QRZ! Ham Radio 3/QRZ Ham Radio Callsign Database - Volume 3.iso/digests/homebrew/930136.txt

Internet Message Format | 1994-06-04 | 22KB

Date: Sat, 18 Dec 93 04:30:28 PST
From: Ham-Homebrew Mailing List and Newsgroup <[e-mail]>
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Subject: Ham-Homebrew Digest V93 #136
To: Ham-Homebrew


Ham-Homebrew Digest         Sat, 18 Dec 93       Volume 93 : Issue  136

Today's Topics:
                         chirping oscillator
                             DF Question
                Guide to the Personal Radio Newsgroups
            Help! Looking for spread-spectrum video link!
               HELP: Looking for RF Sniffer design/kit
                              Ramsey 6m
                          Spray-on shielding
                         VHF switching diodes

Send Replies or notes for publication to: <[e-mail]>
Send subscription requests to: <[e-mail]>
Problems you can't solve otherwise to [e-mail].

Archives of past issues of the Ham-Homebrew Digest are available
(by FTP only) from UCSD.Edu in directory "mailarchives/ham-homebrew".

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: 17 Dec 93 19:55:02 GMT
From: ogicse!hp-cv!sdd.hp.com!col.hp.com!srgenprp![e-mail]
Subject: chirping oscillator
To: [e-mail]

Majec Systems ([e-mail]) wrote:

: I have a chirping, whooping, and generally being anything but, stable
: oscillator. As CW is my preferred form of rf emission this chirping
: oscillator just won't cut it.
:
: The rig is a TEN-TEC pm2 (early 70's qrp rig) It's a direct conversion
: style transceiver.  ...

: This is a fairly crude design in my opinion.The DPDT switch has single
: conductor hookup wire going from the switch to the board (six of them)
: about 2.5 inches long. The switch selects between 80m and 40m lc circuits
: which feed the base of  the bipolar transistor,  the oscillator.   ...

The long leads would likely cause mechanical instability, but not chirp
(except for a possibility mentioned below.)

What are you using for a power supply?  If the power supply voltage is
not rock-solid when you key the transmitter, that could easily cause the
chirp.  For a test, hook up the radio with short, fat leads to a car battery
or well-regulated power supply.  If the chirp goes away, then that's the
problem.

: By the way there is no shielding around the transistor section
: of the oscillator, the inductor is in a metal can but that's it.

The long leads leading to the VFO tank could be picking up RF from the
power amplifier stage, which could cause chirp.  Try shielding the entire
VFO (aluminum foil works for a temporary test) to see if that's the cause.
Check power supply bypassing -- RF can get into the VFO that way too.
One of those could easily bethe problem, since the power amplifier and
oscillator are on the same frequency in direct-conversion transceivers.

AL N1AL

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

Date: 17 Dec 93 18:43:14 GMT
From: ogicse!uwm.edu!math.ohio-state.edu!howland.reston.ans.net!usenet.ins.cwru.edu!slc6![e-mail]
Subject: DF Question
To: [e-mail]

In article <[e-mail]>,
Jan Chojnacki <[e-mail]> wrote:
>(If it wasn't CQ, then it was QST - do it cheap, go to your library
>and fumble around in the stacks <g> ).

The designer of the Handi-Finder wrote an article for QST about it.
I'm sure you could find it in the back issues.

You're right, it could probably be built bargain-basement if you have
the right scrap parts.  Is there a single kit out there that isn't that
way?

What your money goes for in a kit is (1) instructions, (2) less time
spent scrounging parts, (3) less time spent preparing parts (4) lower
capital investment required for construction, (5) packaging, and (6) a
higher chance of successful construction.  This is added value, and the
kit maker charges you for it.

