical filter,
positioning the  zero's that are present in the stopband right on the
frequency causing troubles.

One might get away with better lead dress and shielded wire for the
different modules...

Good luck, Bob T.


From [e-mail] Mon Mar 11 13:56:16 1996
From: Parker Kent <[e-mail]>
Newsgroups: rec.radio.amateur.digital.misc,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.shortwave
Subject: Need Radio Clock Info.
Date: 6 Mar 1996 22:00:19 GMT
Message-ID: <4hl1tj$90r$[e-mail]>

I need any information I can get in
reguards to the radio signals sent from Germany
across Europe giving time information for
Radio Clocks.

Thanks,

Parker Kent


From [e-mail] Mon Mar 11 13:56:17 1996
From: [e-mail] (destiny admin)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.policy
Subject: New Radio Program
Date: 7 Mar 1996 00:38:04 GMT
Message-ID: <4hlb5c$[e-mail]>

Destiny Software is a developer of video games like JAM! (shareware),
Darkseed II and Blood Bowl.  You can check out our WEB site at:

http://www.destiny-software.com/destiny

Now we're experimenting with RADIO!

We have just successfully broadcast good quality music and speech over
the internet (receiving with a 28 800 modem).  (Our compression
algorithm is much faster and better quality than others we've tried.)
We plan to allow non-commercial users to broadcast for free,
encouraging a wide variety of viewpoints in this new medium.
Commercial users are welcome to participate in BETA testing.

The compression is in real time on a 486, so we will support live
broadcasts as soon as we finish the initial testing.

So here's the scoop - we're looking for BETA testers.  If you would
like to become a broadcaster, you need:

1. A permanent IP address.
2. A dedicated machine (or permission to run background tasks)
3. You are either linked to the MBONE or you have a fast connection
4. If you are using a non-windows server, we may need access to your
account to compile for your particular machine.

Basically, you fill your hard drive with samples and a script file to
organize playback.  (The player will repeat the script when it
finishes).  Later we will upgrade so that broadcasters can go live by
plugging a signal into a PC sound card.

Listeners will enter your address into the radio program and voila,
your broadcast will begin playing.  The radio feature will be built
into our soon to be released freeware browser.

If you're interested, send email.

Thanks!








From [e-mail] Mon Mar 11 13:56:18 1996
Newsgroups: rec.radio.amateur.homebrew
From: Curt <[e-mail]>
Subject: Porcelain Insulators
Message-ID: <[e-mail]>
Date: Wed, 6 Mar 1996 03:50:12 GMT

If you have an antenna project in mind for spring, i have some hard to
find Birnbach Porcelain insulators for sale. They are about 8" long &
about 1 1/2" around. These are great for SWL, Ham Hi-Power or any wire
antenna. The price is $4.00ea plus shipping. To reach me:
[e-mail] or phone [phone] before 10pm EST
or you can mail a check with approx $5.00 for shipping to
Curt Haroutunian N9INK
7835 E Southport Rd.
Indianapolis, IN. 46259
An E-Mail message to let me know your check is on the way will hold them
for you as quantity is limited to 80 at the time of this post.


From [e-mail] Mon Mar 11 13:56:19 1996
From: gareth alun evans <[e-mail]>
Newsgroups: aus.electronics,rec.radio.amateur.homebrew,uk.radio.amateur
Subject: Re: Public Domain QRP rig
Date: Fri, 08 Mar 96 20:08:31 GMT
Message-ID: <[e-mail]>
References: <4hmr1m$[e-mail]>
Reply-To: [e-mail]

In article <4hmr1m$[e-mail]>
           [e-mail] "Richard Hosking" writes:
> I have been reading posts on a public domain keyer and this seems a
> great idea. What about a QRP transceiver? I would be willing to do the
> building and testing and distribute the board artwork for those who
> want to build it. (unless someone else would do this also)
> Initially it would be necessary to settle on a specification
> (1) Philosophically - simple or complex?
> (2) Bands of interest - personally I would go for 80/40/20 or one of
> these
> (3) Power - personally I would aim for 5-10 Watts
> (4) Mode - CW or CW/SSB
> (5) What features do people want?
> (6) VFO or crystal locked?

This seems like a good idea. How about going for a rig based upon
modern semiconductor components (such as complete IF strips), but only
providing the facilities available on older valve rigs such as the
KW2000 and the FT101? - ie, basic radio without the CBer/DXer/Contester
gimmicks. What would have been a major project 20 years ago could now
be within the grasp of most hams. The only advance in the direction of
very modern electronics that I would suggest is to consider the use
of DDS to reduce the essentially difficult bits that still remain; that
of creating a stable free-running VFO together with crystal mixers.
The older style rigs, I believe, still sell well to those starting out
on radio.

--
73's de G4SDW Gareth Evans


From [e-mail] Mon Mar 11 13:56:20 1996
From: Svein Henriksen <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: QRO design using 4-1000
Date: Sun, 03 Mar 1996 19:04:58 -0800
Message-ID: <[e-mail]>

Anyone out there with a good design for a linear using the 4-1000. I have
one but little practical experience in amplifier design although I am an
electronics engineer.
Any help would be apresiated.

73 de Svein

E-mail  : [e-mail]


From [e-mail] Mon Mar 11 13:56:21 1996
From: [e-mail] (PFZouave)
Newsgroups: rec.radio.amateur.homebrew
Subject: Question on direction antennas, 310 Mhz
Date: 6 Mar 1996 01:02:26 -0500
Message-ID: <4hj9pi$[e-mail]>
Reply-To: [e-mail] (PFZouave)

I am experimenting with a tiny 310 Mhz transmitter manufactured by Ming
Technologies. Actually, its part of  encoder/transmitter set which is
intended for use,  for example, in triggering garage door openers. I have
discarded the encoder and key the transmitter with a Basic Stamp directly.
It works great as short distance data link.

The transmitter has a solder pad on it from which to connect a length of
wire to act as an antenna. Is there some way to transmit directionally?
Would a grounded reflector on one side of the antenna wire attenuate the
signal, or will signal just defract around it? Is it easier to make the
receiver directional?

Could you email with any relevant thoughts? Thanks!
/=====================================================/
/                                [e-mail]
                   /
/     The absurdity of a claim is not a valid measure of its probability
       /
/=====================================================/


From [e-mail] Mon Mar 11 13:56:22 1996
From: "G.Ioannu" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Shematic for a Cleartone VHF 500/A tranceiver Wanted...
Date: 7 Mar 1996 16:17:36 GMT
Message-ID: <4hn270$[e-mail]>

I would appriciate if anybody could send me the schematic for a VHF
tranceiver made by CLEARTONE. The model is VHF 500/AM.
It was used for Radio Taxis, and I want to convert it for the 2 meter
band.
I contacted Cleartone in UK ( I think it is a UK company ), but they
haven't got any documentation any more.
I'll have to build FM modulation, FM demodulator and PLL, almost
impossible with out the schematic.
I'll be glad to cover any expenses.

Thank you all in advance.

George Ioannu
SV8ARJ



From [e-mail] Mon Mar 11 13:56:22 1996
From: [e-mail] (Wes Stewart)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating
Date: Sun, 10 Mar 1996 15:10:06 LOCAL
Message-ID: <[e-mail]>
References: <[e-mail]>

In article <[e-mail]> Brad Duffield <[e-mail]
.edu> writes:
>Subject: Silver Plating
>From: Brad Duffield <[e-mail]>
>Date: Sun, 10 Mar 1996 00:37:41 -0500

>To all:
[snip]

>They will send you
>a free catalog, but you can also shop them here
>on the internet..<http://peganet.com/dalmar/dalmarhm.html>

>73 Brad WB8MZI

This URL doesn't work for me.


From [e-mail] Mon Mar 11 13:56:23 1996
Newsgroups: rec.radio.amateur.homebrew
Subject: Silver Plating
Message-ID: <[e-mail]>
From: Brad Duffield <[e-mail]>
Date: Sun, 10 Mar 1996 00:37:41 -0500

To all:

Since I first posted a message wanting info
on plating I have found a source of info on
the subject..A company in called Dalmar in FL
makes just what us hams are looking for..They
carry all types of plating supplies for all type
kinds of things, Non Cyanide Silver Solution
being one of them..I have talked to them on
the telephone and have found them very willing
to help with questions..They will send you
a free catalog, but you can also shop them here
on the internet..<http://peganet.com/dalmar/dalmarhm.html>

73 Brad WB8MZI



From [e-mail] Mon Mar 11 13:56:24 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating
Date: Mon, 11 Mar 96 04:36:52 GMT
Message-ID: <4i0ase$[e-mail]>
References: <[e-mail]> <[e-mail]>

   [e-mail] (Wes Stewart) wrote:

>>They will send you
>>a free catalog, but you can also shop them here
>>on the internet..<http://peganet.com/dalmar/dalmarhm.html>
>
>>73 Brad WB8MZI
>
>This URL doesn't work for me.

The correct address is:  http://www.peganet.com/dalmar/dalmarhm.html
Without the "www" prefix it won't work.

73,
Jack  WB3U


From [e-mail] Mon Mar 11 13:56:25 1996
From: [e-mail] (Greg Snellgrove)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: 7 Mar 1996 11:50:51 GMT
Message-ID: <4hmiir$[e-mail]>
References: <[e-mail]> <rohrwerk-0303962308180001@10.0.2.15> <[e-mail]> <4hjtci$[e-mail]>

Antique Electronic Supply lists a product in their catalog for
do-it-yourself electroplating. Says it uses current from any 3 or 6 volt
battery. The silver product cost $12.35 and the plating brush that
connects to the negative side of your battery is $1.35. BTW the brass
product is $2.75, the copper is $2.75 and nickel is $5.60.

73,
Greg, KN4NO




From [e-mail] Mon Mar 11 13:56:27 1996
From: [e-mail] (Tom Bruhns)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: 7 Mar 1996 21:24:58 GMT
Message-ID: <4hnk7a$[e-mail]>
References: <4hnibh$[e-mail]>


Following up to my own posting...

: In other words, the best you stand to gain is 3 percent, assuming you can ke
ep
: either the copper or the silver free of dissipative tarnish.  Of course a
: coating that isn't several skin depths thick won't even do that much good.

OK, so if you believe this, or even if you have your own number, what does
it mean about loss in a filter built with these resonators?  Let's assume a
filter whose loss is entirely in its resonators, and you can improve those
resonators each by 3%.  Let's do two examples.

First, consider a rather lossy filter that looses 3.01dB, or exactly 1/2 the
input power.  Say we put in 100 watts; 50 watts gets to the load and 50 is
dissipated in the resonators.  If we improve the resonators by 3%, then it
will be 48.5 watts in the resonators, leaving 51.5 watts to go to the load.
10*log(51.5/100) is -2.882dB.  So we've improved things by a huge 0.13dB.

Second, consider a better filter that starts at 1.00dB loss.  That's 79.43
watts to the load with 100 watts input, and that means 20.57 watts lost,
which we are assuming is all in the resonators.  If we lower that by 3%, it
drops to 19.95 watts, leaving now 80.05 watts to go to the load.  Now the
loss is .966dB, so we've improved things by a whopping 0.034dB.

If you get more than 3% improvement in Qu of you resonators by silver
plating, I submit that it's not just the plating that's doing it for you:
you've altered the surface finish, or cleaned up some contact resistance.
And to get a large dB improvement, you will have had to start out with some
pretty horrible losses in the filter to begin with.

--
Cheers,
Tom
[e-mail]


From [e-mail] Mon Mar 11 13:56:28 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: Thu, 07 Mar 96 14:58:20 GMT
Message-ID: <4hmton$[e-mail]>
References: <[e-mail]> <4heg2m$[e-mail]> <[e-mail]> <4hh27g$[e-mail]> <[e-mail]>

   [e-mail] (Drew Diamond) wrote:

>Where copper has a resistivity of 1.0, silver is 0.9. Therefore,
>Unless it is done properly (and regular plater's- used only  to doing
>ornamental plating may well not know); silver plating copper coils
>and cavities may actually increase their loss.

I thought the point to silver plating was that silver oxide conducts
much better than copper oxide?  In other words, a silver-plated
surface will greatly outperform the copper after the material ages.

73,
Jack  WB3U


From [e-mail] Mon Mar 11 13:56:29 1996
From: [e-mail] (Elendir)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: 5 Mar 1996 09:41:04 GMT
Message-ID: <4hh27g$[e-mail]>
References: <[e-mail]> <4heg2m$[e-mail]> <[e-mail]>

Gary,

: Vincent, silver plating allows you to lower the *insertion* loss of
: the system while adding another cavity will *increase* the insertion
: loss of the system. They aren't alternative paths to the same solution.

I agree.
Is it really that significant ?

What is the improvement in the insertion loss between a normal copper
cavity and a sliver-plated one ?

VIncent

--
Fox 5 RCS - Round the world and beyond through amateur radio.
VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.


From [e-mail] Mon Mar 11 13:56:29 1996
From: Jim Devenport <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: Wed, 06 Mar 1996 18:19:27 -0700
Message-ID: <[e-mail]>
References: <[e-mail]> <rohrwerk-0303962308180001@10.0.2.15> <[e-mail]>

Supposedly the biggest advantage to silver plating is AFTER it ages and
begins to oxidize.... while corroded copper will normally require
periodic disassembly and cleaning, silver oxidation is still highly
conductive.  (One reference:  ARRL "FM and Repeaters:  A 2 Meter
Duplexer", page 110.  Also the old ARRL VHF manual mentions the relative
merits of silver plating.
--
|-------------------------------------------------------|
|Jim Devenport  WB5AOX                                  |
|All Standard Disclaimers Disclaimed                    |
|My views rarely (if ever) reflect those of my employers|
|HTTP://nis-www.lanl.gov/~jdport/                       |
|-------------------------------------------------------|


From [e-mail] Mon Mar 11 13:56:30 1996
From: Mark Pettigrew <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: Wed, 06 Mar 1996 11:28:39 -0800
Message-ID: <[e-mail]>
References: <[e-mail]> <rohrwerk-0303962308180001@10.0.2.15>

> Brad Duffield wrote:
>
> > I am bulding a set of Duplexers and want to silver plate the inside
> > parts.. Anyone have any info on homebrew silver plating???
> >
> > Brad Duffield WB8MZI
>

How thick a layer of silver do you want? I have a 'silver polish' which
claims to silver plate not only silver (hence avoiding loss of silver
when you polish) but also 'silver plates' metals like copper. I've tried
it on coins, keys, etc, and it certainly coats the copper in a 'silver'
layer, and I have no reason not to believe that the layer is actually
silver. However, it's obviously not very thick.

Mark Pettigrew
G0WLR


From [e-mail] Mon Mar 11 13:56:32 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: Sat, 09 Mar 96 17:36:19 GMT
Message-ID: <4hsfpe$[e-mail]>
References: <4hmton$[e-mail]> <4hmv3r$[e-mail]>

   [e-mail] (W8JI  Tom) wrote:

>The real purpose of *most* silver plating, unless it's on a contact,
>is to impress people. Kinda like a chrome wheels with wide tire on a
>Toyota.

Putting wide tires on an 80 HP street vehicle is even more ridiculous
than most people realize.  A tire sticks to pavement as a function of
pressure per square inch applied against the road surface.  Increasing
the width places a larger patch of rubber on the road, but at the
expense of pressure per square inch.  This increases tread life, but
nothing is gained in terms of the ability of the tire to accelerate
the vehicle or to resist side forces during cornering.

I demonstrated this once by stretching some very short, very narrow
tires onto the 8" front rims of a 454 CID Corvette.  The tires were
barely half the width of the originals, but the car cornered like it
was on rails due to the increased sidewall stiffness.

Looking at specifications of factory high-performance cars from
the 50's and 60's, there's also no distinct relationship between
acceleration times and tire size.  The improvements that did occur
through that era were gradual and they resulted from better tire
compounds, not increased tread width.

Of course, none of this has anything to do with radio, although I've
heard that FM reception in a noisy hot rod can be improved by
silver-plating the antenna.  ;)

73,
Jack  WB3U


From [e-mail] Mon Mar 11 13:56:33 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: 9 Mar 1996 11:25:36 GMT
Message-ID: <4hrprg$[e-mail]>
References: <[e-mail]> <4hnibh$[e-mail]> <[e-mail]>

I would futher suggest that silver plate on "CLEAN" copper could be very
thin as it only has to protect the copper from corrosion. Silver on other
metals such as brass should probably be as thick as the skin depth for
the frequency in use.
Bill K7NOM



From [e-mail] Mon Mar 11 13:56:34 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: 10 Mar 1996 10:26:56 -0500
Message-ID: <4husc0$[e-mail]>
References: <4hteqd$[e-mail]>

Sometimes we get a little lost in the physics. The easiest thing to do is
examine some real world coils, I've done that with new coils and silver
plating makes no worthwhile change in unloaded Q. If the goal is to
prevent surface resistance shange, the coil can be lightly clearcoated or
tinned. The amateur user will never notice the performance difference,
unless it's a sliding or moving contact.

I hope people don't start thinking siver plating makes a big difference,
copper clad steel is a bad RF conductor, or a steel slug will increase the
inductance of a coil at high frequencies.

73 Tom


From [e-mail] Mon Mar 11 13:56:36 1996
From: [e-mail] (Tony King)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: Mon, 11 Mar 1996 01:05:19 GMT
Message-ID: <4hvu20$[e-mail]>
References: <4hnibh$[e-mail]> <4hrmaq$[e-mail]> <4hsgjm$[e-mail]>

I think you have hit the jackpot here...

"most relate to small signal work... surface oxide of other metals can
cause rectification or loss of contact between mechanical connections"

I am now preparing to rework a full set of six cans from a Phelps
Dodge two meter duplexer that I purchased years back and which I have
been experiencing problems with a long time because they were NOT
silver plated inside.

The problem:  after time, the surfaces do oxidize.  Of particular
interest is the contact between the fingers in the adjustable parts of
the duplexer against the bare copper.  The oxidation there causes
rectification and that is THE number one enemy in a duplexer.  When
you start getting rectification ANYWHERE in the repeater system, even
up on the tower from guy wires, loose bolts, wires crossing but not
secured, loose coax connectors, ANYTHING, you will find the SYSTEM
goes to pot.  Silver does make a difference when it comes to
preventing this type of problem in the duplexer.  I am looking forward
to the day when we get rid of the desense caused by the unplated
copper in the COMMERCIAL duplexer!  I plan to use CoolAmp.

No argument about the conductivity of silver vs copper when it is
clean and  when you are running low freq currents.

This is a very interesting thread and I am enjoying it.  I certainly
appreciate all the views expressed and I hope you will appreciate mine
as well.

73,

Tony, WA4UPE (/R, 146.625, Union City, GA, near Atlanta)
[e-mail]

[e-mail] (WB3U) wrote:

>   [e-mail] (W8JI  Tom) wrote:

>>They do it because it looks and solders better, or because of
>>marketing.
>>After all, some things are just "supposed to be silver plated".

>The industry I work in uses cavities, filters, combiners etc. at
>2.5 GHz.  The power levels involved are expensive to achieve and even
>non-technical clients are "dB-sensitive".  Despite that, none of the
>components are silver plated.  The coil in the Johnson Match Boxes
>also isn't plated, yet the efficiency of these tuners is very good
>even after they've aged.

>Like Tom said, there are some applications where silver or gold
>plating is advantageous.  Most relate to small-signal work though,
>where the surface oxide of other metals can cause rectification
>or loss of contact between mechanical connections.  I'm not even sure
>high-power RF switch contacts really benefit much from silver plating
>as opposed to other metals, especially considering that they tend to
>be self-cleaning.  Many tin alloys oxidize slowly and can provide a
>wear surface as good or better than silver.

>Speaking of which, does anyone know offhand if there's a simple (and
>relatively safe) method of tin-plating?

>73,
>Jack  WB3U




From [e-mail] Mon Mar 11 13:56:37 1996
From: [e-mail] (Elendir)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: 11 Mar 1996 10:54:20 GMT
Message-ID: <4i10os$[e-mail]>
References: <4hnibh$[e-mail]> <4hrmaq$[e-mail]> <4hsgjm$[e-mail]> <4hvu20$[e-mail]>

Tony King ([e-mail]) wrote:
: I think you have hit the jackpot here...

: "most relate to small signal work... surface oxide of other metals can
: cause rectification or loss of contact between mechanical connections"

Okay, that's true, copper oxide does rectify the signal.

But what about a quarter wavelength cavity where tuning is achieved
through a screw (thus without any contact) and coupling loops are silver
coated Cu wire ?

And then, if the cavity is sealed, the air inside is never fanned out,
therefore there ought to be only a very small oxide quantity, since once
the oxygen inside has wore out...

Vincent

--
Fox 5 RCS - Round the world and beyond through amateur radio.
VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.


From [e-mail] Mon Mar 11 13:56:38 1996
From: [e-mail] (Tom Bruhns)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: 10 Mar 1996 22:26:45 GMT
Message-ID: <4hvkv5$[e-mail]>
References: <4hteqd$[e-mail]>

Ah, yes, Roy has raised some questions about this that I wanted to
bring up anyway...

Roy Lewallen ([e-mail]) wrote:
: In article <[e-mail]>,
:    [e-mail] (Gary Coffman) wrote:
: >So perhaps we're overlooking a factor here. I think Jack may have
: >given us a clue. Lets see what the oxides of the two metals look
: >like. Right away we notice something striking. CuO has a magnetic
: >susceptability of +267 while AgO has a magnetic susceptability of
: >-19. Hmmm... now that seems to put us on the footing where we found
: >ourselves when discussing steel wire for antennas a few months back.
: >(By way of comparison, the magnetic susceptability of FeO is 293.)
: >The much higher magnetic susceptability of CuO means the skin depth
: >will be *very* thin, and net skin resistivity very high. Meanwhile,
: >the negative value for AgO means that the skin depth will be greater
: >than anticipated, so the margin between the two for RF seems much
: >greater than 3%.

: Either you've misread the CRC book, or things changed a lot in a few years.
: My 59th edition shows the magnetic susceptibility of CuO to be about +239 X
: 10-6 at near room temperature, and that of AgO to be -19.6 X 10-6. FeO is
: listed as +7200 X 10-6. The heading says that the "magnetic moment is
: expressed in cgs units". The magnetic susceptibility I'm familiar with, one
: minus the relative permeability, is dimensionless, so it's not obvious to
: me just what the numbers mean. The heading does describe the entries as
: being "paramagnetic and diamagnetic", so their relative permeabilities must
: be very close to one. Maybe someone more chemically inclined than I can
: explain what these numbers mean. I'm also puzzled about their relationship
: to skin depth. The effect of permeability on skin depth is well-
: established, but the table isn't listing permeability.

Roy's numbers look like what I found, too.  OK, what do they mean?  The
units for permeability and susceptibility are the same:  in cgs,
ergs/gauss, and in MKS, joules/tesla.  To convert from a number in cgs to a
number in MKS (for perm. & susc.), multiply by 0.001.

And here are the relationships between permeability and susceptibility
(from "Reference Data for Engineers"):

    u = u0 +  J/H

where
    u = permeability
    u0 = freespace permeability, 1.2576*10^-6 joules/tesla
    J  = magnetic polarization
    H  = magnetic field strength
    J/H = susceptibility

It's common to express permeability relative to freespace permeability:

    ur = u/u0

If you work through this, you'll see that for the copper oxide, ur is
somewhere around 1.2 and for silver oxide it's just a shade under 1.0.
Neither of these will have an overwhelming affect on skin depth.  (And
copper sulphide has a ur about 1.001.)

: Are oxides of both metals the surface salts you're most likely to see? I'm
: not a chemist, but I'd expect chlorides to be common anywhere near the
: ocean, and sulfides common in industrial areas.

I am, but I'd go to a chemical engineer for this info!  Certainly silver
sulphide is what you see on a lot of silver surfaces exposed to the
elements.

But I really think that Tom (W8JI) and Drew and others that have posted
here have the right idea on this:  the silver plating really doesn't help
that much.  You are much better off to put your energy into making the
copper suface smooth and clean, and then protecting it with a thin coat of
clear acrylic lacquer.  Or does someone have a better type of lacquer
that's commonly available?  (Polystyrene lacquer?  A cheap, safe home
process for putting on thin Teflon coatings?)
--
Cheers,
Tom
[e-mail]


From [e-mail] Mon Mar 11 13:56:40 1996
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating? An alt...
Message-ID: <[e-mail]>
From: Brad Duffield <[e-mail]>
Date: Sun, 10 Mar 1996 01:05:11 -0500

To All:

Since I first posted a request form info
on plating I found a source.. Dalmar a
company in FL makes just what us hams
are looking for..They carry all kind of
plating supplies (one being non Cyanide
Silver Solution). I talked to them on the
phone and they are willing to help with
questions..They well send a free catalog,
but you can shop them here on the internet
at <http://www.peganet.com/dalmar/dalmarhm.html>

73 & Happy Plating

Brad WB8MZI



From [e-mail] Mon Mar 11 13:56:41 1996
From: "Ian White, G3SEK" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating? An alternative?
Date: Fri, 8 Mar 1996 07:40:26 +0000
Distribution: world
Message-ID: <[e-mail]>
References: <[e-mail]>

In article <[e-mail]>, Bob Mueller wrote:
>
>I have never heard of an electroplating bath for silver which contains no
>cyanide.

Then wind your newsreader back to the beginning of this thread and read
about K9EYY's method using spent photographic fixer.

Even more useful is his tip about applying the plating using a wetted
sponge instead of buckets of solution.


73 from Ian G3SEK          Editor, 'The VHF/UHF DX Book'
                          'In Practice' columnist for RadCom (RSGB)
Professionally:
IFW Technical Services     Clear technical English - anywhere.


From [e-mail] Mon Mar 11 13:56:42 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Stupid Qustion
Date: Mon, 11 Mar 96 04:29:05 GMT
Message-ID: <4i0adr$[e-mail]>
References: <4hs98c$[e-mail]>

   [e-mail] (Lysergic Acid Diethylamide) wrote:
>I have a stupid question about the priciple of radios.
>
>I've always been told that a voltage needs a conductor in order for
>current to flow.  So how does an alternation volage of say 30v and
>freq 27mhz leave the antenna if it needs a conductor?

There is no logical explanation for anything that leaves an antenna at
27 MHz.


From [e-mail] Mon Mar 11 13:56:43 1996
From: Michael J Wooding <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: VHF Communications Magazine
Date: Wed, 6 Mar 1996 18:46:39 +0000
Distribution: world
Message-ID: <[e-mail]>

Hi Folks,

For subscribers and interested parties:

Issue 1/1996 of VHF Communications is now at the printers and should be
shipped by March 30th.

For more information on the contents of this issue and on subscribing to
the magazine take a look at our Web site:

http://www.eolas.co.uk/ag/vhfcomm.htm

Thanks and 73 ... Mike

Michael J Wooding   [e-mail] - CompuServe: 100441,377
Web Pages: http://www.eolas.co.uk/ag/vhfcomm.htm (hambits.htm & hamclip.htm)
Tel: [phone]   Fax: [phone]
KM Publications, 5 Ware Orchard, Barby, Nr.Rugby, CV23 8UF, UK
VHF Communications Magazine - Especially Covering VHF, UHF and Microwaves


From [e-mail] Mon Mar 11 13:56:44 1996
From: [e-mail] (David Messinger)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: VOX switch
Date: 7 Mar 1996 18:38:15 -0500
Message-ID: <4hns17$[e-mail]>
References: <4h9val$[e-mail]>

Paul Temple ([e-mail]) wrote:
: Hello,
: I am in need of a cheap easy to build VOX switch.  Does anyone have any
: plans for makeing one I could have?  If so could you tell me where I
: can find them please email me.
: TNX
: 73 DE KF4GDH
: email me at:
: [e-mail]


From [e-mail] Mon Mar 11 13:56:45 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Kelly Leavitt)
Subject: Re: Want mods Icom IC-736
Message-ID: <[e-mail]>
Keywords: ICOM Mods 736
References: <[e-mail]> <4hpsop$[e-mail]>
Date: Fri, 8 Mar 1996 18:49:39 GMT

Yes, I am interested in the AGC schematic.  Did you verify the diode to cut is
in fact D51?
Thanx,
Kelly ([e-mail])
KB2SYD


From [e-mail] Mon Mar 11 13:56:46 1996
From: Lee Blaske <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: What makes crackle( wrinkle) paint crackle (wrinkle)??
Date: 11 Mar 1996 01:28:34 GMT
Message-ID: <4hvvk2$[e-mail]>
References: <4hn3or$[e-mail]> <[e-mail]>

It was expained to me that the Heath light green finish as found on the SB ser
ies is
not a crackle finish.  In fact, that finish is accomplished by some sort of
spattering process using a special paint spraying nozzle.  Ron Eisenbrey, who
refinishes vintage ham gear, just finished a batch of Heath equipment.  It'll
probably be some time before he gets around to Heath again.




From [e-mail] Mon Mar 11 13:56:47 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: WTB Standard C-508A Dualbander
Date: Thu, 07 Mar 1996 20:26:41 GMT
Message-ID: <4hn67k$[e-mail]>

If you have one to sell, E-Mail [e-mail] TIA



From [e-mail] Mon Mar 11 13:56:48 1996
From: [e-mail] (Jack Kovar  KE0AX)
Newsgroups: rec.radio.amateur.homebrew
Subject: WTB: want to build .2watt drive amp 2mtr
Date: 11 Mar 1996 06:03:32 GMT
Message-ID: <4i0fnk$[e-mail]>

        I would like to build a amp for 2mtr fm that would produce
        10- 30 watts output with 200mw input.
        Anyone ever seen QST ect design such a critter?
                                                Thanks,
                                                Jack kovar
                                                [e-mail]



From [e-mail] Mon Mar 11 13:56:49 1996
Subject: XR2211
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail]
Date: Sat, 09 Mar 96 18:42:07 EST
Message-ID: <[e-mail]>


I am looking to build a packet modem around the xr2211, I need a
schematics for it and for tx too.
Sorry, I don't speak english.

Thanks.

LU 6 ENC


From [e-mail] Sat Mar 16 16:05:37 1996
From: [e-mail] (Paul)
Newsgroups: rec.radio.amateur.homebrew
Subject: (none)
Date: 11 Mar 96 09:48:19 GMT
Message-ID: <[e-mail]>

subscribe



From [e-mail] Sat Mar 16 16:05:38 1996
From: [e-mail] (Myron A. Calhoun)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 11 to 6 Meter??
Date: 8 Mar 96 13:45:10 GMT
Message-ID: <[e-mail]>
References: <4gv9if$[e-mail]> <4h4mu2$[e-mail]>

[e-mail] (D W Hemphill KC5NG) writes:
>Many years ago, one of the ham magazines (I don't remember
>which mag or what issue) published an article on converting
>[about two dozen CB boards to 10 meters]
.....

I'm pretty sure that I still HAVE all those articles!
Must have been 25 of them, at least!

--Myron.
--
# Five boxes preserve our freedoms:  soap, ballot, witness, jury, and cartridg
e
# Myron A. Calhoun, PhD EE; Assoc. Prof.     [phone] work, 532-7353 fax
# Amateur packet radio: W0PBV@N0ARY.#NOCAL.CA.USA.NOAM            539-4448 hom
e
# NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol
)


From [e-mail] Sat Mar 16 16:05:39 1996
From: [e-mail] (Ron Gunn)
Newsgroups: rec.radio.amateur.homebrew
Subject: 144.955 MHz AM receiver schematic needed
Date: 12 Mar 1996 18:48:25 GMT
Message-ID: <4i4gtp$[e-mail]>

I need to build an AM receiver that can tune 144.955 MHz. Anybody know
where a schematic for such a beast can be found?

Thanks in advance for any help at all.

--
--------------------------------------
Ron Gunn
email: [e-mail]
npage: http://home.teclink.net/~rgunn/
--------------------------------------


From [e-mail] Sat Mar 16 16:05:40 1996
From: [e-mail] (gudmundur)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: ? High Power Zener Diodes
Date: 14 Mar 1996 04:50:10 GMT
Message-ID: <4i88i2$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>,
[e-mail] says...
>
>
>Hello,
>
>sometimes high power Zener diodes are used to stabilize grid voltages
for
>tubes. For example screen grid on tetrodes with high voltage but low
>current, otherwise control grid/cathode bias for triodes. 10W and 25W
zeners
>are mostly used for this purpose. But there is a problem: standard
zener
>diodes are named ZPD+voltage indicator, high power devices mostly
1Nxxxx.
>
>Who has or where can I find a list identifing these devices?
>
>Thanks a lot in advance!
>
>vy 73, Guenter, DL4MEA@DB0KCP.#BAY.DEU.EU   (AX.25)
>                [e-mail]            (Internet)
>                http://www.scn.de/~koellner (WWW)
I am not sure how you can get a copy, however, here in america is a
company called "North American Philips" a spin off of Philips of the
nederlands. They produce a general purpose replacement line of
semiconductors and a cross referance book listing tens of thousands
of original equipment part numbers. They will have the zeners you are
looking for and a way to find them using equivalent OEM part numbers.
Maybe I could get a catalog to you, or help you find what you want.
I recently used zeners for screen grid voltage stablizing. Big
surprize, Screen grid current is sometimes reverse flow back into
zeners.     73    Don     KD3SH



From [e-mail] Sat Mar 16 16:05:41 1996
From: [e-mail] (Koellner, Guenter)
Newsgroups: rec.radio.amateur.homebrew
Subject: ? High Power Zener Diodes
Date: 12 Mar 96 23:21:00 GMT
Message-ID: <[e-mail]>


Hello,

sometimes high power Zener diodes are used to stabilize grid voltages for
tubes. For example screen grid on tetrodes with high voltage but low
current, otherwise control grid/cathode bias for triodes. 10W and 25W zeners
are mostly used for this purpose. But there is a problem: standard zener
diodes are named ZPD+voltage indicator, high power devices mostly 1Nxxxx.

Who has or where can I find a list identifing these devices?

Thanks a lot in advance!

vy 73, Guenter, DL4MEA@DB0KCP.#BAY.DEU.EU   (AX.25)
                [e-mail]            (Internet)
                http://www.scn.de/~koellner (WWW)


From [e-mail] Sat Mar 16 16:05:42 1996
From: Jake Middlebrook <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: [Q] PC switching PS mods ?
Date: 11 Mar 1996 21:25:20 GMT
Message-ID: <4i25o0$[e-mail]>
References: <[e-mail]>

[e-mail] wrote:
>Has anyone made 5 Volt PC switching power supply modification to 13.8 Volt ?
>thanks info, Danilo +
Your first problem will be the transformer its turns ratio is for 5 volts
while it will probably go to 6 or 7 13.8 will require a ratio change.
Next problem output cap is probably a 5 volt working cap need to change
that diodes may have a piv problem you probably need more inductance in
the filter choke

In short I'm a power supply engineer and I'd hate to try and do that in
my home shop its probably not worth the effort unless you just want to
learn about switching power supplies

gud luck

Jake



From [e-mail] Sat Mar 16 16:05:43 1996
From: Mark Schoonover <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: AM Loop Antennas - Homebrew??
Date: Mon, 11 Mar 1996 14:05:46 -0800
Message-ID: <[e-mail]>

Thanks for Reading!

I would like to build an AM Loop antenna. Can anybody point me to some
plans/schematics?? I live in an apartment, so space is a premium.

Mark -- KA6WKE
San Diego, CA


From [e-mail] Sat Mar 16 16:05:44 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.space,rec.radio.amateur.misc,rec.radio.amateur.homebrew,rec.radio.amateur.equipment,rec.radio.amateur.antenna
Subject: Re: Announsing: Technology Patent Available For Purchase
Date: Mon, 11 Mar 96 09:11:20 PDT
Message-ID: <[e-mail]>
References: <[e-mail]> <4hdlvj$[e-mail]> <[e-mail]> <4hfqtn$[e-mail]>  <[e-mail]>


> Amen, Jim.  If this thing works like this guy spells, he's got a tough sell.


>
> "Announsing", "blatent" and "know one else" indeed. I don't know what his
> device is,  because searching for the number didn't work for me. Sounds like

a
> Peltier device, but I guess it could be cold fusion.
>
> 73, Wes -- N7WS
>
Always nice to see a couple of smarta*sses on the net..Hi fellows

Gerhardt-



From [e-mail] Sat Mar 16 16:05:45 1996
Subject: ASTRO 150 A
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail]
Date: Mon, 11 Mar 96 19:27:26 EST
Message-ID: <[e-mail]>


I am looking for circuit of ASTRO 150 A transceiver.
Please if you know about it send me E-mail and I send you
IRC's for mail.



Victor lu6enc


From [e-mail] Sat Mar 16 16:05:46 1996
From: [e-mail] (Tarkus95)
Newsgroups: rec.radio.amateur.homebrew
Subject: Boat Anchors`
Date: 13 Mar 1996 23:16:38 -0500
Message-ID: <4i86j6$[e-mail]>
Reply-To: [e-mail] (Tarkus95)

Could somebody please direct me to the newsgroup where broadcast engineers
trade horror stories about their stuff blowing up?  I seem to recall it
was a sub-thread of another newsgroup called alt.boatanchors or something
like that.  Any information would be greatly appreciated.  You can e-mail
me direct if you like.

[e-mail]


From [e-mail] Sat Mar 16 16:05:47 1996
From: [e-mail] (God)
Newsgroups: rec.radio.amateur.homebrew
Subject: Changing freq on RS 21-409 transciever
Date: Thu, 14 Mar 96 17:51:56 GMT
Message-ID: <4i9mcm$[e-mail]>

I have a cheap Rat Shack 49.830MHz transciever that I want to refit to
transmit (and recieve if possible) in the cordless phone handset band
(48.76MHz to 49.970MHz). The unit has two crystals in it (which I assume
control freqs). One is 16.45833 (MHz or Khz?) The other is 16.610 (MHz or
Khz?) .. Would it be possible to replace the crystals to change the freqs?
Ideally I'd like to be able to select channel numbers (1-25). Could I use a
voltage controlled oscillator or something? I'm waiting to get the service
manual from rat shack, so I *may* have more details then.

Thanks A Bunch

http://www.netaxs.com/~god


From [e-mail] Sat Mar 16 16:05:48 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Dave Kirkby)
Subject: Re: EIMAC 5CX3000A tube
Message-ID: <[e-mail]>
Date: Thu, 14 Mar 1996 15:00:15 GMT
Reply-To: [e-mail]
References: <4hv7ig$[e-mail]>

> xxI recently picked up a piece of surplus gear with a big EIMAC
> 5CX3000A
> xxtube. I have written to EIMAC to get operating voltages for this
> xxmonster, but they may not respond in time for shopping for a plate
> xxtransformer at this weekend's hamfest.
>
> xxCan somebody please post or e-mail the operating voltages / limiting
> xxspecs for it?
>
> xxThanks
>
> xxJerry Flanders   W4UKU   South Carolina     [e-mail]

Hers my data that I collated some time ago. From Eimac Catalogue.
5000W dissipation
9kV @ 2.5A HT
18.6kW output. Dont ask me what class this is in.
heater = 7.5V @ 75A.


Eimac 3CX5000A3       Triode   110MHz   5,000W  9,000V @     2.50A  18,600W  7
.50V @   75.00A Industrial heating also recommended as a GG FM amp, or linear.




---
Dave Kirkby
Dept of Medical Physics,
University College London,
11-20 Capper St,
London WC1E 6JA
Tel: [phone]
Fax: [phone]







From [e-mail] Sat Mar 16 16:05:49 1996
From: [e-mail] (Wes Stewart)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: FCC-Out of Control??? Please Read
Date: Tue, 12 Mar 1996 06:51:21 LOCAL
Message-ID: <[e-mail]>
References: <4i34kg$[e-mail]>

In article <4i34kg$[e-mail]> [e-mail]
(Rick Eutsler) writes:
>From: [e-mail] (Rick Eutsler)
>Subject: FCC-Out of Control??? Please Read
>Date: Tue, 12 Mar 1996 09:13:10 GMT

By his spamming, it appears that Mr. Eutsler is the one out of control. It
also sounds like these guys got what they deserved.


From [e-mail] Sat Mar 16 16:05:50 1996
From: Vlad <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: FS: HP608 sig. gen. manual
Date: 13 Mar 1996 14:20:09 GMT
Message-ID: <4i6lip$[e-mail]>

For sale HP608 signal generator original user/service manual.
$14 including mailing.
Vlad



From [e-mail] Sat Mar 16 16:05:51 1996
From: [e-mail] (James Moore)
Newsgroups: rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.shortwave,rec.radio.swap
Subject: GrandFather left 2 Garages full of Stuff
Date: 12 Mar 1996 16:47:07 GMT
Message-ID: <4i49qb$[e-mail]>


        GrandFather passed and left 2 garages full of stuff.

        GrandMother wants rid of it.

        If interested call 1 800 996-2971

        Thank You



From [e-mail] Sat Mar 16 16:05:52 1996
From: Bill Funk <[e-mail]>
Newsgroups: rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.shortwave,rec.radio.swap
Subject: Re: GrandFather left 2 Garages full of Stuff
Date: 16 Mar 1996 02:38:03 GMT
Message-ID: <4id9ib$[e-mail]>
References: <4i49qb$[e-mail]> <4i6l9j$[e-mail]>

[e-mail] (Clair Robinson) wrote:
>James Moore ([e-mail]) wrote:
>
>:      GrandFather passed and left 2 garages full of stuff.
>
>:      GrandMother wants rid of it.
>
>:      If interested call 1 800 996-2971
>
>:      Thank You
>
>
>Could you at least tell us what state its in?
=====================
What do you wanna bet this is an ongoing commercial deal?
No descriptions, an 800 number...

--
        Bill Funk - [e-mail]
        ASCIi User Group - http://www.starlink.com:80/~ascii
                User groups: More info than you can shake a CD at!
                             Try one near you!




From [e-mail] Sat Mar 16 16:05:53 1996
From: [e-mail] (Charlie Fortner)
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Subject: ground a 5/8 wave on a trunk lip mount?
Date: Wed, 13 Mar 1996 21:12:15 -0500
Message-ID: <[e-mail]>

I've got a trunk lip mount and I want to use a 5/8 wave antenna with it.
If I attach a piece of wire running from the ground of the antenna to a
suitable ground in the trunk, will this have the same affect as putting
the antenna on the roof of my car?  Thanks.

Charlie Fortner
KF4GJQ


From [e-mail] Sat Mar 16 16:05:53 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Ham-Homebrew Digest V96 #102  RE:the 100watts walkie-talkie
Date: 12 Mar 96 18:32:07 GMT
Message-ID: <[e-mail]>

Hi,
        Please stop intimidate or humiliate the fellow amateur radio operators'
science knowlege in these homebrew email list. Do you know physics ? How could

your have 100 watts output with less than 2 watts consumption ?  Is you comput
er
powered by a hearing aid battery ? Or you are the 21st century Mr. Newton.

Rich




From [e-mail] Sat Mar 16 16:05:54 1996
From: "Lorelei Lindenaux (SAR)" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: HeathKit HP 24
Date: Thu, 14 Mar 1996 20:18:22 -0500
Message-ID: <Pine.SUN.3.91.960314201527.20197B-100000@virtu>



My dad is looking for:  HeathKit HP24 AC Power Supply with or without the HA
                        Amplifier.  Please call him at 1-813-842-4818
                        W4NHP Maurice New Port Richey Fla.
 You can e-mail me at [e-mail]  and I can have him call
you instead.  Thanks,  Lorelei


From [e-mail] Sat Mar 16 16:05:55 1996
From: [e-mail] (Jon Goguen)
Newsgroups: rec.radio.amateur.homebrew
Subject: Help with identifying coax.
Date: 11 Mar 1996 17:09:23 GMT
Message-ID: <[e-mail]>

I have some high quality double-shielded Teflon dielectric coax for which
I would like to get some precision N connectors.  The coax is unmarked
however, and the connector suppliers I've contacted tell me they need a UG
number or other identifier inorder to provide the correct connector.  Can
anyone help identify this cable?  The outer sheath is a very slick plastic
(HMW polyethelene?), lavender in color, about 0.275" diameter.  The
silver-plated braided shield beneath is about 0.190 diameter, and is
separated from the spiral wound flat inner shield (O.D. 0.150") by a thin
layer of wrapped teflon.  The stranded central conductor, inside more
wrapped teflon, is silver-plated, 0.056" O.D. (15 guage), and contains 19
28 or 29 gauge strands.

Any body got a field guide to coax?

Thanks in advance for all responses.

Cheers,

Jon


From [e-mail] Sat Mar 16 16:05:56 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Dave Kirkby)
Subject: Re: Help with identifying coax.
Message-ID: <[e-mail]>
Date: Tue, 12 Mar 1996 16:49:24 GMT
Reply-To: [e-mail]
References: <[e-mail]>

In article [e-mail], [e-mail] (Jon Goguen)
 writes:
> I have some high quality double-shielded Teflon dielectric coax for which
> I would like to get some precision N connectors.  The coax is unmarked
> however, and the connector suppliers I've contacted tell me they need a UG
> number or other identifier inorder to provide the correct connector.  Can
> anyone help identify this cable?  The outer sheath is a very slick plastic
> (HMW polyethelene?), lavender in color, about 0.275" diameter.  The
> silver-plated braided shield beneath is about 0.190 diameter, and is
> separated from the spiral wound flat inner shield (O.D. 0.150") by a thin
> layer of wrapped teflon.  The stranded central conductor, inside more
> wrapped teflon, is silver-plated, 0.056" O.D. (15 guage), and contains 19
> 28 or 29 gauge strands.
>
> Any body got a field guide to coax?
>
> Thanks in advance for all responses.
>
> Cheers,
>
> Jon
Both Times and Shuner do decent catalogues that have coax dimensions and type
no.



---
Dave Kirkby
Dept of Medical Physics,
University College London,
11-20 Capper St,
London WC1E 6JA
Tel: [phone]
Fax: [phone]







From [e-mail] Sat Mar 16 16:05:57 1996
From: [e-mail](Wanda M Desmond)
Newsgroups: rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.swap
Subject: HELP!! NEED service manual for TAC TEC transceiver
Date: 13 Mar 1996 06:30:25 GMT
Message-ID: <4i5q21$[e-mail]>
References: <4i49qb$[e-mail]> <4i5btf$[e-mail]>

I need a service manual for a TacTec (RCA) #MJAW2-EC21G.

Thanks!

John
KE6TGN


From [e-mail] Sat Mar 16 16:05:58 1996
From: Don C Hamiel <hamiel>
Newsgroups: rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.swap
Subject: Re: HELP!! NEED service manual for TAC TEC transceiver
Date: 14 Mar 1996 11:09:38 GMT
Message-ID: <4i8upi$[e-mail]>
References: <4i49qb$[e-mail]> <4i5btf$[e-mail]> <4i5q21$[e-mail]>
To: [e-mail]

What model tac-tec is it?

There is a company called RAB parts. I think they are in PA.
If not, look up Kyodo West. They made some of the Tac-Tec stuff. They made the
310sx line. I have some info on the 310 line and some new scanning control
heads too. They are good little radios (310sx).

Good Luck. 73 de Don N6NLX.



From [e-mail] Sat Mar 16 16:06:01 1996
From: [e-mail] (K5HWH)
Newsgroups: rec.radio.amateur.homebrew
Subject: Help, please.
Date: 12 Mar 1996 19:08:35 -0500
Message-ID: <4i53m3$[e-mail]>
References: <4i5181$[e-mail]>

     Can anyone advise me where in Midland, Texas the Hamfest will be held
this weekend? Also, what is (are) the talk-in frequencies? Thank youin
advance for the help.

Jim
K5HWH


e-mail:  [e-mail]


From [e-mail] Sat Mar 16 16:06:02 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Kelly Leavitt)
Subject: Re: Here are some IC-726 mods, etc.
Message-ID: <[e-mail]>
References: <4i1qv7$[e-mail]>
Date: Mon, 11 Mar 1996 19:08:19 GMT

Bruce:
  Does the same diode open up the tx on the 736?  Just wondering.  Thanks for
the info on the qrp mod.  How closely related are the 726 and the 736?

Kelly


From [e-mail] Sat Mar 16 16:06:03 1996
From: [e-mail] (TIEMANN BRUCE)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Here are some IC-726 mods, etc.
Date: 11 Mar 1996 20:06:19 GMT
Message-ID: <4i213r$[e-mail]>
References: <4i1qv7$[e-mail]> <[e-mail]>

        I have no idea what the similarities/differences between the '726
and '736 are... but a phone call to tech service might answer your
question.  (OTOH, they might not want to answer *that* question!)  I
don't have a '736.

        The recent "Hotrod Your ICOM Transceiver" pair of QST articles
mentioned the electrical identicality of several makes, at least so far as
those particular mods were concerned, and in particular the '725 and '726
were among them, but I don't recall if the '736 was also.  At worst, you
can clip the PLL's D5 just at one place, otherwise leaving it in place,
see what happens, and then bend it back and resolder the clipped lead if
it turns out not to have been the correct thing to do.

        Unless, of couse, this operation lets the smoke out of some other
part(s).  But I doubt it will.

Bruce
N6URH


From [e-mail] Sat Mar 16 16:06:04 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Kelly Leavitt)
Subject: Re: Here are some IC-726 mods, etc.
Message-ID: <[e-mail]>
References: <4i1qv7$[e-mail]> <[e-mail]> <4i213r$[e-mail]>
Date: Mon, 11 Mar 1996 20:49:54 GMT

I intend to give it a try one of these days.  Not real important, just want
to play around a bit.  I'll look up D5 on the schematic and see where it is
connected to/from.

Thanks for all the assistance.

Kelly (KB2SYD)


From [e-mail] Sat Mar 16 16:06:05 1996
From: [e-mail] (Paul Erickson)
Newsgroups: rec.radio.amateur.homebrew
Subject: How to test a 3cx3000 ?
Date: 14 Mar 96 10:29:15 GMT
Message-ID: <[e-mail]>
References: <[e-mail]>

Does anyone have the means of testing a 3cx3000 ? I have one kicking
around in my junk box, and before I turn it into a bookend or something
would like to know if it is functioning (or should I say functionable???)

I'm happy to pay shipping and a reasonable fee if necessary. I won't
need it in any event as my linier plans revolve around some 4cx1000's
and 4cx1500's I have as well, but knowing it is workable would be
nice if I decide to sell or swap it.

cheers, Paul
ve7cqk
email: [e-mail]




From [e-mail] Sat Mar 16 16:06:07 1996
From: Jim Strohm <Jim Strohm@ausq1ak>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Kit QRO HF rigs...Hands Electronics RTX series?
Date: 15 Mar 1996 13:49:44 GMT
Message-ID: <4ibsho$[e-mail]>
References: <[e-mail]>

[e-mail] (Conway Yee) wrote:
>It occurs to me that I can build an outboard solid state amp for these
>rigs and bring them to the 100W class rigs.  Any flaws to this idea?

Your only concern would be that you'd need to turn down the output
from the Hands rig to something that a typical 100-watt-class solid-
state amp would like to see.  The most common "kit" solid-state
amp (not really a kit, but a board and a parts list) likes to see 4
watts or so for 100 - 150 watts out.  This is based on the old
Motorola 140 watt push-pull HF amp designed by Helge Granberg about
a million years ago.  These are easy to build.  You can probably
locate one of these already assembled if you know where to look.

Jim N6OTQ Please direct all flames to 27.185.000.000




From [e-mail] Sat Mar 16 16:06:08 1996
From: Tom Kreyche <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: lightning detector, how?
Date: 12 Mar 1996 16:10:09 GMT
Distribution: world
Message-ID: <4i47l1$[e-mail]>

I just read a review of the SkyScan lightning detector.  It's a hand-held
4x6 inch box which has led's which indicate lightning distances in ranges
of 0-3 miles, 3-8 miles, 8-20 miles, 20-40 miles and has an indicator for
severe storms. Price is $200, Automated Weather Source, 301-258-8390

The reviewer checked it out in weather service office that had doppler
radar and an expensive lightning detector and found that it worked well.

I'd like to build something similar and perhaps build a dual arrangement
to get crude triangulation. Anyone have any references for this type of
instrument?

Obviously with a relatively low frequency radio, e.g.  am broadcast band
you can easily pick up lightning induced noise, but how do you translate
it into distance? The audio output could easily be filtered and
digitized, does amplitude translate directly into distance? What
frequencies are best for lightning detection?

Thanks, Tom Kreyche KG6YJ


From [e-mail] Sat Mar 16 16:06:09 1996
From: [e-mail]    (Bill Newkirk)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: lightning detector, how?
Date: 15 Mar 1996 04:45:35 GMT
Message-ID: <4iaslf$[e-mail]>
References: <4i47l1$[e-mail]>
Reply-To: [e-mail] (Bill Newkirk)

In <4i47l1$[e-mail]>, Tom Kreyche <[e-mail]> writes:
>Obviously with a relatively low frequency radio, e.g.  am broadcast band
>you can easily pick up lightning induced noise, but how do you translate
>it into distance? The audio output could easily be filtered and
>digitized, does amplitude translate directly into distance? What
>frequencies are best for lightning detection?
>
>Thanks, Tom Kreyche KG6YJ

something like that. if i remember right the 3m/ryan stormscope was basically
an
ADF receiver (to get bearing) and they did some stuff to arrive at a "distance
"
number - somewhat proportional to amplitude (a strong strike far away shows
closer than it really is..)

Bill Newkirk WB9IVR                  The Space Coast Amateur Technical Group
Melbourne, FL                       duty now for the future of amateur radio
Lombardi's 1st Law of Business:
Companies succeed in spite of their best effort.  If they succeed at all.



