Ham Radio/Ham Radio CD-ROM (Emerald Software) (1995).ISO/news/ih91260b/ih91266.txt

Internet Message Format | 1991-04-04 | 29KB

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Date: Thu,  4 Apr 91 08:48:27 PST
From: Info-Hams Mailing List and Newsgroup <[e-mail]>
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Subject: Info-Hams Digest V91 #266
To: [e-mail]


Info-Hams Digest            Thu,  4 Apr 91       Volume 91 : Issue 266

Today's Topics:
         Any Fancy frequency standard enthusiasts out there?
                                 ATV
                            ATV: AM or FM
                 Boy Scout RADIO Merit Badge (2 msgs)
                Can you really learn Code from tapes?
                Guide to the Personal Radio Newsgroups
                            HF rig names?
            IAMBIC keyer - What does IAMBIC mean? (2 msgs)
                    KNWD TS-430S PROBLEM/SOLUTION
                            RG8U (4 msgs)
                        Ultrasonics. (2 msgs)

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 Info-Hams Digest are available
(by FTP only) from UCSD.Edu in directory "mailarchives/info-hams".

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: 4 Apr 91 15:33:19 GMT
From: mojo![e-mail]
Subject: Any Fancy frequency standard enthusiasts out there?
To: [e-mail]

Hi gang,

    Well, we have discussed the accuracy of TV stations, and concluded
that some are wonderful, and others suck rocks.  Now lets get into the real
discussion:

    Are there any frequency standards enthusiasts out there?

    You know who I mean, those of you who have closet LORAN-C and GPS
receivers tracking your Rubidium Vapor Frequency References.  People who
get giddy when they talk about 1 part in 10E12 accuracy.  Who know who
Austron is, and what "996" means.  Who can discuss the heratage of Varian,
Efratom, Tracor, Hp, Sulzer, Kode, ....

    You are out there, I can feel it.  (or maybe it is just the radiation
from my RVFR)  Lets talk.

Chuck Harris - WA3UQV
C.F. Harris - Consulting
[e-mail]

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

Date: 4 Apr 91 12:20:18 GMT
From: [e-mail]
Subject: ATV
To: [e-mail]

I am interested in getting involved in ATV.  I am particularly interested
now in FSTV.  Could someone please post or send me (or both) the
frequences in the 430-440Mhz area which covers ATV and the corresponding
UHF TV channels.

Thanks.

Scott, KA1WNU/AG (internet: [e-mail])

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

Date: 4 Apr 91 15:13:10 GMT
From: pa.dec.com!rust.zso.dec.com!shlump.nac.dec.com!sousa.enet.dec.com!sndpit.enet.dec.com![e-mail]
Subject: ATV: AM or FM
To: [e-mail]

In article <[e-mail]>, [e-mail] (Phil Howard KA9WGN) writes...
>[e-mail] (Willie Smith) writes:
>>OK, so even at small deviations (and 6 MHz bandwidths), doesn't FM win over
>>AM just for greater average power?
>
>Not necessarily.  Given that the lower frequency portions of the video
>get more benefit from a constant deviation, being as the modulation index
>is much higher, I'd expect that the high average power level is effectively
>being dedicated unevenly, favoring the lower frequencies.
>[...]

OK, if I understand you correctly, this means the lowest frequencies will
be at least as good as AM and the higher frequencies might be noisier, yes?
If this means that my sync and monochrome stuff is going to work well but
my color (and some fine detail) might be noisy, I can live with that.  In
fact, black and white is probably OK (though a waste of a good color
camcorder :+).  I can always throw more power at it, eh?

>With a given drop in signal strength, AM S/N drops linearly whereas FM
>drops very non-linearly, the curve of which depends on the parameters.

What parameters does it depend on?  Does this mean that within a certain
radius of my transmitter (with an omni antenna) the signal will be good but
outside that it will drop off rapidly?  If so that's good, as my teleop
vehicle will have a limited range and not interfere with other ATV folk far
away.  If anyone can do the math, I'm planning on using a color signal with
no sound (giving 3.6 MHz baseband bandwidth?) on a 900 MHz FM transmitter
with the deviation turned down so as to fit into a 6 MHz ATV sub-band.
With transmitter power of 5 watts into a 1/4-wave whip, and the possible
presence of trees and houses, what's my usable range?  [Like I said, no-one
knows, but hopefully I'll know soon....]