If you think the kit maker charges too much for the added value, you
should build the thing from scratch.  If you think the added value is
worth it, buy the kit.  Just remember whether or not it's worth it is
a personal decision based on one's skills, resources, and junk box.  :-)

 Stephen

--
Stephen Trier  KB8PWA       "The light at the end of the tunnel
Work: [e-mail]     may be an oncoming dragon"
Home: [e-mail]                          - Unknown

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

Date: Wed, 15 Dec 1993 12:00:59 GMT
From: nevada.edu!news.unomaha.edu![e-mail]
Subject: Guide to the Personal Radio Newsgroups
To: [e-mail]

Posted-By: auto-faq 3.1.1.4
Archive-name: radio/personal-intro
Revision: 1.5 09/18/93 16:49:31
Changes: new mailing lists, .packet rmgroup, and .policy updates

(Note:  The following is reprinted with the permission of the author.)

This message describes the rec.radio.amateur.*, rec.radio.cb, rec.radio.info,
and rec.radio.swap newsgroups. It is intended to serve as a guide for the new
reader on what to find where. Questions and comments may be directed to the
author, Jay Maynard, K5ZC, by Internet electronic mail at
[e-mail]. This message was last changed on 18 September
1993 to add the mailing lists for the new rec.radio.amateur newsgroups, to
note the rmgroup of rec.radio.amateur.packet, and to officially retire some
(in)famous threads of discussion on rec.radio.amateur.policy.

History
=======

Way back when, before there was a Usenet, the Internet hosted a mailing list
for hams, called (appropriately enough) INFO-HAMS. Ham radio discussions
were held on the mailing list, and sent to the mailboxes of those who had
signed up for it. When the Usenet software was created, and net news as we
now know it was developed, a newsgroup was created for hams: net.ham-radio.
The mailing list and the newsgroup were gatewayed together, eventually.

As the net grew, and as packet radio came into vogue, packet discussion began
to dominate other topics in the group and on the list. This resulted in the
logical solution: a group was created to hold the packet discussion, and
another corresponding mailing list was created as well: net.ham-radio.packet
and PACKET-RADIO, respectively.

These two groups served for several years, and went through Usenet's Great
Renaming essentially unchanged, moving from net.ham-radio[.packet] to
rec.ham-radio[.packet]. Readership and volume grew with the rest of the
network.

The INFO-HAMS mailing list was originally run from a US Army computer at
White Sands Missile Range, SIMTEL20. There were few problems with this
arrangement, but one was that the system was not supposed to be used for
commercial purposes. Since one of hams' favorite pastimes is swapping
gear, it was natural for hams to post messages about equipment for sale
to INFO-HAMS/rec.ham-radio. This ran afoul of SIMTEL20's no-commercial-use
restriction, and after some argument, a group was created specifically
for messages like that: rec.ham-radio.swap. This group wasn't gatewayed to
a mailing list, thus avoiding problems.

While all this was happening, other folks wanted to discuss other aspects
of the world of radio than the personal communications services. Those
folks created the rec.radio.shortwave and rec.radio.noncomm newsgroups,
and established the precedent of the rec.radio.* hierarchy, which in turn
reflected Usenet's overall trend toward a hierarchical name structure.

The debate between proponents of a no-code ham radio license and its opponents
grew fierce and voluminous in late 1989 and 1990. Eventually, both sides grew
weary of the debate, and those who had not been involved even more so. A
proposal for a newsgroup dedicated to licensing issues failed. A later
proposal was made for a group that would cover the many recurring legal issues
discussions. During discussion of the latter proposal, it became clear that it
would be desirable to fit the ham radio groups under the rec.radio.*
hierarchy. A full-blown reorganization was passed by Usenet voters in January
1991, leading to the overall structure we now use.

After the reorganization, more and more regular information postings began to
appear, and were spread out across the various groups in rec.radio.*. Taking
the successful example of the news.answers group, where informational postings
from across the net are sent, the group rec.radio.info was created in
December, 1992, with Mark Salyzyn, VE6MGS, initially serving as moderator.