From [e-mail] Sat Mar 16 16:06:11 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Gary Coffman)
Subject: Re: lightning detector, how?
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
References: <4i47l1$[e-mail]> <4iaslf$[e-mail]> <4ibmsv$[e-mail]>
Date: Sat, 16 Mar 1996 13:09:53 GMT

In article <4ibmsv$[e-mail]> [e-mail] (W. E. Van Horne)
 writes:
>: In <4i47l1$[e-mail]>, Tom Kreyche <[e-mail]> writes:
>: >Obviously with a relatively low frequency radio, e.g.  am broadcast band
>: >you can easily pick up lightning induced noise, but how do you translate
>: >it into distance? The audio output could easily be filtered and
>: >digitized, does amplitude translate directly into distance? What
>: >frequencies are best for lightning detection?
>: >
>: >Thanks, Tom Kreyche KG6YJ
>
>Atmospheric static (the project was code-named 'Sferics) propagates best
>at ultra-low frequencies.  We used 10-KHz.  Like all low frequency radio
>waves, they propagate via a ground wave, which rapidly dies out with
>distance in a square-law manner), and sky wave that travels all around
>the world.  Over salt water, the latter travels in straight lines, and a
>very simple RDF system will give reliable results over thousands of
>miles of ocean.  The 'Sferics detectors were simple shielded loop
>antennas, one oriented N-S and the other E-W, tuned to resonance at
>10-KHz.  Each developed a signal that was amplified by a three-stage
>amplifier and the raw 10-KHz. outputs were put on the vertical and
>horizontal plates, respectively, of a CRT.  A distant static crash would
>cause a diagonal line to appear on the scope at an angle equal to the
>azimuth, to a high degree of accuracy.

We use a commerical product called the Lightning Tracker. It has
receiving stations, much as you describe, but with a micro calculating
the bearing angle instead of a scope, and adding a timestamp. These are
connected back to a central computer via landline modems. This computer
then does the triangulation and plots the strike locations on a map overlay
for broadcast. The plots correlate well with weather radar displays.

This sort of thing would be really easy to add to a packet network,
using APRS format to report bearings.

A different form of lightning alert system can be built taking advantage
of the fact that VHF signals propagate much less readily over long distances
than LF frequencies. You need two AM receivers, one on LF and the other
on VHF. The outputs of the two receivers feed a coincidence detector.
(Just a windowed AND gate.) When you start getting outputs from the
coincidence detector, a storm is likely approaching your location. It's
then time to start the standby generator, batten down the hatches, and
take cover if appropriate.

You need both receivers and the coincidence detector to avoid falsing
on local interference. Most interference is not extremely broadbanded,
but lightning is. We used a system like this to start the standby
generator at a remote transmitting site for many years. It started
the generator more times than was absolutely necessary, but it saved
our bacon enough times to keep it in place.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Sat Mar 16 16:06:11 1996
From: (Gary) [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: Looking for CK722 Transistor
Date: 11 Mar 1996 19:41:23 GMT
Message-ID: <4i1vl3$[e-mail]>

I am looking for a CK722 Philco transistor. It was in a
blue case and I need one for nostalgia purposes.  It was
my first transistor radio project as a young ham.

        TNX Gary KF9CM



From [e-mail] Sat Mar 16 16:06:12 1996
From: [e-mail] (Jim Weir)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: Wed, 13 Mar 1996 02:08:16 GMT
Message-ID: <4i5amp$[e-mail]>
References: <4i1vl3$[e-mail]>

(Gary) [e-mail] shared the following priceless pearls of wisdom:

>I am looking for a CK722 Philco transistor. It was in a
>blue case and I need one for nostalgia purposes.  It was
>my first transistor radio project as a young ham.

It wasn't Philco, it was Raytheon.  I used one in my first project in
'58 or '59 and I've got ONE left in the nostalgia case.  Sorry.  BTW,
I take it out and measure it for beta and leakage every time I get
spoiled with the current production stuff.

Jim


Jim Weir VP Engineering | You bet your sweet patootie I speak for the
RST Engineering         | company.  I OWN the cotton-pickin' company.
Grass Valley CA 95945   |
http://www.rst-engr.com | AR Adv WB6BHI--FCC 1/C phone--Cessna 182A N73CQ
[e-mail]        | Commercial/CFI-Airplane/Glider-----A&P Mechanic



From [e-mail] Sat Mar 16 16:06:13 1996
From: [e-mail] (K2EK)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: 13 Mar 1996 00:47:02 -0500
Message-ID: <4i5ngm$[e-mail]>
References: <4i5amp$[e-mail]>

In article <4i5amp$[e-mail]>, [e-mail] (Jim Weir) writes:

>>I am looking for a CK722 Philco transistor. It was in a
>>blue case and I need one for nostalgia purposes.
>>
snip...
>It wasn't Philco, it was Raytheon.

Gary - I checked my nostalgia pile to see if I had more than one.  Sorry.
Though the one I have is in a rectangular natural aluminum case (and
labeled Raytheon) - probably circa 1961.

Bill  K2EK


From [e-mail] Sat Mar 16 16:06:14 1996
From: [e-mail] (Bill Meahan)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Distribution: world
Message-ID: <[e-mail]>
References: <4i1vl3$[e-mail]>
Date: Tue, 12 Mar 96 23:56:59 GMT

In article <4i1vl3$[e-mail]> [e-mail] writes:
>
>I am looking for a CK722 Philco transistor. It was in a
>blue case and I need one for nostalgia purposes.  It was
>my first transistor radio project as a young ham.
>
>        TNX Gary KF9CM
>
>

Gee, I remember the CK722 as being made by Raytheon and in a silver
metal can that was of a rounded rectangular shape (kinda like a small
IF transformer) with three thin wire leads from a white insulator.

I know there's one around here SOMEPLACE but, of course, I can't find
it.  Not that I would part with it anyway, but I could at least verify
the physical appearance.

73!

--
Bill Meahan WA8TZG                   [e-mail]
Member of:  ARRL, IMRA, NorCal QRP (#407), G-QRP (#8468), MI-QRP (#M1458)
Hey, this is my OWN computer!  I can say what I want!
        cat: a purr bearing mammal


From [e-mail] Sat Mar 16 16:06:16 1996
From: [e-mail] (Hank Riley)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: 15 Mar 1996 19:35:44 GMT
Message-ID: <4icgqg$[e-mail]>


Well, it's been interesting and certainly nostalgic to hear people
recalling the early Raytheon CK722 transistors and the varying colors
of cases that they were apparently made in over the years.

I can attest to the deep blue *and bare aluminum* case styles, since
I have specimens of both.

I consulted a wonderful 116 page book called "RAYTHEON Transistor
Applications: More than 50 practical Circiuts using Raytheon CK722
Transistors", for a few more factoids.  Price for this book:  50 cents.
(no date marked, unfortunately, but probably easily before 1959).

Inside the front cover is an aerial photograph of "The home of
Raytheon transistors", what apppears to be a brick three story
mill building, complete with smoke stack.

        "This multimillion dollar plant is the largest in
         the world devoted exclusively to the production
         of semiconductors."

Somewhat ironically, the address is *California* Street, Newton,
Massachusetts.

Turning to the spec sheets at the back of the book, there were four
transistors available in the characteristic CK722 case style:
CK721, CK722, CK725, and CK727.  The differences in the first three
seem to be mainly variations in current gain, while the CK727 was
optimized for lower (AF) noise:


        Type            "Average base current
                        amplification factor"

        CK721                   45

        CK722                   22

        CK725                   90

        CK727                   25


At the time of publication, Raytheon also offered about 11
conventionally identified germanium PNP point contact transistors,
from the 2N63 to the 2N133, not all of which were hermetically
sealed. (None of the above CK series were hermetically sealed)

Those were great times back then!  New thread idea: remember
the International Rectifier B2M photocells?

Hank Riley, N1LTV
[e-mail]


From [e-mail] Sat Mar 16 16:06:17 1996
From: [e-mail] (Daniel J. Shepherd)
Newsgroups: rec.radio.amateur.homebrew
Subject: Mods for KW TM-3530A and KDK FM-2030
Date: Sun, 10 Mar 1996 15:06:45
Message-ID: <4hvct9$[e-mail]>

Are there any mods for the Kenwood TM-3530A or the KDK FM-2030?

Thanks, N8VZU (Dan)




From [e-mail] Sat Mar 16 16:06:18 1996
From: [e-mail] (Rich Mulvey)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: need 11 to 6 meters
Date: 11 Mar 1996 02:53:42 GMT
Message-ID: <[e-mail]>
References: <4i00n7$[e-mail]>
Reply-To: [e-mail]

On Mon, 11 Mar 1996 03:47:28 GMT, McCarthy <[e-mail]> wrote:
>looking for plans on going from 11 meters to 6 meters.
>does anyone have any plans? I will cover any cost.
>

   Well, first you have to study for the licence...

---
Rich Mulvey, aa2ys                                        Rochester, NY   USA
[e-mail]
[e-mail]
aa2ys@wb2psi.#wny.ny.us



From [e-mail] Sat Mar 16 16:06:19 1996
From: "Mr. Brooke Clarke" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Need 1n78 point contact mixer diodes
Date: Mon, 11 Mar 1996 09:44:47 -0800
Message-ID: <[e-mail]>
References: <[e-mail]> <4hsn4r$[e-mail]>
To: VINY N1VC <[e-mail]>

VINY N1VC wrote:
>
> I tried the Hot carrier diode approach, specifcally the 1N5711 priced at
> 55 cents. It actually worked up to around 7 GHZ and would have gone higher
> I think. The sensitiviy seemed greater than the orignal mixer. However
> when sweeping it I did see a lot of peaks and valleys or resonances. How
> ever I don't have it properly packaged inside of the mixer, that circular
> "T" piece is not in there. Maybe that will help I will try it next.
>
> Thanks for the suggestion,
>
> Viny Coppola N1VCViny:

When using Schottky (Hot Carrier) diodes in a mixer, you can improve performan
ce by
matching the diode barrier height (Vf @ 1 ma.) to the L.O. power level.  HP, M
A-COM,
Metelics and others make a line of diodes with different barrier heights low,
medium,
high, extra high.

Have Fun,
Brooke




From [e-mail] Sat Mar 16 16:06:20 1996
From: [e-mail] (VINY N1VC)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Need 1n78 point contact mixer diodes
Date: 9 Mar 1996 14:45:30 -0500
Message-ID: <4hsn4r$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail] (VINY N1VC)


I tried the Hot carrier diode approach, specifcally the 1N5711 priced at
55 cents. It actually worked up to around 7 GHZ and would have gone higher
I think. The sensitiviy seemed greater than the orignal mixer. However
when sweeping it I did see a lot of peaks and valleys or resonances. How
ever I don't have it properly packaged inside of the mixer, that circular
"T" piece is not in there. Maybe that will help I will try it next.

Thanks for the suggestion,

Viny Coppola N1VC


From [e-mail] Sat Mar 16 16:06:22 1996
Newsgroups: rec.radio.amateur.homebrew
From: Chris Broadbent <[e-mail]>
Subject: Re: Need books on repairing/building tube radios
Message-ID: <[e-mail]>
References: <[e-mail]> <4hml3k$[e-mail]> <4hngvd$[e-mail]>
Date: Mon, 11 Mar 1996 19:38:10 GMT

[e-mail] wrote:

>I am looking for resources to help in repairing my old tube equipment
>as well as help in building homebrew equipment. Does anyone know of a
>good resource that could help teach me basic repairing techniques
>and/or help in understanding schematics to aid in homebrew
>constructin?

Forgive me if this is already answered, but take a look at the newsgroup
rec.antiues.radio+phono.  Many extremely helpful experts in the field of
old radio restoration live there.  I have benefitted a great deal from
their kind help.

Cheers,

Chris ( [e-mail] )


From [e-mail] Sat Mar 16 16:06:24 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Gary Coffman)
Subject: Re: Need Charger for Lead Acid Gel Cell Battery
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
References: <4i1e7p$[e-mail]>
Date: Tue, 12 Mar 1996 17:21:31 GMT

In article <4i1e7p$[e-mail]> [e-mail] (DABLOODGOD)
writes:
>I bought one of these at a swap meet last month, and now I need a charger
>for it - Its the size of a large car battery - so the small RC plane model
>Ive seen wont really provide enough current. The battery name plate
>describes 2 voltages - 14.2 to 14.4 volts for charging and 13.6-13.8 volts
>for trickle charging ( these voltages are approximate ) The key thing is
>that the charger is supposed to have 2 modes - 2 voltages and be able to
>switch between them when appropriate. I saw a article in a newsprint
>magazine ( World Radio Times ? ) last month, Unfortunately, Ive recently
>moved and trashed the magazine, before I realized that I needed the
>article.
>
>If anyone has that magazine, or has an idea for a charger, or knows who
>sold that I kit, I would appreciate having the information

Just go to Pep Boys or Northern Handyman (or even Sears) and get a
good auto battery charger with dual modes. They aren't expensive,
and they'll do what's needed.

The way the charger determines which mode to be in is by monitoring
the current draw. As the battery approaches full charge at 14.2-14.4
volts, the current will drop. When it drops past a set point, the
charger switches taps on the transformer (usually a relay), and
delivers the "float" voltage of 13.8 volts indefinitely.

An easy way to sample the charge current is with a fractional ohm
resistor in series with one of the battery leads. A comparator is
wired across the resistor and when the voltage falls below the
set point, the comparator changes state and drives the relay.
(Alternatively the charger could use a linear voltage regulator
and use the comparator to change its set point, but that costs
more for a high amp charger.)

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Sat Mar 16 16:06:25 1996
From: [e-mail] (David Gibson)
Newsgroups: sci.electronics.components,rec.radio.amateur.homebrew
Subject: Re: need ferrite beads to pass 6-khz, suppress 25-khz
Date: Sun, 10 Mar 1996 23:07:52 GMT
Message-ID: <4hvjmi$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]

[e-mail] (Alan M. Horowitz) wrote:

>I shouldn't throw away my QST's after reading them, I guess!

>I need a ferrite bead that will keep a 25-khz spurious square-wave (it's
>a legitimate clock signal in another board) from entering my receiver's
>a-to-d.  The wanted analog signal is a voice channel centered around 6 khz.

>Which is the proper formulation of ferrite?  Who are the vendors who will
>sell small quantities?

There is just not that much magic in ferrite beads, I fear! You will
have to design some plain technology, i.e. a true low pass filter. If
the noise is getting in on the signal line, use an active filter in
the signal line. It the noise is coming in through supply leads, you
will need extra decoupling or perhaps an independent regulator. Also,
pay close attention to earthing. Make sure none of the earth return
currents from the circuit with the noisy clock pass through wires or
traces which also serve as earth returns for the adc.

David Gibson
Microconsultants      http://www.microconsultants.com
         FREE PLC software     FREE SPC software
    SPLat low cost programmable industrial controller
          GaugeLink digital caliper interface



From [e-mail] Sat Mar 16 16:06:26 1996
From: Andy Walton <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: PCB design software
Date: 13 Mar 1996 03:01:13 GMT
Message-ID: <4i5dpp$[e-mail]>
References: <3139888f.382937@194.72.192.4>
To: [e-mail]

Try Protel Easytrax, available from Simtel.
Regards, Andy VK3CAH




From [e-mail] Sat Mar 16 16:06:27 1996
From: [e-mail] (Tsachy Lindenbaum)
Newsgroups: rec.radio.amateur.homebrew
Subject: PCB software for WIN95
Date: 10 Mar 1996 18:57:39 GMT
Message-ID: <4hv8n3$[e-mail]>

Hi
Can someone specify a recommended program and a possible download site
for a PCB software for win95 ?
Thanks in advance from Isaac (Tsachy), 4Z4TL



From [e-mail] Sat Mar 16 16:06:27 1996
From: [e-mail] (Garry Foster)
Newsgroups: rec.radio.amateur.homebrew
Subject: PCBs pre sensitised
Date: Fri, 15 Mar 1996 15:56:13 GMT
Message-ID: <4ic3ug$[e-mail]>
Reply-To: [e-mail]

Could someone point me to a source of positive pre sensitized
printed circuit material. I know PCB kits used to sell them.
However I called and got an answering machine sometime ago.
Asked for current information and still havenÆt heard anything so
I am looking for other sources.
                        Thanks Garry WB0NNO




From [e-mail] Sat Mar 16 16:06:28 1996
From: [e-mail] (Marius Hovland)
Newsgroups: rec.radio.amateur.homebrew
Subject: PLEASE HELP!  Schoolproject on making phonecentral/intercom-thing-like-thingy!
Date: 12 Mar 1996 10:10:26 GMT
Message-ID: <4i3iii$[e-mail]>

        Could anyone help me!  I'm making a phonecentral with three
old-type pulse-phones as my school-project. The central is not to be
connected with public-net, the use is only intercom-like.

                                Marius Hovland Tj÷me,Norway
                                E-mail : [e-mail]



From [e-mail] Sat Mar 16 16:06:29 1996
From: Steven B Reed <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Realy amazing kits
Date: Mon, 11 Mar 1996 06:46:07 -0500
Message-ID: <[e-mail]>

#1004 100 WATT (PEP) WALKIE TALKIE

Make any walkie talkie get out with the power of the big guys. This tiny
power converter requires less than 1 watt of driving power to
create a 100 watt PEP output. Even so, the power consumption is less
than 2 watts of energy, so it will operate for long periods on its
small battery pack. Note: This device was designed for use in remote
areas of the world and is not approved by the FCC for use on
the citizens band.

PLANS ONLY KIT #1004 POK . . . . . . . . . . . . . . . . . . . . . . . .
$19.95

So it will just make the other 98 with its good looks.... Didn't some
one write a law about conservation of energy or some other nonsense...
On the other hand, if you hold a 100W ant 6 inches from your head you
could come up with all kinds of neat plans.
==================================================================

#1005 POCKET PAGER

This tiny pocket paging system was designed for rapid signaling of any
person carrying a similar device up to 3000 miles away.
(Shades of Napolean Solo, "Open channel D";) Not a talking system,but
rather a signaling or paging type system. IC circuitry
transmits hundreds of miles in less than 10 milliseconds.

PLANS ONLY KIT #1005 POK . . . . . . . . . . . . . . . . . . . . . . . .
$19.95

At least the radio waves from this one don't travel faster than the
speed of light.  (I didn't do the math, just making a guess!!)


Just thought everyone might enjoy reading these!!!!!!
--
'73 from KB8STB  & KB8ZKP
         Steven  & Sylvia Reed


From [e-mail] Sat Mar 16 16:06:31 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Gary Coffman)
Subject: Re:  Silver Plating
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
References: <4i1bkc$[e-mail]>
Date: Tue, 12 Mar 1996 17:11:26 GMT

In article <4i1bkc$[e-mail]> [e-mail] (Stanley L. F
legler) writes:
>Several postings ago it was stated that CuO has a magnetic susceptability
>of +267.  Does this mean that the bare copper HF antenna that I put up
>last fall will start to become very inefficient as oxides (or chlorides)
>start to form? 73 Stan K8RPA, [e-mail]

Apparently not.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Sat Mar 16 16:06:32 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating
Date: 12 Mar 1996 08:30:38 -0500
Message-ID: <4i3u9u$[e-mail]>
References: <4i1bkc$[e-mail]>

In article <4i1bkc$[e-mail]>, [e-mail] (Stanley
L. Flegler) writes:

>
>Several postings ago it was stated that CuO has a magnetic susceptability

>of +267.  Does this mean that the bare copper HF antenna that I put up
>last fall will start to become very inefficient as oxides (or chlorides)
>start to form? 73 Stan K8RPA, [e-mail]
>
>

No Stan, it doesn't.

You could never measure the change in efficiency, and the numbers were
wrong anyway.

73 Tom


From [e-mail] Sat Mar 16 16:06:33 1996
From: [e-mail] (Tom Bruhns)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: 11 Mar 1996 18:31:30 GMT
Message-ID: <4i1ri2$[e-mail]>
References: <4i10os$[e-mail]>

Elendir ([e-mail]) wrote:

: But what about a quarter wavelength cavity where tuning is achieved
: through a screw (thus without any contact) and coupling loops are silver
: coated Cu wire ?

Usually the screw would still be a metal-to-metal contact which could
corrode and cause rectification, but you're right, if you put the screw
into a Teflon insert so it was capacitively coupled to both the outer and
inner conductors, that could work.  Then you'd have RF on the screw...but
maybe the arrangement could be a short metal cylinder (tube) brazed to the
inside of the outer cavity wall, lined with the Teflon sleeve into which
the screw threaded, and the screw could be "buried" below the outer surface
of the cavity.  Or...after adjustment of the screw, you could solder it in
place (making it really yucky to readjust if you ever needed to--but quite
well sealed at that point against outside air).

: And then, if the cavity is sealed, the air inside is never fanned out,
: therefore there ought to be only a very small oxide quantity, since once
: the oxygen inside has wore out...

If you could backfill with something like dry nitrogen, then really seal
it, it should indeed be fine for a very long time.  If you were really
rabid about this, you could use air-insulated hard lines coupling between
cavities, brazed to the cavities at each end, and put hermetic seals on the
input and output ends, and have tubing that lets you purge the air, then
seal things off.  But I think if you don't really seal things, barometric
pressure changes will eventually pump new atmosphere into the system.
Every storm/fair weather cycle could pump 5 percent new air into it, if
it's not really sealed.  (And if it _is_ sealed, be sure that air pressure
changes don't change the tuning!)

Whew.  Think I'll stay with W8JI's clearcoat!

--
Cheers,
Tom
[e-mail]


From [e-mail] Sat Mar 16 16:06:34 1996
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: Mon, 11 Mar 96 19:21:18 GMT
Message-ID: <4i1udi$[e-mail]>
References: <4hnibh$[e-mail]> <4hrmaq$[e-mail]> <4hsgjm$[e-mail]> <4hvu20$[e-mail]>

In article <4hvu20$[e-mail]>,
   [e-mail] (Tony King) wrote:

>. . .
>"most relate to small signal work... surface oxide of other metals can
>cause rectification or loss of contact between mechanical connections"
>. . .

>The problem:  after time, the surfaces do oxidize.  Of particular
>interest is the contact between the fingers in the adjustable parts of
>the duplexer against the bare copper.
>. . .

Ah, CONTACTS. Now, that's an altogether different question! Start that
thread at your peril -- it's certain to turn into a rope!

73,
Roy Lewallen, W7EL


From [e-mail] Sat Mar 16 16:06:36 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Gary Coffman)
Subject: Re: Silver Plating ?
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
References: <[e-mail]> <4hnibh$[e-mail]>
Date: Fri, 8 Mar 1996 19:15:33 GMT

In article <4hnibh$[e-mail]> [e-mail] (Tom Bruhns) writes
:
>Drew Diamond ([e-mail]) wrote:
>
>: Where copper has a resistivity of 1.0, silver is 0.9. Therefore,Unless it i
s
>: done properly (and regular plater's- used only  to doing ornamental plating

>: may well not know); silver plating copper coils and cavities may actually
>: increase their loss.
>
>Lessee, my reference lists copper as 1.724e-6 ohm-cm resistivity, and
>silver as 1.62e-6 ohm-cm.  Normalizing to copper=1 makes sliver 0.94, not
>even as good as 0.9.  OK, that's for DC, but things get more complicated at
>RF.  If you want to compare copper and (solid) silver in exactly the same
>mechanical configuration, including surface finish, and the material is
>several skin depths thick, then you have to account for the fact that the
>skin depth is not as great in the more conductive silver, and that means
>the gain is NOT 1:0.94, it is only the square root of that or 1:0.97.  In
>other words, the best you stand to gain is 3 percent, assuming you can keep
>either the copper or the silver free of dissipative tarnish.  Of course a
>coating that isn't several skin depths thick won't even do that much good.
>
>I'm just saying I think Drew is right on, even more so.

Perhaps, or perhaps not. Since a lot of RF conductors are silver
plated, and silver isn't cheap, it seems a bit hard to swallow
that those hard headed manufacturing engineers are doing it just
for decoration, especially since most of that silver plate is never
seen by the customer. Even Detroit doesn't chrome plate the *inside*
of its engines without a sound technical reason.

So perhaps we're overlooking a factor here. I think Jack may have
given us a clue. Lets see what the oxides of the two metals look
like. Right away we notice something striking. CuO has a magnetic
susceptability of +267 while AgO has a magnetic susceptability of
-19. Hmmm... now that seems to put us on the footing where we found
ourselves when discussing steel wire for antennas a few months back.
(By way of comparison, the magnetic susceptability of FeO is 293.)
The much higher magnetic susceptability of CuO means the skin depth
will be *very* thin, and net skin resistivity very high. Meanwhile,
the negative value for AgO means that the skin depth will be greater
than anticipated, so the margin between the two for RF seems much
greater than 3%.

Figures are from the CRC Handbook, 47th edition, table starting
on page E-103.

As with steel versus copper for antenna wires, we have to look
beyond DC resistance to find out which material is better suited
to the task. It turns out that oxidized copper is almost as bad
as oxidized steel as an RF conductor. That shouldn't surprise
us, corroded coax (from water wicking into the braid) is a very
lossy medium. Now we know why.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Sat Mar 16 16:06:37 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: Tue, 12 Mar 96 18:56:49 GMT
Message-ID: <4i4hl8$[e-mail]>
References: <4hteqd$[e-mail]> <4hvkv5$[e-mail]> <4i155k$[e-mail]> <[e-mail]>

   [e-mail] (Gary Coffman) wrote:

>I still think there must be some reason other than decoration that
>the *inside* of cavities are silver plated.

Maybe this trend started when cavities were first being sold to the
government.  They'll gladly pay 100% more for a .01% improvement. ;)

73,
Jack  WB3U


From [e-mail] Sat Mar 16 16:06:39 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Gary Coffman)
Subject: Re: Silver Plating ?
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
References: <4hteqd$[e-mail]> <4hvkv5$[e-mail]> <4i155k$[e-mail]>
Date: Tue, 12 Mar 1996 17:10:50 GMT

In article <4i155k$[e-mail]> [e-mail] (Roy Lewallen) w
rites:
>In article <4hvkv5$[e-mail]>,
>   [e-mail] (Tom Bruhns) wrote:
>
>>. . .
>
>>And here are the relationships between permeability and susceptibility
>>(from "Reference Data for Engineers"):
>>    u = u0 +  J/H
>>
>>where
>>    u = permeability
>>    u0 = freespace permeability, 1.2576*10^-6 joules/tesla
>>    J  = magnetic polarization
>>    H  = magnetic field strength
>>    J/H = susceptibility
>
>Thanks for the clarification! The "magnetic susceptibility" referred to in
>my physics book is apparently more correctly "relative magnetic
>susceptibility" since it's dimensionless -- that's what threw me off. With
>the definition you've used, the data in the CRC book make sense.
>
>Roy Lewallen, W7EL

Yeah, thanks, Tom. Looks like that was a blind alley. I still think
there must be some reason other than decoration that the *inside*
of cavities are silver plated. No one is going to see it, so I still
think it's put there for a functional purpose, we just haven't found
it yet.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Sat Mar 16 16:06:41 1996
From: [e-mail] (K2EK)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: 12 Mar 1996 02:12:24 -0500
Message-ID: <4i384o$[e-mail]>
References: <4hmiir$[e-mail]>

In article <4hmiir$[e-mail]>, [e-mail] (Greg Snellgrove)
writes:

>The silver product cost $12.35 and the plating brush that
>connects to the negative side of your battery is $1.35.

For what it is worth, I've used a similar product consisting of a brush
"pen" which held 2 AA cells and a ground return lead out the top.The
plating material comes from a loop of silver wire within the brush.  Dip
the brush in an electrolyte solution and "paint" on the silver...

 While slow, it does a credible job on flat or simple surfaces (such as
1/2" copper water pipe for 2m cavities). Trying to plate a 3.5" diameter
30t coil of 1/8" tubing after forming the coil was another story.
Trying to plate the inside of some homemade waveguide or other irregular /
inaccessible shape is probably impossible.

Bill  K2EK


From [e-mail] Sat Mar 16 16:06:43 1996
From: [e-mail] (Tom Bruhns)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: 14 Mar 1996 16:47:15 GMT
Message-ID: <4i9iij$[e-mail]>
References: <4i1vhj$[e-mail]>

WB3U ([e-mail]) wrote:

..

: The best protective finish I have found for electronic parts is
: polyurethane varnish.  It's somewhat more brittle than other oil-based
: varnishes, but is probably the toughest single-part, air-dry finish
: on the market.  Once it has fully cured (usually three to four weeks),
: polyurethane is nearly as hard as baked enamel.  The only drawback to
: polyurethane is its deterioration in sunlight, but marine and exterior
: versions are available with UV blockers that will significantly extend
: the life of the finish under adverse conditions.

..

Thanks to Jack for a nice posting on using polyurethane varnish.  I had a
brief email exchange with Jack about one issue that remains in my mind, and
agreed to post it here to see if anyone has any difinitive info on it.

My concern is that polyurethane has a rather high dissipation factor.
It was a little hard to find listings, but looks like about 0.05,
compared with .0002 or less for polystyrene, polyethelene and Teflon.
So the question is, given that it's used in a rather thin coating, does
that really make any difference?  Has anyone actually measured the
unloaded Q of a cavity before and after coating with any type of clear
coat, whether it's polyurethane or acrylic or something else?

--
Cheers,
Tom
[e-mail]


From [e-mail] Sat Mar 16 16:06:44 1996
From: [e-mail] (wayne burdick)
Newsgroups: rec.radio.amateur.homebrew,rec.radio.amateur.equipment
Subject: Spanish-language manuals available for new QRP kits
Date: Mon, 11 Mar 1996 15:53:46 -0800
Message-ID: <[e-mail]>

...de Wilderness Radio,
P.O. Box 734
Los Altos, CA 94023-0734
U.S.A.

[phone]    Engles, por favor.    (English only, please.)

No hablemos Espanol en el telephono.   Por Favor, por preguntas en
Espanol, escribe.
(Sorry, we can't answer questions in Spanish on the telephone.  Please
write to the above address if you only speak Spanish.)


From [e-mail] Sat Mar 16 16:06:45 1996
From: [e-mail] (Rob M.)
Newsgroups: rec.radio.amateur.homebrew
Subject: Spread Spectrum
Date: Sun, 10 Mar 1996 22:11:29 GMT
Message-ID: <4hvi8k$[e-mail]>

Are there any web sites, news groups, etc which focus on spread
spectrum. I am interested in building some SS links, but would like
additional "how to" material. Acquiring and locking of signal at the
RX end is the most importandt info I am presently seeking. Any and all
help would be greatly appreciated.


Thanks


Rob



From [e-mail] Sat Mar 16 16:06:46 1996
From: Steven B Reed <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Stupid Qustion
Date: Mon, 11 Mar 1996 06:45:52 -0500
Message-ID: <[e-mail]>
References: <4hs98c$[e-mail]> <4i0adr$[e-mail]>

WB3U wrote:
>
>    [e-mail] (Lysergic Acid Diethylamide) wrote:
> >I have a stupid question about the priciple of radios.
> >
> >I've always been told that a voltage needs a conductor in order for
> >current to flow.  So how does an alternation volage of say 30v and
> >freq 27mhz leave the antenna if it needs a conductor?
>
> There is no logical explanation for anything that leaves an antenna at
> 27 MHz.

The above is true!!!

To answer the question.....

Antennas are electric circuits of a special kind.  In ordinary circuits,
the dimensions of coils, capacitors and connections usually are small
compared with the wavelength that corresponds to the frequency in use.
When this is the case, most of the electromagnetic energy stays in the
circuit itself, and is either used up in performing useful work or is
converted into heat.  But when the dimensions of wiring or components
become appreciable compared with the wavelength, some of the energy
escapes by radiation in the form of electromagnetic waves.  When the
circuit is intentionally designed so that the major portion of the
energy is radiated, the circuit is an antenna.
        (1991 ARRL Antenna Book Ch2 first paragraph)

What actually "leaves" the ant is a Magnetic field.
the only stupid question is one that dosen't get asked!
--
'73 from KB8STB  & KB8ZKP
         Steven  & Sylvia Reed


From [e-mail] Sat Mar 16 16:06:48 1996
From: [e-mail] (Ed Gallup)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Stupid Qustion
Date: Mon, 11 Mar 96 04:52:08 GMT
Message-ID: <4i0bde$[e-mail]>
References: <4hs98c$[e-mail]> <4i0adr$[e-mail]>

In article <4i0adr$[e-mail]>, [e-mail] (W
B3U) wrote:
>   [e-mail] (Lysergic Acid Diethylamide) wrote:
>>I have a stupid question about the priciple of radios.
>>
>>I've always been told that a voltage needs a conductor in order for
>>current to flow.  So how does an alternation volage of say 30v and
>>freq 27mhz leave the antenna if it needs a conductor?
>
>There is no logical explanation for anything that leaves an antenna at
>27 MHz.

    That ^  is good!     However, to answer the poor guy's original question,

a voltage does NOT leave the antenna.  The voltage IN the antenna induces an
electroMAGNETIC wave which leaves the antenna.

  Ed  WB6SAT


From [e-mail] Sat Mar 16 16:06:49 1996
From: [e-mail] (Lysergic Acid Diethylamide)
Newsgroups: rec.radio.amateur.homebrew
Subject: Stupid Qustion
Date: 9 Mar 1996 15:48:28 GMT
Message-ID: <4hs98c$[e-mail]>

I have a stupid question about the priciple of radios.

I've always been told that a voltage needs a conductor in order for
current to flow.  So how does an alternation volage of say 30v and freq
27mhz leave the antenna if it needs a conductor?

I though electricity cannot go through open air except for VERR high
voltages.



From [e-mail] Sat Mar 16 16:06:51 1996
From: [e-mail] (Elendir)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Stupid Qustion
Date: 13 Mar 1996 21:03:21 GMT
Message-ID: <4i7d6q$[e-mail]>
References: <4hs98c$[e-mail]> <4i37j1$[e-mail]> <[e-mail]> <4i65dd$[e-mail]> <[e-mail]>

Gary Coffman ([e-mail]) wrote:
: The explanation I learned (admittedly many years ago) is that a photon
: has zero rest mass, but that it carries a mass equivalent in its
: energy, as related by the Planck Law, E=hv, and the mass energy
: equivalence, E=MC^2. That may be intuitively Newtonian, but it gives
: the right answer for solar sail calculations. I'm not at all sure
: what you mean by "impulsion", but you seem to be implying that it
: is a tensor field quantity of some sort that warps spacetime conversely
: from the way it is warped by gravity. I freely admit ignorance of the
: finer points of General Relativity.

Well, it is almost true. Almost because the true formula for energy
is E^2 = M^2*C^4 + P^2*C^2, simplifying to E = M*C^2 at rest.
Impulsion is P, quantity of motion.
The vector P and energy E can be in special relativity merged into
a quadrivector impulsion-energy (maybe the English word is impulse !)
that get generalized in the general relativity into a tensor field.
You mentioned the equivalence mass <> energy, thereby the metric tensor
is bound to energy, and therefore mass, by the Einstein equation.

Vincent

--
Fox 5 RCS - Round the world and beyond through amateur radio.
VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.


From [e-mail] Sat Mar 16 16:06:53 1996
From: [e-mail] (Elendir)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Stupid Qustion
Date: 13 Mar 1996 09:44:13 GMT
Message-ID: <4i65dd$[e-mail]>
References: <4hs98c$[e-mail]> <4i37j1$[e-mail]> <[e-mail]>

Gary Coffman ([e-mail]) wrote:

: of a wavelength yet radiate well. And I'm not sure we can say fields
: are imaginary when EM radiation can have mass (solar sails, Special
: Relativity, etc). I have a hard time calling anything with mass imaginary.
[...]
: At a deeper level, the vacuum energy is also spacetime, and is
: thus warped by gravitational fields, nicely explaining how an
: EM wave can be bent by gravity, and obversely how an EM "photon"
: can have mass. C then becomes a fundamental property of the

There is a confusion here.
Light and photons do not have any mass.

They follow geodesics of the underlaying spacetime, himself being related
to the topology of the masses.

Solar sails is just radiation pressure ; although photons are weightless
they do carry energy and impulsion, that they are able to give to any body
they encounter.

But, if you imagine a ray of light as being a road on which photons drive,
the presence of weight somewhere near creates a diversion that photons must
follow, therefore curving the ray. Giving a mass to the photon is - precisely
-
trying to explain a pure relativist phenomenon by newtonian theory.

(Impulse-Energy tensor) = K*(Metric tensor)

Vincent
--
Fox 5 RCS - Round the world and beyond through amateur radio.
VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.


From [e-mail] Sat Mar 16 16:06:54 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Stupid Qustion
Date: 12 Mar 1996 02:02:57 -0500
Message-ID: <4i37j1$[e-mail]>
References: <4hs98c$[e-mail]>

In article <4hs98c$[e-mail]>, [e-mail]
(Lysergic Acid Diethylamide) writes:

>I've always been told that a voltage needs a conductor in order for
>current to flow.  So how does an alternation volage of say 30v and freq
>27mhz leave the antenna if it needs a conductor?
>
>I though electricity cannot go through open air except for VERR high
>voltages.

Hi Pigdog,

This is one of the big effects of the universe. Whenever an electron is
accelerated or moved, all the other electrons in the universe try to
re-adjust to the change. So the electron does not really go anywhere, the
"effect" does.

The rate at which this effect moves through the universe is called the
speed of light. We use imaginary things called "fields" to explain this
"effect", electric fields and magnetic fields. We can't make one field
vary without producing the other field, we can't stop one varying field
without stopping the other. Neat, huh? ALL antennas are ELECTROMAGNETIC.

When the little electrons "accelerate" back and forth in the antenna, the
electromagnetic fields we use to explain the effects we observe are
"produced". Actually, there really isn't even a "wave" or anything leaving
the antenna and going anywhere, just the "effect" rippling through the
universe that we hang names on.

On a less serious note, if you take 100-200 micrograms of that stuff after
your signature, you may be able to see these waves rippling through the
universe like tiny golden fishes (Cream, from Swabalar 1969) !
 ;-)

73, Tom


From [e-mail] Sat Mar 16 16:06:55 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Gary Coffman)
Subject: Re: Stupid Qustion
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
References: <4hs98c$[e-mail]> <4i37j1$[e-mail]> <[e-mail]> <[e-mail]>
Date: Thu, 14 Mar 1996 16:50:40 GMT

In article <[e-mail]> [e-mail] (Joe Mack) writes:
>In article <[e-mail]> [e-mail] (Gar
y Coffman) writes:
>>This is a really nice intuitive explanation, but somehow I find it
>>lacking (as I also find the explanation in the Antenna Book lacking).
>>For example, the Antenna Book seems to be saying that an antenna needs
>>to be a large fraction of a wavelength in size to radiate well, but
>>then we have magnetic loops like the Isoloop which are tiny fractions
>>of a wavelength yet radiate well. And I'm not sure we can say fields
>>are imaginary when EM radiation can have mass (solar sails, Special
>>Relativity, etc).                        ^^^^
>
>I think solar sails work because light has _momentum_

Yes indeedy, but momentun has the units of *mass* times velocity.
That's the problem. To get momentum transfer, we have to satisfy
M1*V1=M2*V2, where M1 and V1 are the sail's mass and velocity
and M2 and V2 are the photon's mass and velocity. Setting M2 to
zero yields zero momentum transfer. So we have to assign some
value of mass to M2 in order for a solar sail to work. Since
a solar sail does work, that implies light has mass (or something
equivalent to mass, in this case E=hv becomes through mass
equivalence M=E/C^2). That works too. We find, for example,
that a UV photon delivers more momentum to the sail than an
IR photon because it has greater energy, and hence greater
mass equivalence.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Sat Mar 16 16:06:56 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Stupid Qustion
Date: 15 Mar 1996 14:23:01 -0500
Message-ID: <4icg2l$[e-mail]>
References: <4ibfu6$[e-mail]>

In article <4ibfu6$[e-mail]>, [e-mail] (Elendir)
writes:

>
>Well. It's not that simple. Otherwise the simple cathodic display you
>are using would be a formidable source of RF energy !!!!! You get a
>photon when you use alternative current.
>
>Vincent.

There certainly is photon emission. There just aren't enough electrons
changing directional or acceleration rates over a large area to be a
formidable "RF" energy source.

73 Tom


From [e-mail] Sat Mar 16 16:06:57 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Matthew Francey)
Subject: Re: Stupid Qustion
Message-ID: <[e-mail]>
References: <4hs98c$[e-mail]> <4i37j1$[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
Date: Fri, 15 Mar 1996 15:48:50 GMT

[e-mail] (Gary Coffman) writes:

>>I think solar sails work because light has _momentum_
>
>Yes indeedy, but momentun has the units of *mass* times velocity.
>That's the problem. To get momentum transfer, we have to satisfy
>M1*V1=M2*V2, where M1 and V1 are the sail's mass and velocity
>and M2 and V2 are the photon's mass and velocity. Setting M2 to
>zero yields zero momentum transfer.

you have to balance *momentum*.  in this case, we have two items:
the photon and the mirror:

        p(photon_in) = p(photon_out) + dp(mirror)

if we limit ourselves to a normal reflection, the p(photon_out)
equals -p(photon_in), so the change in the mirror's momentum is:

        dp(mirror) = 2*p(photon_in)
                   = 2E/c,  E = energy of the photon

the sail will be intercepting many ka-billions of photons per unit time.
let us call this flux 'n' photons/second, and as a force is the change
of momentum per unit time:

        F(mirror) = 2*n*E/c

however, it is easier to measure measure the power per unit area
(about 1500W/m^2 at 1au from the Sun), call this 'S', and let the surface
area of the mirror, 'A', enter into the equation:

        F(mirror) = 2*S*A/c

and while the defintion of 'S' was introduced as the power per unit area
from the source, it should be understood that S is really how much of this
power the mirror can reflect (which is a function of wavelength and
material).  left as an exercise for the curious reader is to consider
non-normal incidence, handle the case of photon's that are absorbed by the
mirror, and (bonus) determine the orientation a solar sail ought
to be in order to maximize energy gain, if this mirror is in solar orbit.
--
Matthew Francey | VE3RQX | NAD27: N43o34.210' W079o34.572' +0093m


From [e-mail] Sat Mar 16 16:06:58 1996
From: Peter Shintani <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: want info on how to build a HF/6m Duplexer
Date: 13 Mar 1996 23:53:45 GMT
Message-ID: <4i7n69$[e-mail]>

Hi
        I bought a IC-706 and would like to build a HF/6m duplexer so
I don't have to manually switch antennas. (The IC-706 outputs HF and 6m via
one connector and I have two antennas)
Can someone provide a schematic on how to build a duplexer for Hf and 6m and
or guide me to some source that describes how to design the duplexer.
(Comet makes a commerically available duplexer but it seems a bit expensive)
By the way, I tried to build a low pass and a high pass filter to split the si
gnal but I
seemed
to get some interaction between the filters, so I don't thing designing
separate sections is the correct method to design  duplexer. Each filter indiv
idually
had the correct response but when their inputs were paralleled it didn't work.
I had funny dips in the response.

VE7 CQA
Peter





From [e-mail] Sat Mar 16 16:06:59 1996
From: [e-mail] (Jeff Hall)
Newsgroups: rec.radio.amateur.homebrew
Subject: wanted plans:  j-pole 440..300ohm ant for HT
Date: 12 Mar 1996 00:30:22 GMT
Message-ID: <4i2giu$[e-mail]>

  I am looking for plans for using 300 OHM TV lead to make a 440 ant. for
my uhf HT..I have the plans for the 2 meter. Now I would like the same
sort of ant. to My HT..This way I can roll it up and take it with me to
the great outdoors...Hope someone can help...thanks..Jeff


From [e-mail] Sat Mar 16 16:07:00 1996
From: [e-mail] (progen et2)
Newsgroups: rec.radio.amateur.homebrew
Subject: WARP WAS-1 AUTO SWR SCHEMATICS
Date: 11 Mar 96 13:17:53 GMT
Message-ID: <[e-mail]>


I HAVE OBTAINED A WARP WAS-1 AUTO SWR METER WHICH HAS A NUMBER OF WIRES
DISCONNECTED (DAMAGED) IT ALSO HAS NO REMOTE SENSORS.
DOES ANYONE HAVE SCHEMATICS SO I CAN REPAIR THE MAIN UNIT AND IS IT
POSSIBLE TO BUY OR BUILD A REMOTE SENSOR FOR IT...(THIS UNIT
ONLY WORKS WITH REMOTE SENSORS IT HAS NO OTHER SOCKETS)
I REALLY WANT TO  REPAIR THIS UNIT....
I WILL COVER ANY COSTS OF OBTAINING THESE SCHEMATICS.
PLEASE IF YOU HAVE ANY INFO MAIL ME AT ADDRESS BELOW.

[e-mail]

thanks in advance

WARREN EI6ETB


From [e-mail] Sat Mar 16 16:07:01 1996
From: [e-mail] (Charles Cashion)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: What makes crackle( wrinkle) paint crackle (wrinkle)??
Date: 11 Mar 1996 15:51:57 GMT
Message-ID: <4i1i6t$[e-mail]>
References: <4hn3or$[e-mail]>

Robert M. Miller ([e-mail]) wrote:

 rm> Need paint for Heathkit fine wrinkle green as used on the HW
 rm> and SB series radios.
 rm>         Bob, KE6F

When I was in High School, the electric shop teacher was very fond
of wrinkle finishes. All we used was black enamel. But the way to
make any paint wrinkle is to bake it in a warm oven before it dries.
As it dries. At the time, I was curious what paint we were using,
and I was mildly surprised to find that it was ordinary enamel.
(I cannot tell you how hot to run the oven, but I think 150 to 170
should probably do it. I remember that the oven was not hot enuf to
burn your skin if you touched it.)
Charles
--
+-------------------------------------------------------------------+
| DSC Communications  "...here pigs will fly,                       |
| Charles Cashion          lightning will strike twice,             |
| 214-519-2583              hell will freeze over, and eventually,  |
| [e-mail]     things will get really interesting..." |
+-------------------------------------------------------------------+


From [e-mail] Sat Mar 16 16:07:02 1996
From: [e-mail] (Jim Weir)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: What makes crackle( wrinkle) paint crackle (wrinkle)??
Date: Wed, 13 Mar 1996 02:08:13 GMT
Message-ID: <4i5amm$[e-mail]>
References: <4hn3or$[e-mail]> <[e-mail]> <4hvvk2$[e-mail]>

Lee Blaske <[e-mail]> shared the following priceless pearls
of wisdom:

>It was expained to me that the Heath light green finish as found on the SB se
ries is
>not a crackle finish.  In fact, that finish is accomplished by some sort of
>spattering process using a special paint spraying nozzle.  Ron Eisenbrey, who

>refinishes vintage ham gear, just finished a batch of Heath equipment.  It'll

>probably be some time before he gets around to Heath again.

If I'm not mistaken (and I frequently am) we used to get a good
crackle finish by first applying enamel, waiting until it set up
tacky, then oversprayed with lacquer.  Somehow the solvents in the two
varieties hated each other and got to fighting amidst the hills and
crevices of the finish.

Or something like that.  Oh, the poster who said the Heath finish
wasn't crackle is correct.  I believe the correct term for the Heath
finish is hammertone, and I DON'T know how to do that one easily.

Jim



Jim Weir VP Engineering | You bet your sweet patootie I speak for the
RST Engineering         | company.  I OWN the cotton-pickin' company.
Grass Valley CA 95945   |
http://www.rst-engr.com | AR Adv WB6BHI--FCC 1/C phone--Cessna 182A N73CQ
[e-mail]        | Commercial/CFI-Airplane/Glider-----A&P Mechanic



From [e-mail] Sat Mar 16 16:07:04 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Gary Coffman)
Subject: Re: What makes crackle( wrinkle) paint crackle (wrinkle)??
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
References: <4hn3or$[e-mail]> <[e-mail]> <4hvvk2$[e-mail]> <4i5amm$[e-mail]>
Date: Wed, 13 Mar 1996 17:36:06 GMT

In article <4i5amm$[e-mail]> [e-mail] (Jim Weir) writes:
>
>Or something like that.  Oh, the poster who said the Heath finish
>wasn't crackle is correct.  I believe the correct term for the Heath
>finish is hammertone, and I DON'T know how to do that one easily.

I don't recall a Heath with a hammertone finish (but that doesn't mean
they never used it). That was the finish on old Bud boxes. It vaguely
resembles a sheet of metal that has been lightly hammered with a ball
peen hammer, IE a pattern of varying grey tones, thus the name. The Heaths
I recall all had a textured finish, like that delivered by a roller or a
"spatter" gun. BTW, I seem to recall someone here recently recomending
using a roller to achieve a nice textured cabinet finish.

And I don't know how to achieve a true hammertone finish either.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Sat Mar 16 16:07:05 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Joe Mack)
Subject: Re: What makes crackle( wrinkle) paint crackle (wrinkle)??
Message-ID: <[e-mail]>
References: <4hvvk2$[e-mail]> <4i5amm$[e-mail]> <[e-mail]>
Date: Wed, 13 Mar 1996 20:52:18 GMT

In article <[e-mail]> [e-mail] (Gary
 Coffman) writes:
>In article <4i5amm$[e-mail]> [e-mail] (Jim Weir) writes:
>>

>I don't recall a Heath with a hammertone finish (but that doesn't mean
>they never used it). That was the finish on old Bud boxes. It vaguely
>resembles a sheet of metal that has been lightly hammered with a ball
>peen hammer, IE a pattern of varying grey tones, thus the name. The Heaths
>I recall all had a textured finish, like that delivered by a roller or a
>"spatter" gun. BTW, I seem to recall someone here recently recomending
>using a roller to achieve a nice textured cabinet finish.
>
>And I don't know how to achieve a true hammertone finish either.

A friend of the family's (when I was a kid) worked for a paint
company and he once brought me home a 1pt can of hammertone
paint, which I promptly used on everything metal I had.

So hammertone isn't anything you do, you just paint it on.
Beyond that I have no idea.

Joe Mack NA3T
[e-mail]


>
>Gary
>--
>Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
>Destructive Testing Systems |    we break it.     | with previous uucp addres
ses
>534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
>Lawrenceville, GA 30244     |                     |




From [e-mail] Sat Mar 16 16:07:06 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Gary Coffman)
Subject: Re: What makes crackle( wrinkle) paint crackle (wrinkle)??
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
References: <4hn3or$[e-mail]> <4i1i6t$[e-mail]>
Date: Tue, 12 Mar 1996 17:31:07 GMT

In article <4i1i6t$[e-mail]> [e-mail] (Charles C
ashion) writes:
>Robert M. Miller ([e-mail]) wrote:
>
> rm> Need paint for Heathkit fine wrinkle green as used on the HW
> rm> and SB series radios.
> rm>         Bob, KE6F
>
>When I was in High School, the electric shop teacher was very fond
>of wrinkle finishes. All we used was black enamel. But the way to
>make any paint wrinkle is to bake it in a warm oven before it dries.
>As it dries. At the time, I was curious what paint we were using,
>and I was mildly surprised to find that it was ordinary enamel.
>(I cannot tell you how hot to run the oven, but I think 150 to 170
>should probably do it. I remember that the oven was not hot enuf to
>burn your skin if you touched it.)
>Charles

I routinely use oven drying for enamel paints, as do the auto
manufacturers for their finishes. It won't give you a wrinkle
effect unless the drying agents in the paint allow it to wrinkle.
I looked this up after the first round. Wrinkle finish paints
use *two* carefully chosen solvents with different drying times
in order to achieve the wrinkle effect. One of the solvents needs
to be very volatile, the other not.

Ordinary enamel paints may use more than one solvent too, but
normally their drying times are similar, hence no wrinkles.
It may be that the particular paint you used had solvents that
volatilized sufficiently differently when heated to achieve a
wrinkle finish, but that's not the normal way baked enamels
behave.  I've found that when using Krylon I get a much
*smoother* finish when I bake it than if I let it dry at
room temperature.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Sat Mar 16 16:07:07 1996
From: nickb@alpine (Nicholas Barbieri)
Newsgroups: rec.radio.amateur.homebrew
Subject: WWV radio clock decoding???
Date: 14 Mar 1996 18:52:25 GMT
Message-ID: <4i9pt9$[e-mail]>

Does anybody know how radio clocks like the Heath Most Accurate Clock
decode the WWV signals?  Are they decoding the tones or the BCD on the
subcarrier or both?

Does anybody know of a radio clock for the WWVB station on 60 KHz?

Are there any kits for radio clocks around?

--
Nick Barbieri, KB6QI
Texas Instruments
ASIC Engineering
email: [e-mail]


From [e-mail] Sat Mar 16 16:07:08 1996
From: William W Janssen <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: WWV radio clock decoding???
Date: 15 Mar 1996 07:40:52 GMT
Message-ID: <4ib6u4$[e-mail]>
References: <4i9pt9$[e-mail]>

nickb@alpine (Nicholas Barbieri) wrote:
>Does anybody know how radio clocks like the Heath Most Accurate Clock
>decode the WWV signals?  Are they decoding the tones or the BCD on the
>subcarrier or both?
>
>Does anybody know of a radio clock for the WWVB station on 60 KHz?
>
>Are there any kits for radio clocks around?
>
>--
>Nick Barbieri, KB6QI
>Texas Instruments
>ASIC Engineering
>email: [e-mail]

You can get all the details of the WWV coding from NIST in Boulder
Colarado. Spectracom in Rochester New York did make and I think still
makes a receiver for WWVB at 60 KHz. It will give accurate time and
frequency.

Bill K7NOM



From [e-mail] Sat Mar 16 16:07:09 1996
From: [e-mail] (Dave Moorman)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: WWV radio clock decoding???
Date: Fri, 15 Mar 1996 05:36:50 -0600
Message-ID: <[e-mail]>
References: <4i9pt9$[e-mail]>

In article <4i9pt9$[e-mail]>, nickb@alpine (Nicholas
Barbieri) wrote:

> Does anybody know how radio clocks like the Heath Most Accurate Clock
> decode the WWV signals?  Are they decoding the tones or the BCD on the
> subcarrier or both?
>
> Does anybody know of a radio clock for the WWVB station on 60 KHz?
>
> Are there any kits for radio clocks around?