>I use my spare credit cards (the ones with expire dates in 1990 and earlier)
>as insulation tabs for my HT batteries.  Just cut them to size and don't use
>the part where the number is.

That's a neat idea!

Willie Smith
[e-mail]
[e-mail]
{Usenet!Backbone}!decwrl!sndpit.enet.dec.com!smith

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

Date: 4 Apr 91 11:21:30 GMT
From: sdd.hp.com!zaphod.mps.ohio-state.edu!unix.cis.pitt.edu!gvlf3.gvl.unisys.com!gvlv3.gvl.unisys.com![e-mail]
Subject: Boy Scout RADIO Merit Badge
To: [e-mail]

The following text is from the 1940 edition of the Boy Scouts of
America Radio Merit Badge Manual:

To obtain a Merit Badge for Radio, a Scout must:

1. Receive and send correctly a straight text at not less than
   five words (25 letters) per minute.

2. Know what, if any, licenses are required by Federal Lay
   for operation of: (a) a receiving station; (b) a trans-
   mitting station.

3. Know at least five of the most frequently used "Q" signals.
   Explain the meaning of each.

4. (a) Draw a wiring diagram of a complete receiving set for
   use on short wave with vacuum tube detector and one stage
   amplifier. Use correct symbols and show all essential ap-
   paratus, including antenna and telephones.  Describe each
   detail of apparatus and explain briefly the use of each.
   (b) Using the above diagram, explain how this receiving set
   could be made to operate also as a miniature transmitter.

5. Construct a working receiving set and demonstrate its op-
   erations by receiving signals from at least ten different
   stations.

6. Explain how to install an antenna for use in receiving equip-
   ment and how to ground it properly and protect it against
   lightning and power wires.

   NOTE: The holding of an amateur operator's license and a
   regular amateur station license will exempt the holder from
   examination on all requirements above except 4(a) and (b)
   and 5. Such licenses must be in force at the time the Badge
   is awarded.


+------------------------+-----------------------------------------+
! 73 de Ed               !  Just wondering, how many hams obtained !
! W3BNR @ N3LA.PA.USA.NA !  their license through the BSA or GSA?  !
+------------------------+-----------------------------------------+

----
Ed Naratil                                     (All standard disclaimers apply)
Amateur Packet: W3BNR@N3LA.#epa.PA.USA.NA      [e-mail]

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

Date: 4 Apr 91 12:56:34 GMT
From: soleil!mlb.semi.harris.com!trantor.harris-atd.com!su19f![e-mail]
Subject: Boy Scout RADIO Merit Badge
To: [e-mail]

In article <[e-mail]> you write:
>
>The following text is from the 1940 edition of the Boy Scouts of
>America Radio Merit Badge Manual:
>
>   [...]
>
>+------------------------+-----------------------------------------+
>! 73 de Ed               !  Just wondering, how many hams obtained !
>! W3BNR @ N3LA.PA.USA.NA !  their license through the BSA or GSA?  !
>+------------------------+-----------------------------------------+

I didn't earn Radio Merit Badge, but did learn Morse Code (dots and
dashes) as a Boy Scout.  I think it was to for First Class.  Anyway,
before I got too old, I decided to learn code by dits and dahs.  Then
got my first ham ticket.