In January, 1993, many users started complaining about the volume in
rec.radio.amateur.misc. This led to a discussion about a second
reorganization, which sparked the creation of a mailing list by Ian Kluft,
KD6EUI. This list, which was eventually joined by many of the most prolific
posters to the ham radio groups, came up with a proposal to add 11 groups to
the rec.radio.amateur hierarchy in April 1993. The subsequent vote, held in
May and early June, approved the creation of five groups:
rec.radio.amateur.digital.misc (to replace .packet), .equipment, .homebrew,
.antenna, and .space.

The Current Groups
==================

I can hear you asking, "OK, so this is all neat history, but what does it
have to do with me now?" The answer is that the history of each group has
a direct bearing on what the group is used for, and what's considered
appropriate where.

The easy one is rec.radio.amateur.misc. It is what rec.ham-radio was renamed
to during the reorganization. Any message that's not more appropriate in one
of the other groups belongs here, from contesting to DX to ragchewing on VHF
to information on becoming a ham.

The group rec.radio.amateur.digital.misc is for discussions related to
(surprise!) digital amateur radio. This doesn't have to be the common
two-meter AX.25 variety of packet radio, either; some of the most
knowledgeable folks in radio digital communications can be found here, and
anything in the general area is welcome. The name was changed to emphasize
this, and to encourage discussion not only of other text-based digital modes,
such as AMTOR, RTTY, and Clover, but things like digital voice and video as
well. The former group, rec.radio.amateur.packet, should be removed by
September 21st, 1993. It is obsolete, and you should use .digital.misc
instead (or the appropriate new mailing list, mentioned below).  The group
has .misc as part of the name to allow further specialization if the users
wish it, such as .digital.tcp-ip.

The swap group is now rec.radio.swap. This recognizes a fact that became
evident shortly after the original group was formed: Hams don't just swap ham
radio gear, and other folks besides hams swap ham equipment. If you have radio
equipment, or test gear, or computer stuff that hams would be interested in,
here's the place. Equipment wanted postings belong here too. Discussions about
the equipment generally don't; if you wish to discuss a particular posting
with the buyer, email is a much better way to do it, and the other groups,
especially .equipment and .homebrew, are the place for public discussions.
There is now a regular posting with information on how to go about buying and
selling items in rec.radio.swap; please refer to it before you post there.

The first reorganization added two groups to the list, one of which is
rec.radio.amateur.policy. This group was created as a place for all the
discussions that seem to drag on interminably about the many rules,
regulations, legalities, and policies that surround amateur radio, both
existing and proposed.  Recent changes to the Amateur Radio Rules (FCC
Part 97) have finally laid to rest the Great Usenet Pizza Autopatch Debate
as well as complaints about now-preempted local scanner laws hostile to
amateurs, but plenty of discussion about what a bunch of rotten no-goodniks
the local frequency coordinating body is, as well as the neverending no-code
debate, may still be found here.

The other added group is rec.radio.cb. This is the place for all discussion
about the Citizens' Band radio service. Such discussions have been very
inflammatory in rec.ham-radio in the past; please do not cross-post to both
rec.radio.cb and rec.radio.amateur.* unless the topic is genuinely of interest
to both hams and CBers - and very few topics are.

The rec.radio.info group is just what its name implies: it's the place where
informational messages from across rec.radio.* may be found, regardless of
where else they're posted. As of this writing, information posted to the group
includes Cary Oler's daily solar progagation bulletins, ARRL bulletins, the
Frequently Asked Questions files for the various groups, and radio
modification instructions. This group is moderated, so you cannot post to it
directly; if you try, even if your message is crossposted to one of the other
groups, your message will be mailed to the moderator, who is currently Mark
Salyzyn, VE6MGS. The email address for submissions to the group is
[e-mail]. Inquires and other administrivia should be
directed to [e-mail]. For more information about
rec.radio.info, consult the introduction and posting guidelines that are
regularly posted to that newsgroup.