Far Circuits makes boards for many things including at least one WWV clock
gizmo.  Here's their address:

Far Circuits (Boards from QST, QEX, 73, CQ, HR, Hndbk, Mot A.N.)
18N640 Field Court
Dundee, IL 60118

The usual diclaimers

Dave, K9SW

--
Dave Moorman, Downers Grove, Illinois, USA      Be big, don't belittle!


From [e-mail] Sat Mar 16 16:07:10 1996
From: Andrew Jeffreys <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: XR2211
Date: 14 Mar 1996 17:37:02 GMT
Message-ID: <4i9lfu$[e-mail]>
References: <[e-mail]>
To: [e-mail]

Hi,
   I have managed to successfully build a modem using the XR2211 and the XR220
6
chips.  It uses the BAYCOM software which is freely available, runs at 1200 ba
ud,
and works very well on 2m once the pots have been carefully adjusted!

I used the schematic on Jim Devenport's homepage, for building this modem.  Th
e url
is

        http://nis-www.lanl.gov/~jdport/emul.html

The baycom software can be found on many FTP sites.  The one I used is
FTP.FUNET.FI and can be found in the following directory

        ftp.funet.fi/pub/ham/packet/baycom/baycom15.zip


I hope this is some help to you !

A J Jeffreys   <[e-mail]>



From [e-mail] Thu Mar 21 13:57:12 1996
From: [e-mail] (D W Hemphill KC5NG)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 10m BEACON TRANSMITTER.
Date: 19 Mar 1996 13:20:06 GMT
Message-ID: <4imca6$[e-mail]>
References: <[e-mail]> <4iilvr$[e-mail]>

Here's a suggestion, one that many others are using:
use a modified CB radio!

Buy an old 23-channel crystal-heterodyne CB set at a
flea market or yard sale, should cost less than $10.

Change one of the heterodyne oscillator crystals to
put the set on the desired 10m frequency.

Hard-wire the mic connections to lock the set in TX.

Keying the transmitter could be done by making and
breaking the final output transistor's emitter lead
connection to ground (they are usually tied directly
to ground).  Your keying circuit will have to be
capable of handling about three amps current.

There have been a few articles over the last 15 to
20 years about converting CB radios to 1m CW.  Look
in back issues of 73, Ham Radio, QST, etc.

Good luck!
                           73 de KC5NG



From [e-mail] Thu Mar 21 13:57:13 1996
From: [e-mail] (old goat)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 10m BEACON TRANSMITTER.
Date: Mon, 18 Mar 1996 03:28:10 GMT
Message-ID: <4iilvr$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]

[e-mail] (SAMIR KHAYAT) wrote:

:>Hi,
:>I am looking for a 10m Transmitter KIT (1-5 W) to be used for the 10m
:>Beacon OD5TEN (Locator: KM74WK - Tripoli Lebanon).
:>The Beacon will be running from the same Location of OD5SIX which is running
:>on 50.078.
:>I already have the crystal of the Beacon (28.180) and have built the IDer
:>and put the message in the Eprom.
:>It would be appreciated to give me the address from where I can buy the
:>Kit.

:>Samir ( OD5SK / KC5RYL )

I too am looking for info on a 1-10 watt CW kit for a beacon on 10
meters. I have sent requests to Samir asking if he got any info back
but have not had a responce. Any of you homebrewers out there know
where I can find a kit or plans for the above?

de N5EJS
Russ in LA.




From [e-mail] Thu Mar 21 13:57:14 1996
From: Cliff Soderback <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 144.955 MHz AM receiver schematic needed
Date: Wed, 13 Mar 1996 21:54:59 -0800
Message-ID: <[e-mail]>
References: <4i4gtp$[e-mail]>
To: Ron Gunn <[e-mail]>

Ron Gunn wrote:
>
> I need to build an AM receiver that can tune 144.955 MHz. Anybody know
> where a schematic for such a beast can be found?
>
> Thanks in advance for any help at all.
>
> --
> --------------------------------------
> Ron Gunn
> email: [e-mail]
> npage: http://home.teclink.net/~rgunn/
> --------------------------------------

  144.955 is in the middle of the 2 meter Ham band and only
FM is used on this freq. If you have some other use for a
receiver I would suggest any used scanner. They are cheap
and will cover a large number of frequencies.

                    Cliff, W7VVA


From [e-mail] Thu Mar 21 13:57:16 1996
From: [e-mail](Tim Hynde ka8ddz qrp/Rochester, MI)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 144.955 MHz AM receiver schematic needed
Date: 18 Mar 1996 23:15:10 GMT
Message-ID: <4ikqpu$[e-mail]>
References: <4i4gtp$[e-mail]> <[e-mail]>

In <[e-mail]> Cliff Soderback <[e-mail]> writes:
>
>Ron Gunn wrote:
>>
>> I need to build an AM receiver that can tune 144.955 MHz. Anybody
know
>> where a schematic for such a beast can be found?
>>
>> Thanks in advance for any help at all.
>>
>> --
>> --------------------------------------
>> Ron Gunn
>> email: [e-mail]
>> npage: http://home.teclink.net/~rgunn/
>> --------------------------------------
>
>  144.955 is in the middle of the 2 meter Ham band and only
>FM is used on this freq. If you have some other use for a
>receiver I would suggest any used scanner. They are cheap
>and will cover a large number of frequencies.
>
>                    Cliff, W7VVA


Not true, the frequencys from 144.100 to 148.000 MHz
are allocated for CW, Voice, SSTV, FAX, and RTTY. With
144.000 to 144.100 MHz for CW only.

P.S 146.000 MHz is the middle of the 2m band.

Mr. Gunn, You should peruse the local hamfests, an old 2m AM rig can
usually be had for a song (and about $30 - $40)

Tim, ka8ddz


Cliff
---- The above comment is not intended to offend ----


From [e-mail] Thu Mar 21 13:57:16 1996
From: [e-mail] (Bill Bennett)
Newsgroups: rec.radio.amateur.homebrew
Subject: 40M qrp Kit, Bay area DX Club?
Date: Tue, 12 Mar 1996 16:36:36 GMT
Message-ID: <4i496k$[e-mail]>


There was a evaluation of qrp kits by i believe 73 this month. One of
the kits, a 40 meter xciver was available to their club members only.
I beleve the club  was the bay area DX club.
Does any one know where to get the kit? and /or join their club?



From [e-mail] Thu Mar 21 13:57:17 1996
From: [e-mail] (Tom Bruhns)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 50 MHz FET, low noise
Date: 15 Mar 1996 21:52:36 GMT
Message-ID: <4icor4$[e-mail]>
References: <4ic9es$[e-mail]>

Dana Myers ([e-mail]) wrote:

(in response to Vince's search for an FET that's characterized
well at 50MHz...)

: What kind of mixer are you going to use after the FET preamp?
: If I were using a diode mixer with maybe 7dB of insertion loss,
: I'd tune the preamp for maybe 9dB of gain, and the U310 data
: sheet suggests the IP3 would be around +29dBm!

This reminds me of a design that Macintosh used in FM tuner front ends
many years ago.  I wonder if any readers here have taken a close look at
that circuit or one like it.  As I recall, it used an FET with fairly
high Idss in cascode with a transistor designed for CATV amplifier
service, so the FET kept a low voltage drop (and therefore reasonable
power dissipation), and the CATV transistor allowed a relatively high
voltage and current collector supply.  Supposedly it was very forgiving
of large input signals, but of course folk who buy FM tuners don't
generally look for an IP3 spec, so none was given that I recall.  But
maybe someone here can comment on how well a circuit like this really
works.

--
Cheers,
Tom
[e-mail]


From [e-mail] Thu Mar 21 13:57:20 1996
From: [e-mail] (Elendir)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 50 MHz FET, low noise
Date: 18 Mar 1996 12:10:26 GMT
Message-ID: <4ijjri$[e-mail]>
References: <4hjtl9$[e-mail]> <4i0ran$[e-mail]> <4ic9es$[e-mail]> <4icn67$[e-mail]> <4icrj6$[e-mail]>

Dana Myers ([e-mail]) wrote:

: I recall the NE602 has a very poor IP3, like -15dBm, though it
: has a bunch of gain.  I personally wouldn't use one in a front
: end without a very, very selective front end filter.  If you
: insert most of the selectivity between the pre-amp and the mixer,
: you can maintain a decent NF...

Hmmm... That's true of course. Well, I can also use a mixer made
by MiniCircuits. They work well, I think.

By the way, if I use a 10 dB pre-amp gain, with noise figure < 1 dB,
- 15 dBm shall translate at the real input as -25 dBm.
Now, what source could produce -25 dBm. Let us see :
P(r) = P(e) * l^2 / (2 * pi * R)^2, no ?
That is log Pr = log Pe + 2 log l / (2 * pi * R)
Setting log Pr as -2.5 , log Pe as +5 (100 W dBm), l = 6 m
assuming 2 * pi = 6 (roughly), we get -7.5 = 2 log 1/R or log R = 4
R = 10 km... Mmmm... quite remote :-(

Maybe the NE 602 is not such a good choice :-) Unless I made a mistake !

Vincent

--
Fox 5 RCS - Round the world and beyond through amateur radio.
VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.


From [e-mail] Thu Mar 21 13:57:21 1996
From: [e-mail] (Elendir)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 50 MHz FET, low noise
Date: 19 Mar 1996 11:13:04 GMT
Message-ID: <4im4s0$[e-mail]>
References: <4hjtl9$[e-mail]> <4icn67$[e-mail]> <4icrj6$[e-mail]> <4ijjri$[e-mail]> <4ik7b9$[e-mail]>

Dana Myers ([e-mail]) wrote:

: >Hmmm... That's true of course. Well, I can also use a mixer made
: >by MiniCircuits. They work well, I think.

: That's what I would choose.  I'd start out by designing the front
: end amplifier for a few more dB of gain than the mixer loss, and
: terminate the mixer in another common-gate FET with moderate
: gain, followed by the crystal roofing filter.  This kind of
: arrangement works really well in the few radios I've seen use
: it.

Common gate at 50 MHz ?
I cannot use a XTAL filter, since I have only a 30 MHz XTAL that
transposes 50 to 20. But I think I am going to design some kind
of elliptic low-pass filter to filter out 30 and 80 MHz.

Thank you for the advice.

Vince

PS : Regarding FET noise, the BF 256 is given as NF=0.8 dB f < 100 MHz.
There is also the double-gate BF 998 with NF = 0.7 @ 200 MHz... and the
CAG capability !

--
Fox 5 RCS - Round the world and beyond through amateur radio.
VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.


From [e-mail] Thu Mar 21 13:57:23 1996
From: [e-mail] (Dana Myers)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 50 MHz FET, low noise
Date: 19 Mar 1996 16:14:19 GMT
Message-ID: <4immgr$[e-mail]>
References: <4hjtl9$[e-mail]> <4ijjri$[e-mail]> <4ik7b9$[e-mail]> <4im4s0$[e-mail]>

In article <4im4s0$[e-mail]>, Elendir <[e-mail]> wrote:
>Dana Myers ([e-mail]) wrote:
>
>: >Hmmm... That's true of course. Well, I can also use a mixer made
>: >by MiniCircuits. They work well, I think.
>
>: That's what I would choose.  I'd start out by designing the front
>: end amplifier for a few more dB of gain than the mixer loss, and
>: terminate the mixer in another common-gate FET with moderate
>: gain, followed by the crystal roofing filter.  This kind of
>: arrangement works really well in the few radios I've seen use
>: it.
>
>Common gate at 50 MHz ?

Sure, common gate at 50MHz.  I've seen common gate used down to
2MHz.  I don't know of any reason why it wouldn't be used, and
it offers the advantage of a good termination for a filter without
increasing the NF of the stage, which adding a shunt resistor to
the input of a common source stage almost certainly would do.

>I cannot use a XTAL filter, since I have only a 30 MHz XTAL that
>transposes 50 to 20. But I think I am going to design some kind
>of elliptic low-pass filter to filter out 30 and 80 MHz.

Coupled resonators is probably the filter of choice if the bandwidth
isn't too wide.  Elliptic filters of narrow bandwidth can have
unrealistic component requirements...

--
 * Dana H. Myers KK6JQ, DoD#: j | Views expressed here are      *
 * [phone]               | mine and do not necessarily   *
 * [e-mail]      | reflect those of my employer  *


From [e-mail] Thu Mar 21 13:57:24 1996
From: [e-mail] (Dana Myers)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 50 MHz FET, low noise
Date: 18 Mar 1996 17:43:05 GMT
Message-ID: <4ik7b9$[e-mail]>
References: <4hjtl9$[e-mail]> <4icn67$[e-mail]> <4icrj6$[e-mail]> <4ijjri$[e-mail]>

In article <4ijjri$[e-mail]>, Elendir <[e-mail]> wrote:
>Dana Myers ([e-mail]) wrote:
>
>: I recall the NE602 has a very poor IP3, like -15dBm, though it
>: has a bunch of gain.  I personally wouldn't use one in a front
>: end without a very, very selective front end filter.  If you
>: insert most of the selectivity between the pre-amp and the mixer,
>: you can maintain a decent NF...
>
>Hmmm... That's true of course. Well, I can also use a mixer made
>by MiniCircuits. They work well, I think.

That's what I would choose.  I'd start out by designing the front
end amplifier for a few more dB of gain than the mixer loss, and
terminate the mixer in another common-gate FET with moderate
gain, followed by the crystal roofing filter.  This kind of
arrangement works really well in the few radios I've seen use
it.

--
 * Dana H. Myers KK6JQ, DoD#: j | Views expressed here are      *
 * [phone]               | mine and do not necessarily   *
 * [e-mail]      | reflect those of my employer  *


From [e-mail] Thu Mar 21 13:57:25 1996
From: Zack Lau <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: ? High Power Zener Diodes
Date: Wed, 13 Mar 1996 10:05:58 -0500
Message-ID: <[e-mail]>
References: <[e-mail]>
To: "Koellner, Guenter" <[e-mail]>

Koellner, Guenter wrote:
>
> Hello,
>
> sometimes high power Zener diodes are used to stabilize grid voltages for
> tubes. For example screen grid on tetrodes with high voltage but low
> current, otherwise control grid/cathode bias for triodes. 10W and 25W zeners
> are mostly used for this purpose. But there is a problem: standard zener
> diodes are named ZPD+voltage indicator, high power devices mostly 1Nxxxx.
>
> Who has or where can I find a list identifing these devices?
> The ARRL Handbook has tables which include the 10 and 50 watt
devices.  No 25 watt devices are listed--are 25 watt zeners
popular devices in Europe?

Zack KH6CP/1


From [e-mail] Thu Mar 21 13:57:27 1996
From: "miker in Tigard, OR." <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: [Q] PC switching PS mods ?
Date: 13 Mar 1996 10:03:52 GMT
Message-ID: <4i66i8$[e-mail]>
References: <[e-mail]> <4i25o0$[e-mail]>


>>Has anyone made 5 Volt PC switching power supply modification to 13.8 Volt ?
>>thanks info, Danilo +


You probably can get the +12V output to go to 13.8  That will limit you to 7 a
mps or
so.  You will have to change the voltage sense resistor from the 5V out to the
 12V
output.  Otherwise, there won't be enough energy in the core to keep the 12V u
p under
load.  Yes, also disconnect the rectifier from 5V so you don't blow up the 5V
caps.

Downside is that you might find a lot of receiver birdies from the switcher.
They're
not all that well filtered.
miker




From [e-mail] Thu Mar 21 13:57:28 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (SARUMAN)
Subject: Re: AD7008 DDS Chip
Message-ID: <[e-mail]>
References: <[e-mail]>
Date: Thu, 14 Mar 1996 02:53:56 GMT

>Anyone know how much the Analog Devices AD7008 direct digitial synthesis
>chip costs in single unit quantities? Also, where would I get it from?
>Thanks.

>Robert
 You might try calling Digi-key and/or MCM electronics and inquiring. They bot
h
have 800#'s.
Am I correct in thinking this is a Chip to tune in different FREQ's?
Thanx

<tsb>
                               Midgard Graphics
           3D Animation and Special FX for the hobbyist videographer
                          Email: [e-mail]

--
          Drop into #amigacafe on IRC's undernet for a chat sometime

--

<tsb>

                     A man of many hobby's master of none.




From [e-mail] Thu Mar 21 13:57:29 1996
From: [e-mail] (Johan Forrer)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: AMTOR Spec ?
Date: Wed, 13 Mar 96 09:19:31 PST
Message-ID: <4i6vgr$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>, [e-mail] says...
>
>Can anyone point me to the AMTOR Specification?  Who proposed it?  What
>constitutes conformance to the spec?  Are there link layer protocols
>above the simple error correcting character codes? etc.
>
>Gordon Brunson
>KC0VC
>email: [e-mail]
>
Gordon,

AMTOR is a close relative of SITOR which conforms to CCIR recommendation
476-2 (and later revisions). The CCIR recommendations are available from
ITU in Geneva. The acronym "AMTOR" was coined by Peter Martinez, G3PLX,
who we can say is the father of this amateur radio mode.

Yes, there are several error correcting protocols in use. You may want to
look into and retrieve our discussions of this topic on the TAPR HFSIG
(HF special interest group - web page is at www.TAPR.org). If this topic
excites you, also consider coming to the ARRL DCC that is planned in
September this year in Seattle. You will have the opportunity to hear
about these developments and contribute your own ideas.

Hope this is of interest. Feel free to e-mail me directly if you need
further pointers.

73's

Johan Forrer, KC7WW



From [e-mail] Thu Mar 21 13:57:30 1996
From: Jim <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: AMTOR Spec ?
Date: Thu, 14 Mar 1996 11:51:19 -0800
Message-ID: <[e-mail]>
References: <[e-mail]>

I remember looking it up years ago.  It was a SISTOR spec (the commercial
equivalent of AMTOR) and it was in one of those CCIR or CCITT books.  It
had a title with words like "radio teleprinting" and "maritime" and
such.  I probably still have a copy somewhere.

Cheers.
Jim, WU0I


YourName wrote:
>
> Can anyone point me to the AMTOR Specification?  Who proposed it?  What
> constitutes conformance to the spec?  Are there link layer protocols
> above the simple error correcting character codes? etc.
>
> Gordon Brunson
> KC0VC
> email: [e-mail]


From [e-mail] Thu Mar 21 13:57:31 1996
Newsgroups: rec.radio.amateur.homebrew
From: YourName <[e-mail]>
Subject: AMTOR Spec ?
Message-ID: <[e-mail]>
Date: Tue, 12 Mar 1996 23:05:29 GMT

Can anyone point me to the AMTOR Specification?  Who proposed it?  What
constitutes conformance to the spec?  Are there link layer protocols
above the simple error correcting character codes? etc.

Gordon Brunson
KC0VC
email: [e-mail]



From [e-mail] Thu Mar 21 13:57:32 1996
From: [e-mail] (Tarkus95)
Newsgroups: rec.radio.amateur.homebrew
Subject: Automation System Clock for sale
Date: 13 Mar 1996 23:18:27 -0500
Message-ID: <4i86mj$[e-mail]>
Reply-To: [e-mail] (Tarkus95)

I have an automation system clock that until recently resided at WGHB-AM
in Farmville NC.  It is a Schafer model with nixie-type display tubes.
The internal workings of the clock are a fascinating mixture of electronic
and mechanical mechanisms.  It would be ideal for a ham or hobbyist who
needs a clock for pulse creating or preprogrammed events.  $150 plus
shipping gets it.  E-mail direct.

[e-mail]


From [e-mail] Thu Mar 21 13:57:33 1996
From: [e-mail] (Brian McMahon)
Newsgroups: rec.radio.amateur.homebrew
Subject: Canadian regs on FM transmissions
Date: Wed, 13 Mar 1996 18:50:04 GMT
Message-ID: <4i71qn$[e-mail]>
Reply-To: [e-mail]

I just sent for a fm  transmitter (Ramsey FM-10A, $35!) which I want
to use to distribute stereo throughout the house and yard. With the
proper antenna I was told it could potentially broadcast up to a mile
- the kids are gona love this! So, I started trolling the internet to
see just what the candian regulations are on fm transmissions but so
far I came up empty. Can anyone here point me in the right direction?
And, by the way, is this the right group to ask? I'll check back, but
e-mail is better since I'm not a regular. Thanks for any help.



From [e-mail] Thu Mar 21 13:57:34 1996
Newsgroups: rec.radio.amateur.homebrew
From: Monty Wilson <[e-mail]>
Subject: Re: CB to 10m Conversion
Message-ID: <[e-mail]>
Date: Wed, 20 Mar 1996 19:58:22 GMT
References: <[e-mail]>

In addition to the guy who posted the WWW links, I would just like to
add a couple of tips:

1.  Keep your circuit changes to a minimum.  For a CW rig on 10m or 12m,
you want to start with an AM rig, remove the modulation transformer,
put in a simple keying circuit and sidetone oscillator, and a BFO
unless you know how to make a product detector work easily.  Then open
up the clarifier and make it into a transmit/receive fine tuner.  For a
10m FM conversion (use a rig with the proper Cybernet board unless
you have access to a Hy-Gain board) stick with a by-the-book conversion
here too.  For a SSB radio, get an old crystal controlled 10m SSB rig
and just move the frequency band to 10m or 12m.  Following a magazine
article and keeping it simple is much better than blazing new trails,
because so much of the planning details are already worked out for you.

Another idea for CW is to use a SSB radio because no receiver conversion
is necessary.  But then the tendency is to make a multi-mode transceiver
(just so you can get more stuff in one box) and the more complicated you
make a conversion, the easier it is to make a mistake and have it die on
the table.

2.  Don't neglect a major resource, possibly the biggest: the neighborhood
illegal CBer.  You know the guy.  The one who loves to run 3000W and whom
you've cussed for giving ham radio a bad name?  That same guy down your
street probably knows everything about how to put all kinds of radios on
any given frequency, and where to buy all the crystals and supplies.

3.  Use only plastic tools on those little ferrite cores.  The metal
jeweller's screwdrivers will tear them up, and fast.
--
.........Monty.
[e-mail]




From [e-mail] Thu Mar 21 13:57:35 1996
From: [e-mail] (John Kolb)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Changing freq on RS 21-409 transciever
Date: 15 Mar 1996 04:33:08 GMT
Message-ID: <4iaru4$[e-mail]>
References: <4i9mcm$[e-mail]>

God ([e-mail]) wrote:
: I have a cheap Rat Shack 49.830MHz transciever that I want to refit to
: transmit (and recieve if possible) in the cordless phone handset band
: (48.76MHz to 49.970MHz). The unit has two crystals in it (which I assume
: control freqs). One is 16.45833 (MHz or Khz?) The other is 16.610 (MHz or
: Khz?) .. Would it be possible to replace the crystals to change the freqs?
: Ideally I'd like to be able to select channel numbers (1-25). Could I use a

The crystals used work on the third overtone. 16.61 MHz is the transmit
xtal  3 x 16.610=49.830. 16.45833 is the receive xtal. 16.45833 x 3 =

49.37499, call it 49.375. The 49.375 mixes with the received 49.830
to produce a 455 kHz IF signal.

The crystals can be replaced with others using that method of calcualation
backwards to find the new xtal freqs required to operate on a particular
channel, remembering, of course, any requirement for licensing that might
exist. It would be hard to keep two different adjustable oscillators
tuned properly to transmit and receive. To operate easily, you would
need to build a Phase Locked Loop oscillator, together with the
proper controls to choose the required divisor ratios.

John Kolb



From [e-mail] Thu Mar 21 13:57:36 1996
From: [e-mail] (Elendir)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Conversion of noise voltage into noise figure ?
Date: 20 Mar 1996 12:40:47 GMT
Message-ID: <4ioucf$[e-mail]>
References: <4im80h$[e-mail]> <4io1df$[e-mail]>

qrk ([e-mail]) wrote:

[...]

Thanks for the formulae.

: From my experience, equivalent input noise of a JFET is pretty
: constant from low frequency to high frequency (my experience only goes
: up to 5 MHz), however, the input noise current starts to increase at
: higher frequencies, usually around 100 kHz.  The slope data I have
: seen shows the input noise current increasing at approximately 20 dB
: per decade of frequency.

Well -
Looking at the BFR30/31 data sheet, the corner frequency seems to be
around 100 kHz. At that frequency, the En stops dropping and In begins
increasing.
En drops at about 3 dB per decade from 10 Hz to 100 kHz.
In increase at 10 dB per decade from 100 kHz to 1 MHz where the curve
stops.

Assuming that the corner frequency lies around 100 kHz, if Rs opt at
100 MHz is r, at 50 MHz, Rs opt should be 2r, no ? and NF(50) < NF(100).

How to account for the reactive component ?

Vince
--
Fox 5 RCS - Round the world and beyond through amateur radio.
VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.


From [e-mail] Thu Mar 21 13:57:37 1996
From: [e-mail] (JOHN F. McCLUN)
Newsgroups: rec.radio.amateur.homebrew
Subject: DDS Proto Board, Rcvr Chip &  CP Contrlr 4Sale
Date: 20 Mar 96 17:05:30 GMT
Message-ID: <[e-mail]>

Gang -
    Well, I have been working for about 6 months on a Blue Earth
Computer contoller connected to an AD7008 DDS as a vfo for a QRP
transmitter/recvr.  I have had some success as the transmitter works.
 I have NO MORE time for designing the receiver or creating an
integrated unit. ;'(  :'( .  I am going to try and sell the items to
someone who would continue to make a workable system or would
like to experiment with DDS vfo's.  So here is my list:

***AD7008 Prototyping Board***   from Analog Devices.  Single +5
supply,32 bit phase accumulator, on chip 10 bit DAC, sine - cosine
look up tables, 50 mhz speed.  Board originally was $295 when I
bought it.

***AD607 Single chip receivers - 3 ea.***  These items are VERY
RARE!!!  Used with the AD7008 for full AM,FM,CW, BPFSK,FSK
receiver.

*** Blue Earth 80C51 Prototype Board controller***  Comes with
display, 16 & 4 keypad, 12 I/O lines for controlling devices, Tiny basic
built in interpretter, Com port cable.  Cost over $250 new.

All of this can be used for making your own DDS vfo, tranceiver,
frequency synthesizer, etc.  I am looking for a Sierra Kit with modules
in trade, OHR 4 Bander +, money, other kits, offers (virgins, trips to
Mars, Cryo storage facility for internment) :') .

I am going away for two weeks, so please E-MAIL to:
[e-mail] and not the server listed here.

72&73
John N3REY
Always QRP!


From [e-mail] Thu Mar 21 13:57:38 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (SARUMAN)
Subject: Digital Tuner Circuit?
Message-ID: <[e-mail]>
Date: Fri, 15 Mar 1996 04:34:10 GMT

   Anyone got a good circuit Design for a Digital Tuner? I'm thinking of
building my own 2 M Receiver then later a Transmitter but Can't deal with
Tuning Potentiometers. Preferably the Circuit would have LCD readout.
Please email or point me to a site to FTP or WWW it from. Thanx


<tsb>
                               Midgard Graphics
           3D Animation and Special FX for the hobbyist videographer
                          Email: [e-mail]

--
          Drop into #amigacafe on IRC's undernet for a chat sometime

--

<tsb>

                     A man of many hobby's master of none.




From [e-mail] Thu Mar 21 13:57:39 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Technofreak)
Subject: E.F. Johnson Messenger C.B.
Message-ID: <[e-mail]>
Reply-To: [e-mail]
Date: Wed, 13 Mar 1996 10:56:32 GMT

Does anybody know where I can find the allignment procedures and/or
schematic to the Johnson Messenger model 4730 C.B.



From [e-mail] Thu Mar 21 13:57:40 1996
From: [e-mail] (Bill Nadzam)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: E.F. Johnson Messenger C.B.
Date: Mon, 18 Mar 96 02:02:25 GMT
Message-ID: <4iig7h$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>, [e-mail] (Technofreak) wrote:
>Does anybody know where I can find the allignment procedures and/or
>schematic to the Johnson Messenger model 4730 C.B.
>

Sure, I work on these things too. That radio is covered in good
detail in the Sam's Photo Fact CB-287.

Call them at 1-800-428-7276. They will be happy to make you a
very good copy! Hold onto your wallet, it's gonna cost you
abou $35.

------------------------------------------------
Name: Bill.Nadzam  "K8WN"
E-mail: "Bill Nadzam" <[e-mail]>
------------------------------------------------



From [e-mail] Thu Mar 21 13:57:41 1996
From: [e-mail] (gudmundur)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: EIMAC 5CX3000A tube
Date: 14 Mar 1996 04:38:30 GMT
Message-ID: <4i87s6$[e-mail]>
References: <4hgd7v$[e-mail]> <4hv7ig$[e-mail]>

In article <4hv7ig$[e-mail]>, [e-mail] says...
>
>Boy!  That would sure make a nice driver for a decent sized final!!
>
>[e-mail] (Jerry Flanders) scribed:
>
>xxI recently picked up a piece of surplus gear with a big EIMAC
>5CX3000A
>xxtube. I have written to EIMAC to get operating voltages for this
>xxmonster, but they may not respond in time for shopping for a plate
>xxtransformer at this weekend's hamfest.
>
>xxCan somebody please post or e-mail the operating voltages / limiting
>xxspecs for it?
>
>xxThanks
>
>xxJerry Flanders   W4UKU   South Carolina     [e-mail]
>
>
>I have that information in my desk at work. Call WSBA radio in york
penna if you are serious about the specs, and I will pass along the
info.  717-764-1155  I received a new Eimac specbook for an amateur
project, and it lists the full current production line. Don  KD3SH




From [e-mail] Thu Mar 21 13:57:42 1996
From: Dave Bremer <[e-mail]>
Newsgroups: rec.radio.shortwave,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc
Subject: FR-146 FM Receiver Kit
Date: Tue, 19 Mar 1996 14:20:55 -0600
Message-ID: <[e-mail]>

My partner and I are using the Ramsey FR-146 2-Meter FM receiver kit to
receive data broadcast at a frequency of 155.445 MHz.  The data is sent
with a 6 second delay between each new message.  We are having trouble
squelching out the noise during the 6 second delay period.  The squelch
seems to either cut out nothing or it cuts out everything including the
data being broadcast.  If anyone has any information regarding this kit
or where we could receive help, we would appreciate hearing about it.
Please e-mail any comments or suggestions.

Thanks.

Dave Bremer
St. Cloud State University
Electrical Engineering
[e-mail]


From [e-mail] Thu Mar 21 13:57:43 1996
From: [e-mail] (Dave Clausen,KA4VXT)
Newsgroups: rec.radio.amateur.homebrew
Subject: FS: HT600 2ch VHF $200
Date: Fri, 15 Mar 1996 17:33:24 GMT
Message-ID: <4iboek$[e-mail]>
Reply-To: [e-mail]

In great shape, new case, almost new battery. 5 watt unit.
Will ship UPS COD CASH, u pay cod fee. E-mail for other info
or call 407.880.9412 after 4PM EST

Thanks!
Dave, KA4VXT



From [e-mail] Thu Mar 21 13:57:44 1996
From: mike spooner <[e-mail]>
Newsgroups: uk.radio.amateur,rec.radio.amateur.homebrew,demon.adverts,uk.forsale
Subject: FS: RGB MONITORS
Date: Sun, 17 Mar 1996 16:10:56 +0000
Distribution: world
Message-ID: <[e-mail]>

For sale BARCO CD233 RGB monitors, analog rgbs, external or internal
sync, looped inputs,ttl compatible, frequency response 15 KHz to 15 MHz
14 inch, aspect ratio adjustable for 4/3,  resolution hor 580 pixels
vert 430 pixel any other info needed drop me an E,
      20 UKP + shipping
--
               (*****************************)
               (  [e-mail]  )
               ( micky spooner  01379-852687 )
               (*****************************)


From [e-mail] Thu Mar 21 13:57:45 1996
From: Cliff Soderback <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Subject: Re: ground a 5/8 wave on a trunk lip mount?
Date: Thu, 14 Mar 1996 18:43:41 -0800
Message-ID: <[e-mail]>
References: <[e-mail]>
To: Charlie Fortner <[e-mail]>

Charlie Fortner wrote:
>
> I've got a trunk lip mount and I want to use a 5/8 wave antenna with it.
> If I attach a piece of wire running from the ground of the antenna to a
> suitable ground in the trunk, will this have the same affect as putting
> the antenna on the roof of my car?  Thanks.
>
> Charlie Fortner
> KF4GJQ

 Charlie:
          The wire wouldn't do anything because the 5/8 ant in grounded
in the mount. If you have a fiberglass car then only a 1/2 wave would
work, because you have no ground. Note: a 1/4 wave on top of the
car will work better than any antenna mounted on the trunk.

                              Cliff, W7VVA


From [e-mail] Thu Mar 21 13:57:46 1996
From: Jim Devenport <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
Subject: Re: ground a 5/8 wave on a trunk lip mount?
Date: Thu, 14 Mar 1996 13:40:32 -0700
Message-ID: <[e-mail]>
References: <[e-mail]>
To: Charlie Fortner <[e-mail]>

Hardly.  Your ground normally takes place through the screws that you
tighten under the trunk mount to hold it in place, they are supposed to
pierce the paint and make a ground connection.  For your ground wire to
have any useful effect it would have to be a more direct connection than
that to ground.
Plus, mounting the antenna in or on the vehicle roof not only gives it
the benefit of the surrounding roof surface as a ground plane but
elevates it another foot or more, plus the pattern will be more
omnidirectional since there should be no other metal obstructions in the
near field of the antenna.
In actual operation it may often be difficult to notice any improvement
from trunk to roof mounting.
--
|-------------------------------------------------------|
|Jim Devenport  WB5AOX                                  |
|All Standard Disclaimers Disclaimed                    |
|My views rarely (if ever) reflect those of my employers|
|HTTP://nis-www.lanl.gov/~jdport/                       |
|-------------------------------------------------------|


From [e-mail] Thu Mar 21 13:57:47 1996
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.homebrew
From: [e-mail] (Gary Coffman)
Subject: Re: ground a 5/8 wave on a trunk lip mount?
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
References: <[e-mail]>
Date: Fri, 15 Mar 1996 02:38:20 GMT

In article <[e-mail]> [e-mail]
m (Charlie Fortner) writes:
>I've got a trunk lip mount and I want to use a 5/8 wave antenna with it.
>If I attach a piece of wire running from the ground of the antenna to a
>suitable ground in the trunk, will this have the same affect as putting
>the antenna on the roof of my car?  Thanks.

No. For the current mirror to be effective, it has to be directly
under the antenna. The only way to get top of the car performance
is to mount the antenna on the top of the car. Mounting on the trunk
will result in directional properties because the signal will be
shielded by the cabin to the front, and because the groundplane
under the antenna will be asymmetric. Running a wire inside the
car will have no effect on the antenna pattern. The antenna is
already "grounded" by the trunk lip mount. THe trunk lid is its
groundplane (such as it is).

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Thu Mar 21 13:57:48 1996
Newsgroups: rec.radio.amateur.misc,rec.radio.amateur.equipment,rec.radio.amateur.homebrew
From: [e-mail] (Walter Scott)
Subject: HAL Morse Keyboard ??
Message-ID: <[e-mail]>
Date: Mon, 18 Mar 1996 22:07:59 GMT


In 1973, HAL Communications Corp. sold an MKB-1 Morse Keyboard and a
KB-ID1 Keyboard Identifier.  Does anyone remember these devices?

After building them from kits, they worked well.  Recently I tried to
change the call sign in the Identifier without success.  There appears
to be a race problem in the design.

Does anyone remember these devices?  -The problem that makes the Identifier
pattern sensitive?  -A fix?

73,
  Scott
    KI6KW



From [e-mail] Thu Mar 21 13:57:49 1996
From: <Unknown> (Raymond Hoopes)
Newsgroups: rec.radio.amateur.homebrew
Subject: Ham Radio Equipment For Sale
Date: 14 Mar 1996 01:11:21 GMT
Message-ID: <4i7rnp$[e-mail]>

Yaesu FT-736R. Tranciever , 2 Meter + 70 CM ( 440 MHZ.)
Yeasu YS-500 SWR + Power meter
Yaesu Dynamic Mic.
Cushcraft A430-11 70 CM. FM YAGI Ant.
Cushcraft A144-11 2 Meter YAGI Ant.
Alliance Heavy Duty Rotator Dual Speed


$2000.00 or best offer.


E-Mail [e-mail] or [e-mail]
Phone Number 716-973-3431 ask for Ray Sr.


From [e-mail] Thu Mar 21 13:57:50 1996
From: [e-mail] (JCHol)
Newsgroups: rec.radio.amateur.misc,rec.radio.amateur.digital.misc,rec.radio.amateur.policy,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,sci.electronics
Subject: Re: Ham Radio Online March 11th, 1996
Date: 15 Mar 1996 19:41:11 -0500
Message-ID: <4id2n7$[e-mail]>
References: <4hvrho$[e-mail]>
Reply-To: [e-mail] (JCHol)

I have visited the site twice. Really enjoyed the article about launching
wires into trees.  Keep up the good work.

73 de John, WA5TWL


From [e-mail] Thu Mar 21 13:57:51 1996
From: [e-mail] (Kevin Clark)
Newsgroups: rec.radio.amateur.homebrew
Subject: hamcom inteface
Date: 12 Mar 1996 14:27:09 -0800
Message-ID: <4i4tnt$[e-mail]>


Does anyone know the programming requirements for setting
up a hamcom type interface for use in your own program?

clark



From [e-mail] Thu Mar 21 13:57:52 1996
From: [e-mail] (KN5S)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Help w/ 6 m reciever circuit
Date: 20 Mar 1996 06:20:17 -0500
Message-ID: <4ioplh$[e-mail]>
References: <4inm7k$[e-mail]>

The ARRL Handbook discusses LC circuits in detail.  However, the
suggestion that an LC osc circuit be used on 6 meters is totally wrong.

73,  Mark  KN5S     [Mark  Mandelkern,  Las Cruces,  NM]


From [e-mail] Thu Mar 21 13:57:53 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (SARUMAN)
Subject: Help w/ 6 m reciever circuit
Message-ID: <[e-mail]>
Date: Tue, 19 Mar 1996 22:57:06 GMT

Howdy folks, on page 54 of the March 1996 issue of CQ magazine is a schematic
for a 6 meter FM reciever. I've only got a basic knowledge of Electronics but
the circuit seems pretty easy to do...plus the Parts don't appear too costly
even if I DO screw up ;-)

Anyway in the article it says to make this circuit manually tuneable I should
replace the Crystal with a "series resonant LC combination". Therein lies my
problem. I HAVE NO CLUE what this series resonant LC is....Any help or better
yet part # or circuit schematic would be MOST welcome. The only LC I recall is
LCD as in Liquid Crystal Display....this series resonant LC isn';t a Liquid
Crystal IS IT?
Thanx for the help folks.

Ok lemme push my luck......If someone could provide a circuit to Digitally tun
e
this complete with a LCD readout I'd REALLY be appreciative.

Thanx for the help.



<tsb>
                               Midgard Graphics
           3D Animation and Special FX for the hobbyist videographer
                          Email: [e-mail]

--
          Drop into #amigacafe on IRC's undernet for a chat sometime

--

<tsb>

                     A man of many hobby's master of none.




From [e-mail] Thu Mar 21 13:57:54 1996
From: [e-mail] (Mike Groves)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Help with identifying coax.
Date: Tue, 12 Mar 1996 22:57:56 GMT
Message-ID: <4i50bh$[e-mail]>
References: <[e-mail]>

On 11 Mar 1996 17:09:23 GMT, [e-mail] (Jon Goguen) wrote:

>I have some high quality double-shielded Teflon dielectric coax for which
>I would like to get some precision N connectors.  The coax is unmarked
>however, and the connector suppliers I've contacted tell me they need a UG
>number or other identifier inorder to provide the correct connector.  Can
>anyone help identify this cable?  The outer sheath is a very slick plastic
>(HMW polyethelene?), lavender in color, about 0.275" diameter.  The
>silver-plated braided shield beneath is about 0.190 diameter, and is
>separated from the spiral wound flat inner shield (O.D. 0.150") by a thin
>layer of wrapped teflon.  The stranded central conductor, inside more
>wrapped teflon, is silver-plated, 0.056" O.D. (15 guage), and contains 19
>28 or 29 gauge strands.
>
>Any body got a field guide to coax?
>

If the 2 shields are truely insulated from each other, you've got
Triax.  Difficult to identify, more difficult to get connectors for.

-Mike



From [e-mail] Thu Mar 21 13:57:55 1996
From: Jim Strohm <Jim Strohm@ausq1ak>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Help with identifying coax.
Date: 13 Mar 1996 14:19:50 GMT
Message-ID: <4i6li6$[e-mail]>
References: <[e-mail]>

How about sending the connector supplier a short sample of the co-ax?

If they can't match a connector to a cable that's in their hand,
they're not gonna do much better with the UG number.

Jim N6OTQ




From [e-mail] Thu Mar 21 13:57:56 1996
From: Isaac Kohn <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: HF VFO design
Date: Tue, 19 Mar 1996 01:27:19 -0600
Message-ID: <[e-mail]>

Hi all.  I am starting my first major ham homebrew transmitter.  I need
to design a VFO that is reasonably stable from 1.8-30 Mhz at least,
simply switching tuned elements for different bands.  I would prefer
that it be as simple as possible.  Impedance/power-level shouldn't
matter, because I plan to buffer it.  Is this possible??  Has anyone
ever built such a broadband VFO??  Please help.

Thanks,
Isaac



From [e-mail] Thu Mar 21 13:57:57 1996
From: Isaac Kohn <[e-mail]>
Newsgroups: rec.radio.amateur.antenna,rec.radio.amateur.equpiment,rec.radio.amateur.misc,rec.radio.amateur.homebrew
Subject: HF, multiband antenna, etc. for beginner -- PLEASE HELP!
Date: Sun, 17 Mar 1996 20:00:51 -0600
Message-ID: <[e-mail]>

Greetings all,
I am new to the world of ham radio (don't even have my license yet), and
I'm working on setting up a station.  I'm gonna need an antenna to work
at least the entire HF range, and maybe thru 2m.  I live on the second
floor of a 2-flat, and space outside is limited...  I've been figuring
I'd put up a loop around my ceiling (approx. 12'x12') or on one wall
(similar dimensions), use a transmatch, and hope for the best. Maybe
someone out there has a better idea... It would be convenient if there
were a way I could wire something up in my room or (for lower
frequencies) outside my window... It may not be practical to raise
anything up above the top of the building -- will this affect
propagation in the HF range??  I _may_ be able to find a way to set up a
horizontal dipole that is supported a few inches above the edge of the
roof, so that obstructions are less of a problem.  Anyone have any
suggestions??  Also, I will need plans for a versatile, INEXPENSIVE
Transmatch.  I can probably tolerate somewhat high levels of SWR, if it
will reduce design cost.  Is it feasible to wire several toroid-core
broadband transformers, and switch them in and out appropriately for
each band?? I'd like not to have to retune the antenna every time I
switch bands, and if I could have a knob that did that it would be quite
nice.......   PLEASE RESPOND (pref. by E-mail or E-mail+post) IF YOU CAN
ANSWER ANY OF MY IGNORANT QUESTIONS!!! Thanks a lot everybody.

73's
Isaac Kohn

P.S.  I actually am doing things in the wrong order, as I haven't built
any sort of equipment that would utilize an antenna yet.  If anyone has
any diagrams/ideas for a receiver, and maybe a transmitter, that I could
use for phone (at least AM, SSB would be nice), they would be much
appreciated.  Receiver might just be antenna, tank circuit shunting
unwanted stuff to ground, single-diode detector, and high-gain AF AMP.
This is good because I've already built a 1W output AF AMP, and it works
great.  Xmitter is tough because I only want to use one oscillator, but
I want to span entire HF range.  Prob. with both is switching components
in tuned circuits for different bands....  Help is much appreciated.  As
you can see I am very unexperienced and am dying to get on the air.  Thx
again in advance!


From [e-mail] Thu Mar 21 13:57:58 1996
From: [e-mail] (Steve Lisle)
Newsgroups: rec.radio.amateur.homebrew
Subject: Home Brew GPS Antenna
Date: 15 Mar 96 21:38:15 GMT
Message-ID: <[e-mail]>
Reply-To: [e-mail]

Hi.
I have an ICOM GP22 GPS and with it the Magnetic base type
antenna.
The magnetic antenna is fine for mobile work but I have used
the same antenna positioned up on the instrument panel of
my aircraft with disastrous results to my compass, even though
the antenna was situated about 500mm away from it!
I was wondering is it possible to homebrew a small vertical type
of antenna that I can mount with a suction cap to the windscreen
of the aircraft?



From [e-mail] Thu Mar 21 13:57:59 1996
From: Brian Webb <[e-mail]>
Newsgroups: de.comm.ham,rec.radio.amateur.digital.misc,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc
Subject: HTX-212 & MFJ-1270C TNC
Date: 16 Mar 1996 21:40:52 GMT
Message-ID: <4ifch4$3s8$[e-mail]>

Several weeks ago I purchased a Radio Shack HTX-212 mobile
2-meter radio. I own an MFJ-1270C TNC. What I'd like to do is
hook these two units together so I can operate on packet.

Here are some questions:

1. Does anybody sell a pre-made HTX-212 to MFJ-1270C interface
cable?

2. If I have to make my own cable, does anybody have a schematic?

3. Where can I buy an extra modular mic plug of the type used on
the HTX-212?

4. Have any of you interfaced these rigs and gotten them to work?
If so, is there anything that I should know?

Regards,

Brian Webb, KD6NRP
Thousand Oaks, CA


From [e-mail] Thu Mar 21 13:58:01 1996
From: [e-mail] (Burch Akin)
Newsgroups: de.comm.ham,rec.radio.amateur.digital.misc,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc
Subject: Re: HTX-212 & MFJ-1270C TNC
Date: Tue, 19 Mar 1996 19:44:10 GMT
Message-ID: <4in2vm$[e-mail]>
References: <4ifch4$3s8$[e-mail]>

Brian Webb <[e-mail]> wrote:

>Several weeks ago I purchased a Radio Shack HTX-212 mobile
>2-meter radio. I own an MFJ-1270C TNC. What I'd like to do is
>hook these two units together so I can operate on packet.

>Here are some questions:

>1. Does anybody sell a pre-made HTX-212 to MFJ-1270C interface
>cable?

>2. If I have to make my own cable, does anybody have a schematic?

>3. Where can I buy an extra modular mic plug of the type used on
>the HTX-212?

>4. Have any of you interfaced these rigs and gotten them to work?
>If so, is there anything that I should know?

>Regards,

>Brian Webb, KD6NRP
>Thousand Oaks, CA

I have the same radio and TNC.  I had to make my own cable.  If you
call MFJ they will mail you a schematic.  I think the parts costs
under $5.




From [e-mail] Thu Mar 21 13:58:02 1996
From: Rocci <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Impedance matching
Date: Sat, 16 Mar 1996 08:58:16 -0800
Message-ID: <[e-mail]>
References: <4i821n$[e-mail]>

Workshop wrote:
>
> Hi there
> This is to all those who know anything about impedance matching!
> I have a circuit using a ne602 ic.The input impedance is is quoted
> as bieng 1.5k.I have a Phillips application note (AN1993)
> that uses this ic.The input to the mixer of the ic is from a 50 ohm source.

> Can anyone out there tell me how these values are calculated.The frequency o
f interest
> is 45Mhz

______________________________________________

This circuit is just a parallel resonant circuit with tapped capacitor
("capacitor divider") matching. The series combination of C1 and C2 must
resonate L at the frequency of interest. Also The impedance ratio from
Rin to Rout is roughly the square of the ratio of C2/C1 (the precise
ratio
is a bit more complex, but this estimate will get you pretty close).

The bandwidth of the circuit is a function of the loaded Q, which is
calculated
from:
                QL= Rout/XL
where:          XL = 2*PI*F*L

                _______________________
                |       |
                |       |
       C1=47pf ---      |
               ---      )
        ________|       ) L            Rout = 1500
 Rin=50         |       )
               ---      )
               ---      |
      C2=220pf  |       |
                |       |
        --------------------------------

In your example circuit, C2/C1=4.68.
4.68 squared=22, so this circuit will transform 50 ohms
up to about 1100 ohms. The inductance of L resonates the series
combination of C1 and C2 at about 48 MHz. The IC probably has
about 10 pf of internal capacitance which adds to the total
circuit C to reduce the resonant frequency to 45 MHz.

Joe
WA3CMQ


From [e-mail] Thu Mar 21 13:58:02 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Impedance matching
Date: 17 Mar 96 07:15:29 GMT
Message-ID: <[e-mail]>

The equations for the 50 ohm to 1500 ohm resonant impedance
matching circuit mentioned in a previous issue of this maillist
are shown on page 45 of the April 1996 issue on QST magazine
also.  The Q of the inductor is not taken into consideration,
but is still a good approximation.

What timing, eh?

Chuck Curtis, N2UCN


From [e-mail] Thu Mar 21 13:58:04 1996
From: [e-mail] (Workshop)
Newsgroups: rec.radio.amateur.homebrew
Subject: Impedance matching
Date: 13 Mar 1996 14:17:58 GMT
Message-ID: <4i821n$[e-mail]>

Hi there
This is to all those who know anything about impedance matching!
I have a circuit using a ne602 ic.The input impedance is is quoted
as bieng 1.5k.I have a Phillips application note (AN1993)
that uses this ic.The input to the mixer of the ic is from a 50 ohm source.
The 50 ohm source has been matched to the ic by the following circuit.




                   To pin 1 of
                      |  mixer
                      |
                |-----------
                |          |
                |          |
               === 47p     |
               ===         ()
                |          ()0.28uH
  To 50 ohm ____|          ()  To pin 2 of mixer
   source      ===         ()         |
               === 220p    |          |
                |          |          |
                |          |          |
                ------------          |
                      |_______________|
                      |
                     ===100nF
                     ===
                      |
                     GND
Can anyone out there tell me how these values are calculated.The frequency of
interest
is 45Mhz


From [e-mail] Thu Mar 21 13:58:05 1996
From: [e-mail] (Workshop)
Newsgroups: rec.radio.amateur.homebrew
Subject: Impedance matching
Date: 13 Mar 1996 14:20:42 GMT
Message-ID: <4i826r$[e-mail]>

Hi there
This is to all those who know anything about impedance matching!
I have a circuit using a ne602 ic.The input impedance is is quoted
as bieng 1.5k.I have a Phillips application note (AN1993)
that uses this ic.The input to the mixer of the ic is from a 50 ohm source.
The 50 ohm source has been matched to the ic by the following circuit.




                   To pin 1 of
                      |  mixer
                      |
                |-----------
                |          |
                |          |
               === 47p     |
               ===         ()
                |          ()0.28uH
  To 50 ohm ____|          ()  To pin 2 of mixer
   source      ===         ()         |
               === 220p    |          |
                |          |          |
                |          |          |
                ------------          |
                      |_______________|
                      |
                     ===100nF
                     ===
                      |
                     GND
Can anyone out there tell me how these values are calculated.The frequency of
interest
is 45Mhz
Cheers
Robin


From [e-mail] Thu Mar 21 13:58:06 1996
From: "Ian White, G3SEK" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Interdigital filter design info?
Date: Fri, 15 Mar 1996 13:02:15 +0000
Distribution: world
Message-ID: <[e-mail]>
References: <[e-mail]> <4ia04m$[e-mail]>

Dave Turner wrote:
>
>In article <[e-mail]> Mark Mansfield <[e-mail]> writes:
>>Speaking of interdigital filters, is there a ftp site on the WWW that
>>helps one design interdigital filters. I'd like to build a bandpass
>>filter in the 400-500MHz range and another for 800-900MHz. Maybe a
>>interdigital filter is what I need. Any ideas on this one?
>>
>
>The January 1985 issue of Ham Radio had an article titled
>"computer-aided interdigital bandpass filter design" that included
>a basic program for calculating the dimensions of the digits and
>enclosure. It said it was "For reproducible customized design in
>the 0.4-5 GHz frequency range.

I sent Mark a copy of this program, updates with a more civilized user
interface. If anybody else wants it (as a GWBASIC listing), please e-
mail me.


>
>I tried to reverse engineer the design equations from the program
>and I think I found a bug in the basic program but the error
>(if it were really an error) was very small.

Have you any more specific details, please?


73 from Ian G3SEK          Editor, 'The VHF/UHF DX Book'
                          'In Practice' columnist for RadCom (RSGB)
Professionally:
IFW Technical Services     Clear technical English - anywhere.


From [e-mail] Thu Mar 21 13:58:07 1996
From: [e-mail] (Dave Turner)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Interdigital filter design info?
Date: 14 Mar 1996 20:38:46 GMT
Message-ID: <4ia04m$[e-mail]>
References: <[e-mail]>


In article <[e-mail]> Mark Mansfield <[e-mail]> writes:
>Speaking of interdigital filters, is there a ftp site on the WWW that
>helps one design interdigital filters. I'd like to build a bandpass
>filter in the 400-500MHz range and another for 800-900MHz. Maybe a
>interdigital filter is what I need. Any ideas on this one?
>

The January 1985 issue of Ham Radio had an article titled
"computer-aided interdigital bandpass filter design" that included
a basic program for calculating the dimensions of the digits and
enclosure. It said it was "For reproducible customized design in
the 0.4-5 GHz frequency range.

I tried to reverse engineer the design equations from the program
and I think I found a bug in the basic program but the error
(if it were really an error) was very small.



