QRZ! Ham Radio 4/QRZ Ham Radio Callsign Database - Volume 4.iso/digests/homebrew/940185.txt

Internet Message Format | 1994-11-13 | 14.4 KB

Date: Thu,  7 Jul 94 04:30:23 PDT
From: Ham-Homebrew Mailing List and Newsgroup <[e-mail]>
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Subject: Ham-Homebrew Digest V94 #185
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Ham-Homebrew Digest         Thu,  7 Jul 94       Volume 94 : Issue  185

Today's Topics:
        ACS (Al's Circuit Simulator) version 0.14 is available
                       Adding VOX to an HT mic.
                            AM Transmitter
              Converting Tempo/Yaesu hf to 6m, Possible?
                     Decoding time data from WWVB
          RF Feedback in Mic while talking and touching mic.
                  Satellite fax to HF fax converter
                             Timewave DSP
                              Voice IDer

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Archives of past issues of the Ham-Homebrew Digest are available
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We trust that readers are intelligent enough to realize that all text
herein consists of personal comments and does not represent the official
policies or positions of any party.  Your mileage may vary.  So there.
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Date: Wed, 6 Jul 1994 03:34:09 GMT
From: galileo.cc.rochester.edu!ee.rochester.edu!atd.rochester.ny.us![e-mail]
Subject: ACS (Al's Circuit Simulator) version 0.14 is available
To: [e-mail]

A new version of ACS (Al's Circuit Simulator) has been posted to
alt.sources.  It is also available by ftp from cs.rit.edu or
ee.rochester.edu. (in pub/acs).  If you don't have net access you
can get it by dial-up from (USA) 716-272-1645.

ACS is a general purpose circuit simulator.  It performs nonlinear
dc and transient analyses, fourier analysis, and ac analysis
linearized at an operating point.  It is fully interactive and
command driven.  It can also be run in batch mode or as a server.
The output is produced as it simulates.  Spice compatible models
for the MOSFET (level 1 and 2) and diode are included in this
release.

This version (0.14) includes several improvements including
convergence improvements, a new "alarm" command, and significant
bug fixes in time step control.  There are other minor improvements.

Since it is fully interactive, it is possible to make changes and
re-simulate quickly.  The interactive design makes it well suited
to the typical iterative design process used it optimizing a circuit
design.  It is also well suited to undergraduate teaching where
Spice in batch mode can be quite intimidating.  This version, while
still officially in beta test, should be stable enough for basic
undergraduate teaching and courses in MOS design, but not for
bipolar design.

In batch mode it is mostly Spice compatible, so it is often possible
to use the same file for both ACS and Spice.

The analog simulation is based on traditional nodal analysis with
iteration by Newton's method and LU decomposition.  An event queue
and incremental matrix update speed up the solution for large
circuits.

It also has digital devices for mixed signal simulation.  The
digital devices may be implemented as either analog subcircuits or
as true digital models.  The simulator will automatically determine
which to use.  Networks of digital devices are simulated as digital,
with no conversions to analog between gates.  This results in
digital circuits being simulated faster than on a typical analog
simulator, even with behavioral models.  The digital mode is
experimental and needs work.  There will be substantial improvements
in future releases.

ACS also has a simple behavioral modeling language that allows
simple behavioral descriptions of most components including capacitors
and inductors.  Unfortunately, it is not well documented.

ACS uses an object oriented approach to modeling.  Complex models
like MOSFETS are made of simpler ones like resistors, capacitors,
diodes, and any other models that may already exist.  The model
designer does not need to worry about details like convergence
checking, bypass checking, integration, or how the new device plugs
into the solution matrix because these are already taken care of
by the basic models.  This results in a dramatic improvement in
the time it takes a researcher or model designer to install a new
model, compared to Spice.

The source and documentation can be obtained by anonymous ftp from
ee.rochester.edu or cs.rit.edu in /pub/acs.  It can also be obtained
by dial-up (USA) 716-272-1645 in /pub/acs.  It may be distributed
under the terms of the GNU general public license.  The dial-up
also has some test circuits, pre-compiled executables for Next,
Sun4, MSDOS and possibly others, and documentation in dvi and
postscript.

If you are tired of Spice and want a second opinion, you want to
play with the circuit and want a simulator that is interactive, or
you want to study the source code and want something easier to
follow than Spice, try ACS.

ACS is an ongoing research project.  It is being released in a
preliminary phase in hopes that it will be useful and that others
will use it as a thrust or base for their research.  I also hope
for some comments that may help me direct my research.

