QRZ! Ham Radio 5/QRZ Ham Radio Callsign Database - Volume 5.iso/digests/infoham/940189.txt

Internet Message Format | 1994-11-13 | 11.8 KB

Date: Tue, 22 Feb 94 04:30:08 PST
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Subject: Info-Hams Digest V94 #189
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Info-Hams Digest            Tue, 22 Feb 94       Volume 94 : Issue  189

Today's Topics:
                          Hamblaster Update
                 Honda ignition recall -  now NOISE!!
                            repeater list
              RF Power Amp stages, design. Help needed!

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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.
----------------------------------------------------------------------

Date: Mon, 21 Feb 1994 13:54:01 GMT
From: agate!library.ucla.edu!psgrain!research-01.mskcc.org!psinntp!psinntp!laidbak!tellab5![e-mail]
Subject: Hamblaster Update
To: [e-mail]

2-15-94

I hope that this will clear up a few questions about
the Hamblaster.

Disclaimer

This IS NOT an ad.  The Hamblaster is not a product
that's being sold to amateurs or any other group.
It's a 3 year effort by myself and Will Torgrim N9PEA.
We have been doing this as a hobby, hopefully, to
improve Amateur radio.  Unless we are ready to sell
the Hamblaster as a product or if we can get someone
to back us, I will continue to post our progress.

Finnally,  we have spent thousands of dollars to develope
the Hamblaster and we haven't earned a single penny
for our efforts.  So how can this be an ad?


The Hamblaster is not a software package.  It requires a
special sound card that uses a Texas Instruments TMS320C25
DSP to run filters or audio demodulators.  It can interface
to a TNC via a TTL digital port and replace the TNC's poor
filtering.

It's not compatible with other sound cards but it can
co-exist with them.  I use my Soundblaster Pro and Hamblaster
together. I can, for example, run a filter on the the Hamblaster,
connect it's output the Soundblaster and record a CW signal using
the SB software under the Windows environment.


More "info"

1)  External Power supply

    I think one feature that separates the Hamblaster
    from other sound boards is it's ability to run on
    an external 12 volt supply.  When a filter or modem
    is loaded,  you can turn off the computer and it
    will stay active.

    When it's connected to a PK-232, there's no need
    to leave the computer on in order to keep the DSP
    alive.  Right now, my PK232/Hamblaster is runing
    and it's been operating for about two weeks.

    There still some developement work being done and
    I'm told that the power supply will be on a small
    PC board and sold as an option for about $20.00.


2)  Adaptive (LMS) filter

    There's ongoing developement in this area.  We are
    planing (I don't think this has been done before)
    to add controls to the LMS algorithm.

    Eureka! It works!   2-21-94

    I just received a call from Will last night but I
    wasn't home.  My answer machine got it.  He held
    the phone next to the speaker and I heard SSB with
    a carrier and some other interferance.  He pressed
    a button on his computer and the hetrodyne was gone.

    I don't have any details about the software except
    that it works.   I'll keep you posted.

---
   Jack Albert  WA9FVP             Fellow Radio Hacker
                     Tele [phone]
   Tellabs Operations, Inc.     FAX  [phone]
   1000 Remington Blvd.         [e-mail]
   Bolingbrook, IL  60440

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

Date: 21 Feb 94 20:43:44 CST
From: agate!howland.reston.ans.net!wupost!kuhub.cc.ukans.edu![e-mail]
Subject: Honda ignition recall -  now NOISE!!
To: [e-mail]

This past month, Honda sent out a recall notice for their 90-91 Accords.
They were wanting to replace a part in the distributor which failed when
the car got high mileage.

I had this recall work done on my car a couple of weeks ago, and now have
terrible ignition noise on 2 meters and 440.  Before this work had been
done, the ignition had been really quite quiet -- now it is nearly
unbearable.

One fellow ham said the thought that he'd read something about this on packet
or in one of the ham magazines.

Has anyone else had this problem?  The local Honda folks seem lukewarm about
fixing this problem they created, probably because theyt really don't
understand it.

Any one dealt with Honda about this problem?

Thanks.

Kirk Baxter, N0FPZ/VK1KU

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

Date: 21 Feb 94 20:41:08
From: agate!msuinfo!netnews.upenn.edu!mipg.upenn.edu![e-mail]
Subject: repeater list
To: [e-mail]

>The ARRL is making empty threats. The data in the repeapter directory is
>no more propiratary than the information in the phone book. In fact Wayne
>Green was putting out a directory before the ARRL and they stole it from
>him according to Wayne.

Well, the ARRL might very well be making empty threats but the fact
remains that THEY can pay more for lawyers than I can; the ARRL is not
threatening the body of amateurs in general but ME specifically.  Even
if they are entirely wrong, I am instantly bankrupt when they file a
suit and I have to hire a lawyer to defend me.  Since they have the
bigger stick, they can do absolutely anything they want.  Thus, I am
forced to put the online repeater database project on hold until such
time as this matter is clarified.  Innovation through litigation.