--
Dave Turner     [phone]  [e-mail]


From [e-mail] Thu Mar 21 13:58:09 1996
From: [e-mail] (Conway Yee)
Newsgroups: rec.radio.amateur.homebrew
Subject: Kit QRO HF rigs...Hands Electronics RTX series?
Date: 14 Mar 1996 15:40:36 GMT
Distribution: world
Message-ID: <[e-mail]>

A couple of weeks ago, I posted a question about kit hf rigs.

I got a couple of pointers to Kanga US.  Apparently, they are a one man
operation (definitely a plus...gotta support the little guys) which
distributes kits from Hands Electronics, another one man operation in
Wales.

The Kanga catalog mentions the RTX 206, RTX 210 and several other kit
rigs from Hands electronics.  They are multiband CW/SSB kit rigs
putting out 15 watts.  The design of the rigs is modular and each
module can be purchased separately.  All together, the rigs ain't
cheap but that isn't the point.  Building is more fun than buying.
What I find most annoying is going to do is to go hunting in multiple
catalogs in search of all the parts that I need for a project.  Would
much rather purchase everything in one block.  Besides, I do not
currently know enough to design my own rig.

Anybody build these Hands Electronics rigs?  How difficult are they to
build?  What is the performance of the finished rigs?

It occurs to me that I can build an outboard solid state amp for these
rigs and bring them to the 100W class rigs.  Any flaws to this idea?
--
                                  |       73 de Conway Yee, N2JWQ  | DON'T
                                  | EMAIL     : [e-mail] | TREAD
                                  | TELEPHONE :                    |  ON
                                  | FAX       :                    |  ME!


From [e-mail] Thu Mar 21 13:58:10 1996
From: [e-mail] (Christer Johansson)
Newsgroups: comp.robotics.misc,comp.home.automation,sci.electronics.misc,rec.radio.amateur.homebrew,rec.radio.amateur.misc
Subject: L.O.S.A Contribution Form
Date: Thu, 14 Mar 1996 17:09:37 GMT
Message-ID: <4i9k1d$[e-mail]>
Reply-To: [e-mail]

List Of Stamp Applications (L.O.S.A for short)
==============================================

If you have done something with the BASIC Stamp (big or small)
that you are willing to tell others please use the form below and
write a short description, nothing fancy is needed just a simple
explanation. If you have source code to share that's even better but
it's not necessary.

Then e-mail the form to:

     [e-mail]

With the following as the subject:

     L.O.S.A Contribution

Or you could point your Web-browser to the following URL and fill in
the L.O.S.A form on the Web-page...

     http://www.hth.com/losa.html

The latest version of L.O.S.A is going to be posted to the following
mailing lists and news groups, I will update it approx. once a month.

Mailing lists:

BASIC Stamp Mailing List

News groups:

comp.robotics.misc
comp.home.automation
sci.electronics
sci.electronics.misc
rec.radio.amateur.homebrew
rec.radio.amateur.misc

FTP-site:

     ftp://ftp.parallaxinc.com/pub/text/losa.txt

You can also find the latest version on the following URL...

     http://www.hth.com/losa.html


[--- cut ---]

======================================================================
                    - L.O.S.A Contribution Form -
======================================================================
 New Contribution [ ]  Update [ ]
----------------------------------------------------------------------

 Title :
 Author:                                       Date:

 E-mail: (optional)
----------------------------------------------------------------------

 Stamp model   : BASIC Stamp/BS1-IC/BS2-IC
 Code available: YES/NO
 Filename      : (optional)
 URL           : (optional)
----------------------------------------------------------------------
 Description   : (5-50 rows describing your application)


======================================================================

[--- cut ---]

If you think something are missing in the "L.O.S.A Contribution Form"
please let me know and I will add it.

Regards,

/Christer




From [e-mail] Thu Mar 21 13:58:12 1996
From: [e-mail] (Roger Grady)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: Sat, 16 Mar 1996 04:56:40 GMT
Message-ID: <4idh3b$[e-mail]>
References: <[e-mail]> <4i7vaj$[e-mail]> <4ibqbj$[e-mail]>


Boy this thread brings back memories.  I had a CK722 - bought it from
the 1955 Allied Radio catalog.  That catalog had a full page of
transistors - with several lines describing each one.  I think the
CK722 was one of the cheapest or else I couldn't have afforded it.  I
was only about 12 at the time and didn't have many coins to spend.  I
think I may still have the CK722 (it was one of the blue ones) but if
so, it's no longer functional.  I remember testing it many years ago
and found I had managed to zap it somehow.  My favorite project that I
remember doing with it was an audio oscillator that drove a headphone
and ran off a battery made from a dime and a penny, with a peice of
paper between them and spit for the electrolyte.  Ahh, those were the
days.

Roger Grady, K9OPO



From [e-mail] Thu Mar 21 13:58:13 1996
From: [e-mail] (JGRamsey)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: 16 Mar 1996 15:06:24 -0500
Message-ID: <4if700$[e-mail]>
References: <4icgqg$[e-mail]>
Reply-To: [e-mail] (JGRamsey)

"Those were great times back then!  New thread idea: remember
the International Rectifier B2M photocells?"

Ah-h-h, the ol' B2M photocell, I tried making an "electric eye" with the
B2M and the CK722 (the deep drawn aluminum can version) the '722 was so
leaky that I never could get the B2M's output to overcome the "load" I had
to hang on the '722's base to drain away the leakage! I was 10 years old
or so then. I finally used a CdS cell I got at Olson's on Main Street in
Buffalo.

I also remember selecting out CK722's to find one that would oscillate at
the high end of the AM broadcast band.

I've a few CK722's, 2N170's and even a Bell Telephone Labs Type 1A
transistor - with these specs handwritten on the box:
Insertion gain 24 dB (freq = ??)
Emitter current: 1.1 mA
Collector current: 3.0 mA
Looks like the CK722's leakage wasn't too bad after all!
These goodies are in a box right next to my Intel 1103 and 4004! (yes, a
box with Intel inside!)
Best regards to all, John Ramsey

Hank Riley, N1LTV
[e-mail]


From [e-mail] Thu Mar 21 13:58:14 1996
From: [e-mail] (Paul Bennett)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: 18 Mar 1996 17:18:53 GMT
Distribution: world
Message-ID: <4ik5tt$[e-mail]>
References: <4i1vl3$[e-mail]> <[e-mail]> <4i7ppq$[e-mail]> <4ig5v5$[e-mail]>


Ah yes, the CK722.  Somewhere I still have a bunch of the plastic case ones
stashed away.  BTW I think it was Raytheon that also had an Experimenters Manu
al
for that transistor.  I still have one of those manuals somewhere.
Paul Bennett
N4EGO


From [e-mail] Thu Mar 21 13:58:15 1996
From: (Gary) [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: 13 Mar 1996 11:00:26 GMT
Message-ID: <4i69sa$[e-mail]>
References: <4i5amp$[e-mail]>

>   [e-mail] (Jim Weir) writes:
>  (Gary) [e-mail] shared the following priceless pearls of wisdom:
>
>  >I am looking for a CK722 Philco transistor. It was in a
>  >blue case and I need one for nostalgia purposes.  It was
>  >my first transistor radio project as a young ham.
>
>  It wasn't Philco, it was Raytheon.  I used one in my first project in
>  '58 or '59 and I've got ONE left in the nostalgia case.  Sorry.  BTW,
>  I take it out and measure it for beta and leakage every time I get
>  spoiled with the current production stuff.
>
>  Jim
>
>
>  Jim Weir VP Engineering | You bet your sweet patootie I speak for the
>  RST Engineering         | company.  I OWN the cotton-pickin' company.
>  Grass Valley CA 95945   |
>  http://www.rst-engr.com | AR Adv WB6BHI--FCC 1/C phone--Cessna 182A N73CQ
>  [e-mail]        | Commercial/CFI-Airplane/Glider-----A&P Mechanic
>
>
>>>>
You guys are right it is Raytheon, but you have to remember I am the one
looking for the transistor and it has been 40 years since I've seen the
darn thing..........it was blue, I got that right.

                   TNX Gary KF9CM



From [e-mail] Thu Mar 21 13:58:16 1996
From: William W Janssen <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: 13 Mar 1996 16:41:57 GMT
Message-ID: <4i6tsl$[e-mail]>
References: <4i1vl3$[e-mail]> <[e-mail]>

[e-mail] (Bill Meahan) wrote:
>In article <4i1vl3$[e-mail]> [e-mail] writes:
>>
>>I am looking for a CK722 Philco transistor. It was in a
>>blue case and I need one for nostalgia purposes.  It was
>>my first transistor radio project as a young ham.
>>
>>        TNX Gary KF9CM
>>
>>
>
>Gee, I remember the CK722 as being made by Raytheon and in a silver
>metal can that was of a rounded rectangular shape (kinda like a small
>IF transformer) with three thin wire leads from a white insulator.
>

Mine is made by Rayteon and is black plastic with a clear section near
the leads. It cost about US $7.00 when it was new. I couldn't afford one
but a frend could and he ended up giving it to me.

Bill K7NOM



From [e-mail] Thu Mar 21 13:58:17 1996
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: Thu, 14 Mar 96 00:39:16 GMT
Message-ID: <4i7ppq$[e-mail]>
References: <4i1vl3$[e-mail]> <[e-mail]>

In article <[e-mail]>,
   [e-mail] (Bill Meahan) wrote:
>In article <4i1vl3$[e-mail]> [e-mail] writes:

>Gee, I remember the CK722 as being made by Raytheon and in a silver
>metal can that was of a rounded rectangular shape (kinda like a small
>IF transformer) with three thin wire leads from a white insulator.
> . . .

Yep, Raytheon, and you've got the shape right. But they were blue. . .

Roy Lewallen, W7EL, OF (don't ask)

 - who remembers when there were two available transistors, the CK722 (for
$1) and CK721 (for $3). But $ were much bigger then. . .


From [e-mail] Thu Mar 21 13:58:17 1996
From: [e-mail] (K2EK)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: 13 Mar 1996 21:12:35 -0500
Message-ID: <4i7vaj$[e-mail]>
References: <[e-mail]>


>>I am looking for a CK722 Philco transistor

Gary - must have blown away your original note & E-mail address, so cant
respond directly.  I took another look through my junk box and found a
couple CK-721s.  Same size & pedigree as the 722.  If memory serves (dont
count on it!) the 721 was the NPN version of the 722 - or was it the other
way around... Anyway, I'd be willing to give one up if you are interested.

de Bill  K2EK


From [e-mail] Thu Mar 21 13:58:18 1996
From: [e-mail] (Ed Gallup)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: Thu, 14 Mar 96 03:39:08 GMT
Message-ID: <4i84cf$[e-mail]>
References: <4i5amp$[e-mail]> <4i69sa$[e-mail]>

>>>>>
>You guys are right it is Raytheon, but you have to remember I am the one
>looking for the transistor and it has been 40 years since I've seen the
>darn thing..........it was blue, I got that right.
>
>                   TNX Gary KF9CM
>

   I'll add to this thread.  I have one... MY first transistor acquired in
1961, and I want to keep it.  It is retangular, and  SILVER !


  Ed  WB6SAT


From [e-mail] Thu Mar 21 13:58:19 1996
From: "Ian White, G3SEK" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: Thu, 14 Mar 1996 08:57:50 +0000
Distribution: world
Message-ID: <[e-mail]>
References: <4i1vl3$[e-mail]> <[e-mail]>

>
>Roy Lewallen, W7EL, OF (don't ask)
>
> - who remembers when there were two available transistors, the CK722 (for
>$1) and CK721 (for $3). But $ were much bigger then. . .

Over here they were called Red Spot (for audio) and White Spot
(for RF... well, er, medium-wave).

It's never been the same since they stopped painting transistors by
hand.

73 from Ian G3SEK          Editor, 'The VHF/UHF DX Book'
                          'In Practice' columnist for RadCom (RSGB)
Professionally:
IFW Technical Services     Clear technical English - anywhere.


From [e-mail] Thu Mar 21 13:58:21 1996
From: [e-mail] (David Allen)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: Tue, 19 Mar 1996 22:42:12 GMT
Message-ID: <4ind7r$[e-mail]>
References: <4i1vl3$[e-mail]> <[e-mail]>

[e-mail] (Bill Meahan) wrote:

>In article <4i1vl3$[e-mail]> [e-mail] writes:
>>
>>I am looking for a CK722 Philco transistor. It was in a
>>blue case and I need one for nostalgia purposes.  It was
>>my first transistor radio project as a young ham.
>>
>>        TNX Gary KF9CM
>>
>>

>Gee, I remember the CK722 as being made by Raytheon and in a silver
>metal can that was of a rounded rectangular shape (kinda like a small
>IF transformer) with three thin wire leads from a white insulator.

>I know there's one around here SOMEPLACE but, of course, I can't find
>it.  Not that I would part with it anyway, but I could at least verify
>the physical appearance.

>73!

>--
>Bill Meahan WA8TZG                   [e-mail]
>Member of:  ARRL, IMRA, NorCal QRP (#407), G-QRP (#8468), MI-QRP (#M1458)
>Hey, this is my OWN computer!  I can say what I want!
>        cat: a purr bearing mammal

RCA also made a completly clear case CK722.  A friend's dad worked for
RCA in Cherry Hill (then Delaware Township) and Camden, NJ.  We had
moved from U-Control to RC model airplanes, and this transistor was
the basis of a kit which was one of the first solid-state RC units.
The problem was that the CK722 was hard to get, and my friend's dad
had to pull a few strings to lay hands on one in the spring of 1956.
I'm not sure how widely RCA distributed these things, but you could
see the chip and the fairly crude wire-bond attachments through the
clear plastic case.  We marvelled for hours about the thing, even
though that stuff about holes was Greek to us.

Dave Allen
Falls Church, VA
WA2BSL
[e-mail]



From [e-mail] Thu Mar 21 13:58:22 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: Wed, 20 Mar 1996 00:41:35 GMT
Message-ID: <4inkfj$[e-mail]>
References: <4i1vl3$[e-mail]> <[e-mail]>
Reply-To: [e-mail]

[e-mail] (Bill Meahan) wrote:


>Gee, I remember the CK722 as being made by Raytheon and in a silver
>metal can that was of a rounded rectangular shape (kinda like a small
>IF transformer) with three thin wire leads from a white insulator.

>I know there's one around here SOMEPLACE but, of course, I can't find
>it.  Not that I would part with it anyway, but I could at least verify
>the physical appearance.

The CK722 came in BOTH colors.  The genuine OFs (count me as one)
remember the earlier ones as being blue.  BTW, the package consists of
two cases, a very small metal package containing the actual device
encapsulated in an epoxy-like substance, itself enclosed by the larger
blue or silver can.

I always preferred the GE point-contact 2N107 over the junction CK722,
because its highet Ft (almost 2 MHz,  or should I say 2 MC !!) would
allow better BC band transmitters...

Lordy, how time do fly.

- 73 -

Wayne Hoffman
ARS WB6WLR (Grid DM13at)
Internet [e-mail]
PacBell [phone]



From [e-mail] Thu Mar 21 13:58:23 1996
From: [e-mail] (Dave Turner)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: 14 Mar 1996 20:03:30 GMT
Message-ID: <4i9u2i$[e-mail]>
References: <4i1vl3$[e-mail]> <[e-mail]> <4i7ppq$[e-mail]>


In article <4i7ppq$[e-mail]> [e-mail] (Roy Lewallen) w
rites:
>In article <[e-mail]>,
>   [e-mail] (Bill Meahan) wrote:
>>In article <4i1vl3$[e-mail]> [e-mail] writes:
>
>>Gee, I remember the CK722 as being made by Raytheon and in a silver
>>metal can that was of a rounded rectangular shape (kinda like a small
>>IF transformer) with three thin wire leads from a white insulator.
>> . . .
>
>Yep, Raytheon, and you've got the shape right. But they were blue. . .
>

I bought my first CK722 in 1956 or 1957 (according to my increasingly
vague memory). It was the rounded rectangular shape. It was the color
of dryed blood (dark reddish brown) with a clear layer at the end
where the three thin wire leads entered the case. It was made by
Raytheon.

Personally, I never saw one that was any other color or shape.

--
Dave Turner     [phone]  [e-mail]


From [e-mail] Thu Mar 21 13:58:24 1996
From: "Irina N. Borisova" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: metal detector
Date: 17 Mar 1996 23:44:01 +0300
Distribution: world
Message-ID: <[e-mail]>

   I look for contacts with metal detectors and other searching
technique creators for information exchange.
   M.
   [e-mail]



From [e-mail] Thu Mar 21 13:58:25 1996
From: [e-mail] (Post Office)
Newsgroups: rec.radio.amateur.homebrew
Subject: NDN: Ham-Homebrew Digest V96 #115
Date: 17 Mar 96 14:26:01 GMT
Message-ID: <[e-mail]>
Reply-To: [e-mail]

Sorry. Your message could not be delivered to:

Leslie Dodd,Wellfleet London (Mailbox has been deleted. Try re-entering the
address.)



From [e-mail] Thu Mar 21 13:58:25 1996
From: [e-mail] (Post Office)
Newsgroups: rec.radio.amateur.homebrew
Subject: NDN: Ham-Homebrew Digest V96 #116
Date: 17 Mar 96 23:42:00 GMT
Message-ID: <[e-mail]>
Reply-To: [e-mail]

Sorry. Your message could not be delivered to:

Leslie Dodd,Wellfleet London (Mailbox has been deleted. Try re-entering the
address.)



From [e-mail] Thu Mar 21 13:58:26 1996
From: [e-mail] (Post Office)
Newsgroups: rec.radio.amateur.homebrew
Subject: NDN: Ham-Homebrew Digest V96 #119
Date: 19 Mar 96 14:51:54 GMT
Message-ID: <[e-mail]>
Reply-To: [e-mail]

Sorry. Your message could not be delivered to:

Leslie Dodd,Wellfleet London (Mailbox has been deleted. Try re-entering the
address.)



From [e-mail] Thu Mar 21 13:58:27 1996
From: [e-mail] (Harold R. Smith)
Newsgroups: rec.radio.amateur.homebrew
Subject: NEED ARRL HANDBOOK/J-38
Date: 14 Mar 1996 21:14:44 GMT
Message-ID: <4ia284$[e-mail]>

   I am looking for a 1978 copy of the ARRL handbook, and remnants of or compl
ete J-38 straight key(s)  both items of mine were destroyed in a move (the key
 was disassembled for cleaning and some parts were lost...)  They were pretty
important to me.  If You know where i can get either item, Send me some e-mail
.
  tnx,
    -HRS  (N0QLT/5)
     ([e-mail])
--

..Creative Engineers tend to suffer from A.D.D.
===========================================================================
= ...I was supposed to have been a Jesuit priest, or a Naval Academy grad =


From [e-mail] Thu Mar 21 13:58:28 1996
From: [e-mail] (Glenn E. Little)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Need Charger for Lead Acid Gel Cell Battery
Date: 15 Mar 1996 01:42:23 GMT
Message-ID: <4iahtv$[e-mail]>
References: <4i1e7p$[e-mail]>

In article <4i1e7p$[e-mail]>, [e-mail] (DABLOODGOD)
 says:
>
>I bought one of these at a swap meet last month, and now I need a charger
>for it - Its the size of a large car battery - so the small RC plane model
>Ive seen wont really provide enough current. The battery name plate
>describes 2 voltages - 14.2 to 14.4 volts for charging and 13.6-13.8 volts
>for trickle charging ( these voltages are approximate ) The key thing is
>that the charger is supposed to have 2 modes - 2 voltages and be able to
>switch between them when appropriate. I saw a article in a newsprint
>magazine ( World Radio Times ? ) last month, Unfortunately, Ive recently
>moved and trashed the magazine, before I realized that I needed the
>article.
>
>If anyone has that magazine, or has an idea for a charger, or knows who
>sold that I kit, I would appreciate having the information
>
>Thanks and 73's de Dave, kd6pro.


Unitrode makes an ic for charging starved electrolyte (new name for gell cells
) batteries.
The device requires programming resistors and a pass transistor.
Part number is UC3906N.

73
Glenn Little
WB4UIV



From [e-mail] Thu Mar 21 13:58:29 1996
From: [e-mail] (Arjen Raateland)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Need Charger for Lead Acid Gel Cell Battery
Date: 12 Mar 96 20:11:39 EET
Message-ID: <[e-mail]>
References: <4i1e7p$[e-mail]>

In article <4i1e7p$[e-mail]>, [e-mail] (DABLOODGOD)
 writes:
> I bought one of these at a swap meet last month, and now I need a charger
> for it - Its the size of a large car battery - so the small RC plane model
> Ive seen wont really provide enough current. The battery name plate
> describes 2 voltages - 14.2 to 14.4 volts for charging and 13.6-13.8 volts
> for trickle charging ( these voltages are approximate ) The key thing is
> that the charger is supposed to have 2 modes - 2 voltages and be able to
> switch between them when appropriate. I saw a article in a newsprint
> magazine ( World Radio Times ? ) last month, Unfortunately, Ive recently
> moved and trashed the magazine, before I realized that I needed the
> article.
>
> Thanks and 73's de Dave, kd6pro.

You could look into the circuit described in the ARRL Handbook 1994.
It has a UC3906, which essentially does what you want. I made one
charger based on the UC3906 starting from the Handbook design. I did
make a few changes and additions to the original circuit, though. I'm
now about to do another one.

I have a write-up about my charger circuit that I will send you via
EMAIL.

gl,

--... ...-- -.. . --- .... ..--- --.. .- --..
Arjen Raateland, SAS Support
Finnish Environment Agency
Helsinki, Finland
.-.-. -.-


From [e-mail] Thu Mar 21 13:58:30 1996
From: "Mr. Brooke Clarke" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Need Charger for Lead Acid Gel Cell Battery
Date: Sat, 16 Mar 1996 11:33:08 -0800
Message-ID: <[e-mail]>
References: <4i1e7p$[e-mail]> <4iahtv$[e-mail]>
To: "Glenn E. Little" <[e-mail]>

Glenn E. Little wrote:
>
> In article <4i1e7p$[e-mail]>, [e-mail] (DABLOODGO
D) says:
> >
> >I bought one of these at a swap meet last month, and now I need a charger
> >for it

Try Wal-Mart.  Look for a blister pack holding the charger which is about
the size of a large paperback book.  Around $20.  It is a smart charger
designed to maintain automotive batteries.

Have Fun,
Brooke
N6GCE



From [e-mail] Thu Mar 21 13:58:31 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (J Macfarlane)
Subject: Re: Need Charger for Lead Acid Gel Cell Battery
Message-ID: <[e-mail]>
References: <4iahtv$[e-mail]>
Date: Mon, 18 Mar 1996 11:03:22 GMT

In article <4i1e7p$[e-mail]>, [e-mail] (DABLOODGOD)
 says:
>
>I bought one of these at a swap meet last month, and now I need a charger
>for it - Its the size of a large car battery - so the small RC plane model
>Ive seen wont really provide enough current. The battery name plate
>describes 2 voltages - 14.2 to 14.4 volts for charging and 13.6-13.8 volts
>for trickle charging ( these voltages are approximate ) The key thing is
>that the charger is supposed to have 2 modes - 2 voltages and be able to
>switch between them when appropriate. I saw a article in a newsprint
>magazine ( World Radio Times ? ) last month, Unfortunately, Ive recently
>moved and trashed the magazine, before I realized that I needed the
>article.

Don't have the mag I'm afraid, but I believe that to charge a Sealed
Lead Acid (Gel) battery you need a constant voltage charger with current
limit.

Which one of the two different voltage ranges you use depends on what you
plan to use the battery for. The charger doesn't have to switch between
them automatically. You simply decide the appropriate one and use that.
You charge at the higher voltage (14.2-14.4) if you use the battery
cyclicly (ie heavy discharge followed by charge). You use the lower charge
voltage (13.6-13.8) if you use the battery for standby use, ie it stays on
trickle charge nearly all the time except the odd occasion when you need
to use it (eg when the mains power fails). Also, for gel lead acids, the
charger should limit the maximum current that can flow to about 1/4 of the
battery's Ah rating.

Bearing this in mind, you could temporarily use a bench power supply as
a charger or modify a bench PSU article from another magazine ?

Hope this helps,
James.
-----------------------------------------------------------------------------
James Macfarlane, Faculty of Engineering, University of West of England,
Bristol. Callsign: GYNOY E-mail: [e-mail]
http://www.gbnet.net/orgs/aspire
Opinions expressed are my own, not those of my employer, etc, etc.
-----------------------------------------------------------------------------
I was told and I forgot. I saw and I remembered. I did and I understood.



From [e-mail] Thu Mar 21 13:58:33 1996
From: [e-mail] (Christer Johansson)
Newsgroups: rec.radio.amateur.digital.misc,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.shortwave
Subject: Re: Need Radio Clock Info.
Date: Mon, 11 Mar 1996 17:17:52 GMT
Message-ID: <4i1nb6$[e-mail]>
References: <4hl1tj$90r$[e-mail]>
Reply-To: [e-mail]

Hi Parker,

Parker Kent <[e-mail]> wrote:

>I need any information I can get in
>reguards to the radio signals sent from Germany
>across Europe giving time information for
>Radio Clocks.

Point your Web browser to the following URL...

  http://www.tu-bs.de/rz/sysadmin/dienste/ntp/clock.txt.html

Hope this helps,

/Christer

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
 * High Tech Horizon  -  Christer Johansson  -  E-mail: [e-mail] *
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
 * Vi saljer Parallax, Inc. BASIC Stamp's produkter i Skandinavien *
     >>  World Wide Web On-Line Catalog - http://www.hth.com  <<
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-



From [e-mail] Thu Mar 21 13:58:34 1996
From: [e-mail] (patrick ferrick)
Newsgroups: rec.radio.amateur.homebrew
Subject: Need some coil winding data, please!!
Date: 19 Mar 1996 23:31:14 -0500
Message-ID: <4io1mi$[e-mail]>

Hi all,

I just posted this to sci.electronics, forgetting that this group is
probably a much better source of the info I need...anyway, I need to
make a coil of several hundred microhenries out of some pretty hefty
wire...probably about 12 guage copper or so.

I recall there being an equation in my old ARRL handbook (which I have
lost track of since I moved last)  relating coil size, number of turns
and I think wire guage.  If you have this equation handy and wouldn't
mind enlightening me I would really appreciate it!

thanks,
Pat  KA2AYK



From [e-mail] Thu Mar 21 13:58:34 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Need some coil winding data, please!!
Date: Wed, 20 Mar 96 17:23:48 GMT
Message-ID: <4ipf93$[e-mail]>
References: <4io1mi$[e-mail]>

   [e-mail] (patrick ferrick) wrote:

>I recall there being an equation in my old ARRL handbook (which I
>have lost track of since I moved last)  relating coil size, number of
>turns and I think wire guage.

The formula for the inductance of a single-layer air-core coil is:

L (uH) = (a squared * n squared) / (9a + 10b)

where a = coil radius in inches
      b = coil length in inches
      n = number of turns

Conversely, the number of turns of a single-layer coil for a required
value of inductance can be found from:

n = sq root [ (L * (9a + 10b)) / a squared ]

According to the Handbook, this formula is a close approximation for
coils having a length equal to or greater than 0.8a.

73,
Jack  WB3U


From [e-mail] Thu Mar 21 13:58:36 1996
From: Andy Walton <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: PCB design software
Date: 13 Mar 1996 02:56:58 GMT
Message-ID: <4i5dhq$[e-mail]>
References: <3139888f.382937@194.72.192.4>
To: [e-mail]

Try Protel Easytrax, available from Simtel.
Regards, Andy VK3CAH



From [e-mail] Thu Mar 21 13:58:37 1996
From: Andy Walton <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: PCB design software
Date: 13 Mar 1996 02:56:09 GMT
Message-ID: <4i5dg9$[e-mail]>
References: <3139888f.382937@194.72.192.4>
To: [e-mail]

Try Protel Easytrax, available from Simtel.
Regards, Andy VK3CAH



From [e-mail] Thu Mar 21 13:58:38 1996
From: Andy Walton <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: PCB design software
Date: 13 Mar 1996 02:57:41 GMT
Message-ID: <4i5dj5$[e-mail]>
References: <3139888f.382937@194.72.192.4>
To: [e-mail]

Try Protel Easytrax, available from Simtel.
Regards, Andy VK3CAH



From [e-mail] Thu Mar 21 13:58:39 1996
From: [e-mail] ()
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: QRP..Does anyone have plans for a cheap one.??
Date: 16 Mar 1996 18:57:38 GMT
Message-ID: <4if2v2$[e-mail]>
References: <4i7sdp$[e-mail]>

Dave Perkins ([e-mail]) wrote:
:   Looking for plans for a QRP rig..If anyone has plans or know of any
: article for one, please let me know...Im 17 so I dont have much cash, in
: fact Im pretty much broke..Any help would be extremly appreciated..!!

:   Dave in San Diego


-- Try asking for back issues of QST, 73, CQ .... at your main library.
   Even up here in Edmonton they have QST in original issues going back
   to the 1920's.  The other amateur publications go back at least to the
   late 1960's, I believe.  In your location, they probably have more.

   By researching 1970's to the present, you should find numerous designs
   that are suitable for modern parts sources and spectral purity Xmtr
   requirements.  The ARRL handbooks (1990-95) have QRP designs too.

   Best Regards,
   Shane

                   /|
                  / |
                 /__|
              ______|_____
              \          /
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     [e-mail]






From [e-mail] Thu Mar 21 13:58:40 1996
From: Dave Perkins <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: QRP..Does anyone have plans for a cheap one.??
Date: 14 Mar 1996 01:23:05 GMT
Message-ID: <4i7sdp$[e-mail]>

  Looking for plans for a QRP rig..If anyone has plans or know of any
article for one, please let me know...Im 17 so I dont have much cash, in
fact Im pretty much broke..Any help would be extremly appreciated..!!

  Dave in San Diego



From [e-mail] Thu Mar 21 13:58:41 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (SARUMAN)
Subject: Re: QRP..Does anyone have plans for a cheap one.??
Message-ID: <[e-mail]>
References: <4i7sdp$[e-mail]>
Date: Fri, 15 Mar 1996 03:50:36 GMT

>  Looking for plans for a QRP rig..If anyone has plans or know of any
>article for one, please let me know...Im 17 so I dont have much cash, in
>fact Im pretty much broke..Any help would be extremly appreciated..!!

>  Dave in San Diego

 I think the February 1996 issue of CQ had an article with plans.


<tsb>
                               Midgard Graphics
           3D Animation and Special FX for the hobbyist videographer
                          Email: [e-mail]

--
          Drop into #amigacafe on IRC's undernet for a chat sometime

--

<tsb>

                     A man of many hobby's master of none.




From [e-mail] Thu Mar 21 13:58:42 1996
From: [e-mail] (TIEMANN BRUCE)
Newsgroups: rec.radio.amateur.homebrew
Subject: RF from TV's??
Date: 19 Mar 1996 02:13:48 GMT
Message-ID: <4il58s$[e-mail]>

From [e-mail] Fri Mar 15 10:46:20 MST 1996

Dave Curtis ([e-mail]) wrote:
: Always one to avoid gratuitous mathematics, I believe all the quantum
: physics one needs to know about antennas is:
:   "Accelerate an electron, get a photon.  It's the law."

>Well. It's not that simple. Otherwise the simple cathodic display you
>are using would be a formidable source of RF energy !!!!! You get a
>photon when you use alternative current.

>Vincent.

You also get photons when you accelerate electrons just normally... A
simple chodic display is a formidable source of photons, but since
the electrons had been coming in at a few to a few tens of kV, and are
decelerated within a small fraction of a mm to rest by the phosphor in
the screen, you don't get RF at all, you get X-RAYS.  Nowadays, they try
to keep the voltage low enough that those x-rays aren't particularly
penetrating, and get absorbed by the glass and stuff in front, but older
TV sets used to be something of ionizing radiation hazards, from just
this effect.  It's called "bremsstralung" (though it might be spelled
somewhat differently) and is why paritcle accelerators need to be so long
(when you give these electrons all this energy, they accelerate, emitting
photons, giving most of the energy right back! - so you have to stretch
it out.)

On a slightly more related topic to the thread of this newgroup, Free
Electron Lasers work by wigging or "undulating" a beam of electrons back
and forth by magnets, as they travel along, and presto!, photons come off.
These can be anywhere in the EM spectrum, radio -> x-rays, and I *think*
there are some high-power microwave tubes (klystrons?  carcinotrons?
magnetrons?) that operate by setting up a resonance between electrons that
wiggle, giving off (microwave) photons, and using these photons right back
to wiggle the electrons in just this correct way, so the thing's an
oscillator.

But put me down as agreeing with Dave Curtis, "Accelerate an electron,
get a photon."

Bruce
N6URH



From [e-mail] Thu Mar 21 13:58:44 1996
From: [e-mail] (Filip M Gieszczykiewicz)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Schematic for led blinker
Date: 17 Mar 1996 11:24:59 GMT
Message-ID: <4igsqb$[e-mail]>
References: <[e-mail]> <4if6ia$[e-mail]>
Summary: see some on-line GIFs

In Article '<4if6ia$[e-mail]>', through puissant locution,
 '[e-mail]' soliloquized:
>J. RAINS ([e-mail]) wrote:
>>      I am looking for plans for an LED blinker. I have seen kits for this,
>> but it sounds like something that I can build with parts from Radio Shack.
Does
>> anyone know how to build something like this? Text schematics are greatly
>> appreciated.
>
>       Rat Shack has a simple 8 pin DIP IC that does just this, I think
>       it is $1.19.  Just needs a capacitor to set the time constant and
>       a resistor I believe.  It is a nice one since it lets you control the
>       flash rate and can be used for other things.
>       You could also use an astable multivibrator.  Just bias two BJT's, then
>       set the time constant with some caps.  I don't want to do the ASCII
>       schematic, email me if you want more info.

Greetings. Or you can get a bunch of app notes (recreated from National
Data Book for a project - you can guess what it was) from URL:

http://www.paranoia.com/~filipg/HTML/MINE/PROJECTS/bikelight/F_bikelite.html

Take care.
--
+-->Filip "I'll buy a vowel" Gieszczykiewicz | E-mail: [e-mail]
| http://www.paranoia.com/~filipg/| Sci.Electronics, RC, Misc FAQs + MORE!
| Enjoy your job, work within the law, make lots of money : Choose any two.
| I think for myself. I listen. I make decisions. I speak what I believe.


From [e-mail] Thu Mar 21 13:58:45 1996
From: [e-mail] (Emarit Ranu)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Schematic for led blinker
Date: 16 Mar 1996 19:59:06 GMT
Message-ID: <4if6ia$[e-mail]>
References: <[e-mail]>

J. RAINS ([e-mail]) wrote:

:       I am looking for plans for an LED blinker. I have seen kits for this,
: but it sounds like something that I can build with parts from Radio Shack. D
oes
: anyone know how to build something like this? Text schematics are greatly
: appreciated.

        Rat Shack has a simple 8 pin DIP IC that does just this, I think
        it is $1.19.  Just needs a capacitor to set the time constant and
        a resistor I believe.  It is a nice one since it lets you control the
        flash rate and can be used for other things.
        You could also use an astable multivibrator.  Just bias two BJT's, then
        set the time constant with some caps.  I don't want to do the ASCII
        schematic, email me if you want more info.

--
        -Emarit, KG0CQ  73's   [e-mail]
        Electrical Engineering, Colorado State Univeristy
        Packet:                KG0CQ@KF0UW.#NECO.USA.NOAM
        All generalizations are bad.  Censorship:  ######
        _._  __.  _____  _._.  __._


From [e-mail] Thu Mar 21 13:58:46 1996
From: [e-mail](Mike McLendon)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Schematic for led blinker
Date: 19 Mar 1996 13:09:19 GMT
Message-ID: <4imblv$[e-mail]>
References: <[e-mail]> <4ii3i6$[e-mail]>

Try the LM3909 IC - lets you blink an LED for years off of a 1.5 volt
battery. We used to use lots of these to put LEDs in cow skulls - why?
tt is a long story...

73 - Mike KE4END



In <4ii3i6$[e-mail]> [e-mail]    (Bill Newkirk) writes:
>
>i can never find my digi-key catalog when i need one..harumph.
>
>i believe the absolute easiest way to do a blinking LED would be to
get one
>with the blinker in the LED package. Litronix made these - i would
think there'd
>be some volume of business for that to keep 'em around.
>
>alternately, you could build up an oscillator using a nand or nor gate
and an
>RC feedback network to set flash rate and have the LED connected to
the output.
>
>In <[e-mail]>, [e-mail] (J. RAINS) writes:
>>
>>      I am looking for plans for an LED blinker. I have seen kits for
this,
>>but it sounds like something that I can build with parts from Radio
Shack. Does
>>anyone know how to build something like this? Text schematics are
greatly
>>appreciated.
>>
>>Justin Rains AA9KM
>>[e-mail]
>>
>
>
>Bill Newkirk WB9IVR                  The Space Coast Amateur Technical
Group
>Melbourne, FL                       duty now for the future of amateur
radio
>Lombardi's 1st Law of Business:
>Companies succeed in spite of their best effort.  If they succeed at
all.
>



From [e-mail] Thu Mar 21 13:58:47 1996
From: [e-mail] (Rex Allers)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Message-ID: <[e-mail]>
Date: 13 Mar 96 22:45:20 GMT
References: <4hteqd$[e-mail]> <4hvkv5$[e-mail]>

In article <4hvkv5$[e-mail]>, [e-mail] says...

>But I really think that Tom (W8JI) and Drew and others that have posted
>here have the right idea on this:  the silver plating really doesn't help
>that much.  You are much better off to put your energy into making the
>copper suface smooth and clean, and then protecting it with a thin coat of
>clear acrylic lacquer.  Or does someone have a better type of lacquer
>that's commonly available?  (Polystyrene lacquer?  A cheap, safe home
>process for putting on thin Teflon coatings?)
>--

One comment on a coating to protect from oxidation...

I've only tried this on brass for cosmetic reasons, but I've had success using

clear acrylic floor wax.  Its cheap, may already be in your house, and has kep
t
a brass key looking good for several years.  Just wet the surface with a
light coat from a paper towel or a Q-tip.

I've been thinking about trying it in an RF application but haven't done it
yet.



From [e-mail] Thu Mar 21 13:58:48 1996
From: "Ian White, G3SEK" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: Thu, 14 Mar 1996 08:40:13 +0000
Distribution: world
Message-ID: <[e-mail]>
References: <4hmiir$[e-mail]> <4i384o$[e-mail]>

In article <4i384o$[e-mail]>, K2EK wrote:
>In article <4hmiir$[e-mail]>, [e-mail] (Greg Snellgrove)
>writes:
>
>>The silver product cost $12.35 and the plating brush that
>>connects to the negative side of your battery is $1.35.
>
>For what it is worth, I've used a similar product consisting of a brush
>"pen" which held 2 AA cells and a ground return lead out the top.The
>plating material comes from a loop of silver wire within the brush.  Dip
>the brush in an electrolyte solution and "paint" on the silver...
>
> While slow, it does a credible job on flat or simple surfaces (such as
>1/2" copper water pipe for 2m cavities). Trying to plate a 3.5" diameter
>30t coil of 1/8" tubing after forming the coil was another story.
>Trying to plate the inside of some homemade waveguide or other irregular /
>inaccessible shape is probably impossible.

No problem! K9EEY's 'Ham Radio' article about using spent (silver-
loaded) photographic fixer solution also describes a "brush" made from
sponge wrapped around the end of a carbon rod. In this case the silver
comes from the solution rather than an internal silver anode, so the
sponge has to be dipped back into the jar at frequent intervals.

The carbon rod can be made any size and length you need. The long, slim
copper-plated carbon rods sold as arc-brazing electrodes are great for
plating the insides of tubing. Before using the rod, pare away all the
copper from the end that will contact the sponge and solution. Wrap the
rest of the copper surface tightly with tape to avoid shorts and
unwanted electrolysis of the copper. Obviously you could extend the
"handle" with any length of insulated metal tubing, to reach the bottom
of a cavity for example.




73 from Ian G3SEK          Editor, 'The VHF/UHF DX Book'
                          'In Practice' columnist for RadCom (RSGB)
Professionally:
IFW Technical Services     Clear technical English - anywhere.


From [e-mail] Thu Mar 21 13:58:50 1996
From: [e-mail] (Glenn E. Little)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: 15 Mar 1996 01:58:25 GMT
Message-ID: <4iais1$[e-mail]>
References: <4i1vhj$[e-mail]> <4i9iij$[e-mail]>

In article <4i9iij$[e-mail]>, [e-mail] (Tom Bruhns) says:
>
>WB3U ([e-mail]) wrote:
>
>..
>
>: The best protective finish I have found for electronic parts is
>: polyurethane varnish.  It's somewhat more brittle than other oil-based
>: varnishes, but is probably the toughest single-part, air-dry finish
>: on the market.  Once it has fully cured (usually three to four weeks),
>: polyurethane is nearly as hard as baked enamel.  The only drawback to
>: polyurethane is its deterioration in sunlight, but marine and exterior
>: versions are available with UV blockers that will significantly extend
>: the life of the finish under adverse conditions.
>
>..
>
>Thanks to Jack for a nice posting on using polyurethane varnish.  I had a
>brief email exchange with Jack about one issue that remains in my mind, and
>agreed to post it here to see if anyone has any difinitive info on it.
>
>My concern is that polyurethane has a rather high dissipation factor.
>It was a little hard to find listings, but looks like about 0.05,
>compared with .0002 or less for polystyrene, polyethelene and Teflon.
>So the question is, given that it's used in a rather thin coating, does
>that really make any difference?  Has anyone actually measured the
>unloaded Q of a cavity before and after coating with any type of clear
>coat, whether it's polyurethane or acrylic or something else?
>
>--
>Cheers,
>Tom
>[e-mail]


A microwave oven can be used to determine relative loss of different
materials to RF.
Heat the material in the microwave oven for a short time.
Include a cup of water as a load.
The hotter the material gets, the lossier it is to RF.
I have some bowls the expoded in the microwave oven due to disipation.

73
Glenn Little
WB4UIV


From [e-mail] Thu Mar 21 13:58:51 1996
Date: Wed, 13 Mar 1996 11:09:30 +01
From: Bob Mueller <[e-mail]>
Message-ID: <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating An Alternative?

When I posted under the above title I was amazed at the number of email
responses, well beyond the trigger level at which I promised to post a recipe.
(I have come to expect no answers as that is the typical result, even when I
feel certain somebody out there has the information I need!)
    As I wrote before, the method is one long used by clock makers to put a
silver layer on a copper or brass dial to improve the appearance.  On a matt
surface the dial takes on a nice white color until the power plant sulphur
turns it black.
     Except for the silver compound, the other ingredients can be bought in a
food store.  You may have trouble getting cream of tartar but I get it in
England at Safeway.  Try a drugstore if you fail at the food store.  (my wife
says it is used in some Asian cooking.)
     You can buy silver cloride or make it from silver nitrate.  Adding NaCl t
o
a solution of silver nitrate will cause the cloride to form. Collect it with
a filter paper.  (The collection ought to be quite efficient as silver cloride
has a very low solubility in water.)  Wash out the salt and store the cloride
in a dark place. Or prepare the cloride each time so it is fresh.
      Clean your copper very well, and while it is still wet rub it with a
cloth to apply a thin layer of paste of fine salt in water.  Then run on the
silver cloride paste (the old recipe recommended a piece the size of a marble
for 10 square inches.) The copper should turn grayish and ugly with streaks an
d
all.  Then put on the cream of tartar, applied with the same cloth (Muslin,
they say) where the cream of tartar is in the form of a paste in water. Rub al
l
over and the silver should start to whiten.  Keep your fingers off the surface
during all the processing.  Rubber gloves are good protection against
contamination.  Wash off the parts in the hottest water your hands will
tolerate.  Dry.
     You ought to be able to buy solutions to do this all with less rubbing
and similar bother.  In either case, "homebrew, old-fashioned" or with modern
solutions, you are removing a bit of copper and replacing it with some silver.
I do not know how thick the layer is and the depth is limited: the removal doe
s
not proceed to arbitrary distance into the metal as the new silver protects
the underlying metal.  Conversely, the skin depth is not great at high
frequency and the silver might be thick enough (and more than a couple skin
depths is wasted silver.  It would be valuable for somebody to test and post
the results as to whether he observes the predicted Q-improvement when plating
with some electroless method.)
     Electroplating is the way to go around the limit on thickness. It is not
a
replacement process and thick layers can be added to the surface. But then we
seem to be back to cyanide solutions and living with the slight loss of Q is
better than loosing a life.
     I just received word our system is going down in a few minutes so I must
sign off.  I plan to say a bit on copper plating (and on other metals in pass-
ing) without cyanide but this message will be lost if I do not sign off. 'til
then.....
         Bob






From [e-mail] Thu Mar 21 13:58:53 1996
From: [e-mail] (Elendir)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Stupid Qustion
Date: 15 Mar 1996 10:14:30 GMT
Message-ID: <4ibfu6$[e-mail]>
References: <4hs98c$[e-mail]> <4i37j1$[e-mail]> <[e-mail]> <4i65dd$[e-mail]> <[e-mail]> <4i7d6q$[e-mail]> <4i9vtr$[e-mail]>

Dave Curtis ([e-mail]) wrote:
: Always one to avoid gratuitous mathematics, I believe all the quantum
: physics one needs to know about antennas is:
:   "Accelerate an electron, get a photon.  It's the law."

Well. It's not that simple. Otherwise the simple cathodic display you
are using would be a formidable source of RF energy !!!!! You get a
photon when you use alternative current.

Vincent.
--
Fox 5 RCS - Round the world and beyond through amateur radio.
VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.


From [e-mail] Thu Mar 21 13:58:54 1996
Newsgroups: rec.radio.amateur.homebrew
From: Tom Skelton <[e-mail]>
Subject: Re: Stupid Qustion
Message-ID: <[e-mail]>
Reply-To: [e-mail] (skeltt)
References: <4i37j1$[e-mail]>
Date: Tue, 12 Mar 1996 22:18:43 GMT


>==========W8JI  Tom, 3/11/96==========
>
>In article <4hs98c$[e-mail]>, [e-mail]
>(Lysergic Acid Diethylamide) writes:
>
>>I've always been told that a voltage needs a conductor in order for
>>current to flow.  So how does an alternation volage of say 30v
and freq
>>27mhz leave the antenna if it needs a conductor?
>>
>>I though electricity cannot go through open air except for VERR high
>>voltages.
>
>Hi Pigdog,
>
<snip>
>
>On a less serious note, if you take 100-200 micrograms of that
>stuff after
>your signature, you may be able to see these waves rippling through the
>universe like tiny golden fishes (Cream, from Swabalar 1969) !
> ;-)
>
>73, Tom

Actually, wasn't the song called  S.W.L.A.B.R???

73, tom WB4iUX

ps: I played guitar in a band called The Universal Joint back
then.



From [e-mail] Thu Mar 21 13:58:55 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Stupid Qustion
Date: 12 Mar 1996 20:44:26 -0500
Message-ID: <4i599q$[e-mail]>
References: <4i37j1$[e-mail]>

In article <[e-mail]>, Tom Skelton
<[e-mail]> writes:
>Actually, wasn't the song called  S.W.L.A.B.R???
>
>73, tom WB4iUX
>
>ps: I played guitar in a band called The Universal Joint back
>then.

Yes, and I think it was "Tiny purple fishes, run laughing through your
fingers, and you want to take her with you, to the hard land of the
winter".

The lowest form of EM energy....Bass guitar

1965 Viscounts (Beatles and Motown mostly); 1966 Gypsy Blue, 1967-69 Blue
Cheer (Cream, Hendrix, etc.)

73 Tom


running through your wishes, and she wants tio take you with her, to the
heartland of the witches?"  not tiny Gold fishes....


From [e-mail] Thu Mar 21 13:58:56 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Joe Mack)
Subject: Re: Stupid Qustion
Message-ID: <[e-mail]>
References: <4hs98c$[e-mail]> <4i37j1$[e-mail]> <[e-mail]>
Date: Wed, 13 Mar 1996 20:47:38 GMT

In article <[e-mail]> [e-mail] (Gary
 Coffman) writes:
>In article <4i37j1$[e-mail]> [e-mail] (W8JI  Tom) wri
tes:
>>In article <4hs98c$[e-mail]>, [e-mail]
>>(Lysergic Acid Diethylamide) writes:
>>


>This is a really nice intuitive explanation, but somehow I find it
>lacking (as I also find the explanation in the Antenna Book lacking).
>For example, the Antenna Book seems to be saying that an antenna needs
>to be a large fraction of a wavelength in size to radiate well, but
>then we have magnetic loops like the Isoloop which are tiny fractions
>of a wavelength yet radiate well. And I'm not sure we can say fields
>are imaginary when EM radiation can have mass (solar sails, Special
>Relativity, etc).                        ^^^^

I think solar sails work because light has _momentum_

Joe Mack [e-mail]

>Gary
>--





From [e-mail] Thu Mar 21 13:58:57 1996
From: [e-mail] (Jerry B. Altzman)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Stupid Qustion
Date: 17 Mar 1996 17:20:19 -0500
Message-ID: <4ii373$[e-mail]>
References: <4hs98c$[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>

In article <[e-mail]>,
Gary Coffman <[e-mail]> wrote:
>Yes, thank you Matthew, but that just sidesteps the question.
>Momentum has the units of mass * velocity. If you concede momentum
>to the photon, then neither quantity can be zero.

Hardly. Resistance has units of length. When I talk about momentum, it has
units of inverse length. You can't prove anything about the photon by
looking at what units a particular measurement of it carries.

>Of course velocity isn't zero, by definition it is c. But mass
>is still left unaddressed. Rest mass of the photon is zero, again
>by definition, but a mass equivalence must be there in order for
>momentum to be non-zero. It is the derivation of that mass equivalence

You are hung up on this idea of mass equivalence. Physics thinks
differently. Photons simply carry momentum, like a travelling EM wave
carries momentum.  Photons have no mass, no mass equivalent, *nothing*.
They are simply a measurement of a Fourier mode of an EM wave.

>Gary

//jbaltz
--
jerry b. altzman   Entropy just isn't what it used to be      [phone]
[e-mail]   [e-mail]                KE3ML


From [e-mail] Thu Mar 21 13:58:58 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Gary Coffman)
Subject: Re: Stupid Qustion
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
References: <4hs98c$[e-mail]> <4i37j1$[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
Date: Sun, 17 Mar 1996 17:08:23 GMT

In article <[e-mail]> [e-mail] (Matthew Francey)
 writes:
>[e-mail] (Gary Coffman) writes:
>
>>>I think solar sails work because light has _momentum_
>>
>>Yes indeedy, but momentun has the units of *mass* times velocity.
>>That's the problem. To get momentum transfer, we have to satisfy
>>M1*V1=M2*V2, where M1 and V1 are the sail's mass and velocity
>>and M2 and V2 are the photon's mass and velocity. Setting M2 to
>>zero yields zero momentum transfer.
>
>you have to balance *momentum*.  in this case, we have two items:
>the photon and the mirror:
>
>       p(photon_in) = p(photon_out) + dp(mirror)

Yes, thank you Matthew, but that just sidesteps the question.
Momentum has the units of mass * velocity. If you concede momentum
to the photon, then neither quantity can be zero.

Of course velocity isn't zero, by definition it is c. But mass
is still left unaddressed. Rest mass of the photon is zero, again
by definition, but a mass equivalence must be there in order for
momentum to be non-zero. It is the derivation of that mass equivalence
that is of interest here. (Acually, this has drifted so far from
homebrew issues, it probably should be moved to a more appropriate
group.)

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Thu Mar 21 13:58:59 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Gary Coffman)
Subject: Re: Stupid Qustion
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
References: <4hs98c$[e-mail]> <4i37j1$[e-mail]> <[e-mail]> <4i65dd$[e-mail]>
Date: Wed, 13 Mar 1996 18:04:14 GMT

In article <4i65dd$[e-mail]> [e-mail] (Elendir) writes:
>Gary Coffman ([e-mail]) wrote:
>: of a wavelength yet radiate well. And I'm not sure we can say fields
>: are imaginary when EM radiation can have mass (solar sails, Special
>: Relativity, etc). I have a hard time calling anything with mass imaginary.
[snip]
>There is a confusion here.
>Light and photons do not have any mass.
[snip]
>Solar sails is just radiation pressure ; although photons are weightless
>they do carry energy and impulsion, that they are able to give to any body
>they encounter.
[snip]
>Giving a mass to the photon is - precisely -
>trying to explain a pure relativist phenomenon by newtonian theory.
>
>(Impulse-Energy tensor) = K*(Metric tensor)

The explanation I learned (admittedly many years ago) is that a photon
has zero rest mass, but that it carries a mass equivalent in its
energy, as related by the Planck Law, E=hv, and the mass energy
equivalence, E=MC^2. That may be intuitively Newtonian, but it gives
the right answer for solar sail calculations. I'm not at all sure
what you mean by "impulsion", but you seem to be implying that it
is a tensor field quantity of some sort that warps spacetime conversely
from the way it is warped by gravity. I freely admit ignorance of the
finer points of General Relativity.

It also, I think, is a side issue to the resurrection of the concept
of the vacuum energy as being the aether.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Thu Mar 21 13:59:00 1996
From: [e-mail] (Jerry B. Altzman)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Stupid Qustion
Date: 12 Mar 1996 14:38:20 -0500
Message-ID: <4i4jrc$[e-mail]>
References: <4hs98c$[e-mail]> <4i37j1$[e-mail]> <[e-mail]>

In article <[e-mail]>,
Gary Coffman <[e-mail]> wrote:
>of a wavelength yet radiate well. And I'm not sure we can say fields
>are imaginary when EM radiation can have mass (solar sails, Special
>Relativity, etc). I have a hard time calling anything with mass imaginary.