The groups rec.radio.amateur.antenna, .equipment, .homebrew, and .space are
for more specialized areas of ham radio: discussions about antennas,
commercially-made equipment, homebrewing, and amateur radio space operations.
The .equipment group is not the place for buying or selling equipment; that's
what rec.radio.swap is for. Similarly, the .space group is specifically about
amateur radio in space, such as the OSCAR program and SAREX, the Shuttle
Amateur Radio EXperiment; other groups cover other aspects of satellites and
space. Homebrewing isn't about making your own alcoholic beverages at home
(that's rec.crafts.brewing), but rather construction of radio and electronic
equipment by the amateur experimenter.

Except for rec.radio.swap and rec.radio.cb, all of these newsgroups are
available by Internet electronic mail in digest format; send a mail message
containing "help" on a line by itself to [e-mail] for instructions
on how to use the mail server.

All of the groups can be posted to by electronic mail, though, by using a
gateway at the University of Texas at Austin. To post a message this way,
change the name of the group you wish to post to by replacing all of the '.'s
with '-'s - for example, rec.radio.swap becomes rec-radio-swap - and send to
that [e-mail] ([e-mail], for example). You may
crosspost by including multiple addresses as Cc: entries (but see below). This
gateway's continued availability is at the pleasure of the admins at
UT-Austin, and is subject to going away at any time - and especially if
forgeries and other net.abuses become a problem. You have been warned.

A Few Words on Crossposting
===========================

Please do not crosspost messages to two or more groups unless there is genuine
interest in both groups in the topic being discussed, and when you do, please
include a header line of the form "Followup-To: group.name" in your article's
headers (before the first blank line). This will cause followups to your
article to go to the group listed in the Followup-To: line. If you wish
to have replies to go to you by email, rather than be posted, use the word
"poster" instead of the name of a group. Such a line appears in the headers
of this article.

One of the few examples of productive cross-posting is with the rec.radio.info
newsgroup. To provide a filtered presentation of information articles, while
still maintaining visibility in their home newsgroups, the moderator strongly
encourages cross-posting. All information articles should be submitted to the
rec.radio.info moderator so that he may simultaneously cross-post your
information to the appropriate newsgroups. Most newsreaders will only present
the article once, and network bandwidth is conserved since only one article is
propagated. If you make regular informational postings, and have made
arrangements with the moderator to post directly to the group, please
cross-post as appropriate.

--
Jay Maynard, EMT-P, K5ZC, PP-ASEL | Never ascribe to malice that which can
[e-mail]      | adequately be explained by stupidity.
      "If my car ran OS/2, it'd be there by now" -- bumper sticker
                 GCS d++ p+ c++ l+ m+/- s/++ g++ w++ t+ r

--
73, Paul W. Schleck, KD3FU

[e-mail]

Celebrating 60 years of the Univ. of Maryland ARA - W3EAX (1933-1993)

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

Date: Thu, 16 Dec 1993 15:51:36 GMT
From: sdd.hp.com!elroy.jpl.nasa.gov!swrinde!cs.utexas.edu!howland.reston.ans.net!torn!nott!cunews!freenet.carleton.ca!FreeNet.Carleton.CA![e-mail]
Subject: Help! Looking for spread-spectrum video link!
To: [e-mail]

We are in need of a Spread-Spectrum video transmitter for a tele-robotics
application.  If you know of a company that builds or distributes
such a beast, we would greatly appreciate your sharing this knowledge.

I can be reached at the above address, or at [e-mail],
ph # 613-596-7807, fax: [phone].

--
VE3NFY - Wayne D. Mercer | Email: [e-mail]
Computing Devices Canada |  work: [phone]
PO Box 8508, MS 4140     |   fax: [phone]
Ottawa, Ontario, Canada    K1G 3M9

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

Date: 17 Dec 93 13:31:24 EST
From: titan.ksc.nasa.gov!titan.ksc.nasa.gov![e-mail]
Subject: HELP: Looking for RF Sniffer design/kit
To: [e-mail]

I'm looking for info (circuit diag/designs, kits, etc) that can
be homebrewed and also not to much burnden on the pocket book?
Appreciate any reply directly to above Email addr or posting.