I have asked the folks over at ARRL HQ for a clarification about their
letter.  In particular, I ask whether they believe that they have
proprietary control over the FACTS of the database.  More ominously,
they also claim that my format in some way infringes upon their
copyright.  While this might require only a small adjustment in the
data format, their letter is not clear to me; they may be claiming
ownership to the entire idea of organizing repeater information by
state, location, frequency, etc.

Until such time as the ARRL replies to my queries, or I can figure out
some way around their legal threats, the project is on hold.
Effectively, I must obtain ARRL permission before I can continue and
it probably is not in their best interest to have someone come up with
a usable alternative to their directory.

>Fortunatly there is an answere in the American
>Civil Liberties Union. Give them a ring or if you don't want too I will
>and get their oppinion. The ACLU scares the shit of anybody they bring
>their guns to bare on.

While this is indeed one possibility, the problem is that I must
continue and risk legal exposure.  I must rely on the ACLU to be
willing to defend me and I must hope that the legal system indeed will
end up ruling my way.  Until a court rules, the ACLU opinion is just
that- an opinion.  While I am definitely incensed at the ARRL for
their actions (and I am a member also), I am not sure I care about
this project enough to risk everything.

To be honest though, I am curious what the ACLU thinks of the matter.
Prior to starting on this project, I did ask for an opinion on the
matter and was told that the ARRL holds a copyright on the format but
not on the data itself since FACTS can not be copyrighted.

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

Date: 21 Feb 1994 12:30:11 GMT
From: ghost.dsi.unimi.it!univ-lyon1.fr![e-mail]
Subject: RF Power Amp stages, design. Help needed!
To: [e-mail]

Gary Coffman ([e-mail]) wrote:
: In article <[e-mail]> [e-mail] writes:
: [...]
: >increased power output?
: Well it's usually not quite that simple. Sure it's possible to modify an
: existing PA to output more power. But the key things are impedance matching
: and drive levels when changing out the PA transistor for a higher power one.

 Usually, the formula is : Rout = (Vcc - Vsat)^2 / Pout. It doesn't take
into account the Cout of the transistor, of course. Once you have calculated
the Rout for the current Vcc and Pout, you have to design the matching filter
to bring (up) the Rout to 50 ohms. Vsat is the saturation voltage of the
transistor.

: In fixed equipment, it's often possible to go to a higher supply voltage,
: say double that of the original stage, and if the transistor beta and drive
: level are sufficient to also double current output, then your load impedance
: can remain the same, and the output matching network doesn't have to be
: modified while your power has increased fourfold. Note however, that input
: impedance to the active device will also often be different after you change
: devices, and that has to be matched as well.

 Overall, don't forget that many transistor are design to operate at 13.8 V
and not higher, so if you attempt to increase the voltage, it burns out even
if you have no ROS.

: >Another thing about transistor selection, will a VHF transistor work well in a HF circuit?
: Device gain usually doubles for every octave reduction in operating
: frequency. VHF transistors can have so much gain at HF that stage
: stability can be hard to achieve. Other than that, for Class C operation,
: use of VHF rated transistors in HF circuits is doable. You do have to

 Yes, many VHF devices are unstable at HF frequencies, because the gain is
increased while the transcapacitance increases also. The best solution is to
design a neutrodyne stage, or to carefully design the stage, thereby limiting
the oscillation. Be careful also not to be faced with parasitic VHF/UHF, as
sometimes while the transistor is stable at HF, it is unstable at VHF. So
compute the Stern factor at each frequency, and be careful also of the shift
of the matching network, which can sometimes reflect VHF with the proper phase
to make it oscillate. The best way to handle this is to insert low-pass filters
after the stage.

 Vince. (12 weeks, and waiting)
--
 PSG    Vainqueurs de la coupe de France 1982, 1983, 1993
 PSG    Champions de France 1985/86  1/2 Finaliste C3: 1993
 PSG    PARIS SAINT GERMAIN FC --- NOTRE HISTOIRE DEVIENDRA LEGENDE.

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

Date: 22 Feb 1994 07:56:03 GMT
From: agate!howland.reston.ans.net!wupost!crcnis1.unl.edu!unlinfo.unl.edu![e-mail]
To: [e-mail]

References <[e-mail]>, <2k0eup$[e-mail]>, <[e-mail]>
Subject : Re: Keyboards at testing sessions

[e-mail] (Mike Waters) writes:

 >The need is not to show that someone *is* or *could* cheat, but for them to
 >prove that they *could not* cheat..  If you want to use some piece of
 >equipment in a testing session *you* must show that (a) you are not using
 >it to cheat and (b) it won't disturb the other test takers.

Oh, we are back to guilty_until_proven_innocent now? Be real!

 >Showing an empty hard drive or none at all is one very easy way to do this.
 > Certainly there are other waysto do this.  Remember the onus in not on the
 >VEs to try to anticipate every possible way for someone to cheat, but to
 >ensure fair tests

You failed to answer the question. What has a hard drive got to do
with cheating? How is a hard drive going to help you cheat?

Gary

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End of Info-Hams Digest V94 #189
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