Last time I checked, the photon (the thing that EM fields are made
of) was still massless (well, the most recent experiment that I found
had its mass as less than 10**-27 eV). It is correct to say that the
EM field carries momentum, which is usually thought of as something
(like a ball) travelling with a particular velocity, but field theory
depends actually on the photon being massless. Of course, other fields
can be thought of as having mass (mediated by massive particles like the
Z and W) but the EM field as it stands doesn't carry any mass. However,
the field is measurable, so it's hard now to call the field "imaginary".

>I was reading an article the other day that goes back to an older
>concept, that of waves in the aether. The concept of aether was
>discarded at the turn of the century (thanks to Michelson-Morley)
>but it has arisen again in the context of the vacuum energy. It
>seems modern theory (and experiment, Casmir Effect) show that the
>vacuum isn't empty. Rather it is seething with enormous energy
>fluctuations (and in fact that the universe itself is just a
>temporary fluctuation in the vacuum energy via E=MC^2).

This whole problem with the vacuum is quite an old one and is a subject of
current debate among physicists.

>Gary

//jbaltz
--
jerry b. altzman   Entropy just isn't what it used to be      [phone]
[e-mail]   [e-mail]                KE3ML


From [e-mail] Thu Mar 21 13:59:01 1996
From: [e-mail] (Elendir)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Stupid Qustion
Date: 14 Mar 1996 09:18:07 GMT
Message-ID: <4i8o8f$[e-mail]>
References: <4hs98c$[e-mail]> <4i37j1$[e-mail]> <[e-mail]> <4i65dd$[e-mail]> <[e-mail]> <4i7d6q$[e-mail]>

I wrote :

: Well, it is almost true. Almost because the true formula for energy
: is E^2 = M^2*C^4 + P^2*C^2, simplifying to E = M*C^2 at rest.
: Impulsion is P, quantity of motion.

Now, a photon is never at rest. You cannot help but letting a photon go
at light speed. You cannot speed it down.
Whereby its mass must be zero, otherwise it would have an infinite energy.
Wherefore the true relation for a photon is E^2=P^2*C^2 or E=pc.

p = h*f/c.

Once you have its impulse (impulsion ?) you can easily calculate radiation
pressure.

Vincent
--
Fox 5 RCS - Round the world and beyond through amateur radio.
VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.


From [e-mail] Thu Mar 21 13:59:03 1996
From: Dave Curtis <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Stupid Qustion
Date: 14 Mar 1996 20:35:07 GMT
Message-ID: <4i9vtr$[e-mail]>
References: <4hs98c$[e-mail]> <4i37j1$[e-mail]> <[e-mail]> <4i65dd$[e-mail]> <[e-mail]> <4i7d6q$[e-mail]>

Always one to avoid gratuitous mathematics, I believe all the quantum
physics one needs to know about antennas is:

  "Accelerate an electron, get a photon.  It's the law."

Antennas are merely convenient, efficient, places to accelerate
some electrons.

-Dave NG0X


[e-mail] (Elendir) wrote:
>Gary Coffman ([e-mail]) wrote:
>: The explanation I learned (admittedly many years ago) is that a photon
>: has zero rest mass, but that it carries a mass equivalent in its
>: energy, as related by the Planck Law, E=hv, and the mass energy
>: equivalence, E=MC^2. That may be intuitively Newtonian, but it gives
>: the right answer for solar sail calculations. I'm not at all sure
>: what you mean by "impulsion", but you seem to be implying that it
>: is a tensor field quantity of some sort that warps spacetime conversely
>: from the way it is warped by gravity. I freely admit ignorance of the
>: finer points of General Relativity.
>
>Well, it is almost true. Almost because the true formula for energy
>is E^2 = M^2*C^4 + P^2*C^2, simplifying to E = M*C^2 at rest.
>Impulsion is P, quantity of motion.
>The vector P and energy E can be in special relativity merged into
>a quadrivector impulsion-energy (maybe the English word is impulse !)
>that get generalized in the general relativity into a tensor field.
>You mentioned the equivalence mass <> energy, thereby the metric tensor
>is bound to energy, and therefore mass, by the Einstein equation.
>
>Vincent
>
>--
>Fox 5 RCS - Round the world and beyond through amateur radio.
>VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.




From [e-mail] Thu Mar 21 13:59:04 1996
From: [e-mail](Tim Hynde)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Stupid Qustion (What a great troll....)
Date: 12 Mar 1996 23:26:57 GMT
Message-ID: <4i5181$[e-mail]>
References: <4hs98c$[e-mail]>

In <4hs98c$[e-mail]> [e-mail] (Lysergic
Acid Diethylamide) writes:
>
>I have a stupid question about the priciple of radios.
>
>I've always been told that a voltage needs a conductor in order for
>current to flow.  So how does an alternation volage of say 30v and
freq
>27mhz leave the antenna if it needs a conductor?
>
>I though electricity cannot go through open air except for VERR high
>voltages.
>


From [e-mail] Thu Mar 21 13:59:05 1996
From: [e-mail] (TIEMANN BRUCE)
Newsgroups: rec.radio.amateur.homebrew
Subject: RE:the 100watts walkie-talkie
Date: 12 Mar 1996 22:21:33 GMT
Message-ID: <4i4tdd$[e-mail]>
References: <[e-mail]>

From [e-mail] Tue Mar 12 15:07:04 MST 1996

>Hi,

>       Please stop intimidate or humiliate the fellow amateur radio operators'
>science knowlege in these homebrew email list. Do you know physics ? How
>could your have 100 watts output with less than 2 watts consumption ?  Is you
>computer powered by a hearing aid battery ? Or you are the 21st century Mr.
>Newton.

Well, he could be speaking of having less than a 1/50 duty cycle and mean 100
W PEP, not average, but actually I think he means there's a 98 watt resistor
in the circuit, and it's hooked up backwards.

Like Bugs Bunny says, standing on thin air, he "never studied law."

Bruce
N6URH

DANGER!!!!  ONE MILLION OHMS!!!


From [e-mail] Thu Mar 21 13:59:05 1996
Distribution: world
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Brian Carling)
References: <4huiq4$[e-mail]>
Date: Wed, 13 Mar 1996 13:30:00 -0500
Subject: USA QSL BUREAU
Message-ID: <[e-mail]>

Newsgroups: rec.radio.amateur.homebrew
From: [e-mail]
"mail sometimes bounces here, please resend if needed!"

Entered 4:54 p.m. Sunday

A GREAT idea whose time has come! I was jjust thinking about doing
something like this the other morning while I was taking a shower,
he he!

73 - AF4K, Bry
(An SASEnvelope is on the way!)

Please reply to me at my NEW e-mail address:
[e-mail]

10>NOW SEND "QSL VIA USBURO" ON THE AIR!
10>USA QSL BUREAU FOR ALL YOUR DOMESTIC QSL CARDS, ALL 10
10>DISTRICTS, TERRITORIES AND TRUSTEESHIPS OF THE U.S.A.

 * SLMR 2.1a * Infantry: A sapling.


From [e-mail] Thu Mar 21 13:59:06 1996
From: [e-mail] (K2EK)
Newsgroups: rec.radio.amateur.homebrew
Subject: VHF Converter Alignment
Date: 12 Mar 1996 17:50:02 -0500
Message-ID: <4i4v2q$[e-mail]>

I am trying to resurrect an old Janel 144CF 2m converter I picked up at a
flea some time ago.  I suspect its alignment was seriously screwed up by
prior owner's diddling (images, instability, etc).  Tuning consists of 3
tuned circuits before and after the mixer stage, with a single tuned
circuit at RF amp input. The LO seems fine.

Lacking a swept signal generator, NF meter etc, I am wondering if it is
possible to simply stagger tune the circuits - say at 144, 144.5 and
145MHz - using an HT with 30db pad (about 1mW output) for a signal source
and tuning for a peak reading voltmeter reading on the IF receiver's audio
output?

Any suggestions will be most welcome...

Bill  K2EK




From [e-mail] Thu Mar 21 13:59:07 1996
From: [e-mail] (Koellner, Guenter)
Newsgroups: rec.radio.amateur.homebrew
Subject: WG: Mail failure
Date: 13 Mar 96 17:51:00 GMT
Message-ID: <[e-mail]>


> I'm looking for serious tested designs using either one QBL5/3500
> tetrode or a 3CX3000A7 triode for the 144MHz band.
> For Moonbounce operation, I'm already using a 3CX1500A7 but need more
> 'fruitjuce' !.
>
> Regards
> Jean-marc

I would prefer a W6PO design, it is the most flexible design I know for
different sizes of tubes. There are also some statements on "symmetric and
asymetric loads" caused from the anode resonator made by him that I agree
to. It is really easy to be built. I am currently building one using a GS35B

tube.

By the way, I am still searching for a suiting design for a 1.5kW+ tube for
70cm. Until now I have the YL1040 design by OZ9ZI adn a 8938 design from the

"Radio Handbook". Do you know any other, maybe one using not the standard
flat plate line but a cavety design as they are more known for the 23cm
amps?

vy 73, Guenter, DL4MEA@DB0KCP.#BAY.DEU.EU   (AX.25)
                [e-mail]            (Internet)
                http://www.scn.de/~koellner (WWW)


From [e-mail] Thu Mar 21 13:59:08 1996
From: "Mr. Brooke Clarke" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: What am I allowed to transmit?
Date: Fri, 15 Mar 1996 21:11:44 -0800
Message-ID: <[e-mail]>
References: <[e-mail]>
To: [e-mail]

[e-mail] wrote:
>
> Hello!
>
>     I'd like to play around with some transmitter circuits with a range of
> maybe a couple of hundred feet. What is the maximum power allowed without a
> licence and for what range of frequencies? BTW, I live in Canada so obviousl
y
> Canadian rules apply  here.
>
>    Thanks for any help.

Mike:
In the USA there is a provision for unlicensed operation in the frequency
range of 160 to 190 kHz, maixmum power is limited to 1 Watt and maximum
antenna+feedline limited to 15 meters (50 ft.).  The EIRP is in the
milliwatt range since the antenna is electrically very short.  The
maximum range is on the order of 2,000 miles due to very good
propagation.  You might check out the Long Wave Club Of America and the
Canadian version of the FCC to see if this is available to you.

Have Fun,
Brooke



From [e-mail] Thu Mar 21 13:59:09 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: What am I allowed to transmit?
Date: Thu, 14 Mar 1996 08:44:34
Message-ID: <[e-mail]>

Hello!

    I'd like to play around with some transmitter circuits with a range of
maybe a couple of hundred feet. What is the maximum power allowed without a
licence and for what range of frequencies? BTW, I live in Canada so obviously
Canadian rules apply  here.

   Thanks for any help.


Mike Thompson
University of New Brunswick
Fredericton, NB




From [e-mail] Thu Mar 21 13:59:10 1996
From: [e-mail](Glenn Sparks)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: What makes crackle( wrinkle) paint crackle (wrinkle)??
Date: 13 Mar 1996 20:51:57 GMT
Message-ID: <4i7chd$[e-mail]>
References: <4hn3or$[e-mail]> <[e-mail]> <4hvvk2$[e-mail]> <4i5amm$[e-mail]> <[e-mail]>

For wrinkle we used to use the enamel / laquorer method, I'v never
tried to emulate the Heath, for hammertone, our local ACE hardware
store carries it.  I haven't tried it, but probably should on an old
pair of Morrows I am restoring.

Glenn Sparks

In <[e-mail]> [e-mail] (Gary
Coffman) writes:
>
>In article <4i5amm$[e-mail]> [e-mail] (Jim Weir) writes:
>>
>>Or something like that.  Oh, the poster who said the Heath finish
>>wasn't crackle is correct.  I believe the correct term for the Heath
>>finish is hammertone, and I DON'T know how to do that one easily.
>
>I don't recall a Heath with a hammertone finish (but that doesn't mean
>they never used it). That was the finish on old Bud boxes. It vaguely
>resembles a sheet of metal that has been lightly hammered with a ball
>peen hammer, IE a pattern of varying grey tones, thus the name. The
Heaths
>I recall all had a textured finish, like that delivered by a roller or
a
>"spatter" gun. BTW, I seem to recall someone here recently recomending

>using a roller to achieve a nice textured cabinet finish.
>
>And I don't know how to achieve a true hammertone finish either.
>
>Gary
>--
>Gary Coffman KE4ZV          |    You make it,     | Due to provider
problems
>Destructive Testing Systems |    we break it.     | with previous uucp
addresses
>534 Shannon Way             |    Guaranteed!      | Email to
[e-mail]
>Lawrenceville, GA 30244     |                     |



From [e-mail] Thu Mar 21 13:59:12 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: What makes crackle( wrinkle) paint crackle (wrinkle)??
Date: Wed, 13 Mar 96 18:33:51 GMT
Message-ID: <4i74ma$[e-mail]>
References: <4hn3or$[e-mail]> <[e-mail]> <4hvvk2$[e-mail]> <4i5amm$[e-mail]>

  [e-mail] (Jim Weir) wrote:

>Oh, the poster who said the Heath finish wasn't crackle is correct.
>I believe the correct term for the Heath finish is hammertone, and I
>DON'T know how to do that one easily.

Early SB-series Heath gear is definitely not hammertone - it is indeed
a wrinkle finish.  I can't comment on how Heath applied it, however.

Incidentally, does anyone else remember Heath selling touch-up paint
at one time for that equipment?  I seem to remember being told that it
was available in a regular spray can.  Yes?  No?

73,
Jack  WB3U


From [e-mail] Thu Mar 21 13:59:13 1996
From: [e-mail] (K2EK)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: What makes crackle( wrinkle) paint crackle (wrinkle)??
Date: 13 Mar 1996 21:06:06 -0500
Message-ID: <4i7uue$[e-mail]>
References: <4i74ma$[e-mail]>

In article <4i74ma$[e-mail]>,
[e-mail] (WB3U) writes:

>Early SB-series Heath gear is definitely not hammertone - it is indeed
>a wrinkle finish.  I can't comment on how Heath applied it, however.
>
>Incidentally, does anyone else remember Heath selling touch-up paint
>at one time for that equipment?  I seem to remember being told that it
>was available in a regular spray can.  Yes?  No?
>
>

Jack et al...  Heath used several color schemes over the years.  My first
transmitter - a DX-20 - had a medium grey wrinkle cabinet with a
semi-gloss light grey fron panel.  I am currently restoring a IM-18 VTVM
which has a light brown or tan semi gloss front panel and darker brown
"splatter" cabinet.  It looks a little like semi-glass latex applied with
a roller.  I am also restoring a SB-610 monitor scope which is the more
recent light and dark green and is definately wrinkle.  A similar color
scheme was used in the early 60s (Mohawk, Marauder, Warrior, etc) but they
were gloss enamel for both panels and cabinets.

I too remember touch up paint being available in a spray can.

Bill  K2EK


From [e-mail] Thu Mar 21 13:59:14 1996
From: [e-mail] (Rich Mulvey)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: What makes crackle( wrinkle) paint crackle (wrinkle)??
Date: 15 Mar 1996 02:19:01 GMT
Message-ID: <[e-mail]>
References: <4hn3or$[e-mail]> <[e-mail]> <4hvvk2$[e-mail]> <4i5amm$[e-mail]>
Reply-To: [e-mail]

On Wed, 13 Mar 1996 02:08:13 GMT, Jim Weir <[e-mail]> wrote:
>Lee Blaske <[e-mail]> shared the following priceless pearls
>of wisdom:
>
>>It was expained to me that the Heath light green finish as found on the SB s
eries is
>>not a crackle finish.  In fact, that finish is accomplished by some sort of
>>spattering process using a special paint spraying nozzle.  Ron Eisenbrey, wh
o
>>refinishes vintage ham gear, just finished a batch of Heath equipment.  It'l
l
>>probably be some time before he gets around to Heath again.
>
>If I'm not mistaken (and I frequently am) we used to get a good
>crackle finish by first applying enamel, waiting until it set up
>tacky, then oversprayed with lacquer.  Somehow the solvents in the two
>varieties hated each other and got to fighting amidst the hills and
>crevices of the finish.
>
>Or something like that.  Oh, the poster who said the Heath finish
>wasn't crackle is correct.  I believe the correct term for the Heath
>finish is hammertone, and I DON'T know how to do that one easily.
>

   Well, you can get Hammertone(tm) paint at many craft shops - I
use it for all of my homebrew rigs, and love it.

- Rich

---
Rich Mulvey, aa2ys                                        Rochester, NY   USA
[e-mail]
[e-mail]
aa2ys@wb2psi.#wny.ny.us



From [e-mail] Thu Mar 21 13:59:15 1996
From: [e-mail](Frank L. Jamison )
Newsgroups: rec.radio.amateur.homebrew
Subject: WTB/T:4-400 Chimneys/Air Sockets
Date: 16 Mar 1996 05:14:40 GMT
Message-ID: <4idio0$[e-mail]>

I need a pair of Chimneys and sockets for 4-250/4-400's.  Forward
condition and price.
        F. 'Jamie' Jamison     W5YSM/VK2AIX


From [e-mail] Thu Mar 21 13:59:16 1996
From: [e-mail] (Dana Myers)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: WTB: want to build .2watt drive amp 2mtr
Date: 13 Mar 1996 06:37:17 GMT
Message-ID: <4i5qet$[e-mail]>
References: <4i0fnk$[e-mail]>

In article <4i0fnk$[e-mail]>,
Jack Kovar  KE0AX <[e-mail]> wrote:
>       I would like to build a amp for 2mtr fm that would produce
>       10- 30 watts output with 200mw input.
>       Anyone ever seen QST ect design such a critter?
>                                               Thanks,
>                                               Jack kovar
>                                               [e-mail]

I actually built such a thing myself - I used a Toshiba SAV17 (I think)
hybrid power amplifier for 2m FM, purchased from RF Parts in
San Marcos, CA [phone].  Last I looked, the module cost
something like $70, but it will produce over 50W of output for around
200mW of drive, and is 50 ohm in/out.  You'll need to add an
LC low-pass filter to improve the harmonic suppression to the
necessary -60dBc, and you can control the output power by
varying the power supply to the internal driver stage.

Be very careful with your T/R switch, as this amplifier has a
lot of gain and will oscillate easily if the output is coupled
to the input.

--
 * Dana H. Myers KK6JQ, DoD#: j | Views expressed here are      *
 * [phone]               | mine and do not necessarily   *
 * [e-mail]      | reflect those of my employer  *


From [e-mail] Thu Mar 21 13:59:17 1996
From: [e-mail] (Mike Keitz)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: WTB: want to build .2watt drive amp 2mtr
Date: 14 Mar 1996 01:01:02 GMT
Message-ID: <4i7r4e$[e-mail]>
References: <4i0fnk$[e-mail]> <4i5qet$[e-mail]>


In article <4i5qet$[e-mail]>, [e-mail] (Dana Myers) sa
ys:
>
>In article <4i0fnk$[e-mail]>,
>Jack Kovar  KE0AX <[e-mail]> wrote:
>>       I would like to build a amp for 2mtr fm that would produce
>>       10- 30 watts output with 200mw input.
>>       Anyone ever seen QST ect design such a critter?
>>                                               Thanks,
>>                                               Jack kovar
>>                                               [e-mail]
>
>I actually built such a thing myself - I used a Toshiba SAV17 (I think)
>hybrid power amplifier for 2m FM, purchased from RF Parts in
>San Marcos, CA [phone].  Last I looked, the module cost
>something like $70, but it will produce over 50W of output for around
>200mW of drive, and is 50 ohm in/out.  You'll need to add an
>LC low-pass filter to improve the harmonic suppression to the
>necessary -60dBc, and you can control the output power by
>varying the power supply to the internal driver stage.


The S-AV17 is the stock amplifier in many Kenwood 2m FM mobile radios
and possibly other brands.  It's a two stage bipolar transistor class-C
amplifier, so it's only suitable for FM.  Be careful when mounting these
not to bend the baseplate and crack the ceramic (this seems to be the
primary mode of failure).

Another approach is to obtain a commercial mobile radio and remove the
power amplifier, harmonic filter, and T/R switch from it.  Then for <$50
you'll have a 50 ohm in/out amplifier, heat sink, harmonic filter, and
half of the T/R switch.  (You'll need another relay to select whether the
HT goes into the amplifier or the straight-thru receive path, but this
relay only needs to handle 200 mW of course).  Most of the Motorola
models were built assuming 400 mW of drive from the exciter, so rated
output may not be obtainable with only 200 mW. (But, see below).  This
project would end up quite a bit buliker than a module-based amplifier
would be.
>
>Be very careful with your T/R switch, as this amplifier has a
>lot of gain and will oscillate easily if the output is coupled
>to the input.

Very true.  This is the main problem with trying to boost a 200 mW
HT signal.  My C508 440 MHz amplifier had some trouble with this, I ended
up having to settle for 15W of output instead of 20, which of course is
still "noticeably better" (17 dB) than 280 mW.  This is with a 4-stage
amplifier from an RCA "700" radio (early '70s vintage), and homemade
reed relays.

-Mike KD4QDM


From [e-mail] Thu Mar 21 13:59:19 1996
From: [e-mail] (Rod Lane)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: WTB: want to build .2watt drive amp 2mtr
Date: 14 Mar 1996 04:16:09 GMT
Distribution: world
Message-ID: <4i86i9$[e-mail]>
References: <4i0fnk$[e-mail]> <4i5qet$[e-mail]>

Look in the new '96 ARRL Handbook.  There's an amp just like this one.
They call it a "brick" amp.  The setup includes a table for a pad you
install on the PCB that'll allow almost any drive level from .5 to 5
watts.



From [e-mail] Thu Mar 21 13:59:20 1996
From: [e-mail] (Art Alto)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: WWV radio clock decoding???
Date: 17 Mar 1996 00:12:39 -0500
Message-ID: <4ig707$[e-mail]>
References: <[e-mail]>

Also, see Don Lancaster's TTL Cookbook or CMOS Cookbook (I forget which
one it's in) which were published in the mid-'70's.  There's a schematic
for a decoder, but not a receiver there.

Art N6VIG


From [e-mail] Thu Mar 21 13:59:20 1996
From: Isaac Kohn <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: XR2211
Date: Sun, 17 Mar 1996 20:20:18 -0600
Message-ID: <[e-mail]>
References: <[e-mail]>

[e-mail] wrote:
>
> I am looking to build a packet modem around the xr2211, I need a
> schematics for it and for tx too.
> Sorry, I don't speak english.
>
> Thanks.
>
> LU 6 ENCFor someone that doesn't speak english, the _English_ post is pretty

intelligible...

73's
Isaac


From [e-mail] Sun Mar 24 17:27:23 1996
From: [e-mail] (Bobby Raymer)
Newsgroups: rec.radio.amateur.homebrew
Subject: (none)
Date: 20 Mar 96 20:56:00 GMT
Message-ID: <[e-mail]>

add ham-homebrew




From [e-mail] Sun Mar 24 17:27:24 1996
From: Markus Buehler <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 10m Repeater Switzerland HELP wanted
Date: Sat, 23 Mar 1996 18:22:33 -0800
Message-ID: <[e-mail]>
References: <[e-mail]> <[e-mail]>

Thank you for your answer.
[e-mail] wrote:
> If you HAVE to put tx/rx together at same site, tx and rx are not together,
there will be a link on UHF/SHF
> Whats the call sign???  It is HB9HD


From [e-mail] Sun Mar 24 17:27:25 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 10m Repeater Switzerland HELP wanted
Date: Sat, 23 Mar 96 00:12:48 -0500
Message-ID: <[e-mail]>
References: <[e-mail]>

Markus Buehler <[e-mail]> writes:

>Are there 10 m repeaters at such high locations in the united states

There are a few here, a couple in Carribean area. Think at least some
must be at the 2000m mark. Good coverage? Yes when local propogation
and half way around world when band opens.

>We are interested in what kind of antennas where used.

Wind and static charge would both be enemies at exposed altitude. Something
that is a DC ground type such as Cushcraft Ringo is one way of doing it.
1/4 wave is more of a sky warmer as opposed to the 1/2 wave Ringo type. More
radiation is sent upward with the 1/4 into space rather than toward
horizon as compared with 1/2 wave.

>Also the lightning protection is a big problem.

Lightning arrestors. Polyphase here in US is one company with products that
should take care of problem (not a plug for Polyphase).

>Which kind of tx and rx constructions are the best for 10m

Whatever is laying around for used 29-30 Mhz FM gear. A lot of conversions
have been done with the 30Mhz "Business Band" FM mobile equipment in
Ham radio mags.

>Any other tips are real welcome.

Think real hard about how much power on the tx. If you HAVE to put tx/rx
together at same site, expect to battle the rx desense problem. Filters/
or antenna duplexers are huge and costly due to size because of low
frequency. Thats why the migration to the 2m and 70cm where these
aren't necessary if there is enough vertical space between  rx
and tx on a tower. Even about 30 ft. is enough at these frequencies.

>Any other tips are real welcome.

Consider using 10m input and 70cm out for the system? A 2000m site whould
give decent range for the 70cm output, and there wouldn't be the
long range users when band opens up again. Unless you like the company
then go for it and make in and out 10m.

>A 10 watt beacon is ready to put up to the tx location. We are only

Whats the call sign???


From [e-mail] Sun Mar 24 17:27:26 1996
From: (Gary) [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: CB to 10m Conversion
Date: 23 Mar 1996 16:22:03 GMT
Message-ID: <4j18fb$[e-mail]>
References: <[e-mail]>

>   Shelby Merrick <[e-mail]> writes:
>  Does anyone have some pointers on modifying a cb for 10m output?  Would
>  one have to use transverters of some sort, or could you tune the radio
>  internally down to 10m?  I have a couple of rat shack 11m good for
>  nothing cb's laying around and need a use for them.  Thanx in advance.
>
>  73's
>  KE4AKA
>  Shelby
>
>>>>
Hi Shelby,

By manipulating the loop oscillator crystal frequency of your CB set,
you can move the 40 channel (400Khz aprox.) segment to ant part of
10 meters. It's best to start with a SSB radio for CW but you can
use an AM setif you want to go up to 29 Mhz (AM window).

If you want to "E"mail me on specific modification of your particular
rig, you need to tell me:

1. The chip number of your PLL.
2. What frequency you want to go to.


                                     "73" Gary KF9CM




From [e-mail] Sun Mar 24 17:27:27 1996
From: [e-mail] (Elendir)
Newsgroups: rec.radio.amateur.homebrew
Subject: Conversion of noise voltage into noise figure ?
Date: 19 Mar 1996 12:06:41 GMT
Message-ID: <4im80h$[e-mail]>

Hi, that's me again :-)
(BTW, shall I say : it is me or it is I ?)

Anyhow.
I have here some FET data sheets where they give as a noise parameter
the "Equivalent input noise voltage" in nV/sqrt(Hz).

I can't locate the paper where I had written the formula to convert this
parameter into more traditional NF in dB.

Can someone help me ? (If I remember, NF was also depending on the noise
current). By the way, it is given @ 100 Hz, so I suppose we are speaking
about flicker noise here. Is there any way to guess NF at, let's say,
50 MHz ?

THX,
Vincent
--
Fox 5 RCS - Round the world and beyond through amateur radio.
VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.


From [e-mail] Sun Mar 24 17:27:28 1996
From: [e-mail] (Elendir)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Conversion of noise voltage into noise figure ?
Date: 20 Mar 1996 14:43:42 GMT
Message-ID: <4ip5iu$[e-mail]>
References: <4im80h$[e-mail]> <4io1df$[e-mail]> <4ioucf$[e-mail]>

Continuing my last message :

Elendir ([e-mail]) wrote:
: How to account for the reactive component ?

I have taken the BF 981 (Dual-Gate MOSFET) in which are given noise circles
for 100 and 200 MHz.

Taking two samples of NF for real Rs at each frequency, it gives :

100 MHz : en = 1.18 nV  in = 2.46 pA    Rsopt = 479 O
200 MHz : en = 1.19 nV  in = 3.64 pA    Rsopt = 326 O

Okay, we see that at VHF range, en is stable while it is in which varies.

Assuming a law : in = a * F ^ b, we find :
a = 0.18 and b = 0.57, where a is in pA and F in MHz.

Therefore we interpolate :

50 MHz  : en = 1.18 nV  in = 1.67 pA    Rsopt = 705 O   NFopt = 0.9 dB

However, both value do not take in account the reactive Bs component which
seems to be quite large.

And, moreover, at 100 MHz and Ysopt = 0.5 - 1.2 i mS, NF = 0.6 dB !!!
And, at 200 MHz, Ysopt = 0.5 - 2.56 i mS, NF = 0.7 dB.

We see that the Gs has not changed, whereas the Bs did !

Therefore, how to guess that reactive component which we cannot obviously
ignore !

Vincent

--
Fox 5 RCS - Round the world and beyond through amateur radio.
VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.


From [e-mail] Sun Mar 24 17:27:30 1996
From: [e-mail] (qrk)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Conversion of noise voltage into noise figure ?
Date: Wed, 20 Mar 1996 04:36:15 GMT
Message-ID: <4io1df$[e-mail]>
References: <4im80h$[e-mail]>

[e-mail] (Elendir) wrote:

>I have here some FET data sheets where they give as a noise parameter
>the "Equivalent input noise voltage" in nV/sqrt(Hz).

>I can't locate the paper where I had written the formula to convert this
>parameter into more traditional NF in dB.

>Can someone help me ? (If I remember, NF was also depending on the noise
>current). By the way, it is given @ 100 Hz, so I suppose we are speaking
>about flicker noise here. Is there any way to guess NF at, let's say,
>50 MHz ?

The information below is from an excellent book on noise called
"Low-Noise Electronic Design" by C.D. Motchenbacher and F.C. Fitchen,
published by John Wiley & Sons, ISBN 0-471-61950-7.  This book is 20
years old. I believe that there is a newer edition out with a slightly
different title.

NF = 10 log[(Eni^2) / (Et^2)]

   = 10 log[(Et^2 + En^2 + (In^2 * Rs^2)) / (Et^2)]

where:
  Eni = equivalent noise input
  Et  = rms thermal noise voltage of a resistance
  En  = rms equivalent noise voltage generator (the transistor)
  In  = rms equivalent noise current generator (the transistor)
  Rs  = resistance of signal source

Et = sqrt[4 * k * T * R * (delta freq)]

  -or an approximation-

Et = 0.1268 * sqrt(Rs),  in nV/sqrt(Hz) at room temperature.

From my experience, equivalent input noise of a JFET is pretty
constant from low frequency to high frequency (my experience only goes
up to 5 MHz), however, the input noise current starts to increase at
higher frequencies, usually around 100 kHz.  The slope data I have
seen shows the input noise current increasing at approximately 20 dB
per decade of frequency.

-
Mark Chun  |  [e-mail]  |  Santa Barbara, CA



From [e-mail] Sun Mar 24 17:27:31 1996
From: [e-mail] (Brian Wagner)
Newsgroups: rec.radio.amateur.homebrew
Subject: Crystals
Date: 21 Mar 1996 12:10:31 GMT
Message-ID: <4irgvn$[e-mail]>

I am in the process of building the rock bending receiver for 7MHz as describe
d
in QST (August 95), but I cannot find a source for the crystal.  I need a 7MHz

fundamental mode quartz crystal (the kind that are about the size of a postage

stamp), and also a socket for the crystal.  Anyone out there know of a place t
o
mail order this crystal?

Thanks for the help,
Brian, N2IFF



From [e-mail] Sun Mar 24 17:27:32 1996
Newsgroups: rec.radio.swap,rec.radio.amateur.homebrew,rec.radio.amateur.equipment
From: [e-mail] (dale b. allen)
Subject: Re: FS: HP431C Power Meter and HP478A Thermistor Mount
Keywords: Power Meter, HP431,HP478,Thermistor Mount
References: <4ip2hi$[e-mail]>
Date: Thu, 21 Mar 1996 14:05:08 GMT
Message-ID: <4irnmk$[e-mail]>

InThe Power Meter and Thermistor mount have been sold. Dale article
<4ip2hi$[e-mail]>,
   [e-mail] (dale b. allen) wrote:
>Xref: newsgate.melpar.esys.com rec.radio.swap:39185
rec.radio.amateur.homebrew:11969 rec.radio.amateur.equipment:24309
>Newsgroups:
rec.radio.swap,rec.radio.amateur.homebrew,rec.radio.amateur.equipment
>Path: newsgate.melpar.esys.com!inpc12
>From: [e-mail] (dale b. allen)
>Subject: FS: HP431C Power Meter and HP478A Thermistor Mount
>Keywords: Power Meter, HP431,HP478,Thermistor Mount
>Sender: [e-mail] (Melpar News Administrator)
>Organization: e-systems
>Date: Wed, 20 Mar 1996 13:51:46 GMT
>X-Newsreader: News Xpress Version 1.0 Beta #3
>Message-ID: <4ip2hi$[e-mail]>
>Status: N
>
>I have an HP431C Power Meter and companion HP478A Thermistor Mount for Sale.
>Both are working units and I'll include the original manual for the 431C.
Will
>sell both for $125 (shipping included in CONUS). Ask Tucker if this is a good

>deal. He wants over $700.
>                                                       Dale
>
>+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>+ Dale B. Allen  [phone]  Internet: [e-mail] +
>+ E-Systems, Falls Church Division    FAX: [phone]         +
>+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ Dale B. Allen  [phone]  Internet: [e-mail] +
+ E-Systems, Falls Church Division    FAX: [phone]         +
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++


From [e-mail] Sun Mar 24 17:27:33 1996
From: Jay Wicklund <[e-mail]>
Newsgroups: rec.radio.swap,rec.radio.amateur.homebrew,rec.radio.amateur.equipment
Subject: Re: FS: HP431C Power Meter and HP478A Thermistor Mount
Date: Wed, 20 Mar 96 16:18:59 PDT
Message-ID: <[e-mail]>
References: <4ip2hi$[e-mail]>


In article <4ip2hi$[e-mail]>,
rec.radio.amateur.homebrew:14806 rec.radio.amateur.equipment:28004
>
> I have an HP431C Power Meter and companion HP478A Thermistor Mount
for Sale.
> Both are working units and I'll include the original manual for the
431C. Will
> sell both for $125 (shipping included in CONUS). Ask Tucker if this
is a good
> deal. He wants over $700.
>                                                       Dale
>
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> + Dale B. Allen  [phone]  Internet: [e-mail] +
> + E-Systems, Falls Church Division    FAX: [phone]         +
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>
That's a great deal folks, if the units are working.  I paid more than
that for the HP478A  - and didn't even get the connecting cable.  If I
didn't already have one, I'd snap it up....73 de KI7RH



From [e-mail] Sun Mar 24 17:27:34 1996
From: "C. Wheeler" <[e-mail]>
Newsgroups: rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.shortwave,rec.radio.swap
Subject: Re: GrandFather left 2 Garages full of Stuff
Date: 20 Mar 1996 05:26:57 GMT
Message-ID: <4io4v1$[e-mail]>
References: <4i49qb$[e-mail]> <[e-mail]> <4ik6j2$[e-mail]>

[e-mail](Jon Shay ) wrote:
>In <[e-mail]> [e-mail] (Dick Hughes)
>writes:
>>
>>[e-mail] (James Moore) wrote:

>>>     If interested call 1 800 996-2971

>>I noticed this same post in rec.motorcycles.  Must have a lot of
>>stuff!  I think he is playing with us.
>
>I think the CLUE here is 1-800......"Sure I'm gonna pay for a 1-800
>service so I can sell my grandfathers junk"....To heck with a YARD SALE
>that would'nt cost a dime!

From calling the number myself (since I heard it was O.O.S.) and listening
to the OOS announcement, it sounds like a paging terminal.  Probably a
personal 800 number from Skytel or other carrier.  Perhaps the poster
discovered it was not a wise move to publish his pager number here after
he got flooded with calls (like the one I just made) and changed it.



From [e-mail] Sun Mar 24 17:27:35 1996
From: [e-mail](Jon Shay )
Newsgroups: rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.shortwave,rec.radio.swap
Subject: Re: GrandFather left 2 Garages full of Stuff
Date: 18 Mar 1996 17:30:10 GMT
Message-ID: <4ik6j2$[e-mail]>
References: <4i49qb$[e-mail]> <[e-mail]>

In <[e-mail]> [e-mail] (Dick Hughes)
writes:
>
>[e-mail] (James Moore) wrote:
>
>>
>>      GrandFather passed and left 2 garages full of stuff.
>>
>>      GrandMother wants rid of it.
>>
>>      If interested call 1 800 996-2971
>>
>>      Thank You
>>
>
>I noticed this same post in rec.motorcycles.  Must have a lot of
>stuff!  I think he is playing with us.
>
>Dick Hughes

I think the CLUE here is 1-800......"Sure I'm gonna pay for a 1-800
service so I can sell my grandfathers junk"....To heck with a YARD SALE
that would'nt cost a dime!


From [e-mail] Sun Mar 24 17:27:36 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: HELP ! Need broadband impedance match !
Date: Fri, 22 Mar 96 17:06:24 GMT
Message-ID: <4iun11$[e-mail]>
References: <1996Mar22.065407.1@noah>

  [e-mail] wrote:

>       I have a problem (...don't we all :{)). I am trying to
>accomplish a broadband impedance match. Can anyone suggest some
>references I may be able to use ? I have stuff on a narrowband
>match, but it's inadequate. Any help would be appreciated, especially
>technical books. Thanks in advance.

What's the frequency range and power level?  What input and output
impedances are involved?

73,
Jack  WB3U


From [e-mail] Sun Mar 24 17:27:38 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (J Macfarlane)
Subject: Re: Help needed. Yeasu FT-411 hack
Message-ID: <[e-mail]>
Date: Mon, 18 Mar 1996 16:10:50 GMT

Thanks for all the replies I received via e-mail concerning increasing the
frequency range of a Yaesu FT-411.

It looks like you have to press the up and down buttons together while
turning on the power. Unfortunately, this didn't work on my rig for some
reason. So I went inside the rig to do the hardware varsion of this which
involves changing some of the internal jumper settings.
Information on how to do this(and lots of other stuff) can be found at ftp
oak.oakland.edu in the directory: pub/hamradio/mods/yeasu. This site has
lots of other cool ham stuff aswell.

Anyway, I can now tune 130-185 MHz (although my rig is pretty dead at
frequencies over about 147 MHz. This could be because its a UK version.
Our 2m badn only goes 144-146. I belive in the States this is 144-148MHz.
My main reason for doing this mod is for when I use my 2m rig with a
Microwave Modules 2m-70cm transverter - the 432 MHz band is much bigger
than the previously limited 2MHz range of my transceiver.

Thanks again,
James.
-----------------------------------------------------------------------------
James Macfarlane G7NOY, Faculty of Engineering, University of West of England,

Bristol. [e-mail] URL: http://www.gbnet.net/orgs/aspire
Opinions expressed are my own, not those of my employer, etc, etc.
-----------------------------------------------------------------------------
I was told and I forgot. I saw and I remembered. I did and I understood.



From [e-mail] Sun Mar 24 17:27:39 1996
From: [e-mail](Wanda M Desmond)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: HF VFO design
Date: 21 Mar 1996 07:31:00 GMT
Message-ID: <4ir0jk$[e-mail]>
References: <[e-mail]> <4iojqa$[e-mail]> <4iqa79$[e-mail]>

>>   Isaac Kohn <[e-mail]> wrote:
>>
>>>Hi all.  I am starting my first major ham homebrew transmitter.  I
>>>need to design a VFO that is reasonably stable from 1.8-30 Mhz at
>>>least, simply switching tuned elements for different bands.  I would

>>>prefer that it be as simple as possible.  Impedance/power-level
>>>shouldn't matter, because I plan to buffer it.  Is this possible??
>>>Has anyone ever built such a broadband VFO??  Please help.

73 Magazine (I think) did an article on a digital VFO a few months ago
(I can't find it right now). It used the Analog Devices AD7008 CMOS DDS
Modulator. It covered the complete HF band. Go to AD's Web site and get
a copy of the data sheet.

In the article, the author was selling a kit to build the VFO.

Sorry I can't find the magazine.

John
KE6TGN


From [e-mail] Sun Mar 24 17:27:40 1996
From: Isaac Kohn <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: HF VFO design
Date: Wed, 20 Mar 1996 13:45:37 -0600
Message-ID: <[e-mail]>

Thanks a lot to everybody who answered and helped me on this!!

73's
Isaac


From [e-mail] Sun Mar 24 17:27:41 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: HF VFO design
Date: Sat, 23 Mar 96 00:46:17 GMT
Message-ID: <4ivhv5$[e-mail]>
References: <4ipknl$[e-mail]> <[e-mail]>

   [e-mail] (Dan Tayloe ) wrote:

>I found the amount of current through the pin diode had a *great*
>effect on the frequency of the VFO.  I tried a few approaches and
>came to the conclusion that the pin diode approach was going to have
>a major affect on the stability of my VFO.

It will effect a VCXO the same way.  My transceiver uses the CW
receive crystal in transmit by switching in a small variable cap to
produce transmit offset.  A switching diode "connects" the cap into
the circuit.

In one configuration of the mode switch, two 1N914 diodes were in
series with the switching diode and 9.8 volts was applied.  In another
position, only one 1N914 was in series and 10.5 volts was applied.
That slight difference in current through the switching diode in the
xtal oscillator (9 MHz) resulted in a frequency shift of about 75-100
Hz.

73,
Jack  WB3U


From [e-mail] Sun Mar 24 17:27:43 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Dan Tayloe )
Subject: Re: HF VFO design
Reply-To: [e-mail]
Date: Fri, 22 Mar 1996 15:04:34 GMT
Message-ID: <[e-mail]>
References: <4ipknl$[e-mail]>

>>Isaac Kohn ([e-mail]) wrote:
>>: Hi all.  I am starting my first major ham homebrew transmitter.  I need
>>: to design a VFO that is reasonably stable from 1.8-30 Mhz at least,
>>: simply switching tuned elements for different bands.  I would prefer
>>: that it be as simple as possible.  Impedance/power-level shouldn't
>>: matter, because I plan to buffer it.  Is this possible??  Has anyone
>>: ever built such a broadband VFO??  Please help.


>Build a VFO that uses diodes (PIN diodes if you can get ones with long
>enough lifetimes for HF use) to switch among a rather large number of
>fairly narrow frequency ranges.


I have attempted to use pin diodes to switch to various sections of the same
band (40M) so that I could use a varactor diode to tune over a more narrow
range.

I found the amount of current through the pin diode had a *great* effect on
the frequency of the VFO.  I tried a few approaches and came to the conclusion
that the pin diode approach was going to have a major affect on the stability
of my VFO.

Having said that, the pin diode switching does work quite well in a Phase lock
ed
VCO, since the loop tracks out the instability caused pin diode.


- Dan Tayloe, WB0NVB, Phoenix, AZ




From [e-mail] Sun Mar 24 17:27:44 1996
From: nickb@alpine (Nicholas Barbieri)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: lightning detector, how?
Date: 19 Mar 1996 18:14:26 GMT
Message-ID: <4imti2$[e-mail]>
References: <4i47l1$[e-mail]> <4iaslf$[e-mail]> <4ibmsv$[e-mail]> <[e-mail]>

: >very simple RDF system will give reliable results over thousands of
: >miles of ocean.  The 'Sferics detectors were simple shielded loop
: >antennas, one oriented N-S and the other E-W, tuned to resonance at
: >10-KHz.  Each developed a signal that was amplified by a three-stage
: >amplifier and the raw 10-KHz. outputs were put on the vertical and
: >horizontal plates, respectively, of a CRT.  A distant static crash would
: >cause a diagonal line to appear on the scope at an angle equal to the
: >azimuth, to a high degree of accuracy.

I saw a Discovery Channel program that says the researchers use 8 KHz.
Apparently, the US Forest Service monitors lightning strikes to get a
head start on forest fires.  Maybe it's correlated with satellite photos?

--
Nick Barbieri
Texas Instruments
ASIC Engineering
email: [e-mail]


From [e-mail] Sun Mar 24 17:27:45 1996
From: [e-mail] (Gordon Symonds)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: 21 Mar 1996 12:11:35 GMT
Message-ID: <4irh1n$[e-mail]>
Reply-To: [e-mail] (Gordon Symonds)

The Raytheon CK722 came in black, red silver, blue (at least).  You
could colour coordinate your radio!

The original packaging is a small cardboard envelope, abot 2" x 1".



From [e-mail] Sun Mar 24 17:27:46 1996
From: [e-mail] (Randall Gawtry)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: Sun, 17 Mar 96 04:55:15 GMT
Message-ID: <4ig5v5$[e-mail]>
References: <4i1vl3$[e-mail]> <[e-mail]> <4i7ppq$[e-mail]>

In article <4i7ppq$[e-mail]>,
   [e-mail] (Roy Lewallen) wrote:
>In article <[e-mail]>,
>   [e-mail] (Bill Meahan) wrote:
>>In article <4i1vl3$[e-mail]> [e-mail] writes:
>
>>Gee, I remember the CK722 as being made by Raytheon and in a silver
>>metal can that was of a rounded rectangular shape (kinda like a small
>>IF transformer) with three thin wire leads from a white insulator.
>> . . .
>
>Yep, Raytheon, and you've got the shape right. But they were blue. . .
>
>Roy Lewallen, W7EL, OF (don't ask)
>
> - who remembers when there were two available transistors, the CK722 (for
>$1) and CK721 (for $3). But $ were much bigger then. . .
The CK722 came in both an natural aluminum case and a blue case. I had one of
each when I was in 8th grade. But I broke the leads on the blue one and don't
have a clue where it or the other one went. When combined with a 1N34 diode
they sure beat a chunk of galena and a cats' whisker in a crystal radio.. I
still have the piece of galena!
73,
Randy Gawty, K0CBH


From [e-mail] Sun Mar 24 17:27:47 1996
From: Cecil Moore <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: 19 Mar 1996 17:58:26 GMT
Distribution: world
Message-ID: <4imsk2$[e-mail]>
References: <4i1vl3$[e-mail]> <[e-mail]> <4i7ppq$[e-mail]>

[e-mail] (Roy Lewallen) wrote:
> - who remembers when there were two available transistors, the CK722 (for
>$1) and CK721 (for $3). But $ were much bigger then. . .

I remember when CK722s were much more expensive around 1956. They gave
us a few in electronics lab at Texas A&M. Took us about 2 minutes to
blow them all to smithereens. The prof was extremely upset and we all
decided that transistors were a temporary fad and would never compete
with tubes.

73, Cecil, KG7BK, OOTC  (not speaking for my employer)




From [e-mail] Sun Mar 24 17:27:48 1996
From: Isaac Kohn <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Looking for schematics for Swan 350
Date: Fri, 22 Mar 1996 09:52:56 -0600
Message-ID: <[e-mail]>

What bands does the Swan 350 cover??  Does anyone have the schematic??
I'd pay cost of copying+shipping if you can send a copy to me.  Thanks.

73's
Isaac


From [e-mail] Sun Mar 24 17:27:49 1996
From: [e-mail] (Post Office)
Newsgroups: rec.radio.amateur.homebrew
Subject: NDN: Ham-Homebrew Digest V96 #118
Date: 19 Mar 96 07:56:01 GMT
Message-ID: <[e-mail]>
Reply-To: [e-mail]

Sorry. Your message could not be delivered to:

Leslie Dodd,Wellfleet London (Mailbox has been deleted. Try re-entering the
address.)



From [e-mail] Sun Mar 24 17:27:50 1996
From: [e-mail] (Timothy A. Smith)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: NDN: Ham-Homebrew Digest V96 #118
Date: 23 Mar 1996 01:06:33 GMT
Distribution: world
Message-ID: <4iviqp$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]


>Sorry. Your message could not be delivered to:
>
>Leslie Dodd,Wellfleet London (Mailbox has been deleted. Try re-entering the
>address.)
>






From [e-mail] Sun Mar 24 17:27:51 1996
From: [e-mail] (Timothy A. Smith)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: NDN: Ham-Homebrew Digest V96 #118
Date: 23 Mar 1996 01:08:01 GMT
Distribution: world
Message-ID: <4ivith$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]


>Sorry. Your message could not be delivered to:
>
>Leslie Dodd,Wellfleet London (Mailbox has been deleted. Try re-entering the
>address.)
>






From [e-mail] Sun Mar 24 17:27:51 1996
From: [e-mail] (VINY N1VC)
Newsgroups: rec.radio.amateur.homebrew
Subject: Need directional coupler
Date: 21 Mar 1996 12:50:38 -0500
Message-ID: <4is4te$[e-mail]>
Reply-To: [e-mail] (VINY N1VC)


Need coaxial microwave directional couplers down in the 2 ghz range.

Thanks beforehand

Viny Coppola



From [e-mail] Sun Mar 24 17:27:52 1996
From: [e-mail] (Stephen Schoonees)
Newsgroups: alt.engineering.electrical,alt.bbs.pcboard,alt.electronics.analog.vlsi,rec.radio.amateur.homebrew,sci.electronics.cad
Subject: Need electronic project - where kan I find projects on the Internet?
Date: Sat, 23 Mar 1996 13:26:01 GMT
Message-ID: <4j1c4a$[e-mail]>
Reply-To: [e-mail] (Stephen Schoonees)

Hi

  I'm a second year electronic student and need a project for one of
my subjects.

  It must be something that I can build, (a pcboard), thus easy enough
to understand the operation of the circuit. (more or less).  I've been
looking for a nice FM radio receiver (TDA7000 ?) to build but couldn't
find anything practical.  I'm interested in radio communications.  Any
FM receiver, practical to build will be nice.

  I'm still very new on the Internet (first month) so can anybody help
me finding or searching projects on the Internet?

  Thanks...
     Stephen.



From [e-mail] Sun Mar 24 17:27:56 1996
From: [e-mail] (VINY N1VC)
Newsgroups: rec.radio.amateur.homebrew
Subject: Need microwave attenuators
Date: 21 Mar 1996 12:51:57 -0500
Message-ID: <4is4vt$[e-mail]>
Reply-To: [e-mail] (VINY N1VC)


Need microwave coaxial attenuators fixed or stepping.
Thanks beforehand.

Viny Coppola


From [e-mail] Sun Mar 24 17:27:57 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (David Harmon)
Subject: Re: Need some coil winding data, please!!
Message-ID: <[e-mail]>
References: <4io1mi$[e-mail]> <4ipf93$[e-mail]>
Date: Thu, 21 Mar 1996 05:05:41 GMT

[e-mail] (patrick ferrick) wrote:
>
>I recall there being an equation in my old ARRL handbook (which I
>have lost track of since I moved last)  relating coil size, number of
>turns and I think wire guage.

Excerpted from comp.archives.msdos.announce:

 50126 Feb 28 14:05 ftp://garbo.uwasa.fi/pc/ham/coil01.zip

: This program computes the electrical self inductance of various shapes
: and sizes of air core coils, using accurate formulae from U. S. Bureau
: of Standards circulars and the physics literature.  Geometries treated
: are: straight round wire, circular solenoidal current sheet, N-turn
: circular loop, circular toroid with circular winding, multi-layer
: square solenoid, circular torus ring with rectangular winding,
: multi-layer circular solenoid, single-layer circular solenoid of round
: wire, single-layer square solenoid, and wire gauge calculation.  For
: non-U.S. users this version includes a new menu item to switch between
: metric and English dimensional units.


From [e-mail] Sun Mar 24 17:27:58 1996
From: Ken Burtchaell <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: PCB design software
Date: 21 Mar 1996 02:11:08 GMT
Message-ID: <4iqdrs$[e-mail]>
References: <3139888f.382937@194.72.192.4> <4i5dj5$[e-mail]> <[e-mail]> <4ikkhp$[e-mail]> <[e-mail]>
To: [e-mail]

I agree Paintbrush is quite adequate for boards I make,which basically 50
ohm lines.  73 Ken



From [e-mail] Sun Mar 24 17:27:59 1996
From: Norman Kohn <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: SSB generation/crystal filters
Date: Fri, 22 Mar 1996 09:38:29 -0600
Message-ID: <[e-mail]>

G'morning all,

        Is it possible at all to make a filter (presumably using
crystals) that cuts off sharply enough (at 1000Khz) to pass one
sideband, but not the other?? In other words, is it practical to assume
I can find/build a HP and a LP filter for USB and LSB at an IF of 1
Mhz??

        If this isn't practical, I have another potential plan that
ought to be inexpensive and relatively effective, IF it works.  That is,
could I have a quadrupler (or higher multiplication) at AF level, then
mix with 4 Mhz, then filter for sidebands -- 4 times less sharpness
needed -- and then divide by 4??  Or would AF multiplier distort voice
too much??

Thanks to all for helping, and 73's,
Isaac K.


From [e-mail] Sun Mar 24 17:28:00 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Gary Coffman)
Subject: Re: Stupid Qustion
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
References: <[e-mail]> <4i65dd$[e-mail]> <[e-mail]> <4i7d6q$[e-mail]> <4i9vtr$[e-mail]> <4ibfu6$[e-mail]>
Date: Wed, 20 Mar 1996 17:41:31 GMT

In article <4ibfu6$[e-mail]> [e-mail] (Elendir) writes:
>Dave Curtis ([e-mail]) wrote:
>: Always one to avoid gratuitous mathematics, I believe all the quantum
>: physics one needs to know about antennas is:
>:   "Accelerate an electron, get a photon.  It's the law."
>
>Well. It's not that simple. Otherwise the simple cathodic display you
>are using would be a formidable source of RF energy !!!!! You get a
>photon when you use alternative current.

Is that like alternative energy? (Sorry couldn't resist.)

You most certainly do get radiation when you accelerate a charge,
even in a CRT. The amount and frequency of the radiation depend
on several other factors, however. One major factor is current,
and beam current in ordinary CRTs is tiny. Another factor is the
amount of acceleration. In a CRT there are four separate accelerations,
beam accleration, beam decleration, and horizontal and vertical beam
deflection. Of these, beam deceleration is the most intense, and
generates soft X-rays. Beam acceleration is second most intense,
and generates millimeter wave radiation. Deflection is least intense,
but more gross, and generates radiation at the frequencies which
are reciprocals of the deflection timing, IE for ordinary NTSC TV
CRTs that's 15.749 kHz and 59.94 Hz. Very little of the latter
propagate out of the tube due to the small coupling area with
respect to a wavelength (most of the interference generated at
these frequencies comes from the H fields of the magnetic deflection
coils outside the envelope (amperes of current flow in these coils),
and not from the beam itself).