TNX
Tom
AD4NA

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

Date: 17 Dec 1993 18:19:54 GMT
From: news.service.uci.edu!cerritos.edu!news.Arizona.EDU!math.arizona.edu!noao!ncar!gatech!howland.reston.ans.net!@network.ucsd.edu
Subject: Ramsey 6m
To: [e-mail]

In article <[e-mail]> [e-mail] (Danny Anderson) writes:
>Did anyone see the Ramsey 6m kit?  The ad says a 12 year old did the 2m
>kit.  It would be real embarrassing if I ordered one and couldn't get it
>to work.  Does anyone do 6m?  In our area there is about 7 repeaters.
>Would it be safe to say, that you would not find anyone or hardly anyone
>on them?  If I got one, how do you check when the radio is good for DX?
>If the conditions for DX are good do the repeaters still work?


I've built the Ramsey FX-440, and reviewed the 220 and 2m radio
kit designs.  They're quite mediocre.  The spectral purity of
the transmitted signal is variable and often not legal, and the
receiver is extremely poor by modern standards.

For the $200 price tag of the kit and cabinet, you could buy a
VHF lo-band Micor with a 60W output level, and four channels
worth of crystals and elements.  You'd have a considerably
superior radio, though it would be larger and use crystals.

Alternatively, you could save your money up longer and buy
an Azden mobile with many features the Ramsey doesn't have,
including CTCSS, DTMF and a good receiver.

The Ramsey kits can be cleaned up to provide a clean transmitted
signal, but the receiver will always be mediocre.  Though Ramsey
kits appear to be targeted at beginners, it requires much more
than beginner skill to make the radios work reasonably.

Dana

--
 * Dana H. Myers KK6JQ, DoD 466 | Views expressed here are *
 * [phone]   | mine and do not necessarily *
 * [e-mail] | reflect those of my employer *
 * This Extra supports the abolition of the 13 and 20 WPM tests *

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

Date: Thu, 16 Dec 1993 16:05:11 GMT
From: sdd.hp.com!col.hp.com!srgenprp![e-mail]
Subject: Spray-on shielding
To: [e-mail]

S. A. Modena ([e-mail]) wrote:
: Would anyone be able to steer me to a product and source for spray on
: shielding?  Such as I see as a sprayed on black crinkle layer on the
: inside of plastic bezel parts on PCs...are there conductive-upon-
: drying spray (or dip) paints vailable?

Steve

  I've used the MS-485 spray-on coating on fiberglass to make homemade
parabolic reflectors reflective.  The MS stuff is nickle based and
doesn't give quite as high conductivity as silver based products but it
is certainly less expensive.  They claim surface resistivity of
5 ohm per square when applied in a .002" layer. For RFI I expect it
would be just fine.  It's also available in bulk.
  It is black but not a crinkle finish, at least not the way I've used it.


73
Glenn Elmore n6gn

ax.25  n6gn@wx3k.#nocal.ca.usa.na
amateur IP: [e-mail]
Internet: [e-mail]

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

Date: Thu, 16 Dec 1993 10:06:21 GMT
From: ucsnews!sol.ctr.columbia.edu!math.ohio-state.edu!cs.utexas.edu!swrinde!gatech!europa.eng.gtefsd.com!library.ucla.edu!agate!doc.ic.ac.uk!uknet!pipex!pavo.csi.cam.ac.uk!pmms.cam.ac.uk!
Subject: VHF switching diodes
To: [e-mail]

Following the recent PIN diode discussion, allow me this one.
I am no expert.

I am working on a circuit using BA482 diodes, described as
"VHF switching diodes". Who makes them? What are their specs?
Are they PIN diodes?

Thanks,
Andrew Thomason

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

End of Ham-Homebrew Digest V93 #136
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