Albert Davis, 136 Doncaster Rd., Rochester, NY 14623.
email: [e-mail],  [e-mail],  or [e-mail]
fax: [phone]

------------------------------

Date: Thu, 7 Jul 1994 02:39:24 GMT
From: ihnp4.ucsd.edu!swrinde!gatech!usenet.ins.cwru.edu!news.ecn.bgu.edu!feenix.metronet.com![e-mail]
Subject: Adding VOX to an HT mic.
To: [e-mail]

What is the best way to add VOX to an HT ?   I have a throat mic for my
HT that I use to go riding ( bicycles ) and I have to keep taking my hand off
the bars to press the PTT button.  I purchased a VOX kit only to find out
that it requires an external 9v power source.  The extra battery pack for
the VOX circut makes it some what impractical ( the radio is big enough
the cause some minor placement problems already ). Does any one know a
better way ?  I am using a kenwood 78A with the Genesys t-05 throat mic.

dismondo.

------------------------------

Date: 6 Jul 1994 23:24:50 -0700
From: ihnp4.ucsd.edu!usc!cs.utexas.edu!convex!news.onramp.net!news.sprintlink.net!news.world.net!news.teleport.com!news.teleport.com![e-mail]
Subject: AM Transmitter
To: [e-mail]

ALL-A-N Carhart ([e-mail]) wrote:
:Where might I find a make-your-own-AM-transmitter kit?
:If it is low enough power, the FCC allows transmissions on the AM band, correct?
: Why not hook up a CD player (or tape player or even FM radio) to a transmitter
: with the power to only go a few feet...



I hesitate to even utter the name in an amateur radio group, but you will find
relevant discussions in alt.radio.pirate.  The thread "Transmitter Kit Sources
FAQ" mentions a number of sources for cheap ($30) micro-power FM stereo and
AM transmitter kits including Ramsey Electronics (Victor NY), DC Electronics
(Scottsdale AZ), and Panaxis Productions (Paradise CA).  I have no idea if
they are any good.  Also threads on what's allowed under FCC rules.

FM radio would be a better bet for listening to CD's in your car, with an
audio bandwidth of ~15Khz vs the ~5Khz of AM radio (plus you get stereo).
Might be worth replacing the AM radio with a junkyard AM/FM one (~$10?).

Trashing some other guy's reception as you roll by can be avoided by carefully
choosing an unoccupied channel.  On FM, you could verify the channel is still
unoccupied every 50 miles or so by briefly turning off your transmitter.
Perhaps the transmitter could take it's power from the CD's motor circuit, and
thus automatically shut off after each CD?  Propagation of AM signals is
less predictable, and at night you may occasionally find your radio howling
due to interference from stations a thousand miles away.

These interferance issues could be avoided entirely by pulling the coaxial
plug at the radio that runs to the antenna, and inserting your own plug with
coax running to the transmitter (could add some switching arrangement, and may
need to attenuate the transmitted signal).

----------------------------------------------------------------------------
[e-mail]    Jerry Gaffke    Portland Oregon USA

------------------------------

Date: Wed, 6 Jul 1994 13:39:23 GMT
From: ihnp4.ucsd.edu!swrinde!emory!europa.eng.gtefsd.com!uhog.mit.edu!nntp.club.cc.cmu.edu!cantaloupe.srv.cs.cmu.edu!dolphin![e-mail]
Subject: Converting Tempo/Yaesu hf to 6m, Possible?
To: [e-mail]

Are there plans to convert Tempo/Yaesu hf rigs to 6m operation?

Is it worth doing this?  Is anybody on 6m?

I know that there are transvertors to do this, but this rig can put out
100w or so, and I don't want to have to attenuate the output & then
reamplify the rf back to 100 or so watts.

I am not afraid to get inside and make modifications to the rig.
(even if permanent)

This is a 95% tube rig.


Ideas, Thoughts, comments, snyde remarks?

    Ed N3SDO
    [e-mail]

------------------------------

Date: Wed, 06 Jul 94 20:38:44 CST
From: ihnp4.ucsd.edu!dog.ee.lbl.gov!agate!iat.holonet.net!vulcan![e-mail]
Subject: Decoding time data from WWVB
To: [e-mail]

Hi:

Is anyone out there automatically decoding time data from WWVB (60 kHz) ?
I have built the 60 kHz receiver from the articles in 73 magazine earlier
this year, and have tried to detect the encoded time data.
Unfortunately, the noise level seems to be much greater than the signal ?
I was wondering if there was anyone out there that was doing this
already, and if so, would they care to exchange email messages.