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Sun Mar 24 17:28:01 1996
From: [e-mail] (MAILLET D.)
Newsgroups: rec.radio.amateur.homebrew
Subject: tube CFTH   TH3T  1100   info?
Date: 21 Mar 1996 13:32:12 GMT
Message-ID: <4irlos$[e-mail]>

pse help me for info
this tube HF  CFTH  THT3  1100
carracteristique, tension ....
tnx
[e-mail]




From [e-mail] Sun Mar 24 17:28:02 1996
From: [e-mail] (gudmundur)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Various transmitter-design questions
Date: 22 Mar 1996 03:10:54 GMT
Message-ID: <4it5nu$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>,
[e-mail] says...
>
>A few more questions here.  Seeing as a multi-octave VFO is
impractical,
>I'm designing a super-het transmitter.  I want to cover most-all of
the
>HF range.  The way I'm currently thinking about doing it is:

Why such a complicated approach to this project? For ham coverage only
look at a Swan 350 Schematic and improvise. For a general coverage
application read the circuit descriptions in the owners manual of a
Yaesu 747 or similar. Wide band is easier than you think, and you need
not re-invent the wheel. 73 and good luck.  KD3SH



From [e-mail] Sun Mar 24 17:28:03 1996
From: [e-mail] (VINY N1VC)
Newsgroups: rec.radio.amateur.homebrew
Subject: Want HP415 meter
Date: 21 Mar 1996 12:48:29 -0500
Message-ID: <4is4pd$[e-mail]>
Reply-To: [e-mail] (VINY N1VC)


Need HP415 SWR meter.
Thanks for reading

Viny Coppola


From [e-mail] Sun Mar 24 17:28:04 1996
From: [e-mail] (Harry H. Brown)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: WTB: copy of QEX article
Date: 22 Mar 1996 19:25:16 GMT
Distribution: world
Message-ID: <4iuuqs$[e-mail]>
References: <4ipmco$[e-mail]>
Reply-To: [e-mail]


Jim, I have a copy of it.

Send me your address and I will send a copy of it. This subject came up someti
me last fall and I remember talking with someone about it. Was it you? At the
time, I didn't know where it was but did find it last week.

 73, Harry, W3IIT





From [e-mail] Sun Mar 24 17:28:05 1996
From: "Mr. Brooke Clarke" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: WWV radio clock decoding???
Date: Mon, 18 Mar 1996 18:17:29 -0800
Message-ID: <[e-mail]>
References: <4i9pt9$[e-mail]> <4ib6u4$[e-mail]>
To: [e-mail]

William W Janssen wrote:
>
> nickb@alpine (Nicholas Barbieri) wrote:
> >Does anybody know how radio clocks like the Heath Most Accurate Clock
> >decode the WWV signals?

Although Heathkit no longer is in the general kit business, they are
still in the education business.  One of their products is an updated
version of the GC-1000 along with a remote clock that is driven from  it.
 I forget if they are available as kits, but I expect that the manuals
are available.

Have Fun,
Brooke




From [e-mail] Sat Mar 30 14:40:15 1996
From: Cliff Goodman <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: *BEGINER IN RADIOS* NEED HELP
Date: 28 Mar 1996 03:28:48 GMT
Message-ID: <4jd11g$[e-mail]>


       I am thinking about creating radio station later on in my life but
I would like to learn as much as possible about it right now, so if any
of you guys could tell me about the real basics of starting a radio
station or even give me the titles to some goos books to read about it.
    any info is greatly appreciated,




From [e-mail] Sat Mar 30 14:40:16 1996
Newsgroups: rec.radio.amateur.homebrew
Subject: 10 Ghz Gunplexers
Message-ID: <1996Mar25.100441.1531@batman>
From: [e-mail]
Date: Mon, 25 Mar 1996 17:06:26 GMT
Reply-To: [e-mail]

I am trying to locate the 73 magazine articles that describe using two
gunnplexers as a high speed data link for packet.

Any help would be appreciated.
Thanks
Byron WB7ACJ



From [e-mail] Sat Mar 30 14:40:17 1996
From: [e-mail] (VINY N1VC)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 10 Ghz Gunplexers
Date: 25 Mar 1996 23:38:16 -0500
Message-ID: <4j7sbo$[e-mail]>
References: <1996Mar25.100441.1531@batman>
Reply-To: [e-mail] (VINY N1VC)

Wasn't that in Ham Radio mag? Late 80's I think. It also is described in
the 1992
Radio Amateur Handbook.

REgards,
Viny Coppola


From [e-mail] Sat Mar 30 14:40:18 1996
From: Zack Lau <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 10 Ghz Gunplexers
Date: Tue, 26 Mar 1996 10:05:38 -0500
Message-ID: <[e-mail]>
References: <1996Mar25.100441.1531@batman>
To: [e-mail]

[e-mail] wrote:
>
> I am trying to locate the 73 magazine articles that describe using two
> gunnplexers as a high speed data link for packet.
>
> Any help would be appreciated.
> Thanks
> Byron WB7ACJ

try this link:

ftp://col.hp.com/hamradio/packet/n6gn/uwavelink/uwv.html

Zack KH6CP/1


From [e-mail] Sat Mar 30 14:40:19 1996
From: Markus Buehler <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: 10m Repeater Switzerland HELP wanted
Date: Fri, 22 Mar 1996 19:47:01 -0800
Message-ID: <[e-mail]>

Hello thank you for reading this message:
We, a small group of ham operators, will build a 10m repeater.
Both RX and TX are located up at about 2000 meters in the swiss
mountains.
A 10 watt beacon is ready to put up to the tx location. We are only
waiting for warmer weather conditions. It will operate on 29.660 mc.
What we are looking for:
Are there 10 m repeaters at such high locations in the united states
or else where ?
We are interested in what kind of antennas where used.
Also the lightning protection is a big problem.
Which kind of tx and rx constructions are the best for 10m
repeaters.
Any other tips are real welcome.
Thanks a lot.
Marc   HB9CPW


From [e-mail] Sat Mar 30 14:40:20 1996
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: 40m QRP transmatch ideas ??
Date: Sun, 24 Mar 96 21:46:06 GMT
Message-ID: <4j4fp1$[e-mail]>
References: <4isu0p$[e-mail]>

In article <4isu0p$[e-mail]>,
   Michelle Nicolls <[e-mail]> wrote:
>Does anyone have any ideas for a cheap, very compact, cheap,
> homebrewable
>cheap, Qrp transmatch for 40 meters? I just built a NN1G 40-40 and would
>like to build a matching tuner. Any other neet little QRP projects would
> also be of interest.
>                        Thank you, Troy Nicolls
>
>32 yrs old and still cant type!

_Solid State Design for the Radio Amateur_, p. 167, Fig. 60. Delete the 75
pF fixed capacitor. Reducing the inductance by a factor of two and
increasing the variable caps about the same amount will reduce the loss,
although it's not bad on 40 m. (I use this design with additional inductors
switched in parallel with L1 for use up to 15 m.) Adding a 33k or so
resistor from the wire connecting the switch sections to the top of the 27
ohm resistor will give you a meter deflection when in the OP position, so
you have an indication of tx output.

I've used this circuit for many years.

Roy Lewallen, W7EL


From [e-mail] Sat Mar 30 14:40:21 1996
From: [e-mail] (Mike Klopfer)
Newsgroups: rec.radio.amateur.homebrew,sci.physics.electromag
Subject: 6 or 7 port reflectometer for getting s parameters
Date: 26 Mar 1996 22:15:16 -0600
Message-ID: <4jafck$[e-mail]>

I've been looking at some articles on 6/7 port reflectometers. I'm wondering
if anyone has used such a device to get s parameters of a device. I'm
looking for an inexpensive alternative to a network analyser. Several of
the articles have mentioned using the method of "sliding terminations" to
calibrate these. Does this method involve the use of another calibrated
device to calibrate the reflectometer? Are there inexpensive devices that
have a variable calibrated impedance in the 1-10GHz range? One article on
calibration of these reflectometers had a diagram with one block for a
variable phase shifter and on block for a variable attenuator. Does anyone
have a suggestion for specific devices that could be used for these
functions. Thanks for the help.

mike



From [e-mail] Sat Mar 30 14:40:22 1996
From: [e-mail] (Mike Klopfer)
Newsgroups: rec.radio.amateur.homebrew,sci.physics.electromag
Subject: Re: 6 or 7 port reflectometer for getting s parameters
Date: 28 Mar 1996 21:06:53 -0600
Message-ID: <4jfk4d$[e-mail]>
References: <4jafck$[e-mail]> <4jej8b$[e-mail]>

A recent article about these reflectometers is in IEEE trans. Instruments and
Measurement vol 45, no 1 Feb 1996. I don't understand enough of the terminolog
y
for this to help me but it has references. I was looking at the Dec. 1977 issu
e
of IEE Trans. Microwave Theory and Techniques. This has several articles on
6 port reflectometers and some look like good introductions to calibration.
There's a Dec 1991 article of IEEE T I & M that's titled "A wideband millimete
r
wave six port reflectometer using four diode detectors calibrated without a
power ratio standard" which I haven't read but the title gives me hope that
this can be calibrated without requiring the use of any calibrated device.

mike



From [e-mail] Sat Mar 30 14:40:23 1996
Newsgroups: rec.radio.amateur.homebrew,sci.physics.electromag
From: [e-mail] (Dan Swanson)
Subject: Re: 6 or 7 port reflectometer for getting s parameters
Message-ID: <[e-mail]>
References: <4jafck$[e-mail]> <4jej8b$[e-mail]>
Date: Thu, 28 Mar 1996 22:34:55 GMT

I once made a six port reflectometer.  You can make a six port coupler.
It is a 3D object. Imagine two Y-junctions stacked above each other and
separated by lambda/4.  Then connect the ends of those 3ports together
with 25 ohm line(2 50 ohm lines in parallel.) The six outputs come of
the edge of the boards that the Y-junctions are printed on.

This actually worked as reflectometer. Put source at one port. One diode
detector goes to X-axis of scope, One diode detector to Y-axis of scope.
One port to unknown, remaining ports terminated.

A sliding line with short circuit at end traces a perfect circle (the
outer edge of the Smith chart.

Got the coupler idea from old MTT article. May be able to find it.

Dan


======================================================
| Dan Swanson           | EMAIL: [e-mail] |
| Watkins-Johnson Co.   |        [e-mail]  |
| 3333 Hillview Ave.    |   TEL: [phone]        |
| Palo Alto, CA  94304  |   FAX: [phone]        |
======================================================


From [e-mail] Sat Mar 30 14:40:25 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: >>>>HELP - Small VHF Xmitter for Airborne Telemetry<<<<
Date: Tue, 26 Mar 1996 12:25:10 -0800
Message-ID: <[e-mail]>

Can someone help me by pointing me to a schematic or an article of a small VHF
 transmitter? It is
to be used to relay telemetry from a series of high altitude rockets. Followin
g are the (desired)
specs:

Frequency:      2m band or nearby; XTAL controlled;
RF Power:       50-250 mW output;
Supply:         9-12 VDC (battery);
Modulation:     N/A

Complexity (ie. size and weight) should be as low as possible, as should the c
ost - lets face it -
the typical life of these devices will be measured in minutes. I would preffer
 to build the
xmitters myself as integral part of a telemetry package.

I have hundreds of various scanner crystals that fit in this category. They ha
ve fundamental
frequencies around 16MHz, but I don t really know if I can use them for this p
roject.

I would very much appreciate any help in this matter. I can be also reached at

        mailto:[e-mail]

My thanks to all those who reply!

73s

Chris (WR1F)


From [e-mail] Sat Mar 30 14:40:26 1996
From: Will Flor <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: >>>>HELP - Small VHF Xmitter for Airborne Telemetry<<<<
Date: 27 Mar 1996 18:46:14 GMT
Message-ID: <4jc2dm$[e-mail]>
References: <[e-mail]>

[e-mail] wrote:
>Can someone help me by pointing me to a schematic or an article of a small VH
F transmitter? It is
>to be used to relay telemetry from a series of high altitude rockets. Followi
ng are the (desired)
>specs:
>
>Frequency:     2m band or nearby; XTAL controlled;
>RF Power:      50-250 mW output;
>Supply:                9-12 VDC (battery);
>Modulation:    N/A
>
>Complexity (ie. size and weight) should be as low as possible, as should the
cost - lets face it -
>the typical life of these devices will be measured in minutes. I would preffe
r to build the
>xmitters myself as integral part of a telemetry package.
>

   The common "wireless mike" kits that are pretty commonly available for the
FM broadcast band are, I believe, also available for the 2m band.  Some of
these kits have power outputs in the lower end of the power range you're
looking for, and can be powered with 9V batteries.
   Have you looked for ads for these cheap, easy-to-assemble kits?  I know tha
t
they're available in the frequency range you're looking for, but I don't
remember which manufacturer offers them there.  Ramsey, perhaps?

73 de Will KB9JTT




From [e-mail] Sat Mar 30 14:40:27 1996
From: Mike Sims <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Amp. Tank Circuit
Date: Thu, 28 Mar 1996 19:06:22 -0500
Message-ID: <[e-mail]>

Situation is a 4CX1600 amp. using a pi/L tank.  The amp./tank circuit
works okay on 20, 15 and 10 meters (efficiency).  However, on 40 and
80ty meters the efficiency is way off and the output capacitor on the
tank circuit are at max. capacity.  I have padded additional capacitance
across the output capacitor to above the calculated value.  The tank's
input capacitance tunes the band okay.  The amp. has been tried at the
upper and lower end of 80ty and 40ty.  The amp. is working into a big
dummy load (five gallons of transformer oil with two 15 inch non
inductive 100 ohm resistors in parallel in the oil).

The L or output coil is made of a small air wound coil for ten meters
and a coil wound on three T200-6 toroids using number 12 wire.  The
inductance and appropriate taps was measured using a Autek Analyzer at
the frequency of use.

Will be trying an air core coil on forty meters to see if the toroid is
causing the problem.

Any answers of suggestions?

        Mike, K4GMH


From [e-mail] Sat Mar 30 14:40:28 1996
From: [e-mail](Glenn Sparks)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Baycom TNC
Date: 25 Mar 1996 19:12:37 GMT
Message-ID: <4j6r75$[e-mail]>
References: <4iru7a$[e-mail]>

Baytek is a software packages that uses a very simple modem.  The
schematics for it are included in the documentation I beleive.  I have
also seen old Bell 202 modems converted for baycom use.

SParky  KI5GY


In <4iru7a$[e-mail]> [e-mail] (Bobby Ratliff)
writes:
>
>Does anyone know where I can get the prints for a baycom clone?  I am
>wanting to build my own tnc and can't seem to find the prints
anywhere.
>
>Thanks,
>
>Bobby R. Ratliff
>KD4MKB
>[e-mail]
>[e-mail]
>



From [e-mail] Sat Mar 30 14:40:31 1996
From: jessica <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Baycom TNC
Date: 26 Mar 1996 01:06:35 GMT
Distribution: world
Message-ID: <4j7fus$[e-mail]>
References: <4iru7a$[e-mail]>

hi name is toby... n9fdf.... i have print for both baycom modem
 the one that use 7910 ic and one that use the xr2211 and xr 2206..
 if you want them let me know...
73 n9fdf. toby.




From [e-mail] Sat Mar 30 14:40:32 1996
From: Bill Nadzam <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: CB to 10m Conversion
Date: Fri, 22 Mar 1996 10:20:07 -0800
Message-ID: <[e-mail]>
References: <[e-mail]>
To: Shelby Merrick <[e-mail]>

I can help you with this, but you'll need to choose a radio. There
are many CB's that will work well as 10 Meter radios, but each has
it's own conversion technique. So what is the radio? Keep in mind
that the most modern designs can not be modified. That was done
so that the CB crowd would not jump over their 40 channel limits.
the older designs could be modified very easy, and allow you to get
up on the 10 meter band. Some of those radios are still sold today.
One is the Cobra 148GTL and the Uniden Grant XL.

> Does anyone have some pointers on modifying a cb for 10m output?  Would
> one have to use transverters of some sort, or could you tune the radio
> internally down to 10m?  I have a couple of rat shack 11m good for
> nothing cb's laying around and need a use for them.  Thanx in advance.--
----------------------------------------------
Name: Bill Nadzam "K8WN"
E-mail: [e-mail] (Bill Nadzam)
----------------------------------------------


From [e-mail] Sat Mar 30 14:40:32 1996
From: [e-mail] (John Kolb)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: CB to 10m Conversion
Date: 21 Mar 1996 01:48:23 GMT
Message-ID: <4iqch7$[e-mail]>
References: <[e-mail]>

Shelby Merrick ([e-mail]) wrote:
: Does anyone have some pointers on modifying a cb for 10m output?  Would
: one have to use transverters of some sort, or could you tune the radio
: internally down to 10m?  I have a couple of rat shack 11m good for
: nothing cb's laying around and need a use for them.  Thanx in advance.

There were lots of articles int 73 Magazine in the early 80's
on converting different CB rigs to 10 meters. Basicly they all
involve studying the block diagram of the rig, changing one
or more of the crystals, and perhaps re-tuning some of the
tuned circuits.

Start by buying the service manual for the particular CB you have
to get the detailed theory of operation of the synthesizer involved.

John Kolb



From [e-mail] Sat Mar 30 14:40:33 1996
From: [e-mail] (MAILLET D.)
Newsgroups: rec.radio.amateur.homebrew
Subject: CFTH tube info
Date: 28 Mar 1996 17:52:51 GMT
Message-ID: <4jejlj$[e-mail]>

hello;
does anyone have the specs on  an CFTH tube
ref: TH3T 1100

                        thanks in advance.




From [e-mail] Sat Mar 30 14:40:34 1996
From: [e-mail] (Alan Peake)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Conversion of noise voltage into noise figure ?
Date: Mon, 25 Mar 1996 10:15:11
Message-ID: <[e-mail]>
References: <4im80h$[e-mail]> <4io1df$[e-mail]>


>NF = 10 log[(Eni^2) / (Et^2)]

>   = 10 log[(Et^2 + En^2 + (In^2 * Rs^2)) / (Et^2)]

In a 50 ohm RF system, I find the following useful:

input noise power( in dBw) =
 -174 + 10*log10(Bandwidth) + 10*log10(Noise Factor - 1)

Noise Factor is 10*log10(Noise Figure)
-174 + 10*log10(Bandwidth) is the noise in 50 ohms at room temp.

e.g. for a system with 2dB noise figure and 2400 Hz bandwidth,
the input referred noise is

-174 + 33.8 - 2.3 = -142.5 dBw or -112.5 dBm which is about .53 uV rms


Alan





From [e-mail] Sat Mar 30 14:40:36 1996
From: George Harris <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew,rec.radio.cb,rec.radio.swap
Subject: Counter Help
Date: 26 Mar 1996 14:34:24 GMT
Message-ID: <4j8v9g$fcq$[e-mail]>

Hi,

I've just purchased a Heath Co. Model SM-105A Counter at a
HamFest.
Could anybody help me with a schematic for this unit? Does anyone
know where I can find LED display parts for this unit?  I would
greatly appreciate it for any help on this subject.

73's

Thunder

--
Don't do anything that I wouldn't, At least don't get CAUGHT!!!!


From [e-mail] Sat Mar 30 14:40:37 1996
From: Clifford Buttschardt <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Crystal Parameters
Date: Tue, 26 Mar 1996 19:07:48 -0800
Message-ID: <[e-mail]>
References: <4j7gjc$[e-mail]>

Hi Simon....that's tough!  During WW2 there were a number of crystal
bridges around that might be had.  Modern test equipment for crystal
manufacture is available but rather costly.  You might be best to look
for one of these older crystal bridges..Cliff Buttschardt  W6HDO

On Tue, 26 Mar 1996, M Simon wrote:

>
> How can I measure the L & C values for a quartz crystal.
>
> R is easy but L & C stump me.
>
>
> Simon
>
>
>


From [e-mail] Sat Mar 30 14:40:37 1996
From: [e-mail] (M Simon)
Newsgroups: rec.radio.amateur.homebrew
Subject: Crystal Parameters
Date: Tue, 26 Mar 1996 01:17:37 GMT
Message-ID: <4j7gjc$[e-mail]>


How can I measure the L & C values for a quartz crystal.

R is easy but L & C stump me.


Simon



From [e-mail] Sat Mar 30 14:40:39 1996
From: [e-mail] (M Simon)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Crystal Parameters
Date: Wed, 27 Mar 1996 14:28:21 GMT
Message-ID: <4jbja3$[e-mail]>
References: <4j7gjc$[e-mail]> <[e-mail]>

Clifford Buttschardt <[e-mail]> wrote:

>Hi Simon....that's tough!  During WW2 there were a number of crystal
>bridges around that might be had.  Modern test equipment for crystal
>manufacture is available but rather costly.  You might be best to look
>for one of these older crystal bridges..Cliff Buttschardt  W6HDO

>On Tue, 26 Mar 1996, M Simon wrote:

>>
>> How can I measure the L & C values for a quartz crystal.
>>
>> R is easy but L & C stump me.
>>
>>
>> Simon

Thanks for the reply. What I was looking for is a circuit or
theory of operation.

I can design a test set based on the above info. A tube version
would be OK. I can translate.

Simon


... How many Zen Masters does it take a light bulb to change?

None, the Master say, en-LIGHT-enment should come from within.







From [e-mail] Sat Mar 30 14:40:39 1996
From: Zack Lau <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Crystal Parameters
Date: Wed, 27 Mar 1996 21:13:56 -0500
Message-ID: <[e-mail]>
References: <4j7gjc$[e-mail]>
To: M Simon <[e-mail]>

M Simon wrote:
>
> How can I measure the L & C values for a quartz crystal.
>
> R is easy but L & C stump me.
>
> Simon

Try measuring the unloaded Q.  You should then be
able to calculate L and C.

Zack KH6CP/1.


From [e-mail] Sat Mar 30 14:40:40 1996
From: [e-mail] (K2EK)
Newsgroups: rec.radio.amateur.homebrew
Subject: Digital Voltmeter circuit needed
Date: 26 Mar 1996 10:52:32 -0500
Message-ID: <4j93s0$[e-mail]>

Hello -

I would like to use digital display for an az-el rotator system.  What is
needed are 2 dedicated
DVMs capable of reading 3.60 and 9.00 volts respectively... Obviously I do
not want to tie up
multiple DVMs.  Seven segment LED display would be ideal.

From what I have found on my own, it looks fairly simple using an A/D
converter and PC.  Close,
but still not practical.

Does anyone have a handy volt meter circuit for driving LED (or LCD)
displays from an A/D - or
point me in the right direction?

Are there alternatives?  I thought about using a timer chip and counter.
But that seems overly
complicated and harder to calibrate.

Thanks...

Bill  K2EK


From [e-mail] Sat Mar 30 14:40:41 1996
From: [e-mail] (PFZouave)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Digital Voltmeter circuit needed
Date: 26 Mar 1996 17:54:43 -0500
Message-ID: <4j9sjj$[e-mail]>
References: <4j93s0$[e-mail]>
Reply-To: [e-mail] (PFZouave)

If you really like to "roll your own", you can knock something together
with some A/D chips and a couple of displays. You might be able to cobble
something together with a Parallax Basic Stamp and an LCD display from
Scott Edwards.(Computer control might be nice. The chip has simple A/D
capabilities.) Or, you could just BUY two digital panel meters from
someone...Digikey carries 'em, I know.
/=====================================================/
/                                [e-mail]
                   /
/     The absurdity of a claim is not a valid measure of its probability
       /
/=====================================================/


From [e-mail] Sat Mar 30 14:40:42 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Mark Zenier)
Subject: Re: Digital Voltmeter circuit needed
Message-ID: <[e-mail]>
References: <4j93s0$[e-mail]>
Date: Tue, 26 Mar 1996 20:22:35 GMT

in <4j93s0$[e-mail]>, K2EK wrote:
: I would like to use digital display for an az-el rotator system.  What is
: needed are 2 dedicated
: DVMs capable of reading 3.60 and 9.00 volts respectively... Obviously I do
: not want to tie up
: multiple DVMs.  Seven segment LED display would be ideal.

Why not, you can get digital panel meters or radio shack grade
pocket DVMs real cheap.  Jameco has some LCD DPMs for $15 in the
last catalog I checked.  Bound to be some LED units in the surplus
market.

If you want to roll your own, the common DVM chips are the 7106, 7107,
'16, '17, '26 from Harris (formerly Intersil), Telcom (formerly Teledyne
Semi.) and Maxim.  (Digikey sell both Harris and Telcom, about $5 for the
chip.)   One type is has a multiplexed LED driver (the '7 chips) , the
other drives LCD displays (the '6 chips).  These are 2000 count dual
slope integration method voltmeters in a single chip.  Good for +/-
2.000 volt or 200.0 mV as normally used, but you can use another
reference voltage and get any calibration you want within the chip's
range, and divide it down if it's bigger.  Be aware, the datasheets on
these chips are kind of murky.

Harris has a good web site (I think it's www.semi.harris.com).

Mark Zenier  [e-mail]  [e-mail]



From [e-mail] Sat Mar 30 14:40:43 1996
From: [e-mail] (John Lumkes)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Digital Voltmeter circuit needed
Date: 26 Mar 1996 22:28:31 GMT
Message-ID: <4j9r2f$[e-mail]>
References: <4j93s0$[e-mail]>

I would like to use digital display for an az-el rotator system.  What is

needed are 2 dedicated

DVMs capable of reading 3.60 and 9.00 volts respectively... Obviously I do

not want to tie up

multiple DVMs.  Seven segment LED display would be ideal.



Try National's LM3914 10 segment LED driver. You just need the chip,
some resistors, and a 10 segment LED display (Radio shack has them)
and your set to go. I think I saw a design using this in last years
73' (I think, I can look it up if you want). JDR carries the chip for
just over $2. I also have a book "Intro to Op-Amps" which shows
the circuit. If you want more info feel free to email me.

Thanks, John
[e-mail]
AA9QP



From [e-mail] Sat Mar 30 14:40:44 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Michael L. Ardai)
Subject: Re: Digital Voltmeter circuit needed
Message-ID: <[e-mail]>
References: <4j93s0$[e-mail]>
Date: Tue, 26 Mar 1996 19:45:10 GMT

In article <4j93s0$[e-mail]> [e-mail] (K2EK) writes:
-Hello -
-
-I would like to use digital display for an az-el rotator system.  What is
-needed are 2 dedicated
-DVMs capable of reading 3.60 and 9.00 volts respectively...

There are tons of surplus panel-mount digital meters out there for about
$10-$15 out there.  Even Rat Shack has one (277-303, RSU11461498) for $19.
Look in the back of Popular Electronics or Electronics Now...

These are all digital voltmeters with a 0-199mV range.  Just feed it
with a resistive divider to scale it.  It's a lot easier than building your
own.  If you reall want to build one, look at the old Intersil 7106 and
7107 chips; that's what is used in most of those panel meters,

/mike
--
\|/     Michael L. Ardai        N1IST       [e-mail]     \|/
-*- --- Boston Amateur Radio Club:  http://www.barc.org/barc --- -*-
/|\        or send "info barc-list to [e-mail]        /|\


From [e-mail] Sat Mar 30 14:40:45 1996
From: [e-mail] (Curtis, Charles)
Newsgroups: rec.radio.amateur.homebrew
Subject: RE: Digital Voltmeter circuit needed
Date: 27 Mar 96 22:07:00 GMT
Message-ID: <[e-mail]>


>Date: 26 Mar 1996 10:52:32 -0500
>From: [e-mail] (K2EK)
>Subject: Digital Voltmeter circuit needed
>
>Hello -
>
>I would like to use digital display for an az-el rotator system.  What is
>needed are 2 dedicated
>DVMs capable of reading 3.60 and 9.00 volts respectively... Obviously I do
>not want to tie up
>multiple DVMs.  Seven segment LED display would be ideal.

Try Stock # 7515-ME, LED Panel Volt Meter from Marlin P. Jones & Assoc. Inc.
1-800-652-6733 to order.  1-407-848-8236 for info.  Listed at $11.95 ea.
These are compact 3-1/2 digit, LED voltmeters, 0-200 mVDC full scale, 7-12
VDC powered.  You can easily add scaling resistors to suit your voltage
measurement requirements.  I have never purchased these.  Other sources do
exist for similar devices.  This was simply the first catalog that I
happened to locate them in for you.

73 de Chuck, N2UCN


From [e-mail] Sat Mar 30 14:40:46 1996
From: [e-mail] (David DiGiacomo)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Digital Voltmeter circuit needed
Date: 29 Mar 1996 21:23:19 GMT
Message-ID: <4jhkc7$[e-mail]>
References: <4j93s0$[e-mail]> <[e-mail]>

In article <[e-mail]>,
Mark Zenier <[e-mail]> wrote:
>in <4j93s0$[e-mail]>, K2EK wrote:
>: I would like to use digital display for an az-el rotator system.  What is
>: needed are 2 dedicated
>: DVMs capable of reading 3.60 and 9.00 volts respectively... Obviously I do
>: not want to tie up
>: multiple DVMs.  Seven segment LED display would be ideal.
>
>Why not, you can get digital panel meters or radio shack grade
>pocket DVMs real cheap.  Jameco has some LCD DPMs for $15 in the
>last catalog I checked.  Bound to be some LED units in the surplus
>market.

A lot of vendors have the "PM128" LCD DPMs for about $10.  Circuit
Specialists also has the "PM129" LED version for $11.50.

I think these units use the 7126/7127.  Note, they don't have a negative
supply generator, so the common mode input range does not extend to the
negative supply.

Circuit Specialists, Inc.
P.O. Box 3047
Scottsdale, AZ 85271-3047
[phone]
[phone]
[phone] fax
http://www.cir.com/about/about.htm


From [e-mail] Sat Mar 30 14:40:48 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: diplexer design
Date: Mon, 25 Mar 1996 21:18:05 GMT
Message-ID: <4j75pc$[e-mail]>

the project I am working on requires a diplexer to be designed:



Transmitter:

                            ____   /|
                           |          |/ |
                           |             |           <--horn antenna
                           |____ |\ |
                               ||       \|
                               ||
                               ||
                               ||
                               ||                   <--    coax
                               ||                    (tower)
                               ||
                       ___ ||____
                      |                 |
                      |                 |            <--   Diplexer
                      |________|
                        ||          ||
                        ||          ||
                    __||__   _ ||___
                    |         |   |          |      <--transmitters
                    |____|   |____ |

                 XMTR#1  XMTR #2


In this system, the outputs of two transmitters operationg at
different frequencies are combined using a device known as a
"diplexer", are sent up a long cable to the top of the tower, and are
transmitted using a horn.

The diplexer, to operate, must take energy from transmitter #1 and
deliver it to the antenna, without letting any enrgy get to
transmitter #2, and vice versa.

What I was wondering is how a diplexer design can be acheived.  That
is after BP filtering the desired frequencies from each transmitter
with parallel stubs, can I just connect the two XMTR output lines and
expect them to mix?


Thanks for responding.


 >
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx




From [e-mail] Sat Mar 30 14:40:49 1996
From: [e-mail] (Tom Bruhns)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: diplexer design
Date: 28 Mar 1996 17:44:55 GMT
Message-ID: <4jej6n$[e-mail]>
References: <[e-mail]>

Gary Coffman ([e-mail]) wrote:

: A diplexer consists of a high pass and a low pass filter with their
: outputs Teed together to feed the antenna. The theory is that each
: filter presents a very high impedance at the other frequency, so that
: it beomes essentially "not there" to the other signal. Thus the signals
: behave as if they were directly connected between the antenna and
: their respective radios. The filters may require additional stopband
: elements for the opposite frequency to achieve this.

Exactly so.  The "not there" can be achieved with a parallel-tuned trap
in series at the input to a filter, which is tuned to reject the other
band.  Then the reactance that trap has on the pass frequency must be
included in the design of _that_ path.  Or, you could use a series-tuned
shunt trap at the input to a filter and connect the filter through a 1/4
wave transmission line so that the short circuit the trap represents
reflects back as an open for the other band.  Be sure to keep your
bookkeeping straight, so you know which circuit is a short on which
band, and which line is 1/4 wave on which band, etc.  !!  Another
alternative (really more just an alternate viewpoint of the same thing)
is to include the reactance that each filter reflects back to the
junction in the calculations for the other filter.

--
Cheers,
Tom
[e-mail]


From [e-mail] Sat Mar 30 14:40:50 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: Diplexers
Date: Mon, 25 Mar 1996 16:14:56 GMT
Message-ID: <4j6k0u$[e-mail]>

Does anyone know what a diplexer is, and what makes one up?  Can a
differential coupler be used to model it?

Thanks



From [e-mail] Sat Mar 30 14:40:51 1996
From: [e-mail] (Tom Bruhns)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Diplexers
Date: 25 Mar 1996 22:33:08 GMT
Message-ID: <4j76v4$[e-mail]>
References: <4j6k0u$[e-mail]>

[e-mail] wrote:
: Does anyone know what a diplexer is, and what makes one up?  Can a

A circuit that splits a broad spectrum into two narrower segments, for
example for using a 146MHz/440MHz antenna with two rigs or a dual-band
rig with separate antenna connectors for each band; or using a
single-connector dual-band rig with two antennas.

: differential coupler be used to model it?

Differential coupler?  If you are thinking "directional coupler," then no,
they are not at all the same.

I made a satisfactory diplexer from a small handful of coils and pF-range
capacitors, three BNC connectors, and some copper-clad board.  There have
been designs in QST.


--
Cheers,
Tom
[e-mail]


From [e-mail] Sat Mar 30 14:40:52 1996
From: Patrick Millar <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: DTMF Decoder
Date: Mon, 25 Mar 1996 10:31:59 -0500
Message-ID: <[e-mail]>

Hello,

I am looking for a DTMF decoder chip.  Can anyone recommend a particular
model?

Patrick Millar VE3BFC
[e-mail]


From [e-mail] Sat Mar 30 14:40:53 1996
From: [e-mail] (John Kolb)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: DTMF Decoder
Date: 29 Mar 1996 16:07:40 GMT
Message-ID: <4jh1sc$[e-mail]>
References: <[e-mail]>

Patrick Millar ([e-mail]) wrote:

: I am looking for a DTMF decoder chip.  Can anyone recommend a particular
: model?

The 8870 works well and is available from a number of mfgrs in
both DIP and surface mount styles:

Mitel  MT8870
Teltone  M-8870
also available from Starbuck (Exar) and National

John Kolb   KK6IL


From [e-mail] Sat Mar 30 14:40:54 1996
From: [e-mail] (Sarah F. Wassum)
Newsgroups: dc.general,rec.radio.amateur.homebrew
Subject: Re: Electronic Parts Store in DC Area?
Date: Fri, 29 Mar 96 14:30:01 EST
Message-ID: <[e-mail]>
References: <4jfsh4$[e-mail]>

In article <4jfsh4$[e-mail]>
[e-mail] writes:

>Does anyone know an electronic parts retail store (except Radio Shack) in
>Northern Virginia or Montgomery county, MD ? Thanks.
>
>---
> Takashi Mori, AA9AT/4
>
Arlington Electronics.  Unfortunately, I have forgotten the
exact location, and no phone book here...I think they are listed.



From [e-mail] Sat Mar 30 14:40:55 1996
From: [e-mail] (Stanley L. Flegler)
Newsgroups: rec.radio.amateur.homebrew
Subject: Etching Teflon
Date: 28 Mar 1996 21:03:23 GMT
Message-ID: <4jeuqr$[e-mail]>

I'm working on a project where I want to glue some Teflon to a surface
for insulation.  I've heard that you need to etch it before glue will
adhere properly.  I presume that an acid is needed.  Does anyone know
which acid, what concentration, and how long?  73  Stan K8RPA,
[e-mail]



From [e-mail] Sat Mar 30 14:40:56 1996
From: [e-mail] (John Ballentine)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Etching Teflon
Date: 29 Mar 1996 04:27:09 GMT
Message-ID: <4jfoqt$[e-mail]>
References: <4jeuqr$[e-mail]>
Reply-To: [e-mail] (John Ballentine)


In a previous article, [e-mail] (Stanley L. Flegler) says:

>I'm working on a project where I want to glue some Teflon to a surface
>for insulation.  I've heard that you need to etch it before glue will
>adhere properly.  I presume that an acid is needed.  Does anyone know
>which acid, what concentration, and how long?  73  Stan K8RPA,
>[e-mail]
>
>
Not an acid, a very strong base. In the good old days, it was sodium
amide. Made by dissolving sodium metal in liquid ammonia, not something
I would want to do and I'm a chemist. These days sodium naphthenate is
used. You can buy it under the name Tetraetch. You dip the board in
the solution, then you have to rise off the naphthalene residue with
acetone and then hot water.

It is still not a real pleasant process. It is one reason printed circuit
shops don't like to work with Teflon. It is really needed to get a plated
through hole to stay in place.
--
John Ballentine WB2SNB          Divina natura dedit agros,
Chandler, Arizona               ars humana aedificavit urbes.


From [e-mail] Sat Mar 30 14:40:57 1996
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Etching Teflon
Date: Fri, 29 Mar 96 17:54:15 GMT
Message-ID: <4jh82b$[e-mail]>
References: <4jeuqr$[e-mail]> <4jfoqt$[e-mail]>

In article <4jfoqt$[e-mail]>,
   [e-mail] (John Ballentine) wrote:
>
>In a previous article, [e-mail] (Stanley L. Flegler) says:
>
>>I'm working on a project where I want to glue some Teflon to a surface
>>for insulation.  I've heard that you need to etch it before glue will
>>adhere properly.  I presume that an acid is needed.  Does anyone know
>>which acid, what concentration, and how long?  73  Stan K8RPA,
>>[e-mail]
>>
>>
>Not an acid, a very strong base. In the good old days, it was sodium
>amide. Made by dissolving sodium metal in liquid ammonia, not something
>I would want to do and I'm a chemist. These days sodium naphthenate is
>used. You can buy it under the name Tetraetch. You dip the board in
>the solution, then you have to rise off the naphthalene residue with
>acetone and then hot water.
>
>It is still not a real pleasant process. It is one reason printed circuit
>shops don't like to work with Teflon. It is really needed to get a plated
>through hole to stay in place.

Is an adhesive used to bond Teflon to other surfaces? I was under the
impression that it was mechanically bonded. If an adhesive is used, what is
it?

Roy Lewallen, W7EL


From [e-mail] Sat Mar 30 14:40:58 1996
From: [e-mail] (Gary E Snyder Jr)
Newsgroups: rec.radio.amateur.homebrew
Subject: Ethernet to IR
Date: Tue, 26 Mar 96 18:01:08 GMT
Message-ID: <4j9c0m$[e-mail]>

Help!
Several years ago I saw a discussion on using 10base2 ethernet cards connected

to InfraRed emitters/detectors fo a high speed link. It seems a $20 10MBps
card and some 'simple' IR gear will make a very nice high speed point to point

link. The problem is, of course, I can't find the information I saved and
surfing hasn't helped. I'm pretty sure it was a ham usnet group that was
discussing this stuff around 1992.

Any help or pointers ?
Thanks
G
N7QAM


From [e-mail] Sat Mar 30 14:40:59 1996
From: Will Flor <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Ethernet to IR
Date: 28 Mar 1996 19:48:29 GMT
Message-ID: <4jeqed$[e-mail]>
References: <4j9c0m$[e-mail]>

[e-mail] (Gary E Snyder Jr) wrote:
>Help!
>Several years ago I saw a discussion on using 10base2 ethernet cards connecte
d
>to InfraRed emitters/detectors fo a high speed link. It seems a $20 10MBps
>card and some 'simple' IR gear will make a very nice high speed point to poin
t
>link. The problem is, of course, I can't find the information I saved and
>surfing hasn't helped. I'm pretty sure it was a ham usnet group that was
>discussing this stuff around 1992.
>
>Any help or pointers ?
>Thanks
>G
>N7QAM

I can't help you find the information you need, but if you do find it, I'd be
interested in seeing how they do collision detection; that's what's kept Ether
net off
radio for years, and caused AT&T to develop WaveLAN, for example.  Please post
 the
results, if you find them.

Thanks and good luck.

73 de Will KB9JTT




From [e-mail] Sat Mar 30 14:41:00 1996
From: Al Wong <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Ft-5200 Mic connector pin outs
Date: 27 Mar 1996 23:04:25 GMT
Message-ID: <4jchhp$[e-mail]>

Help....


Can anyone help me with the microphone connector pin outs for the Yaesu
FT-5200?


Thanks,

Al Wong                 The above opinion does not reflect that
KF4GDD                  of my employer.  As with ALL my opinions,
[e-mail]        I write them, you intrepret them.




From [e-mail] Sat Mar 30 14:41:01 1996
From: "Bill C." <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: fuses vs. circuit breakers vs. polyswitch
Date: Wed, 27 Mar 1996 12:20:35 -0800
Message-ID: <[e-mail]>
References: <4ik0es$[e-mail]> <4j4866$[e-mail]>

Philip,

For absolute reliability nothing beats a standard fuse of correct rating.
Breakers more often fail to break than fuses fail to fuse. Statistics on
record will back me on this, but if pressed it would take a long time to
find those records. Would this aircraft tolerate the additional weight of
closely matched breakers backed up by fuses with a greater margin? This
would offer double protection (something aviation adores) with the
convenience of breakers. The idea is to have the breaker trip before the
fuse blows. If the breaker fails (doesn't open on overload), then the
fuse goes. If the fuse ever does blow in such a system... you know it
saved your life!

      Bill


From [e-mail] Sat Mar 30 14:41:02 1996
From: [e-mail] (Wilbert Knol)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: fuses vs. circuit breakers vs. polyswitch
Date: Thu, 28 Mar 1996 22:29:26 GMT
Message-ID: <4jf423$[e-mail]>
References: <4ik0es$[e-mail]>
Reply-To: [e-mail]

Tom Kreyche <[e-mail]> wrote:

>None of electronics are critical to aircraft operation so the primary
>goals are: prevention of short circuit induced fires and instrument
>protection. The instruments need to run as long as possible while the
>batteries discharge.

>Circuit breakers appear to have a voltage drop of about 1.5 v which
>minimizes useful battery life, so it appears to be a bad option for a
>system which isn't charging continuously. Fuses would be difficult to
>change in flight but have obvious advantages of little voltage drop,
>cheap, etc.

>My plan is to fuse both + and - on the batteries as close to terminals as
>possible, use fairly high value fuses to protect against shorts, say 10
>or 20 amps. They can't be changed in flight, but if one blows, I can
>switch to the other battery.


You only need one fuse, located right at a battery terminal, to break
the circuit. Using 2 fuses only increases voltage drop.

I suggest you use independent wiring for the radio and the
instruments.  Both circuits independently fused, right at the battery
terminal, by fuses rated below the current carrying capability of the
wiring. This will prevent the wiring from igniting in case of a short.

Seeing the loads are pretty much fixed, you can even decide to reduce
the fuse rating to just above the full working load, using slow blow
fuses to accommodate turn-on surges. this will extend protection to
your radio and instruments when they develop a fault resulting in an
unusually high current.

A comment on breakers vs fuses. Breakers often have both thermal and
magnetic trip values. The magnetically sensed breaking action is very
quick, the thermal action much slower and dependant on the amount of
overload and the duration. The magnetic trip point is usually several
times the nominal breaker rating. Fuses rely on thermal action only.

Wilbert, ZL2BSJ.



>The next question is what to do about individual instruments. Nothing? or
>fuse each one? or put Raychem PolySwitches on each one? They're listed in
>Digi-Key, are cheap and have minimal resistance.

>Any suggestions?

>Thanks, Tom KG6YJ






From [e-mail] Sat Mar 30 14:41:03 1996
From: [e-mail] (Roy Lewallen)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: fuses vs. circuit breakers vs. polyswitch
Date: Fri, 29 Mar 96 17:50:04 GMT
Message-ID: <4jh7qg$[e-mail]>
References: <4ik0es$[e-mail]> <4j4866$[e-mail]> <[e-mail]> <[e-mail]>

In article <[e-mail]>, Mark Schoonover <[e-mail]> wrote:
>Kinda funny they call it a 'fuse' when it's designed
>to split apart. Just an end of the day observation.

Now, don't be too picky when dealing with a language in which "fat chance"
and "slim chance" mean the same thing (while "wise man" and "wise guy"
don't).

Roy Lewallen, W7EL


From [e-mail] Sat Mar 30 14:41:07 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: HELP ! Need broadband impedance match !
Date: 24 Mar 96 06:26:06 -0330
Message-ID: <1996Mar24.062606.1@leif>
References: <1996Mar22.065407.1@noah> <4j1hpc$[e-mail]>


Fabe wrote...

>>      I have a problem (...don't we all :{)). I am trying to
>>accomplish a broadband impedance match.
>

> Depends.  What are you trying to match ....
>
> Uncle Brian  VK6BQN
>

Ok guys and gals, I will come clean !

I am trying to match an acoustic transducer which has a nearly constant
resistive value of 50 ohms, but which has a capacitive reactive component
decreasing linearly from 1000 to 600 ohms, over a frequency range from
150 KHz to 180 KHz. I would like to conjugate 'match out' that reactive
component, or at least minimize it. This may not seem like a ham
problem, but really impedance matching is a pretty general concept
(at least to dopy me...).

A simple loading coil won't buy me much, the variance in the reactance
is my major headache. I know the answer is a ladder network, but
calculation of the ladder values requires an analytical look at things
and I am...let me say... referencelessness.

Sorry for using the extra bandwidth in this repost. Thanks for the
queries thus far too !

Take care...
Fabe


From [e-mail] Sat Mar 30 14:41:08 1996
From: [e-mail] (MAILLET D.)
Newsgroups: rec.radio.amateur.homebrew
Subject: help data for tube TH3T 1100
Date: 25 Mar 1996 17:59:48 GMT
Message-ID: <4j6muk$[e-mail]>

hello, pse help me
y want to used tube CFTH
        TH3T 1100 for ampli-lineare HF
tnx
[e-mail]




From [e-mail] Sat Mar 30 14:41:09 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (SARUMAN)
Subject: Re: Help w/ 6 m reciever circuit
Message-ID: <[e-mail]>
References: <4ioplh$[e-mail]>
Date: Thu, 21 Mar 1996 23:16:14 GMT

>The ARRL Handbook discusses LC circuits in detail.  However, the
>suggestion that an LC osc circuit be used on 6 meters is totally wrong.

>73,  Mark  KN5S     [Mark  Mandelkern,  Las Cruces,  NM]

  This is what it said in the March 96 issue of CQ on building the reciever. T
o
replace the Crystal with a Series LC to allow manual tuning.

<tsb>
                               Midgard Graphics
           3D Animation and Special FX for the hobbyist videographer
                          Email: [e-mail]

--
          Drop into #amigacafe on IRC's undernet for a chat sometime

--

<tsb>

                     A man of many hobby's master of none.




From [e-mail] Sat Mar 30 14:41:10 1996
From: Jim Devenport <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Help w/ 6 m reciever circuit
Date: Thu, 21 Mar 1996 11:23:07 -0700
Message-ID: <[e-mail]>
References: <4inm7k$[e-mail]> <4ioplh$[e-mail]>
To: KN5S <[e-mail]>

How so totally wrong?  Even if the oscillator runs at 50 MHZ, which I
doubt, it is POSSIBLE, albeit difficult, to get usable stability with an
LC VFO for a rig operating at 50 MHZ.   After all, I've used homebrew
VFO's in old Motorola rockbound rigs for 2 meter FM, so it should be
even easier for a 50 MHZ transceiver.  Now, if he's hoping to tune SSB
with a VFO, then I'd certainly agree not to waste the effort.  But AM
and FM should be possible.
This particular circuit sounds like it may use an NE602 osc/mixer
circuit for a single conversion receiver, which means the VFO (Variable
Frequency Oscillator, of course) to replace the crystal would indeed be
running very close to 50 mhz.  In this case the VFO should be operated
at, say, 8 or 9 MHZ +- and multiplied and filtered to the desired
injection frequency.  If it's a dual conversion receiver he could use a
VFO for one of the lower frequency conversion oscillators with better
stability.
--
|-------------------------------------------------------|
|Jim Devenport WB5AOX                                   |
|All Standard Disclaimers Disclaimed                    |
|My views rarely (if ever) reflect those of my employers|
|HTTP://nis-www.lanl.gov/~jdport/                       |
|-------------------------------------------------------|


From [e-mail] Sat Mar 30 14:41:11 1996
From: Ken Burtchaell <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Help w/conductive epoxy
Date: 25 Mar 1996 12:23:28 GMT
Message-ID: <4j6380$[e-mail]>
References: <[e-mail]>
To: [e-mail]

There is some material made by a company called Circuit Works that is
sold by some of the big catalog outfits.It's expensive too,$14.95 for a
little supply!  73 Ken W6GHV



From [e-mail] Sat Mar 30 14:41:12 1996
From: [e-mail] (James P. Meyer)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Help w/conductive epoxy
Date: Tue, 26 Mar 1996 00:59:21 GMT
Message-ID: <[e-mail]>
References: <[e-mail]>

[e-mail] (David Feldman) wrote:

>holes (there isn't a good way of drilling into the trunk lid anyway) and I
>can't think of any other way of attaching wire braid to the metal body parts.

     Most hoods and trunk lids are bolted to the hinges.  Just remove one
of the bolts and clean the paint off before you replace the bolt with a
good sized electrical terminal lug and a "star" washer under the head.  No
drilling OR epoxy needed.  It's simple, unless I'm missing something.


        Jim




From [e-mail] Sat Mar 30 14:41:13 1996
From: [e-mail] (FrankB2686)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Help w/conductive epoxy
Date: 29 Mar 1996 01:39:39 -0500
Message-ID: <4jg0jb$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail] (FrankB2686)

Mouser Electronics Catalog lists conductive epoxy. Also some larger
electronics stores stock it.

73 Frank WD6AGS


From [e-mail] Sat Mar 30 14:41:14 1996
From: [e-mail] (Scott)
Newsgroups: rec.radio.amateur.homebrew
Subject: HELP.... New ham needs simple design for HF transmitter
Date: Tue, 26 Mar 1996 20:01:23 GMT
Message-ID: <4j9ieb$[e-mail]>

I need a simple design for an HF transmitter (A-1) that generates at
least 50 watts of power input and is variable frequency.

Please send info to "[e-mail]"

Thanks!!



From [e-mail] Sat Mar 30 14:41:15 1996
From: [e-mail] (KN5S)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: HELP.... New ham needs simple design for HF transmitter
Date: 27 Mar 1996 16:18:45 -0500
Message-ID: <4jcbbl$[e-mail]>
References: <4j9ieb$[e-mail]>

The ARRL Handbook and other ARRL  publications have transmitter design
information.

The internet is no substitute for midnight oil burnt over a good textbook.



73,  Mark  KN5S     [Mark  Mandelkern,  Las Cruces,  NM]


From [e-mail] Sat Mar 30 14:41:16 1996
From: [e-mail](Tim Hynde ka8ddz qrp/Rochester, MI)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: HF VFO design
Date: 21 Mar 1996 01:08:57 GMT
Message-ID: <4iqa79$[e-mail]>
References: <[e-mail]> <4iojqa$[e-mail]>

In <4iojqa$[e-mail]> [e-mail]
(WB3U) writes:
>
>   Isaac Kohn <[e-mail]> wrote:
>
>>Hi all.  I am starting my first major ham homebrew transmitter.  I
>>need to design a VFO that is reasonably stable from 1.8-30 Mhz at
>>least, simply switching tuned elements for different bands.  I would
>>prefer that it be as simple as possible.  Impedance/power-level
>>shouldn't matter, because I plan to buffer it.  Is this possible??
>>Has anyone ever built such a broadband VFO??  Please help.

The W1FB Notebook has some nice and very simple VFO designs for HF use,
It would be a great starting point.

Tim, ka8ddz


From [e-mail] Sat Mar 30 14:41:17 1996
From: [e-mail] (Tom Bruhns)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: HF VFO design
Date: 20 Mar 1996 19:02:13 GMT
Message-ID: <4ipknl$[e-mail]>
References: <[e-mail]>

Isaac Kohn ([e-mail]) wrote:
: Hi all.  I am starting my first major ham homebrew transmitter.  I need
: to design a VFO that is reasonably stable from 1.8-30 Mhz at least,
: simply switching tuned elements for different bands.  I would prefer
: that it be as simple as possible.  Impedance/power-level shouldn't
: matter, because I plan to buffer it.  Is this possible??  Has anyone
: ever built such a broadband VFO??  Please help.


Wow, you are trying to do the next-to-impossible on your _first_ major
homebrew transmitter project??  Well, you probably shouldn't try it, but
if you are set on doing that, here's a possible route:

Build a VFO that uses diodes (PIN diodes if you can get ones with long
enough lifetimes for HF use) to switch among a rather large number of
fairly narrow frequency ranges.  You can tune within each band with your
choice of part:  mechanical capacitor, mechanical inductor, or varicap
diode(s).  But whatever you use, include a varicap which can tune it
over a narrow range, perhaps 50kHz, and use either frequency or phase
locking driving that varicap to keep the frequency stable.  See the
HP8640B signal generator for a way to do phase locking to the frequency
you tuned manually; it basically counts the frequency before you select
"lock", then uses that count to run the phase locking loop.  Frequency
locking is even easier, since you only need to count the LS bits to be
able to track slow drifts.  For either phase or freq locking, you could
build a switch into the tuning knob so it would lock except when you
pushed it in to tune, for example--maybe even put a brake on it so when
it's released, it stays put, though that's probably overkill.

But you are probably better off to constrain the problem, and build a VFO
that covers about half a MHz, hetrodyning to get to the desired band.

--
Cheers,
Tom
[e-mail]


From [e-mail] Sat Mar 30 14:41:19 1996
From: [e-mail] (Jewels)
Newsgroups: rec.radio.amateur.homebrew
Subject: HOMEBREW
Date: Tue, 26 Mar 1996 21:59:53 GMT
Message-ID: <4j9pad$[e-mail]>

I am looking for a homebrew newsgroup.  This was the closest I got to
one and it looks like I am at the wrong spot.  Pleaasssee, can someone
point me in the right direction?

Julie
[e-mail]



From [e-mail] Sat Mar 30 14:41:20 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Larry DeSoto)
Subject: Re: HOMEBREW
Message-ID: <[e-mail]>
References:  <4j9pad$[e-mail]>
Date: Tue, 26 Mar 1996 22:36:36 GMT

In article <4j9pad$[e-mail]>, [e-mail] (Jewel
s) writes:
> I am looking for a homebrew newsgroup.  This was the closest I got to
> one and it looks like I am at the wrong spot.  Pleaasssee, can someone
> point me in the right direction?
>
> Julie
> [e-mail]

I guess it depends on what you want to homebrew.  If it's electronic
equipment, you're in the right spot.  If it's beer, try
rec.crafts.winemaking or rec.crafts.brewing,  If it's homebrew sin,
try the alt newsgroups.

--
Larry                                 *************************
                                      *                       *
                                      *  Speaking for myself  *
                                      *                       *
                                      *************************


From [e-mail] Sat Mar 30 14:41:21 1996
From: [e-mail](Tim Hynde ka8ddz qrp/Rochester, MI)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: HowTo reduce HR2600 pwr ?
Date: 25 Mar 1996 14:45:49 GMT
Message-ID: <4j6bit$[e-mail]>
References: <[e-mail]> <4j65ci$[e-mail]>


>
>>Is there a way I can reduce the HR2600 power output using internal
>>controls so that I can feed the needed low power to a transverter,
>>rather than by heating up the shack with an external attenuator?


There is a pot for adjusting the output power, I used a simple switch
mounted to the side that would select one of two pots for high and low
power.


From [e-mail] Sat Mar 30 14:41:22 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: HowTo reduce HR2600 pwr ?
Date: 25 Mar 1996 06:00:02 -0700
Message-ID: <4j65ci$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail]

>Is there a way I can reduce the HR2600 power output using internal
>controls so that I can feed the needed low power to a transverter,
>rather than by heating up the shack with an external attenuator?
>
>John, KM6LJ

        I used a miniature relay to substitute for the shorting board in the final's
current circut. Using the normally-closed contacts, full-power is availible. W
hen
the transverter is on, it energizes the relay and makes the final almost dead.
 The
output will vary, but I get about 1/2 watt at the antenna jack. You can bring
the
relay coil wire out through that molex jack.

Jim N7TCF
[e-mail]


From [e-mail] Sat Mar 30 14:41:23 1996
From: [e-mail] (Clint Bradford)
Date: 24 Mar 96 13:17:00
Newsgroups: rec.radio.amateur.homebrew
Subject: HTX-202 Deviation
Message-ID: <[e-mail]>




>>I was tring to use autopatch but my I was not successful.

If you have trouble getting the touch-tones on the HTX-202 2-meter Ham Radio
Transceiver (Cat No. 19-1120 ) to work with the local Repeater, try resetting
the unit's touch-tone audio level.

To do this, you can adjust the touchtone pot (RV 1001) down until the tones
don't decode, then up again until it JUST works. (Simply tuning down is NOT
as reliable as this metho  You uld make NO other adjustments!

Also, many repeaters will read back the tones once they decode properly. If
you are unsure how to do this, you can find out from another repeater member.


This is all R.S. would have to say about there HTx-202. If you have had any
problems with using the phone patch, this should cure it. Some have been
setting the << Auto Reply >> function in the main setup to << ON >> to
cure this problem. If you have, set it back to << OFF >> before adjusting
(RV 1001) pot.
---
 * wcECHO 4.1 ~ AR-Net: ATTENTION to Details * Mira Loma, CA * 909-681-6221
--
|Fidonet:  Clint Bradford 1:2619/228
|Internet: [e-mail]
|
| Standard disclaimer: The views of this user are strictly his own.



From [e-mail] Sat Mar 30 14:41:24 1996
From: [e-mail] (Mike)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: HTX-202 Deviation
Date: Tue, 26 Mar 1996 00:44:40 GMT
Message-ID: <4j7f03$[e-mail]>
References: <4io8lm$[e-mail]> <4j49qs$[e-mail]>

[e-mail] (John Darrell Kesling) wrote:

>KE6VOT wrote:
>>Hi,
>>I was tring to use autopatch but my I was not successful.
>>Talking to another ham, who had been listening to my attemp,
>>told me that my deviation was weak.  How do I change this on a
>>HTX-202.  I'm also new at this so simplistic instructions would be
>>helpful.
>>      Thanks,
>>              Steve
>>KE6VOT
>>e-mail [e-mail]

>The HTX-202 has 3 deviation adjustments:

> RV1     Microphone
> RV1001  DTMF
> RV1002  CTCSS

>You will need to locate RV1001 for your adjustment.  For best results
>you should have a deviation meter or some other way to measure the deviation
>as you make the adjustment and adjust for 3.5-4Khz of deviation.  You
>may be able to obtain acceptable results by the tweaking method though.

>I seem to remember a different problem with the HTX-202 that caused
>problems with some autopatches.  It's been a while since I owned one
>and this is from memory since I no longer have the operation manual.
>But what I remember is a setup option that would keep the transmitter
>keyed for a period of time after pressing one of the DTMF keys.  This
>time delay was too long for some autopatches.  Turning this option off
>may take care of your problem.  It's worth a try and much easier than
>opening up the radio.

>73 - John
>--
>----------------------------------------------------------------------
>John Kesling  -  [e-mail]   or   [e-mail]
>----------------------------------------------------------------------
>  WA8ZGO      -  via AX.25 packet radio [e-mail]
>----------------------------------------------------------------------


The radio comes apart real easy.  Four screws on the bottom (after you
remove bat pack)  one screw on back.  Try to memorize how the battery
attachment goes on, be careful here. The rv1 mic adjustment is
backward, ccw=increase gain.  Never tried the other pots.  I think RV1
will bring up the TT levels as well as the mic gain.  This pot is
labled MIC also and you can see it has a blue shaft (in my radio)
Mike WB9EKT




From [e-mail] Sat Mar 30 14:41:26 1996
From: [e-mail] (John Darrell Kesling)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: HTX-202 Deviation
Date: 24 Mar 1996 20:03:40 GMT
Message-ID: <4j49qs$[e-mail]>
References: <4io8lm$[e-mail]>

KE6VOT wrote:
>Hi,
>I was tring to use autopatch but my I was not successful.
>Talking to another ham, who had been listening to my attemp,
>told me that my deviation was weak.  How do I change this on a
>HTX-202.  I'm also new at this so simplistic instructions would be
>helpful.
>       Thanks,
>               Steve
>KE6VOT
>e-mail [e-mail]

The HTX-202 has 3 deviation adjustments:

 RV1     Microphone
 RV1001  DTMF
 RV1002  CTCSS

You will need to locate RV1001 for your adjustment.  For best results
you should have a deviation meter or some other way to measure the deviation
as you make the adjustment and adjust for 3.5-4Khz of deviation.  You
may be able to obtain acceptable results by the tweaking method though.

I seem to remember a different problem with the HTX-202 that caused
problems with some autopatches.  It's been a while since I owned one
and this is from memory since I no longer have the operation manual.
But what I remember is a setup option that would keep the transmitter
keyed for a period of time after pressing one of the DTMF keys.  This
time delay was too long for some autopatches.  Turning this option off
may take care of your problem.  It's worth a try and much easier than
opening up the radio.

73 - John
--
----------------------------------------------------------------------
John Kesling  -  [e-mail]   or   [e-mail]
----------------------------------------------------------------------
  WA8ZGO      -  via AX.25 packet radio [e-mail]
----------------------------------------------------------------------



From [e-mail] Sat Mar 30 14:41:27 1996
From: "Irina N. Borisova" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: I look for metal detectors creators for information exchange.
Date: 28 Mar 1996 22:02:57 +0300
Distribution: world
Message-ID: <[e-mail]>




From [e-mail] Sat Mar 30 14:41:28 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: linear amplifiler
Date: 27 Mar 1996 13:35:28 -0500
Message-ID: <4jc1pg$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>, [e-mail]
(Gary Coffman) writes:

>>      I make a linear  to hf bands, and I used four 6KD6 tubes, with
1300V
>>and 1 amper. My tubes is now burred.
>>      I want a new tubes and I think that I doubler the voltagem = 2800
V
>>and 0.5 ampers I can use a one 3 - 500 z tubes.
>>      I ask by any especialist what do you think about my decision ?
>
>You'll have to redesign the output network. The sweep tubes wanted a
>load line of approximately 1300 ohms that had to be transformed from
>50 ohms by the output network. The 3-500Z will want a loadline of
>approximately 5600 ohms at the voltage and current you propose, so
>the existing output network won't provide the transformation.
>

The impedance is much lower than the simple resistance calculated by the
current and voltage.

The only accurate way to calculate the impedance is to know the maximum
available fundamental current and voltage at the anode under operating
conditions. That can be done by using the constant current characteristics
of the tube to determine the loadline and fundamental voltage and current.

The older ARRL Handbooks give some simple rules of thumb that are pretty
good. The new Handbook has some theoretical errors on matching, so I'm
unsure of it's accuracy. That section may still be correct.

With a typical class B amplifier the correct source Z is around half the
dc plate impedance calculated by the operating E/I. So the sweep tubes
would be ~650 ohms and the 3-500Z  will be ~3000 ohms, depending on the
conduction angle.

I think a more simple change would be to use parallel 811A tubes, rather
than a 3-500.

73 Tom


From [e-mail] Sat Mar 30 14:41:29 1996
From: [e-mail] (Elendir)
Newsgroups: rec.radio.amateur.homebrew
Subject: LNA input design problem (double match ?)
Date: 25 Mar 1996 20:39:40 GMT
Message-ID: <4j70ac$[e-mail]>

Hi -
once more, a question. :-)

In the process of designing an (hypothetic) input stage for my 50 MHz
transverter, I have, of course found some good filters that are 50 ohms
input and output.
I have also selected an appropriate Dual-Gate MOSFET (BF 998) given for
less than 0.4 dB @ 50 MHz.

The classical design process would be, regarding the input :
to design an input-impedance matching network to xform the 50 ohms
into Gopt.

But, if I do this and connect the filter to the input design, its
characteristics shift, because the input network does not transform the
Yin of the BF998 into 50 ohms !

What am I to do ?

How to design an input stage that will both xform :
50 ohms into Gopt to be seen by the BF998 AND
Yin into 50 ohms to be seen by the filter ?

Thanks !
Vincent

--
Fox 5 RCS - Round the world and beyond through amateur radio.
VAL D'AOSTE / VALLE D'AOSTA : Le tresor des Alpes / Il tesoro delle Alpi.


From [e-mail] Sat Mar 30 14:41:30 1996
From: [e-mail] (Dana Myers)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: LNA input design problem (double match ?)
Date: 27 Mar 1996 18:40:25 GMT
Message-ID: <4jc22p$[e-mail]>
References: <4j70ac$[e-mail]>

In article <4j70ac$[e-mail]>, Elendir <[e-mail]> wrote:
>Hi -
>once more, a question. :-)
>
>In the process of designing an (hypothetic) input stage for my 50 MHz
>transverter, I have, of course found some good filters that are 50 ohms
>input and output.
>I have also selected an appropriate Dual-Gate MOSFET (BF 998) given for
>less than 0.4 dB @ 50 MHz.
>
>The classical design process would be, regarding the input :
>to design an input-impedance matching network to xform the 50 ohms
>into Gopt.
>
>But, if I do this and connect the filter to the input design, its
>characteristics shift, because the input network does not transform the
>Yin of the BF998 into 50 ohms !
>
>What am I to do ?

I'm no expert in this (I've been waiting to respond in hope that one
of the real experts would answer), but I've got the following
comments...

It sounds like you're using the FET in a common-source configuration,
and the gate is primarily reactive, with a fairly small series
resistance.  An LC matching circuit at the gate is going to have a
fairly high Q, and will only provide a 50 ohm match over a limited
frequency range.  Moving outside this range, the input impedance
will rapidly become reactive.

LC filters depend on non-reactive termination; as the termination
becomes reactive, the LC filter characteristic changes.  With a
filter, the termination outside the desired bandpass is at least
as important as the termination inside the desired bandpass, and
the matching circuit to the FET gate is almost certain to
mis-terminate the filter - something you've already discovered.

>How to design an input stage that will both xform :
>50 ohms into Gopt to be seen by the BF998 AND
>Yin into 50 ohms to be seen by the filter ?

If you want to use the FET amplifier to terminate a filter, you'll
need to make the FET have a non-reactive input impedance over a
fairly wide range (at least an octave above and below the desired
bandpass frequency).  You can do this by shunting the FET gate
to ground via a resistor, and then use a broadband transformer to
match the filter to this resistance, or you can use an amplifier with
an input characteristic more suitable for terminating a filter.  The
problem with shunt loading the FET is that you'll certainly
degrade the noise figure, perhaps dramatically.  A grounded gate
FET happens to offer a well-defined input resistance without
compromising the noise figure, which makes it a natural choice
for terminating filters (and mixers, too).

Most LNA designs I've seen have very little in the way of input
filtering, instead depending on the narrow band nature of the
input matching circuit to give some filtering.  If you don't
expect to have a lot of strong interfering signals on nearby
frequencies, you're probably best off using the simple matching
circuit before the FET amplifer, and the LC filter after the
amplifier.  Afterall, the insertion loss of the filter would
directly degrade your noise figure if you place it in front of the
amplifier, but will have little influence placed after the
amplifier if the gain of the amplifier is significant.

Alternatively, you could investigate changing the amplifier
configuration to common gate.

--
 * Dana H. Myers KK6JQ, DoD#: j | Views expressed here are mine and should *
 * [phone]               | not be interpreted or represented as     *
 * [e-mail]      | those of Sun Microsystems, Inc.          *



From [e-mail] Sat Mar 30 14:41:32 1996
From: [e-mail] (Myron A. Calhoun)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for CK722 Transistor
Date: 21 Mar 96 03:06:28 GMT
Message-ID: <[e-mail]>
References: <4i1vl3$[e-mail]> <[e-mail]> <4i6tsl$[e-mail]>


<>In article <4i1vl3$[e-mail]> [e-mail] writes:
<>>I am looking for a CK722 Philco transistor. It was in a
<>>blue case and I need one for nostalgia purposes....

<[e-mail] (Bill Meahan) wrote:
<>Gee, I remember the CK722 as being made by Raytheon and....

William W Janssen <[e-mail]> writes:
<Mine is made by Rayteon and is black plastic with a clear section near
<the leads. It cost about US $7.00 when it was new....

I STILL HAVE my first half dozen or so!-)   (grin grin!)

I was a really-poor high-school cheapskate and bought them when they
dropped "below" a dollar (i.e., 99 cents each; about 1958 or 59), built
two TRF radios (with three or four stages of audio gain) small enough to
hide in a hollowed-out school book, sold one to my best friend, and used
the other myself (in study hall).

Later my friend GAVE his radio back to me (that's why I called him my
BEST friend!), and, of course, I still had my own radio, so that's why
I still have six or eight of them.

Mine are blue, too.

--Myron.
--
# Five boxes preserve our freedoms:  soap, ballot, witness, jury, and cartridg
e
# Myron A. Calhoun, PhD EE; Assoc. Prof.     [phone] work, 532-7353 fax
# Amateur packet radio: W0PBV@N0ARY.#NOCAL.CA.USA.NOAM            539-4448 hom
e
# NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol
)


From [e-mail] Sat Mar 30 14:41:33 1996
From: [e-mail] (Mike Lawlor)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Looking for schematics for Swan 350
Date: Thu, 28 Mar 1996 21:56:23 GMT
Message-ID: <4jf210$[e-mail]>
References: <[e-mail]>

Isaac Kohn <[e-mail]> wrote:

>What bands does the Swan 350 cover??  Does anyone have the schematic??
>I'd pay cost of copying+shipping if you can send a copy to me.  Thanks.

>73's
>Isaac
Hi Isaac ,

The Swan 350 covers 3.5 , 7, 14, 21 and 28MHz.  I used one for many
years but it has been retired for about 10 years now.  The Schematic
Diagram I have is dated 1965  so it is a very elderly set. Also it
doesn't have IRT....important if you like CW.

73

Mike EI3CN



From [e-mail] Sat Mar 30 14:41:34 1996
From: [e-mail] (Rane Curl)
Newsgroups: rec.radio.amateur.homebrew
Subject: Low Frequency Counter.
Date: 25 Mar 1996 22:03:13 GMT
Message-ID: <4j7571$[e-mail]>

I need a simple (cheap) low frequency timed counter with an LCD
display. Frequencies up to ca. 100 cps; timing intervals of the order
of 10-50 seconds. Seems simple enough, but I have not seen a kit or
even small (ca. 5 digit) LCD display at a low price. Suggestions?

Rane L. Curl    N8REG



From [e-mail] Sat Mar 30 14:41:35 1996
From: Ken Burtchaell <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Microwave Oscillators
Date: 24 Mar 1996 13:26:43 GMT
Message-ID: <4j3iij$[e-mail]>

Looking for PLL Brick oscillators 4-10 Ghz Typical manufactuers Frequency
West,California Microwave,etc. Tnx and 73 Ken W6GHV



From [e-mail] Sat Mar 30 14:41:36 1996
From: [e-mail] (John Stroppel)
Newsgroups: rec.radio.amateur.homebrew
Subject: mods. for HW-99
Date: 26 Mar 1996 14:36:22 GMT
Distribution: world
Message-ID: <4j8vd6$[e-mail]>

Any one have mods to correct the drift in a Heathkit HW-99 VFO? Have the
manual,  but need the schematic.     thanks

John WA0VYZ

--
 John Stroppel                         | Internet: [e-mail]
 The University of Iowa - Hygienic Lab | Amateur Radio: WA0VYZ
 Oakdale Research Campus, OH-M7A       | Voice:    [phone]
 Iowa City, IA   52242                 | Fax:      [phone]


From [e-mail] Sat Mar 30 14:41:37 1996
From: Rick Stealey <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Murata filter ques?
Date: 25 Mar 1996 22:16:11 GMT
Message-ID: <4j75vb$[e-mail]>

Anyone know what BW this filter is?
Murata CFM-455-D1

Is this an AM bandwidth, FM, SSB?  I found it in a homebrew
circuit hanging off of a CB set in a hamfest.  The original
homebrewer 15 yrs ago obviously knew what he was doing, but for
some (?!) reason the schematic wasn't included in the $2 price !

Thanks,
73,
Rick   KT2Q



From [e-mail] Sat Mar 30 14:41:39 1996
From: [e-mail] (Steve Muther)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Murata filter ques?
Date: 26 Mar 1996 00:24:20 GMT
Message-ID: <4j7dfk$[e-mail]>
References: <4j75vb$[e-mail]>

In article <4j75vb$[e-mail]> Rick Stealey <[e-mail]>
writes:
>Anyone know what BW this filter is?
>Murata CFM-455-D1
>
>Is this an AM bandwidth, FM, SSB?  I found it in a homebrew
>circuit hanging off of a CB set in a hamfest.  The original
>homebrewer 15 yrs ago obviously knew what he was doing, but for
>some (?!) reason the schematic wasn't included in the $2 price !
>
>Thanks,
>73,
>Rick   KT2Q
>

From the Murata catalog, The CFM-455-D (did not see a D1 suffix listed)
has the following specs:

Center Freq.:           455KHz
3dB BW:                 +/-7KHz (min)
6dB BW:                 +/-10KHz (min)
Ripple                  3dB (max)
60dB BW:                +/-20KHz (max)
Insertion Loss:         3dB (max)
In/Out Impedance:       1500 Ohms

Steve Muther WF6R




From [e-mail] Sat Mar 30 14:41:39 1996
From: Vlad <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Murata filter ques?
Date: 26 Mar 1996 15:16:14 GMT
Message-ID: <4j91nu$[e-mail]>
References: <4j75vb$[e-mail]>
To: [e-mail]

CFM455D filter has +/- 7.0 KHz @ 3 dB bandwidth and +/- 20 KHz @ 60 dB
bandwidth.
It is a AM filter.
Vlad



From [e-mail] Sat Mar 30 14:41:40 1996
From: [e-mail] (Charles Curtis)
Newsgroups: rec.radio.amateur.homebrew
Subject: RE:  Murata filter ques?
Date: 27 Mar 96 02:03:54 GMT
Message-ID: <[e-mail]>

> Date: 25 Mar 1996 22:16:11 GMT
> From: Rick Stealey <[e-mail]>
> Subject: Murata filter ques?
>
> Anyone know what BW this filter is?
> Murata CFM-455-D1
>
> Is this an AM bandwidth, FM, SSB?  I found it in a homebrew
> circuit hanging off of a CB set in a hamfest.  The original
> homebrewer 15 yrs ago obviously knew what he was doing, but for
> some (?!) reason the schematic wasn't included in the $2 price !

My Murata catalog gives the following specs for a CFM455D
ceramic filter.

Multielement Ladder Filter
Center Freq:  455 +/- 1.5 Khz
6dB BW:       +/- 10 Khz
50dB BW:      +/- 20 Khz
Ripple:       3 dB within 3 dB BW; 6 dB within 6 dB BW
Spurious Res: 50 dB min
Insr loss:    3 dB max
Input Z:      1500 ohms
Output Z:     1500 ohms

Unfortunately the pinout is not shown in my catalog.  It
appears as a rectangular can with four leads on the bottom, one in
each corner.  There is a tab on the bottom of one long side of the
can.  My *guess* is that pins 1 and 2 are for input and pins 3 and 4
are for output.  The long side is shown to be 20 mm long and the short
side 7.5 mm with a height (not including pin or tab length) of 10.5 mm.
Looking at the bottom, with the tab toward you, pins 1 and 2
are on the left (pin 1 is above pin 2) and pins 3 and 4 are on
the right (pin 3 above pin 4).  The catalog does not show
prices.  I have a phone number that was good on 7 Aug 1995:
[phone].  I hope this helps somewhat.

73 de Chuck, N2UCN
amprnet: [e-mail]           internet: [e-mail]
ax25   : n2ucn@wa2soc.#nnj.nj.usa.na     internet: [e-mail]


From [e-mail] Sat Mar 30 14:41:42 1996
From: Clifford Buttschardt <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Murata filter ques?
Date: Tue, 26 Mar 1996 16:04:38 -0800
Message-ID: <[e-mail]>
References: <4j75vb$[e-mail]>

Rick, your CFM455D filter is a ceramic unit in which the 3db bandwidth is
plus/minus 7 KHz,the six db BW is +/- 10 KHz with 3 db passband ripple.
The BW at 60 db is +/- 20 KHz.  The input and output impedance is 1500
ohms and the loss is 3 db..73  Cliff Buttschardt  W6HDO

On 25 Mar 1996, Rick Stealey wrote:

> Anyone know what BW this filter is?
> Murata CFM-455-D1
>
> Is this an AM bandwidth, FM, SSB?  I found it in a homebrew
> circuit hanging off of a CB set in a hamfest.  The original
> homebrewer 15 yrs ago obviously knew what he was doing, but for
> some (?!) reason the schematic wasn't included in the $2 price !
>
> Thanks,
> 73,
> Rick   KT2Q
>
>
>


From [e-mail] Sat Mar 30 14:41:43 1996
From: [e-mail] (Claude Frantz)
Newsgroups: alt.engineering.electrical,alt.bbs.pcboard,alt.electronics.analog.vlsi,rec.radio.amateur.homebrew,sci.electronics.cad
Subject: Re: Need electronic project - where kan I find projects on the Internet?
Date: 25 Mar 96 09:22:24 GMT
Message-ID: <habi.827745744@bauv111>
References: <4j1c4a$[e-mail]>
Reply-To: [e-mail]

[e-mail] (Stephen Schoonees) writes:

>Hi

>  I'm a second year electronic student and need a project for one of
>my subjects.

What are these subjects ?
--
Claude
([e-mail])
The opinions expressed above represent those of the writer
and not necessarily those of her employer.


From [e-mail] Sat Mar 30 14:41:44 1996
From: Jay Wicklund <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Need pointer to articles on AD7008 DDS...
Date: Fri, 29 Mar 96 10:19:43 PDT
Message-ID: <[e-mail]>
References: <4ja2tm$[e-mail]>



> I just caught a reference a week or so ago regarding one or more
articles about
> building a VFO using an AD7008 DDS chip.  I have an article about
use of a
> Harris DDS chip (DigiBrain/DigiVFO? in CQ or QST mag...don't
remember which).
>
> Could someone point me to the magazine issue(s) that contained such
an article?
>
> Thanks!
Hi Scott, there was a recent article in the March 96 QST with the
Harris chip.

I could only find two articles that used the AD7008 part, I thought
that there was at least one more, but I couldn't find it.
1. October, 1995 issue of 73 - page 14
2. December, 1995 issue of QEX

The QEX article was for a microprocessor controlled HF receiver, but
it used a 7008 for the VFO.

Both articles were interesting, but I didn't think that either one was
particularly informative.  I liked the Digibrain article in QST
better.

73....de KI7RH (Jay)



From [e-mail] Sat Mar 30 14:41:45 1996
From: [e-mail] (Dana Myers)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Need some coil winding data, please!!
Date: 21 Mar 1996 09:03:11 GMT
Message-ID: <4ir60f$[e-mail]>
References: <4io1mi$[e-mail]> <4ipf93$[e-mail]> <[e-mail]>

In article <[e-mail]>,
David Harmon <[e-mail]> wrote:
>[e-mail] (patrick ferrick) wrote:
>>
>>I recall there being an equation in my old ARRL handbook (which I
>>have lost track of since I moved last)  relating coil size, number of
>>turns and I think wire guage.
>
>Excerpted from comp.archives.msdos.announce:
>
> 50126 Feb 28 14:05 ftp://garbo.uwasa.fi/pc/ham/coil01.zip

This appears to be a very nice implementation using Nagoaka's
accurate method to calculate solenoidal inductance, which saved
me from posting notes regarding Nagoaka.  Since I use a real
operating system, I was delighted to find the source code and
a makefile was included for Unix, and I had no trouble building
the binary on Solaris x86 2.5 with gcc.

--
 * Dana H. Myers KK6JQ, DoD#: j | Views expressed here are      *
 * [phone]               | mine and do not necessarily   *
 * [e-mail]      | reflect those of my employer  *


From [e-mail] Sat Mar 30 14:41:46 1996
From: George Harris <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew,rec.radio.cb,rec.radio.swap
Subject: Palomar HF Tube Amp Questions?
Date: 27 Mar 1996 17:01:41 GMT
Message-ID: <4jbs9l$hs4$[e-mail]>

I've just purchased a Palomar HF Multi-Band Tube Amp at a
HamFest. I can't find a model number on the unit to identify it.
Palomar Electronics is no longer in business so they can't help
me. Can anyone help me to identify the unit I have and a possible
source for Schematics.

P.S.    The unit uses 6 6LF6 Tubes.

Thanks Alot!

George

--
Don't do anything that I wouldn't, At least don't get CAUGHT!!!!


From [e-mail] Sat Mar 30 14:41:47 1996
From: Tiger X-term <t9>
Newsgroups: rec.radio.amateur.homebrew,rec.radio.cb,rec.radio.swap
Subject: Re: Palomar HF Tube Amp Questions?
Date: 28 Mar 1996 05:07:08 GMT
Message-ID: <4jd6ps$[e-mail]>
References: <4jbs9l$hs4$[e-mail]>
To: [e-mail]

Try calling RF parts in San Marcos Ca.. I don't have their number handy right
now. It is in the 619 area code. Some of the ex Palomar people work for them.
They should be abl to help you.

Good Luck..Don N6NLX.



From [e-mail] Sat Mar 30 14:41:47 1996
From: [e-mail] (Russ Renaud)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Parabolic Dish (18")?
Date: 26 Mar 1996 16:20:47 GMT
Message-ID: <4j95gv$[e-mail]>
References: <4j8ttl$[e-mail]>
Reply-To: [e-mail] (Russ Renaud)

MHorn22377 ([e-mail]) writes:
> I am looking for an eighteen inch parabolic dish for a project.  I only
> need the dish and not any electronics.
>
> If anyone knows where to get this inexpensively(<$30), please E-mail me.
>
KA9LNV shows how to build a stressed dish in "Mode S, The Book", using
fishing line, wood dowel rod, and hardware cloth.

I imagine the cost would be well under $30.00.


From [e-mail] Sat Mar 30 14:41:48 1996
From: William W Janssen <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Parabolic Dish (18")?
Date: 27 Mar 1996 10:58:37 GMT
Message-ID: <4jb70t$[e-mail]>
References: <4j8ttl$[e-mail]> <[e-mail]>

[e-mail] (SARUMAN) wrote:
>>I am looking for an eighteen inch parabolic dish for a project.  I only
>>need the dish and not any electronics.
>
>>If anyone knows where to get this inexpensively(<$30), please E-mail me.
>
>>Thanks in advance,
>>Michael R. Horn
>>[e-mail]
>
>The MCM Electronics Catalog has the DSS Dish for $13 or so
>
>

Don't forget that the DSS is an OFFSET FEED type and requires
a different feed than you would use on a center feed dish. The offset
feed is better though.

Bill K7NOM



From [e-mail] Sat Mar 30 14:41:49 1996
From: [e-mail] (MHorn22377)
Newsgroups: rec.radio.amateur.homebrew
Subject: Parabolic Dish (18")?
Date: 26 Mar 1996 09:11:01 -0500
Message-ID: <4j8ttl$[e-mail]>
Reply-To: [e-mail] (MHorn22377)

I am looking for an eighteen inch parabolic dish for a project.  I only
need the dish and not any electronics.

If anyone knows where to get this inexpensively(<$30), please E-mail me.

Thanks in advance,
Michael R. Horn
[e-mail]


From [e-mail] Sat Mar 30 14:41:50 1996
From: Zack Lau <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Parabolic Dish (18")?
Date: Thu, 28 Mar 1996 12:13:06 -0500
Message-ID: <[e-mail]>
References: <4j8ttl$[e-mail]> <[e-mail]> <4jb70t$[e-mail]> <[e-mail]>

Zack Lau wrote:
>
> What type of feed you do recommend?  An article by Paul Wade in the

December

> 1995 QEX indicates that a simple rectangular horn feed gives excellent
> efficency, at least when compared to the best center fed dishes (10 GHz).

For circular polarization, Paul suggested a varient of the W2IMU
feed as a starting point for experimentation--IEEE Transactions
on Antennas and Propagation AP-15 March 1967 pp 307-308.

--Zack KH6CP/1


From [e-mail] Sat Mar 30 14:41:51 1996
From: [e-mail] (Joe Landis - Systems & Network Mgr)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Parabolic Dish (18")?
Message-ID: <[e-mail]>
Date: 26 Mar 96 16:17:01 EST
References: <4j8ttl$[e-mail]> <4j95gv$[e-mail]>
Distribution: world

In article <4j95gv$[e-mail]>, [e-mail] (R
uss Renaud) writes:
> MHorn22377 ([e-mail]) writes:
>> I am looking for an eighteen inch parabolic dish for a project.  I only
>> need the dish and not any electronics.
>>
>> If anyone knows where to get this inexpensively(<$30), please E-mail me.
>>
> KA9LNV shows how to build a stressed dish in "Mode S, The Book", using
> fishing line, wood dowel rod, and hardware cloth.
>
> I imagine the cost would be well under $30.00.

MCM Electronics (don't have the number handy) sells replacement off-center fed
18" dishes (DBSS style). They're about $15, I think. N1BWT wrote an article in
QEX a month or 2 ago on how to mount-n-feed em for 10Ghz. They work very well
-
a friend of mine has one up and running. I would too if I hadn't already picke
d
up a 24" dish for quite a bit more :(
I'll try to find the MCM's number later and post it.

73,
Joe - AA3GN
--
Joe Landis - Systems and Network Manager - North American Drager - Telford, PA
[e-mail]                        ..speaking only for myself, of course..


From [e-mail] Sat Mar 30 14:41:52 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Parabolic Dish (18")?
Date: Thu, 28 Mar 96 07:01:49 GMT
Message-ID: <4jddt3$[e-mail]>
References: <4j8ttl$[e-mail]>

   [e-mail] (MHorn22377) wrote:

>I am looking for an eighteen inch parabolic dish for a project.  I
>only need the dish and not any electronics.
>
>If anyone knows where to get this inexpensively(<$30), please E-mail
>me.

Older-style MMDS receive dishes were made with detachable feeds and
were commonly available in 18", 21", 24" and 36" sizes.  Many
MMDS system operators have now begun to use dishes with integrated
downconverters, and some have a surplus of the older style dishes.

If you're in a large metropolitan area, see if there's a Wireless
Cable operator neaby.  A call to one of the technicians or the
installation crew manager might get you what you're looking for at a
very reasonable price.

Incidentally, these are all center-feed designs.

73,
Jack  WB3U


From [e-mail] Sat Mar 30 14:41:54 1996
From: Clifford Buttschardt <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Parabolic Dish (18")?
Date: Thu, 28 Mar 1996 11:02:42 -0800
Message-ID: <[e-mail]>
References: <[e-mail]> <4j8ttl$[e-mail]> <4jbkrb$[e-mail]>

Why not consulst QEX magazine for last month?  That was the best article
I've ever read on the subject of off center feeds!  Cliff Buttschardt W6HDO


On 27 Mar 1996, Zack Widup wrote:

>
> In a previous article, [e-mail] (SARUMAN) says:
>
> >>I am looking for an eighteen inch parabolic dish for a project.  I only
> >>need the dish and not any electronics.
> >
> >>If anyone knows where to get this inexpensively(<$30), please E-mail me.
> >
> >>Thanks in advance,
> >>Michael R. Horn
> >>[e-mail]
> >
> >The MCM Electronics Catalog has the DSS Dish for $13 or so
> >
> >
>
> The thing I don't like about those DSS antennas is that they are
> off-center feeds. This gets your feed out of the way of the signal into
> the dish, but I have always had a harder time pointing the things.
>
> 73, Zack W9SZ
>
>
>


From [e-mail] Sat Mar 30 14:41:54 1996
From: Zack Lau <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Parabolic Dish (18")?
Date: Wed, 27 Mar 1996 21:05:46 -0500
Message-ID: <[e-mail]>
References: <4j8ttl$[e-mail]> <[e-mail]> <4jb70t$[e-mail]>
To: William W Janssen <[e-mail]>

Bill K7NOM wrote:
>
> Don't forget that the DSS is an OFFSET FEED type and requires
> a different feed than you would use on a center feed dish. The offset
> feed is better though.

What type of feed you do recommend?  An article by Paul Wade in the
1995 QEX indicates that a simple rectangular horn feed gives excellent
efficency, at least when compared to the best center fed dishes (10 GHz).

Zack KH6CP/1  13 grids on 10 GHz--anyone in FN23, FN24, or Montreal?


From [e-mail] Sat Mar 30 14:41:56 1996
From: [e-mail] (Joe Landis - Systems & Network Mgr)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Parabolic Dish (18")?
Message-ID: <[e-mail]>
Date: 27 Mar 96 19:13:54 EST
References: <4j8ttl$[e-mail]> <4j95gv$[e-mail]> <[e-mail]>
Distribution: world

In article <[e-mail]>, [e-mail] (Joe Landis - Syste
ms & Network Mgr) writes:
> In article <4j95gv$[e-mail]>, [e-mail]
(Russ Renaud) writes:
>> MHorn22377 ([e-mail]) writes:
>>> I am looking for an eighteen inch parabolic dish for a project.  I only
>>> need the dish and not any electronics.
>>>
>>> If anyone knows where to get this inexpensively(<$30), please E-mail me.
>>>
>> KA9LNV shows how to build a stressed dish in "Mode S, The Book", using
>> fishing line, wood dowel rod, and hardware cloth.
>>
>> I imagine the cost would be well under $30.00.
>
> MCM Electronics (don't have the number handy) sells replacement off-center f
ed
> 18" dishes (DBSS style). They're about $15, I think. N1BWT wrote an article
in
> QEX a month or 2 ago on how to mount-n-feed em for 10Ghz. They work very wel
l -
> a friend of mine has one up and running. I would too if I hadn't already pic
ked
> up a 24" dish for quite a bit more :(
> I'll try to find the MCM's number later and post it.

Me again - MCM can be reached at 800-543-4330. And yes, the feed can be tricky
,
but the off center feed does move all of the obstructions out of the pattern
and can make for a much more efficient antenna. See Pauls article.
Once you establish the geometry of the system,,
you can fix a parallel rail below the dish and mount a compass and even
a crude peep site for aiming.
Joe - AA3GN
--
Joe Landis - Systems and Network Manager - North American Drager - Telford, PA
[e-mail]                        ..speaking only for myself, of course..


From [e-mail] Sat Mar 30 14:41:57 1996
From: [e-mail] (John Ballentine)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: PCB plated thru holes
Date: 29 Mar 1996 04:31:55 GMT
Message-ID: <4jfp3r$[e-mail]>
References: <4jfhlc$[e-mail]>
Reply-To: [e-mail] (John Ballentine)


In a previous article, [e-mail] (Ken Burtchaell) says:

>I am looking for a method to simulate plated thru holes in thin(.010
>duroid).This is for small quanity work,one of a kind boards for amateur
>microwave projects.
>
>I had a thought about drilling holes in the board and filling them in
>with conductive epoxy.
>
>Any comments?
>
>Tnx in advance.    73  Ken  W6GHV
>
>
You would be better off putting a wire through the hole and soldering
it to the copper on both sides, then cutting off any excess. Many
people use copper eyelet rivets if they can't do plated through holes.
The conductivity of conductive epoxy is not that great in as small a
cross section as a hole.
--
John Ballentine WB2SNB          Divina natura dedit agros,
Chandler, Arizona               ars humana aedificavit urbes.


From [e-mail] Sat Mar 30 14:41:58 1996
From: Ken Burtchaell <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: PCB plated thru holes
Date: 29 Mar 1996 02:24:44 GMT
Message-ID: <4jfhlc$[e-mail]>

I am looking for a method to simulate plated thru holes in thin(.010
duroid).This is for small quanity work,one of a kind boards for amateur
microwave projects.

I had a thought about drilling holes in the board and filling them in
with conductive epoxy.

Any comments?

Tnx in advance.    73  Ken  W6GHV



From [e-mail] Sat Mar 30 14:41:59 1996
From: [e-mail] (Bob Boardman)
Newsgroups: rec.radio.amateur.homebrew
Subject: Plans for 2m SSB 10w-to-??? Linear Amp?
Date: 26 Mar 1996 17:32:56 GMT
Message-ID: <4j99o8$[e-mail]>
Reply-To: [e-mail]


    I've been looking for a linear amp to use with my Icom IC-211 2 meter
  all-mode rig, which only puts out 10 watts.  Most of the commercial amps
  I've seen are either designed for HTs and use 2-5 watts in for 30-40 watts
  out, FM only, or are desinged for the newer and more powerful all-mode rigs
  and use 25 watts in for 150 watts out.  The 1996 _ARRL Handbook_ only has
  plans for a 2m "brick", for FM only.  If anyone knows of a commercial amp
  that meets these requirements, I might consider it, but I'm leaning towards
  building my own at this point.  If anyone knows where I might find a good se
t
  of plans for such an amp, I'd appreciate a pointer.  I'm open to either an
  all solid state or a tube design, that could be built by someone with a mode
st
  amount of experience in kit building.

  TIA,

  -Bob

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
=
| Bob Boardman, Albuquerque, New Mexico - KC5SFW - ARRL, Upper Rio FM Society
|
|         <[e-mail]>     PGP 2.6.2 public key available
|
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
=


From [e-mail] Sat Mar 30 14:42:00 1996
From: [e-mail] (Dean Denter)
Newsgroups: rec.radio.amateur.equipment,rec.radio.amateur.homebrew
Subject: Re: Rechargeable Battery Source?
Date: 26 Mar 1996 20:15:09 GMT
Message-ID: <4j9j8d$[e-mail]>
References: <4j98u5$[e-mail]>

In article <4j98u5$[e-mail]>,
        [e-mail] (John Hill) writes:
>Does anyone have a source for either Nickel Metal-Hydride or Lithium-Ion
>type cells? I am particularly interested in AA cells. It seems that none
>of the big HT battery pack dealers have any. Thanks in advance...John
>

Try the RC hobby suppliers/magazines, the battery distributors seem
to target the radio control guys more than hams.  I've been getting
most of my cells from Tower Hobbies (Sanyo Cadnica cells -- they also
have NiMH cells (with and without solder tabs)), they seem to have
better prices than the ham suppliers do (not an ad, just a satisfied
customer).

regards,
Dean.
--
Dean Denter               work -> [e-mail]
VA3CDD                    play -> [e-mail]
[[[[[[[[[[[[[[I speak only for myself]]]]]]]]]]]]]]



From [e-mail] Sat Mar 30 14:42:01 1996
From: [e-mail] (John Hill)
Newsgroups: rec.radio.amateur.equipment,rec.radio.amateur.homebrew
Subject: Rechargeable Battery Source?
Date: Tue, 26 Mar 96 16:14:08 GMT
Message-ID: <4j98u5$[e-mail]>

Does anyone have a source for either Nickel Metal-Hydride or Lithium-Ion
type cells? I am particularly interested in AA cells. It seems that none
of the big HT battery pack dealers have any. Thanks in advance...John

John Hill NJ0M
[e-mail]


From [e-mail] Sat Mar 30 14:42:02 1996
From: Peter Dingemans <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: schematics for VHF amp using 2c39 / 4cx250 ?
Date: Thu, 28 Mar 1996 18:12:59 -0800
Message-ID: <Pine.PCN.3.91.960328180505.7053A@[130.115.53.110]>
References: <4j8v9u$[e-mail]> <4je7ud$[e-mail]>



G'day everyone,

I'd like to know if anyone has schematics for a VHF amp using those
valves (esp. the 2c39). Even though valves may seem old-fashioned,
they're still the cheapest way to get quite a lot of power in the air for
very little money. (a used 2c39 costs about 10 dutch guilders, which is
about 7US$). Compare that with the price of a BLX/BLY  VHF power-transistor!

I know there are still quite a lot of amateurs around who use these
valves, and if they have a simple schematic, I'd like to hear from them.
I currently have some schematics for the 2m and 70cm, but they use
coaxial techniques, while I'd rather use 'normal' wound coils (much
easier to build/modify).

So, if anyone has a simple schematic or any experience with tube-amps,
please let me know.

Also, any web-sites with schematics or any other info on using RF-valves
will be appreciated. I've been looking for a week, but have found
practically nothing.

Have a nice day,

Peter Dingemans,
Rotterdam,
The Netherlands.


From [e-mail] Sat Mar 30 14:42:04 1996
From: [e-mail] (gudmundur)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: schematics for VHF amp using 2c39 / 4cx250 ?
Date: 29 Mar 1996 04:41:17 GMT
Message-ID: <4jfpld$[e-mail]>
References: <4j8v9u$[e-mail]> <4je7ud$[e-mail]> <Pine.PCN.3.91.960328180505.7053A@[130.115.53.110]>

In article <Pine.PCN.3.91.960328180505.7053A@[130.115.53.110]>,
[e-mail] says...
>
>
>
>G'day everyone,
>
>I'd like to know if anyone has schematics for a VHF amp using those
>valves (esp. the 2c39). Even though valves may seem old-fashioned,
>they're still the cheapest way to get quite a lot of power in the air
for
>very little money. (a used 2c39 costs about 10 dutch guilders, which
is
>about 7US$). Compare that with the price of a BLX/BLY  VHF
power-transistor!
>

Avoid coil type tank cicuit for 4CX250 and it's relatives when
working above 70-90 mhz. The circulating currents are unpredictable,
and the ovrall efficiency drops off rapidly. Coax tanks are forgiving
at 2M vhf after a small learning curve. Almost any ARRL handbook from
1965 to present has good homebrew amp ideas. Do you have access to
these books?      73    KD3SH



From [e-mail] Sat Mar 30 14:42:05 1996
From: "Charles H. Reichert" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Siliconix VMP-4
Date: Thu, 28 Mar 1996 12:50:34 -0600
Message-ID: <[e-mail]>
References: <4jd3lc$[e-mail]>

JohnsonHE wrote:
>
> Looking to purchase Siliconix VMP-4 FET transistors. If you have a few or
> a bunch you'd like to turn loose of, leave message to [e-mail].
> Device no longer made.


I don't have any VMP-4 but have the following:
(Make offer for Lot)

    Siliconix 28VDC Power FETs -> 175Mhz
    These devices have never been used.
        Still in packaging.

Qty - 4  40W  DV2840S
      3  20W  DV2820S
      6   5W  DV2805S
      2   5W  DV2805W
      With Spec Sheets
--
                         \|/
                         ^ ^
                       ( O O )
====================.ooO==U==Ooo.====================
|          KD9JQ               847-358-3827 Home    |
|    Charles H. Reichert       847-632-6669 Work    |
|      955 Concord Ln.                              |
|  Hoffman Ests., IL. 60195   [e-mail]  |
=====================================================


From [e-mail] Sat Mar 30 14:42:06 1996
From: [e-mail]
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: Tue, 26 Mar 96 14:07:11 PDT
Message-ID: <[e-mail]>
References: <4i1vhj$[e-mail]> <4i9iij$[e-mail]>  <4iais1$[e-mail]>


In Article<4iais1$[e-mail]>, <[e-mail]> writes:


 > In article <4i9iij$[e-mail] >, [e-mail] (Tom
Bruhns) says:
 >  >
 >  >WB3U ([e-mail]) wrote:
 >  >
 >  >..
 >  >
 >  >: The best protective finish I have found for electronic parts is
 >  >: polyurethane varnish.  It's somewhat more brittle than other
oil-based
 >  >: varnishes, but is probably the toughest single-part, air-dry
finish
 >  >: on the market.  Once it has fully cured (usually three to four
weeks),
 >  >: polyurethane is nearly as hard as baked enamel.  The only drawback
to
 >  >: polyurethane is its deterioration in sunlight, but marine and
exterior
 >  >: versions are available with UV blockers that will significantly
extend
 >  >: the life of the finish under adverse conditions.
 >  >
 >  >..
 >  >
 >  >Thanks to Jack for a nice posting on using polyurethane varnish.  I
had a
 >  >brief email exchange with Jack about one issue that remains in my
mind, and
 >  >agreed to post it here to see if anyone has any difinitive info on
it.
 >  >
 >  >My concern is that polyurethane has a rather high dissipation
factor.
 >  >It was a little hard to find listings, but looks like about 0.05,
 >  >compared with .0002 or less for polystyrene, polyethelene and
Teflon.
 >  >So the question is, given that it's used in a rather thin coating,
does
 >  >that really make any difference?  Has anyone actually measured the
 >  >unloaded Q of a cavity before and after coating with any type of
clear
 >  >coat, whether it's polyurethane or acrylic or something else?
 >  >
 >  >--
 >  >Cheers,
 >  >Tom
 >  >[e-mail]
 >
 >
 > A microwave oven can be used to determine relative loss of different
 > materials to RF.
 > Heat the material in the microwave oven for a short time.
 > Include a cup of water as a load.
 > The hotter the material gets, the lossier it is to RF.
 > I have some bowls the expoded in the microwave oven due to disipation.
 >
 > 73
 > Glenn Little
 > WB4UIV
Glenns microwave Idea is a good one.  I chill the object in the freezer
first.  Seems to make it easier to note temperature differences.
73
w7gsm



From [e-mail] Sat Mar 30 14:42:07 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: 26 Mar 1996 18:57:43 -0500
Message-ID: <4ja09n$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>, [e-mail]
writes:

> > The hotter the material gets, the lossier it is to RF.
> > I have some bowls the expoded in the microwave oven due to disipation.
> >
> > 73
> > Glenn Little
> > WB4UIV
>Glenns microwave Idea is a good one.  I chill the object in the freezer
>first.  Seems to make it easier to note temperature differences.
>73
>w7gsm

Perhaps that test should be qualified a little more. The hotter the
material gets, the lossier the material is when subjected to microwave
frequency electromgnetic fields!
That test doesn't necessarily indicate loss at other frequencies, or for
one field or another! For example, a tree provides very little absorsion
of HF electromagnetic fields,yet it will almost totally absorb microwave
frequency energy. A magnetic material may be very low loss at HF,  and
extremely dissipative at UHF or higher.

:-)
73 Tom


From [e-mail] Sat Mar 30 14:42:08 1996
From: Christopher Trask <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: SSB generation/crystal filters
Date: 24 Mar 1996 21:09:01 -0700
Message-ID: <4j568t$[e-mail]>
References: <[e-mail]>

Norman Kohn <[e-mail]> wrote:
: G'morning all,

:       Is it possible at all to make a filter (presumably using
: crystals) that cuts off sharply enough (at 1000Khz) to pass one
: sideband, but not the other?? In other words, is it practical to assume
: I can find/build a HP and a LP filter for USB and LSB at an IF of 1
: Mhz??

:       If this isn't practical, I have another potential plan that
: ought to be inexpensive and relatively effective, IF it works.  That is,
: could I have a quadrupler (or higher multiplication) at AF level, then
: mix with 4 Mhz, then filter for sidebands -- 4 times less sharpness
: needed -- and then divide by 4??  Or would AF multiplier distort voice
: too much??

        It's actually far more practical these days to make a phase-
shift type SSB generator than to try and make (UGH!) or buy crystal
filters.  With only six poles and using 1% resistors and 2% capacitors
(readily available), you can make a very inexpensive SSB generator that
will have 40dB of unwanted sideband suppression with a baseband of
50-2500 Hz. It requires the phase shifter, two mixers, and a combiner.
By changing the polarity of one of the two phase shifted channels, you
can select either USB or LSB.  Total cost would be around $20.

        I know that the question was about generating SSB signals with
a crystal filter, but I thought that this would be helpful as alter-
natives were also presented.

        There is a third method, referred to as the Weaver modulator,
but I have found it to be less practical than the phase-shift approach.

                                          Regards,

                                          Chris

------------------------------------------------------------------------------
Chris Trask / N7ZWY                       Circuit Design for the RF Impaired
ATG Design Services                       __  __     ____  ___       ___ ____
[e-mail]       _~_            /__)/__) / / / / /_  /\  / /_    /
                         (@ @)          /   / \  / / / / /__ /  \/ /___  /
----------------------ooO~(_)~Ooo---------------------------------------------


From [e-mail] Sat Mar 30 14:42:10 1996
From: [e-mail] (KN5S)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: SSB generation/crystal filters
Date: 25 Mar 1996 06:11:24 -0500
Message-ID: <4j5v0s$[e-mail]>
References: <4j568t$[e-mail]>

Methods of SSB generation are discussed in detail in the ARRL Handbook.



73,  Mark  KN5S     [Mark  Mandelkern,  Las Cruces,  NM]


From [e-mail] Sat Mar 30 14:42:11 1996
From: [e-mail] (Occolowitz John)
Newsgroups: rec.radio.amateur.equipment,rec.radio.amateur.homebrew
Subject: Re: Ten-Tec 1209 transverter kit: comments?
Date: 30 Mar 1996 00:09:31 GMT
Message-ID: <4jhu3r$[e-mail]>
References: <4j8v9u$[e-mail]> <4jap1k$[e-mail]>

In article <4jap1k$[e-mail]>, [e-mail] (Parf) wrote:
>Hi Dean,
>While I have not built the TT kit I did hear a # of them on 6M last Es
>season- they were consistantly the nicest sounding sigs on the air.
>Previous postings here indicate the instructions hark back to the
>excellent days of Heath. Note also they now have a 2M to 6M downconverter
>to place your 2M all-mode on 6. I've been told the 1st run is sold out! I
>have no affiliation w/ TT in fact I don't own a TT!- but if I had serious
>interests in HF I would own nothing but TT.
>
>Dale WA2YPY

Ordered 1209 today, salesmam quoted 3 week delivery delay.

John KB9MIE


From [e-mail] Sat Mar 30 14:42:11 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Michael Fayette)
Subject: test
Message-ID: <[e-mail]>
Reply-To: [e-mail]
Date: Thu, 21 Mar 1996 13:44:10 GMT






From [e-mail] Sat Mar 30 14:42:13 1996
From: [e-mail] (Eric Edin)
Newsgroups: sci.electronics.design,rec.radio.amateur.homebrew,comp.arch.embedded,comp.dsp
Subject: Re: The US$89 DSP eval kit from Analog Devices
Date: 21 Mar 1996 22:20:35 GMT
Message-ID: <4isknj$[e-mail]>
References: <4irm6f$[e-mail]>

Douglas L. Datwyler ([e-mail]) wrote:
: Can those who have purchased this US$89 DSP evaluation board containing the
: ADSP-2181 please comment on projects they have done, the packaged tools,
: documentation, the hardware, anything else?