Thank you
Gary Tennyson
KO4CY
[e-mail]

Gary Tennyson
[e-mail]

------------------------------

Date: Wed, 6 Jul 1994 12:38:43 GMT
From: cantaloupe.srv.cs.cmu.edu!dolphin![e-mail]
Subject: RF Feedback in Mic while talking and touching mic.
To: [e-mail]

>I have a RCI 2950 with a Texas Star DX 667V amplifier'
>and a cheap Mag-mount base with a base loaded antenna with about
>a 3.5" whip on top.


Ok, You are probably getting rf everywhere!  Do you mean a 3.5 foot antenna,
or a 3.5 inch antenna?  You say its a magnet mount, you DEFINATELY need a
solid ground!!! I have had problems with cb & 2m magnet antennas getting
sufficient ground.  I have heard of others that tried magnets for hf mobile,
with "hot" microphone results.

I am assuming that you are running inside a house since you are using an amp.

I am not experienced with hf transmitting, Im just a no code tech that hacked
cb & swl for a few years and recently jumped in head first.  I expect that
a longer whip and solid electrical ground to waterpipes, heating radiators,
I even expect that metal forced air heating ducts might make an improved
rf ground indoors.

    My 2 cents, hope its useful
    Ed N3SDO

------------------------------

Date: Wed, 6 Jul 1994 17:06:18 GMT
From: ihnp4.ucsd.edu!library.ucla.edu!europa.eng.gtefsd.com!newsxfer.itd.umich.edu!nntp.cs.ubc.ca!unixg.ubc.ca!quartz.ucs.ualberta.ca!gov.nt.ca![e-mail]
Subject: Satellite fax to HF fax converter
To: [e-mail]

Has anyone ever built a converter to change the AM wefax from NOAA
satellites to FM wefax for reception with an HF fax demodulator?
Is it possible?  I'd like to be able to receive satellite photos
direct from the satellites but don't want to spend another $XXX
to buy a satellite wefax demodulator.  I've found that by carefully
tuning the signal from the satellite in SSB with a very narrow
bandwidth I can copy the pictures a little bit but doppler shift
makes this process very difficult.  It would be much easier to
receive the signal in FM from the satellite and convert the audio
tone's amplitude modulations to frequency modulation and feed it
to my HFFAX demodulator.
Alternately, is there software available to do the same thing with
a simple interface?
Thanks,
John - VE8EV

=============================================================
John Boudreau VE8EV     INTERNET: [e-mail]
Inuvik, NWT, CANADA       PACKET: VE8EV@KL7GNG.#NAK.AK.USA.NA
=============================================================

------------------------------

Date: 6 Jul 1994 16:42:09 GMT
From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!noc.near.net!sunfish.hi.com!brainiac.hi.com![e-mail]
Subject: Timewave DSP
To: [e-mail]

Do the Timewave DSP's use an algorithm similar to the one described by W9GR
in QEX (LMS adaptive filter using short-delay time-shifted input), or is
there more to the Timewave noise reduction algorithm?

How about the JPS units - anyone know the algorithms used for white noise
reduction and pink noise reduction?

Steve Byan                                  internet: [e-mail]
Hitachi Computer Products (America), Inc.
1601 Trapelo Road                           phone: [phone]
Waltham, MA 02154                           FAX: [phone]

------------------------------

Date: 7 Jul 94 00:57:38 GMT
From: [e-mail]
Subject: Voice IDer
To: [e-mail]

Hi All,

Has anybody used one of those Hallmark greeting cards with the voice
synthesizer, as a voice id'er for a repeater?

If so, what kind of circuit did you end up with?  I am using a 555 timer,
but am having trouble linking it to the repeater (Kenwood).

Any ideas would be greatly appreciated.  A schematic would be even better,
and would be shared with others who find this idea interesting.

TNX  73 de KB0LRB  Lynn Geitgey
[e-mail]

------------------------------

Date: 6 Jul 1994 15:29:43 GMT
From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!gatech!ncar![e-mail]
To: [e-mail]

References <[e-mail]>, <[e-mail]>, <2v401p$[e-mail]>
Subject : Re: AM Transmitter

    Although this is a 'homebrew' newsgroup, I also wanted to
post this 'solution' (which I emailed the original poster).
    A simple and relatively inexpensive route would be for
him to buy an FM Converter for his AM radio.  I owned one for
several years, and it served me well.  It only cost around $16,
and was easy to install.  With it he can still use the CD adapter.
    Now this might bring up questions of fidelity but remember
the end processor is an AM radio, with its possible narrow bandwidth.
ren N0PVI
dona nobis pacem

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End of Ham-Homebrew Digest V94 #185
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