: Thanks,

: Douglas L. Datwyler    WR7O
: [e-mail]

  Well worth the $89($100 for me with shipping).  I like the 'c like'
language.  The setup code is
complex, but well documented code is included.  Figuring out what
register moves are legal seems harder than with TI's 320c26, but there is
a lot more memory and it is all equally accessible, and it runs 3 times
faster.
  Kit comes with power supply, and I think there was a serial cable.  I
didn't expect either for that price.
  If you will be driving hardware with the analog output, you will need
to disable it or make it harmless during power-up.  The kit emits a nice
message intended for speakers at power up.
  The board is probably twice the size of TI's 320c26 kit if that is
important.
  I wish the A/D-D/A was faster.  Using mono, you can get 88khz which
makes ragged sine waves above 10 khz and the processor is barely working
at that rate.
  The documentation is missing a good language reference.  I have an old
ADSP-2101-2102 user's manual and it was necessary for me to spend a lot
of time reading it to understand the language and hardware.
  Hope this helps,
  Eric


From [e-mail] Sat Mar 30 14:42:14 1996
From: [e-mail] (Henry B. Smith)
Newsgroups: sci.electronics.design,rec.radio.amateur.homebrew,comp.arch.embedded,comp.dsp
Subject: Re: The US$89 DSP eval kit from Analog Devices
Date: 21 Mar 1996 21:38:13 -0800
Message-ID: <4itec5$[e-mail]>
References: <4irm6f$[e-mail]> <4isknj$[e-mail]>

Eric Edin ([e-mail]) wrote:
:   Well worth the $89($100 for me with shipping).  I like the 'c like'
: language.  The setup code is
: complex, but well documented code is included.  Figuring out what
: register moves are legal seems harder than with TI's 320c26, but there is
: a lot more memory and it is all equally accessible, and it runs 3 times
: faster.
: ... etc ...
:

Here's some more info.

Software included:
  A windows based demonstration program.
  DOS Based Assembler
  DOS Based Linker
  DOS Based Promspliter
  DOS Based Simulator.  This is nice because there is no debugger.  You
                        can do a lot with this simulator, including creating
                        plots of your output.
  Demo programs

If you are serious about programming the 2181 (thats the chip on the
board) you will the "ADSP-2100 Family User's Manual", which is free from
ADI.  An additional helpful book is "ADSP-2100 Family Assembler Tool &
Simulator Manual" also free from ADI.

I agree with the previous post that said the assembly language is easier
than the TI TMS32Cxx.

The set up for the serial port and the 1847 Stereo CODEC is a bit complex
but there are several demo programs that can be boiler plated.

ADI has a web page: http://www.analog.com with information (search on
EZKIT LITE).  There are several samples of FFT, FIR, IIR and others.

Good luck,

Henry
--
Henry Smith ([e-mail])



From [e-mail] Sat Mar 30 14:42:17 1996
Date: Tue, 26 Mar 1996 21:42:23 +01
From: Bob Mueller <[e-mail]>
Message-ID: <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Thermistor mounts needed

I would like to obtain one or two thermistor mounts for a microwave power mete
r
so I can study the construction and maybe also ways to get dead ones up and
running again.  I would like the sort for coaxial cable, not for waveguides.
I would expect to repay you the cost of shipping and something besides for the
help and trouble.  I do not anticipate finding anyone offering functioning
mounts, though I welcome any offers for those if you have one gathering dust!

    Bob<iff161@DJUKFA11>

PS  I don't care much about who made them;  I'll probably learn as much from
any decent brand and there have been several companies who made them.



From [e-mail] Sat Mar 30 14:42:18 1996
From: Clifford Buttschardt <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Thermistor mounts needed
Date: Thu, 28 Mar 1996 11:00:55 -0800
Message-ID: <[e-mail]>
References: <[e-mail]>

Bob, you might learn just as much about these mounts by looking back in
older Ham Radio magazines for a homemade mount constructed with 1/200 amp
fuses.  We used to construct these and use them without effort as high as
1296 Mhz for little more than the cost of the fuses.  Cliff Buttschardt W6HDO


On Tue, 26 Mar 1996, Bob Mueller wrote:

> I would like to obtain one or two thermistor mounts for a microwave power me
ter
> so I can study the construction and maybe also ways to get dead ones up and
> running again.  I would like the sort for coaxial cable, not for waveguides.
> I would expect to repay you the cost of shipping and something besides for t
he
> help and trouble.  I do not anticipate finding anyone offering functioning
> mounts, though I welcome any offers for those if you have one gathering dust
!
>
>     Bob<iff161@DJUKFA11>
>
> PS  I don't care much about who made them;  I'll probably learn as much from
> any decent brand and there have been several companies who made them.
>
>
>


From [e-mail] Sat Mar 30 14:42:19 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Transmitting tubes!
Date: Fri, 29 Mar 96 18:27:29 GMT
Message-ID: <4jhaev$[e-mail]>
References: <4jg1om$[e-mail]>

   [e-mail] (Dino Darling) wrote:

>Hello!  I would like to build a tube transmitter (not amplifier).
>I need to learn more about tubes and I need YOUR help.  It is my
>understanding that you can use TV sweep tubes for transmitters BUT
>that this parctice is NOT recommended.  What is a good RF tube
>capable of 100 watts output and what books do you suggest?
>
>I think Yaesu used the 6146 tube.  Is this a good choice?
>
>My goal is to BUILD my own transmitter/receiver and to put the
>Amateur back in radio.  THANKS!!!

Heathkit, Collins and many others used the 6146 and its variants long
before the Japanese entered the market.  Yes, it's a good, rugged
design and probably the most appropriate to the 100 watt output level.
Actually, a pair of 6146B's will deliver about 120 watts in class AB1
(SSB/CW) and about 160-170 watts in class C (CW only).

There were a number of 6146 designs in ARRL Handbooks during the 60's
and early 70's.  The '72 Handbook described a heterodyne-type CW
transmitter with (2) 6146B's that included a built-in T-R switch for
QSK.  The transmitter was a hybrid (only the driver and finals were
tube-type), but it covered 160 thru 10 meters (no WARC).

Incidentally, as much as I enjoy the glow of tubes, I wouldn't
personally build a transmitter with a tube-type final at this power
level.  If you do, be prepared to scrounge *many* parts at hamfests,
or to end up with a project that will be much more expensive than its
solid-state counterpart. One option in this regard might be to buy a
used Heath HW-101 or similar with the matching AC power supply and
scrap the whole thing for parts.

However you decide to do this, I recommend that you become very
familiar with the potential cost of the entire project (and determine
whether parts necessary to complete it are even available) before you
spend a nickel.  Commercial tube-type transmitters are plentiful on
the used market at reasonable prices.  A homebrew version could easily
cost twice as much and have little or no resale value.

73,
Jack  WB3U


From [e-mail] Sat Mar 30 14:42:20 1996
From: [e-mail] (K2EK)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Transmitting tubes!
Date: 29 Mar 1996 15:49:15 -0500
Message-ID: <4jhicb$[e-mail]>
References: <4jg1om$[e-mail]>

In article <4jg1om$[e-mail]>, [e-mail] (Dino
Darling) writes:

> What is a good RF tube capable of
>100 watts output and what books do you suggest?
>
>I think Yaesu used the 6146 tube.  Is this a good choice?
>
>

EVERYONE used a pair of 6146Bs with a 12BY7 driver... well, almost
everyone.

Yes, that will make a good lineup.  You can also use a pair of 807 or 1625
(the 12.6v equivalent) if you want to include the nostalgia element.  For
real fun, get hold of a 6L6 or 6DQ6... Either makes a nice 1 tube
transmitter in the 15-25w range.

TV sweep tubes will work.  One of my favorite activities was finding a
junked TV by the curb on the way home from school and  making a
transmitter out of it by dinner time. The only "external" parts needed
were a couple air variable capacitors, some wire and a crystal.  Get hold
of any ARRL handbook from the 60s or early 70s.  They are loaded with
ideas you can try and the tube tables are indespensible.


Bill K2EK


From [e-mail] Sat Mar 30 14:42:21 1996
From: [e-mail] (Edward)
Newsgroups: rec.radio.amateur.homebrew
Subject: Trying to locate SB220 parts
Date: 25 Mar 1996 23:46:49 GMT
Message-ID: <4j7b99$[e-mail]>

I am trying to locate parts for my Heathkit SB-220 amp. I have been told
that there is a company in Florida called "Harbach Electronics".
I have not been able to locate them. If anyone has the phone number or
knows the city it is located in, please drop me a line. If anyone knows
of any other sources for SB-220 parts, I would love to hear about them
as well.......Thank You



From [e-mail] Sat Mar 30 14:42:22 1996
From: [e-mail] (David Tait)
Newsgroups: rec.radio.amateur.equipment,rec.radio.amateur.homebrew
Subject: Want info: Cubic Corp 1201 HF Tcvr
Date: 28 Mar 1996 12:45:08 GMT
Message-ID: <4je1kk$[e-mail]>

Hi,

Several years ago now I bought (cheaply) a HF transceiver which
was badged "AEL 1201".  The company AEL claimed to have no knowledge
of such a radio.  Recently I learned that the 1201 was actually
only distributed by AEL and then only for a short period.  It seems
the radio was built by Cubic Corporation (I think).  I would be
very grateful if anyone could supply me with contact details for
Cubic, or better still, let me know where I can get information
(just the schematic would be great) on this radio.  It has a
TTL based synth giving 12 channels and I would like enough info
to be able to homebrew a replacement synth/VFO.

Many thanks,

David
--
David Tait,                       Tel:   [phone]
Electrical Engineering Dept,      Fax:   [phone]
The University,                 Radio:   G0JVY
Manchester,  M13 9PL,  UK.     E-mail:   [e-mail]


From [e-mail] Sat Mar 30 14:42:24 1996
From: [e-mail] (Ed Ganger)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: X-Tal / Stable TX's???
Date: Fri, 22 Mar 1996 17:29:26 -0400
Message-ID: <[e-mail]>
References: <[e-mail]>

In article <[e-mail]> "mooney p
atrick ( bs cmsc)" <[e-mail]> writes:

>  Help!  If anyone could help me find information or possible e-mail info
>to me on the contruction of stable VHF transistor based transmitters
>using crystals or cap/coil oscillators.  Any frequency within the range
>30MHz - 200MHz is what I'm looking for.  The info I find on XTAL
>transmitters in most books require either large circuits or are vague in
>their construction.

>  I'm not looking for power since the maximum range will be > 1000 feet,
>but fewer components and small size are critical.  Any help would be
>greatly appreciated.


>  Thanks.

>                              -  Patrick Mooney

I am in the midst of building up a CW QRP xmitter around a
"Crystal Clock Oscillator" of the sort used in computers and
such ...

I was lucky and found one in my junk box at 21.194 MHZ ...

They are available from many of the mail order houses at stock
frequencies up to 100MHz and by special order from crystal
manufacturers like FOX, JAN, US Crystal at specific frequencies.
In less than 10 lots, custom frequencies might be kind of pricey,
tho---
Regards,
Ed


From [e-mail] Sat Mar 30 14:42:25 1996
From: [e-mail] (Richard Karlquist)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: X-Tal / Stable TX's???
Date: 26 Mar 1996 17:49:01 GMT
Message-ID: <4j9amd$[e-mail]>
References: <[e-mail]>

In article <[e-mail]>,
mooney patrick ( bs cmsc) <[e-mail]> wrote:
>
>  Help!  If anyone could help me find information or possible e-mail info
>to me on the contruction of stable VHF transistor based transmitters
>using crystals or cap/coil oscillators.  Any frequency within the range
>30MHz - 200MHz is what I'm looking for.  The info I find on XTAL
>transmitters in most books require either large circuits or are vague in
>their construction.
>
>  I'm not looking for power since the maximum range will be > 1000 feet,
>but fewer components and small size are critical.  Any help would be
>greatly appreciated.
>
>
>  Thanks.
>
>                              -  Patrick Mooney
>

Step 1:  Build an LC Colpitts oscillator that oscillates at the frequency
of interest (no xtal yet).  Be sure to put in an adjustable capacitor so
you can tune the frequency to within 1% of the crystal frequency.

Step 2:  Now insert the xtal in series with the emitter as far as RF current
is concerned; you'll need some other method of DC return since DC can't
go thru the xtal.

Step 3:  Adjust tuning capacitor (see step 1) for maximum output power.

Step 4:  If desired, put a 10 to 60 pF. trimmer capacitor in series with
the xtal to trim frequency.

Rick Karlquist N6RK
[e-mail]


From [e-mail] Tue Apr 02 09:07:15 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (SARUMAN)
Subject: Re: HOMEBREW
Message-ID: <[e-mail]>
References: <4j9pad$[e-mail]>
Date: Wed, 27 Mar 1996 04:03:35 GMT

>I am looking for a homebrew newsgroup.  This was the closest I got to
>one and it looks like I am at the wrong spot.  Pleaasssee, can someone
>point me in the right direction?

>Julie
>[e-mail]

Home Brew WHAT? If it's BEER Brewing you want try rec.crafts.brewing


<tsb>
                               Midgard Graphics
           3D Animation and Special FX for the hobbyist videographer
                          Email: [e-mail]

--
          Drop into #amigacafe on IRC's undernet for a chat sometime

--

<tsb>

                     A man of many hobby's master of none.




From [e-mail] Tue Apr 02 09:07:16 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Palomar HF Tube Amp Questions?
Date: 27 Mar 1996 17:52:42 -0500
Message-ID: <4jcgrq$[e-mail]>
References: <4jbs9l$hs4$[e-mail]>

In article <4jbs9l$hs4$[e-mail]>, George Harris
<[e-mail]> writes:

>I've just purchased a Palomar HF Multi-Band Tube Amp at a
>HamFest. I can't find a model number on the unit to identify it.
>Palomar Electronics is no longer in business so they can't help
>me. Can anyone help me to identify the unit I have and a possible
>source for Schematics.
>
>P.S.   The unit uses 6 6LF6 Tubes.
>
>Thanks Alot!
>
>George
>
>

Hi George,

That was a CB amp. Good luck on getting it to work on the ham bands. Even
if you get it to put out RF, it will be a NASTY dirty signal.

Palomar got out of the illegal CB trade.

73 Tom


From [e-mail] Tue Apr 02 09:07:18 1996
From: Leon Heller <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Wanted Receiver for 137 Mhz, or a KIT for homebrew!
Date: Wed, 27 Mar 96 23:05:04 GMT
Message-ID: <[e-mail]>
References: <4ja0ov$[e-mail]>
Reply-To: [e-mail]

In article <4ja0ov$[e-mail]> [e-mail] "Geert Pirens" writ
es:

> Hello all of you in this area.
>
>
> Can someone help me with my problem?
>
> I like to receive the next satellites: NOAA, METEOR. But for to
> receive these sat's you must have a receiver at 137 Mhz.
>
> Now I'm loking for some information where I can buy me sutch receiver.
>
> A homebrew kitt wil also do !!
>
> All information and reactions in case with my problem is WELKOM !!!!
>
> Thanks already for those who will respons to my letter.
>
> you can also send mail via FidoNet :  Geert Pirens  2:292/115.9

Maplin Electronics here in the UK on [phone] have a satellite
book with details of weather satellite Rx construction. Cirkit on
[phone] do a weather satellite Rx kit, and PC software to go
with it. Spectrum Communications on [phone] also do a weather
satellite Rx kit.

73, Leon
--
Leon Heller, G1HSM                | "Do not adjust your mind, there is
E-mail [e-mail]  |  a fault in reality": on a wall
Phone: [phone]         |  many years ago in Oxford.


From [e-mail] Tue Apr 02 09:07:19 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Gary Coffman)
Subject: Re: diplexer design
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
References: <4j75pc$[e-mail]>
Date: Thu, 28 Mar 1996 02:18:44 GMT

In article <4j75pc$[e-mail]> [e-mail] writes:
>
>What I was wondering is how a diplexer design can be acheived.  That
>is after BP filtering the desired frequencies from each transmitter
>with parallel stubs, can I just connect the two XMTR output lines and
>expect them to mix?

A diplexer consists of a high pass and a low pass filter with their
outputs Teed together to feed the antenna. The theory is that each
filter presents a very high impedance at the other frequency, so that
it beomes essentially "not there" to the other signal. Thus the signals
behave as if they were directly connected between the antenna and
their respective radios. The filters may require additional stopband
elements for the opposite frequency to achieve this.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Tue Apr 02 09:07:20 1996
From: [e-mail] (Dino Darling)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Palomar HF Tube Amp Questions?
Date: 29 Mar 1996 06:52:20 GMT
Message-ID: <4jg1b4$[e-mail]>
References: <4jbs9l$hs4$[e-mail]> <4jcgrq$[e-mail]>

In article <4jcgrq$[e-mail]>, [e-mail] says...
>
>In article <4jbs9l$hs4$[e-mail]>, George Harris
><[e-mail]> writes:
>
>>I've just purchased a Palomar HF Multi-Band Tube Amp at a
>>HamFest. I can't find a model number on the unit to identify it.
>>Palomar Electronics is no longer in business so they can't help
>>me. Can anyone help me to identify the unit I have and a possible
>>source for Schematics.
>>
>>P.S.   The unit uses 6 6LF6 Tubes.
>>
>>Thanks Alot!
>>
>>George
>>
>>
>
>Hi George,
>
>That was a CB amp. Good luck on getting it to work on the ham bands. Even
>if you get it to put out RF, it will be a NASTY dirty signal.
>
>Palomar got out of the illegal CB trade.
>
>73 Tom

Tom, the 300-A was a 80, 40, 20, 10 meter amp.  I have one.



From [e-mail] Tue Apr 02 09:07:21 1996
From: "C. J. Hawley" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: PCB plated thru holes
Date: Fri, 29 Mar 1996 09:19:21 -0600
Message-ID: <[e-mail]>
References: <4jfhlc$[e-mail]> <4jgupt$[e-mail]>
To: David Negaard <[e-mail]>

David Negaard wrote:
>
> Ken Burtchaell ([e-mail]) wrote:
> : I am looking for a method to simulate plated thru holes in thin(.010
> : duroid).This is for small quanity work,one of a kind boards for
> : amateur microwave projects.

> I no longer remember what they're called, but when I was learning
> miniature and microminiature electronic repair in the Navy, we had
> these items that were essentially 'hole-liners,' and they worked
> great...  They were sized to fit the through-hole, and had one rolled
> lip.  The other lip was straight, but after inserting the item, the
> technician would flare the straight end, then flatten it, then solder
> both sides to the pads.

I think they are just called eyelets. Look in the hardware section of
Allied Radio or Newark Electronics.

Charles Jack Hawley Jr.
Amateur Radio KE9UW (A.K.A. 'Chuck' in Ham Radio)
BMW K100RS, BMWMOA #224 (A.K.A. 'Jack' in Motorcycles)
[e-mail]
Sr. Research Engineer Emeritus
Univ of Ill, Urbana-Champaign



From [e-mail] Tue Apr 02 09:07:22 1996
From: "Gene P. Smith" <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Kenwood 930 ant. tuner
Date: Fri, 29 Mar 1996 10:29:02 -0800
Message-ID: <[e-mail]>

Need mod for all band operation of ant. tuner.
 Thanks, 73 AC4WV.
 My email = [e-mail]



From [e-mail] Tue Apr 02 09:07:22 1996
From: Ken Burtchaell <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: PCB plated thru holes
Date: 29 Mar 1996 12:13:40 GMT
Message-ID: <4jgk5k$[e-mail]>
References: <4jfhlc$[e-mail]> <4jfp3r$[e-mail]>
To: [e-mail]

Tnx for the reply.I have used both the methods that you suggest.The
problem with them is you lose the flat plane surface of the ground plane
side which is essential in getting a good rf bond at microwave
frequencies to the enclosure and the associated input and output
connectors.

73  Ken W6GHV



From [e-mail] Tue Apr 02 09:07:24 1996
From: [e-mail] (Joe Landis - Systems & Network Mgr)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: PCB plated thru holes
Message-ID: <[e-mail]>
Date: 29 Mar 96 15:43:10 EST
References: <4jfhlc$[e-mail]> <4jgupt$[e-mail]>
Distribution: world

In article <4jgupt$[e-mail]>, [e-mail] (Davi
d Negaard) writes:
> Ken Burtchaell ([e-mail]) wrote:
> : I am looking for a method to simulate plated thru holes in thin(.010
> : duroid).This is for small quanity work,one of a kind boards for
> : amateur microwave projects.
>
> : I had a thought about drilling holes in the board and filling them in
> : with conductive epoxy.
>
> : Any comments?
>
> : Tnx in advance.    73  Ken  W6GHV
>
> I no longer remember what they're called, but when I was learning
> miniature and microminiature electronic repair in the Navy, we had
> these items that were essentially 'hole-liners,' and they worked
> great...  They were sized to fit the through-hole, and had one rolled
> lip.  The other lip was straight, but after inserting the item, the
> technician would flare the straight end, then flatten it, then solder
> both sides to the pads.
>
> 73 de KB0PXK

Rivets? For bigger holes and slots, use strips of copper foil or flashing.
Joe - AA3GN
--
Joe Landis - Systems and Network Manager - North American Drager - Telford, PA
[e-mail]                        ..speaking only for myself, of course..


From [e-mail] Tue Apr 02 09:07:25 1996
From: [e-mail] (Tom Bruhns)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: PCB plated thru holes
Date: 29 Mar 1996 18:32:51 GMT
Message-ID: <4jhacj$[e-mail]>
References: <4jfhlc$[e-mail]>

Ken Burtchaell ([e-mail]) wrote:
: I am looking for a method to simulate plated thru holes in thin(.010
: duroid).This is for small quanity work,one of a kind boards for amateur
: microwave projects.

: I had a thought about drilling holes in the board and filling them in
: with conductive epoxy.

: Any comments?


Some of the folk here doing prototyping in the 1-2GHz region were using
a conductive ink successfully.  It was heavily silver-laden.  It was
something sold in a "pen" for PC board repair work.  Thier measured
performance was only very modestly different from the plated through holes
on the finished manufactured boards.

The way I've been doing vias on proto surface mount boards etched in my
kitchen is to drill 0.0135" holes and put 30-gauge silver-plated wire-wrap
wire through them, flattening over each end.  The result stands off the
board surface by perhaps 0.008", which may be more than you wanted for your
RF seal, but if you put some RF gasket material in, it seems like it would
OK.  You could even run the 30 gauge wire all along that edge of the board,
to make it uniform, if you can stand the height. (That's pretty thin
material you are using!)


--
Cheers,
Tom
[e-mail]


From [e-mail] Tue Apr 02 09:07:26 1996
From: [e-mail] (Richard Karlquist)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Crystal Parameters
Date: 29 Mar 1996 23:55:21 GMT
Message-ID: <4jht99$[e-mail]>
References: <4j7gjc$[e-mail]>

In article <4j7gjc$[e-mail]>, M Simon <[e-mail]> wrote:
>
>How can I measure the L & C values for a quartz crystal.
>
>R is easy but L & C stump me.
>
>
>Simon

Measure the Q and then 6.28*F*L = R*Q and 6.28*F*C = 1/(R*Q).

To measure Q, find the frequency difference between +45 degrees of
phase and -45 degrees of phase (or between the 3dB down amplitude points).
The resonant frequency divided by this difference is the Q.

Rick N6RK
[e-mail]



From [e-mail] Tue Apr 02 09:07:27 1996
From: [e-mail] (W8JI  Tom)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Amp. Tank Circuit
Date: 30 Mar 1996 00:27:33 -0500
Message-ID: <4jigo5$[e-mail]>
References: <[e-mail]>

Hi Mike,
In article <[e-mail]>, Mike Sims
<[e-mail]> writes:

>Situation is a 4CX1600 amp. using a pi/L tank.  The amp./tank circuit
>works okay on 20, 15 and 10 meters (efficiency).  However, on 40 and
>80ty meters the efficiency is way off and the output capacitor on the
>tank circuit are at max. capacity.  I have padded additional capacitance
>across the output capacitor to above the calculated value.  The tank's
>input capacitance tunes the band okay.

If the loading cap is at maximum C , it's a sign something in the tank is
off. Pi-L's can behave strange if component values are off. There are
several modes of operation the network could be in if some value is off.

What did you use for the median impedance of the network? By that I mean
the design impedance at the loading capacitors connection point. Or where
did you get the values?

How do you know the inductors are the right values when mounted in the
final operating location? Did you measure them (and how) or just calculate
the sizes?

>The L or output coil is made of a small air wound coil for ten meters
>and a coil wound on three T200-6 toroids using number 12 wire.  The
>inductance and appropriate taps was measured using a Autek Analyzer at
>the frequency of use.

If the toroid core has tapped turns to switch bands, it could be trouble.
There isn't enough flux leakage to allow proper use of most cores in
tapped resonant circuits.
The mutual coupling can get you in trouble fast. I wouldn't trust the
Autek fully in this application, the simple scheme it uses to measure L or
C is subject to error.

Remember ferrous cores change permeability with frequency, so inductance
needs to be measured somewhere around the operating frequency. I don't
have any info on a -6 core. Maybe the material isn't good?

>Will be trying an air core coil on forty meters to see if the toroid is
>causing the problem.

That may be a good idea.

Another thing is all tubes can behave poorly on some frequencies,
depending on bypassing. Tetrodes are a particular headache.

Is the cathode grounded directly? How big is the screen bypass?

73 Tom


From [e-mail] Tue Apr 02 09:07:29 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Henry Baker)
Subject: Re: Parabolic Dish (18")?
Message-ID: <hbaker-2903961925210001@10.0.2.15>
References: <[e-mail]>
Date: Sat, 30 Mar 1996 03:25:21 GMT

In article <[e-mail]>, [e-mail] wrot
e:

> Other sources of cheap parabolic dishes include lampshades (read
> G3RUH's classic article), certain saucepan lids (my wok's lid looks
> about right... :-), some garbage can lids, and those saucer-shaped
> snow sleds. If the object is the right shape, but not conductive, a
> few minutes work with aluminium foil and glue will fix the problem.

I would imagine that an umbrella would work, so long as you stayed within
a million miles or so of it to make sure that it opens...  :-)

--
www/ftp directory:
ftp://ftp.netcom.com/pub/hb/hbaker/home.html



From [e-mail] Tue Apr 02 09:07:30 1996
From: Ken Burtchaell <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Paper for Toner transfer
Date: 30 Mar 1996 04:20:13 GMT
Message-ID: <4jicpt$[e-mail]>

>I picked up some "cooking paper" at my local grocery store for $2.50.This is
a roll(16.5Ftx11.875In) described as a non-stick linin=
g for baking.The paper is too thin to pass thru my printer by itself so I moun
ted it to a ordinary sheet of printer paper.I printed =
some artwork to the sheet,ironed the sheet to a board and then just cooled the
 whole board assembly in water.This sheet then peeled =
neatly away from the board leaving the toner completelylattached to the board.
    73   Ken  W6GHV



From [e-mail] Tue Apr 02 09:07:31 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Low Frequency Counter.
Date: Sat, 30 Mar 96 05:39:33 GMT
Message-ID: <4jihra$[e-mail]>
References: <4j7571$[e-mail]>

   [e-mail] (Rane Curl) wrote:

>I need a simple (cheap) low frequency timed counter with an LCD
>display. Frequencies up to ca. 100 cps; timing intervals of the order
>of 10-50 seconds. Seems simple enough, but I have not seen a kit or
>even small (ca. 5 digit) LCD display at a low price. Suggestions?

A frequency counter with a Period function is useful for this,
although you have to convert the readout to frequency. In the Period
function, the clock is reset by the signal, not the internal timebase.
So, the lower the frequency, the longer the elapsed time that reads on
the display.  This is probably the best way to accurately measure very
low frequency signals.

Other than that, I suppose you could buy a counter with a 10 MHz
timebase and replace the crystal with a 1 MHz or 100 KHz equivalent.

73,
Jack  WB3U


From [e-mail] Tue Apr 02 09:07:32 1996
From: [e-mail] (Peter L. Williamson)
Newsgroups: rec.radio.amateur.homebrew
Subject: Data on CB1 FM Rx. chip
Date: 30 Mar 96 06:57:08 GMT
Message-ID: <[e-mail]>

I recently looked at a FM receiver of UK origin which used what appeared to
be a single conversion FM if chip witha Pll demodulator.  it was marked PS
SB followed by CB1.
Can anybody help with data on this chip?
Tnx. Peter Williamson VK4AWP



From [e-mail] Tue Apr 02 09:07:34 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Anyone willing to help on a Homebrew project???
Date: Sat, 30 Mar 96 06:58:03 GMT
Message-ID: <4jimei$[e-mail]>
References: <4jhv2a$[e-mail]>

Post / CC by mail

   [e-mail] (Mark) wrote:

>1- Automatically divert my regular stereo output to a dummy load when
>a signal is incomming to the HT and breaks the squelch (would prefer
>to be solid state switch, but willing to live with mechanical relays
>for each channel of the stereo)
>
>2 - Would like to be able to divert the audio output from the HT (at
>the same time) to an amplifer on the circuit board and put through
>one or more speakers of the existing stereo system.  (This is not as
>important as the first goal, but would be nice as a part of the whole
>circuit)

Hi Mark,

I posted something to another radio group recently on this same topic.
Rather than reinvent the wheel, I've reprinted it below. Incidentally,
there is no need to connect the output of a solid-state audio amp to a
dummy load.  That's a holdover from tube circuits, where the voltage
across the secondary of the output transformer could rise without a
load and short the transformer.  The only (resistive) load that's
harmful to solid-state audio amplifiers is one that's too low an
impedance.

Reprint follows:
--------------------------------------

This is difficult to do with passive circuitry because the signal from
one radio cannot be allowed to feed back into the output amplifier of
another.  I can think of two ways to do this:

First, the output of each radio is fed to a high-value resistor
(2-10,000 ohms).  The opposite end of the resistors are tied together
and fed to an audio amplifier that drives the speaker.  Of course,
this requires that power be applied to the mixer.  If it is desired to
separate the signals so that only one radio is heard at a time, some
type of logic circuit would also be required.

The second method would work by sampling the output of each radio
through a low-value resistor, say 20-50 ohms, and feeding each sample
to a rectifier and filter.  The output of each filter would drive a
sensitive DPDT reed relay.  One pole of the relay would connect the
output of the active radio directly to the speaker, the other pole
would be wired in a way to lock out all the other radios.  There
would be a *slight* connect and disconnect delay due to the filters,
but this would be a totally passive system.
-----------------------------------

Additional note:  In the system you described, the second method
above would only require one rectifier/filter and one DPDT relay.
Also, do not attempt to use the chassis of the vehicle, the stereo or
the HT as a common ground to the "negative" speaker terminal (in order
to use a simpler relay).  If you can't find the relay needed for this
project and you need to leave the negative speaker lead connected to
the stereo and HT all the time, be sure to check the speaker terminals
first for the presence of DC.  Higher power car decks apply 1/2 VCC
(about 6.7 VDC) to both sides of the speaker.

73,
Jack  WB3U


From [e-mail] Tue Apr 02 09:07:35 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (John Seney)
Subject: Mac Ham Users Group
Message-ID: <[e-mail]>
Date: Sat, 30 Mar 1996 09:09:21 GMT


"Macnet Roster" (ver. 739) has just been updated and is now a stand-alone
application! The version number = the number of hams using Macs.

"Macnet Roster" lists:

    o CALL SIGN @ HOME PBBS
    o FULL NAME
    o ADDRESS
    o CITY, STATE, ZIP
    o INTERNET ADDRESS
    o MACS USED
    o RADIOS USED
    o SOFTWARE USED
    o PASSIONS
    o COMMENTS

of every known amateur radio operator in the world that uses a Mac computer.

You can use "Macnet Roster" to find other Mac users that you can then
communicate with directly. Compare notes on software, applications, ideas,
hints and kinks, and make new ham friends that use the same computer you do.
(You already know how cool you are - imagine accessing "the rest of us"!)

      If you'd like the latest "Macnet Roster":

    Send me a formatted disk in a self addressed and stamped disk mailer
    that is in a large envelope clearly marked "ROSTER".

Or connect to my home page via the WWW

http://www.mv.com/ipusers/wd1v

Put YOUR INFO (via EMAIL or disk using TEACH TEXT) if you'd like to be include
d
in the "Macnet Roster" or send an update to your stats to me via pkt or email
anytime.


                 John D. Seney |_|_|_|_| e-mail: [e-mail]
             144 Pepperidge Dr |_|   |_| www http://www.mv.com/ipusers/wd1v
     Manchester, NH 03103-6150 |_|_ _|_| wireless: [e-mail]
      Voice Mail: 603-533-3472 | | | | | skytel page: [e-mail]


From [e-mail] Tue Apr 02 09:07:36 1996
From: [e-mail] (Paul Kimball)
Newsgroups: rec.radio.amateur.homebrew
Subject: mailing list and newsgroup
Date: 30 Mar 96 13:24:10 GMT
Message-ID: <60329203434$[e-mail]>

Hello, Iam the sys admin for Lasernet.com.  I had a user by the name
of Richard Wilkerson who subscribed to your mailing list and a newsletter.  He
 is no longer with us, and he failed to unsubscribe.
Please remove him and any one from lasernet.com who my be on your
mailing lists.

Thank You kindly,

Paul Kimball, [e-mail]


From [e-mail] Tue Apr 02 09:07:37 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Gary Coffman)
Subject: Re: Amp. Tank Circuit
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
References: <[e-mail]> <4jigo5$[e-mail]>
Date: Sat, 30 Mar 1996 15:45:24 GMT

In article <4jigo5$[e-mail]> [e-mail] (W8JI  Tom) writ
es:
>
>Remember ferrous cores change permeability with frequency, so inductance
>needs to be measured somewhere around the operating frequency. I don't
>have any info on a -6 core. Maybe the material isn't good?

The cores could be *saturating* too, and that'd be really bad news.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Tue Apr 02 09:07:39 1996
Newsgroups: rec.radio.amateur.homebrew
From: [e-mail] (Gary Coffman)
Subject: Re: Low Frequency Counter.
Message-ID: <[e-mail]>
Reply-To: [e-mail] (Gary Coffman)
References: <4j7571$[e-mail]> <4jihra$[e-mail]>
Date: Sat, 30 Mar 1996 15:53:09 GMT

In article <4jihra$[e-mail]> [e-mail] (WB
3U) writes:
>   [e-mail] (Rane Curl) wrote:
>
>>I need a simple (cheap) low frequency timed counter with an LCD
>>display. Frequencies up to ca. 100 cps; timing intervals of the order
>>of 10-50 seconds. Seems simple enough, but I have not seen a kit or
>>even small (ca. 5 digit) LCD display at a low price. Suggestions?
>
>A frequency counter with a Period function is useful for this,
>although you have to convert the readout to frequency. In the Period
>function, the clock is reset by the signal, not the internal timebase.
>So, the lower the frequency, the longer the elapsed time that reads on
>the display.  This is probably the best way to accurately measure very
>low frequency signals.
>
>Other than that, I suppose you could buy a counter with a 10 MHz
>timebase and replace the crystal with a 1 MHz or 100 KHz equivalent.

Ramsey (yeah, I know) offers a frequency multipler for this use.
It multiplies the input frequency by 10x or 100x before presenting
it to the counter. This lets you measure low frequency signals with
better precision (if not accuracy) on an ordinary counter. I've
used it to precisely measure audio frequencies. An oscilloscope
and a precision frequency source is a better method, however.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | Due to provider problems
Destructive Testing Systems |    we break it.     | with previous uucp address
es
534 Shannon Way             |    Guaranteed!      | Email to [e-mail]
Lawrenceville, GA 30244     |                     |


From [e-mail] Tue Apr 02 09:07:40 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Silver Plating ?
Date: Sat, 30 Mar 96 18:33:42 GMT
Message-ID: <4jjv72$[e-mail]>
References: <[e-mail]> <4ja09n$[e-mail]>

   [e-mail] (W8JI  Tom) wrote:

>A magnetic material may be very low loss at HF, and extremely
>dissipative at UHF or higher.

For most HF work, I worry more about the dielectric constant than
the dissipation factor.  Generally speaking, unwanted capacitance is
more troublesome below 30 MHz than the loss within the material.

Considering that glass has one of the the highest delectric constants
of commonly-used materials, I don't think the microwave test provides
any useful information in this regard.

73,
Jack  WB3U


From [e-mail] Tue Apr 02 09:07:40 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: PCB plated thru holes
Date: Sat, 30 Mar 96 18:41:03 GMT
Message-ID: <4jjvkr$[e-mail]>
References: <4jfhlc$[e-mail]> <4jhacj$[e-mail]>

   [e-mail] (Tom Bruhns) wrote:

>The way I've been doing vias on proto surface mount boards etched in
>my kitchen is to drill 0.0135" holes and put 30-gauge silver-plated
>wire-wrap wire through them, flattening over each end.  The result
>stands off the board surface by perhaps 0.008", which may be more
>than you wanted for your RF seal, but if you put some RF gasket
>material in, it seems like it would OK.

This is what conductive epoxy is for - even thru-plated holes may not
provide a sufficiently level surface to avoid its use.  Many microwave
equipment manufacturers buy the epoxy in sheets and sandwich it
between the board and enclosure.

73,
Jack  WB3U


From [e-mail] Tue Apr 02 09:07:41 1996
From: [e-mail] (WB3U)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Amp. Tank Circuit
Date: Sat, 30 Mar 96 18:52:51 GMT
Message-ID: <4jk0au$[e-mail]>
References: <[e-mail]> <4jigo5$[e-mail]> <[e-mail]>

   [e-mail] (Gary Coffman) wrote:

>The cores could be *saturating* too, and that'd be really bad news.

That was my first reaction, too.  Flux is generated within the core as
a function of volts-per-turn.  This particular application probably
places a considerable voltage across the winding and probably doesn't
require a large number of turns.

My news server isn't showing the original article yet, but if the
number of turns and the input/output impedance (or voltage across the
toroid) was posted, I could calculate the flux.

73,
Jack  WB3U


From [e-mail] Tue Apr 02 09:07:42 1996
From: [e-mail] (HH357)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Low Frequency Counter.
Date: 30 Mar 1996 20:14:39 -0500
Message-ID: <4jkm9v$[e-mail]>
References: <[e-mail]>
Reply-To: [e-mail] (HH357)

Startek sells a counter that starts at 10 Hz. Price about $149.
                          cheers


From [e-mail] Tue Apr 02 09:07:43 1996
From: [e-mail] (Brian [e-mail])
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: PCB plated thru holes
Date: Sat, 30 Mar 1996 20:42:12 GMT
Message-ID: <4jk672$[e-mail]>
References: <4jfhlc$[e-mail]> <4jfp3r$[e-mail]> <4jgk5k$[e-mail]>
Reply-To: [e-mail]

Ken Burtchaell <[e-mail]> wrote:

>Tnx for the reply.I have used both the methods that you suggest.The
>problem with them is you lose the flat plane surface of the ground plane
>side which is essential in getting a good rf bond at microwave
>frequencies to the enclosure and the associated input and output
>connectors.

>73  Ken W6GHV

If they're the "one-off" kind of thingy, why not just drill
the hole thru and solder both sides with a wire lead
going through?

Uncle Brian  VK6BQN




From [e-mail] Tue Apr 02 09:07:44 1996
From: Steve Clements <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Toe dipping
Date: Sat, 30 Mar 1996 21:55:45 GMT
Message-ID: <[e-mail]>

Just one of those irritating test msgs sorry guys...
-
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
 STEVE CLEMENTS (radio : G1YBB @ GB7MAD.#24.GBR.EU)
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-


From [e-mail] Tue Apr 02 09:07:45 1996
From: [e-mail] (Richard Karlquist)
Newsgroups: rec.radio.amateur.homebrew,sci.physics.electromag
Subject: Re: 6 or 7 port reflectometer for getting s parameters
Date: 31 Mar 1996 01:48:39 GMT
Message-ID: <4jko9n$[e-mail]>
References: <4jafck$[e-mail]>

In article <4jafck$[e-mail]>,
Mike Klopfer <[e-mail]> wrote:
>I've been looking at some articles on 6/7 port reflectometers. I'm wondering
>if anyone has used such a device to get s parameters of a device. I'm
>looking for an inexpensive alternative to a network analyser. Several of
>the articles have mentioned using the method of "sliding terminations" to
>calibrate these. Does this method involve the use of another calibrated
>device to calibrate the reflectometer? Are there inexpensive devices that
>have a variable calibrated impedance in the 1-10GHz range? One article on
>calibration of these reflectometers had a diagram with one block for a
>variable phase shifter and on block for a variable attenuator. Does anyone
>have a suggestion for specific devices that could be used for these
>functions. Thanks for the help.
>
>mike
>

Six port network analyzers tend to be fairly narrow band (since they involve
quadrature couplers) and calibration intensive.  Their main advantage is the
possibility of extreme accuracy since no phase measurements are necessary
(everything is done with power meters).  You probably don't want to try to
use this technique for a poor man's network analyzer.

Several alternative suggestions:

1. You can buy an HP 8410 network analyzer for about a kilobuck +/-.  That's
pretty cheap.  (I sit across the aisle from one of it's designers).

2. A spectrum analyzer with tracking generator will do scalar 2 port measureme
nts.
You can save money by building your own tracking generator.  Spectrum analyzer
s
are also available used for a kilobuck +/-.

3. You can get 1 port vector measurements with an HP 4815 vector impedance
meter.  They also go for a kilobuck +/- used.


Rick Karlquist, N6RK
HP Santa Clara Division
[e-mail]



From [e-mail] Tue Apr 02 09:07:46 1996
From: Wayne Glover <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Transmitting tubes!
Date: 31 Mar 1996 07:03:31 GMT
Message-ID: <4jlao4$[e-mail]>
References: <4jg1om$[e-mail]> <4jhicb$[e-mail]>
To: [e-mail]

>>
>>I think Yaesu used the 6146 tube.  Is this a good choice?
>>

Actually the Yaesu FT101B through the FT101E used a pair of 6JS6C sweep
tubes driven by a 12BY7A.

Not the best transmitter tubes in the world, but the story I heard was
that in the '50s-'70s rf tubes like the 6146s were not available to the
Japanese,(embargos or whatever) so they used whatever they had.

73s

Wayne,  KI$XR



From [e-mail] Tue Apr 02 09:07:47 1996
From: [e-mail] (JohnsonHE)
Newsgroups: rec.radio.amateur.homebrew
Subject: siliconix VMP-4
Date: 31 Mar 1996 09:51:35 -0500
Message-ID: <4jm65n$[e-mail]>
Reply-To: [e-mail] (JohnsonHE)

Sorry, was out of pocket for couple weeks and lost stored answers. Still
looking for discontinued FET's. Anyone with any stock, if you replied, I
need it again.
Or send to [e-mail]


From [e-mail] Tue Apr 02 09:07:48 1996
From: Charles Bolland <[e-mail]>
Newsgroups: rec.radio.swap,rec.radio.amateur.antenna,rec.radio.amateur.digital.misc,rec.radio.amateur.equipment,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.amateur.policy,rec.radio.amateur.space,rec.radio.noncomm,rec.radio.scanner,rec.radio.shortwave,rec.radio.swap
Subject: Shortwave etc database program....
Date: Sun, 31 Mar 1996 10:51:57 -0800
Message-ID: <[e-mail]>

Sir,

A stand alone IBM compatible Broadcasting Radio Station Database
program for Longwave, Mediumwave, or Shortwave.  4000 records...
Completely read/write and updateable...

If you'd like a copy, send your EMail address and Postal Address
which will be used to pass you more detailed information on
the full featured program....

The above program will be sent via EMAIL...

All information will be kept confidential....

Chuck

KA4PRF


From [e-mail] Tue Apr 02 09:07:49 1996
From: [e-mail] (Nan Gwa)
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Transmitting tubes!
Date: 31 Mar 1996 11:54:22 -0500
Message-ID: <4jmdbu$[e-mail]>
References: <4jlao4$[e-mail]>

In article <4jlao4$[e-mail]>, Wayne Glover <[e-mail]>
writes:

>Subject:       Re: Transmitting tubes!
>From:  Wayne Glover <[e-mail]>
>Date:  31 Mar 1996 07:03:31 GMT
>
>>>
>>>I think Yaesu used the 6146 tube.  Is this a good choice?
>>>
>
>Actually the Yaesu FT101B through the FT101E used a pair of 6JS6C sweep
>tubes driven by a 12BY7A.
>
>Not the best transmitter tubes in the world, but the story I heard was
>that in the '50s-'70s rf tubes like the 6146s were not available to the
>Japanese,(embargos or whatever) so they used whatever they had.
>
>73s
>
>Wayne,  KI$XR
>
>

My venerable old 1973 ARRL Handbook, in a section entitled "A Sweep
Tube Linear Amplifier", states, "Because only low-duty-cycle transmission
is suitable for sweep tubes operated at high power levels, this amplifier
cannot be used for a-m, fm, or RTTY service."  Aside from problems the
Japanese may have had, why would anyone have wanted to make a sweep
tube amplifier anyway?

Tom Donaly KA6RUH



From [e-mail] Tue Apr 02 09:07:50 1996
From: William W Janssen <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Transmitting tubes!
Date: 31 Mar 1996 11:59:40 GMT
Message-ID: <4jls3c$[e-mail]>
References: <4jlao4$[e-mail]> <4jmdbu$[e-mail]>

[e-mail] (Nan Gwa) wrote:
>In article <4jlao4$[e-mail]>, Wayne Glover <[e-mail]>
>writes:
>
>>Subject:      Re: Transmitting tubes!
>>From: Wayne Glover <[e-mail]>
>>Date: 31 Mar 1996 07:03:31 GMT
>>
>>>>
>>>>I think Yaesu used the 6146 tube.  Is this a good choice?
>>>>
>>
>>Actually the Yaesu FT101B through the FT101E used a pair of 6JS6C sweep
>>tubes driven by a 12BY7A.
>>
>>Not the best transmitter tubes in the world, but the story I heard was
>>that in the '50s-'70s rf tubes like the 6146s were not available to the
>>Japanese,(embargos or whatever) so they used whatever they had.
>>
>>73s
>>
>>Wayne,  KI$XR
>>
>>
>Aside from problems the
>Japanese may have had, why would anyone have wanted to make a sweep
>tube amplifier anyway?
>
>Tom Donaly KA6RUH
>
Sweep tubes can handle larg PEAK currents. Ideal for low duty cycle
equipment. They were cheep also.

Bill K7NOM



From [e-mail] Tue Apr 02 09:07:52 1996
From: Gareth Edwards <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Etching Teflon
Date: Sun, 31 Mar 96 15:03:16 GMT
Message-ID: <[e-mail]>
References: <4jeuqr$[e-mail]> <4jfoqt$[e-mail]> <4jh82b$[e-mail]>
Reply-To: [e-mail]

In article <4jh82b$[e-mail]>
           [e-mail] "Roy Lewallen" writes:

> In article <4jfoqt$[e-mail]>,
>    [e-mail] (John Ballentine) wrote:
> >
> >In a previous article, [e-mail] (Stanley L. Flegler) says:
> >
> >>I'm working on a project where I want to glue some Teflon to a surface
> >>for insulation.  I've heard that you need to etch it before glue will
> >>adhere properly.  I presume that an acid is needed.  Does anyone know
> >>which acid, what concentration, and how long?  73  Stan K8RPA,
> >>[e-mail]
> >>
> >>
> >Not an acid, a very strong base. In the good old days, it was sodium
> >amide. Made by dissolving sodium metal in liquid ammonia, not something
> >I would want to do and I'm a chemist. These days sodium naphthenate is
> >used. You can buy it under the name Tetraetch. You dip the board in
> >the solution, then you have to rise off the naphthalene residue with
> >acetone and then hot water.
> >
> >It is still not a real pleasant process. It is one reason printed circuit
> >shops don't like to work with Teflon. It is really needed to get a plated
> >through hole to stay in place.
>
> Is an adhesive used to bond Teflon to other surfaces? I was under the
> impression that it was mechanically bonded. If an adhesive is used, what is
> it?
>
> Roy Lewallen, W7EL
>

I work as a microwave engineer and consequently do a lot of work with
PTFE. I have never found anything to satisfactorily bond teflon; the
trick is to do the design right so that the Teflon part is mechanically
retained, as it is quite soft andholds onto barbed metal parts quite
well.

Lobbing my tuppence into the pile,

Gareth
GM7WFT

--
I don't want the world; I just want your half. - TMBG
------------------------------------------------------------------
|  Gareth Edwards       |  [e-mail]           |
|  Edinburgh,           |  Home of Edinburgh Beige Cricket Club  |
|  Scotland             |  PGP public key available on request   |
------------------------------------------------------------------


From [e-mail] Tue Apr 02 09:07:53 1996
From: Roland Burgan <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: Low Frequency Counter.
Date: 31 Mar 1996 15:52:59 GMT
Message-ID: <4jm9or$[e-mail]>
References: <4j7571$[e-mail]> <4jihra$[e-mail]>
To: [e-mail]

The Harris ICM7216(A,B,C,or D, depending on needs) will work to
10 Mhz...just add a few external parts, LEDs.
Call 1-800-442-7747 for technical data sheets.



From [e-mail] Tue Apr 02 09:07:54 1996
From: Ed Hare <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: PCB plated thru holes
Date: 31 Mar 1996 16:43:19 GMT
Message-ID: <4jmcn7$[e-mail]>
References: <4jfhlc$[e-mail]>
To: [e-mail]

Ken Burtchaell <[e-mail]> wrote:

>I am looking for a method to simulate plated thru holes in thin(.010
>duroid).This is for small quanity work,one of a kind boards for amateur
>microwave projects.

>I had a thought about drilling holes in the board and filling them in
>with conductive epoxy.

>Any comments?

Hi, Ken.

It might be a lot easier to fill the holes with a small piece of wire
soldered to the two pads you want "plated through."  Manufacturers buy
true double-sided boards to save production costs and time, but home
constructors can usually afford the few extra minutes to do it the "hard"
way.

BTW -- the 1995 ARRL Handbook has a nice sidebar on how to homebrew
double-sided boards using this technique.  It is found in the
circuit-construction chapter.

73 from ARRL HQ, Ed Hare, KA1CV, ARRL Lab Supervisor




From [e-mail] Tue Apr 02 09:07:55 1996
From: George Sereikas <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: NEED R-390A Meters! Can Anyone Help?
Date: 31 Mar 1996 17:57:17 GMT
Message-ID: <4jmh1t$[e-mail]>

Thanks for reading this message. I am looking for the meters for
my Collins R-390A receiver. One is the "Carrier Level" meter and
the other is the "Line Level Meter". If anyone has either of
these meters (or one of them) or knows where I can find them, I
would appreciate your getting back to me. Thanks much!
George
KC2MF
[e-mail]




From [e-mail] Tue Apr 02 09:07:57 1996
From: Will Flor <[e-mail]>
Newsgroups: rec.radio.amateur.homebrew
Subject: Re: antennae for SS communications
Date: 31 Mar 1996 21:01:51 GMT
Message-ID: <4jmrrv$[e-mail]>
References: <4isoo9$[e-mail]> <4jhfbo$[e-mail]> <hbaker-2903961927160001@10.0.2.15>

[e-mail] (Henry Baker) wrote:
>In article <4jhfbo$[e-mail]>, Will Flor <[e-mail]> wrote:
>
>> [e-mail] (Robert A. Lanier) wrote:
>> >I am looking for information on antennae for spread-spectrum
>> >communications. Can I use a regular Yagi or dipole or do I need a
>> >special configuration (hybrid?)  ?
>>
>> You don't need any special type of antenna; the only thing you
>> have to be careful of, especially with high-gain directional
>> antennas, is that the SWR remains low across the entire band
>> segment your transmisison is being spread around.  To link
>> remote sites to a central main site ("star" configuration)
>> I've used regular Yagis at the remote sites and an omnidirectional
>  ^^^^^^^^^^^^^^^^^^^^^^^...
>> multi-bay vertical at the central site, all on 900 MHz using
>> frequency-hopping SS.  For shorter ranges patch antennas are
>> pretty common.
>
>Could you tell us more about your setup, including type of equipment,
>power, distances, data rates, etc. ??
>

Sure.  The network I've described above used the Percom Wireless Bridge 920, w
hich
uses frequency-hopping SS on the 900 MHz band.  There's also a Wireless Bridge
 2400
for the 2.4GHz band.  The tranmit power of these units is low; under a half-wa
tt; possibly
much less than that.  They spec at 2Mbit/sec but in our tests we seemed to be
able to
transfer files at about one-third to one-half the speed of a 10-Base-T Etherne
t LAN.  The
ranges involved were relatively small; about three miles or so was the longest
 link path.

73 de Will KB9JTT




From [e-mail] Tue Apr 02 09:07:59 1996
From: [e-mail] (Ed Mitchell)
Newsgroups: rec.radio.amateur.misc,rec.radio.amateur.digital.misc,rec.radio.amateur.policy,rec.radio.amateur.homebrew,rec.radio.amateur.misc,rec.radio.scanner,rec.radio.shortwave,sci.electronics,rec.radio.pirates
Subject: April edition, Ham Radio Online is now available
Date: 31 Mar 1996 23:33:52 GMT
Message-ID: <4jn4p0$[e-mail]>

The April edition of Ham Radio Online magazine is now available at
http://www.accessone.com/~vbook
or
http://www.accessone.com/~vbook/hronline.htm

This month features original stories on packet radio path quality, spread
spectrum
communications, more information on making your own solar observations, gettin
g
started in shortwave listening and an amazing list of hidden or not so hidden
renditions of Morse code in popular music. We will be adding more stories over
the coming weeks - this is a dynamic magazine with upates appearing as often
as daily.

As usual, Ham Radio Online also features Amateur radio newsletters from around
the world, real-time ionospheric propagation reports, real-time aurora
conditions,
real-time MUF calculations, real-time earthquake and severe weather reports an
d
so much more.

Stop and by and enjoy. We are free - and free of ads too - your stories are
always
welcome at  Ham Radio Online.

Thanks and 73,
Ed and Kim Mitchell,
KF7VY and N7VPL


------------------------
Ed (KF7VY) and Kim (N7VPL) Mitchell
personal email to [e-mail]
Visit Ham Radio Online, it's free! at
http://www.accessone.com/~vbook/hronline.htm