--

Harv Hobson                             Harris GASD
WB4NPL                                  P.O. Box 94000, M/S 101/4827
[e-mail]            Melbourne  FL  32902
407-727-6642                            USA

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

Date: 4 Apr 91 09:21:00 GMT
From: [e-mail]
Subject: Can you really learn Code from tapes?
To: [e-mail]

>In article <[e-mail]>, [e-mail] (Rob Heins) writes:
>|>
>|>Seriously though, with the new Technician Class, why waste time using code
>|>you're never going to use.  At least, I know I won't...If I ever decide to
>|>get a Ham license, (or a ham for dinner) I'm not gonna spend a lot of time
>|>to learn something I'll never use.

and Patrick writes *items deleted*
>|>
>
>I'd be careful about making life-long decisions with no experience.
>Let's say you decide to skip the ham dinner and get a license.  Probably
>it's a good bet that you'd get a Technocode.  Fine.  But from there on,
>you'll be exposed to the ham experience and there's no telling if you'll
>decide to use CW or not.
                                   and then the code people have got
>you....
>--
>                                             >>>==>PStJTT
>                                     Patrick St. Joseph Teahan Taber, KC1TD

My Turn.....
============================================================================
I just can't help but to respond to this.  I have been trying sense I was
10 years old to get my Ham License, I'm 34.  Now that the "NEW" NO-CODE
License has came into effect, I am going to get my NO-CODE with the hopes
that it will inspire me to go on for my General and go further up the scale.

I have tried the ARRL tapes, The tapes supplied with Heath Co's Novice Kit,
Gorden Wess (sp) Tapes and some others some friends have made.  It seems that
once every year I get this urg to try again and again it doesn't happen.
I've even set in for 6-8-and even 15 week NOVICE CLASSES given by my friends
and future Ham Brothers and sisters and still I'm unable to even comeup with
the required 5 wpm for novice.  The Radio Theorey (sp) is easy.  So I'm
going to keep trying.

Just wanted to get it off my chest.  I don't like anybody bashing Ham Radio.
No matter what shape form or fashion it is in.

Wish me LUCK.....

Tim Wright  Future Ham.
Morehead, Ky.
WRIGHT@morekypr

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

Date: 4 Apr 91 12:46:01 GMT
From: dog.ee.lbl.gov!ncis.tis.llnl.gov!lll-winken!elroy.jpl.nasa.gov!usc!cs.utexas.edu!bcm!lib![e-mail]
Subject: Guide to the Personal Radio Newsgroups
To: [e-mail]

This message describes the rec.radio.amateur.*, rec.radio.cb, 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 2 April
1991.

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 structure we now use.

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.packet is for discussions related to (surprise!)
packet radio. This doesn't have to be the common two-meter AX.25 variety
of packet radio, either; some of the most knowledgable folks in radio digital
communications can be found here, and anything in the general area is welcome.

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 are the place for public discussions.

The 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. The neverending no-code debate goes here, as does
the New Jersey scanner law, the legality of ordering a pizza on the
autopatch, what a bunch of rotten no-goodniks the local frequency
coordinating body is, and so on.

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.amateur.misc and .packet groups are available by Internet email
in digest format; send a mail message containing "help" on a line by itself
to [e-mail] for details.

A Note 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.


--
Jay Maynard, EMT-P, K5ZC, PP-ASEL | Never ascribe to malice that which can
[e-mail]  | adequately be explained by stupidity.
  "You can even run GNUemacs under X-windows without paging if you allow
          about 32MB per user." -- Bill Davidsen  "Oink!" -- me

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

Date: 4 Apr 91 13:48:56 GMT
From: genrad![e-mail]
Subject: HF rig names?
To: [e-mail]

Hi, I need to get names of popular (and not so popular) HF rigs.  I pulled
out the HRO catalog and got some already, listed below.  Anyone else got
other suggestions I may have missed?  Email me if you do.  THANKS!

Transceivers:
ICOM    IC781, IC725, IC726, IC765, IC735, IC751A
Kenwood    TS950SD, TS940S, TS440S, TS140S, TS6805
TenTec    OMNI V562, Paragon 585, Argonaut II 535, Delta II 536
Yaesu    FT1000D, FT1000, FT767GX, FT757GX Mark II, FT650, FT747GX

Transmitters:
NONE LISTED....do hams only buy transceivers, not transmitters?

Receivers:
ICOM    R9000, R7000, R71A
Kenwood R2000, R5000
Yaesu    FRG8800

Other than short wave listening, what function do receivers serve
if there are no transmitters to go along with them?  Do hams use a
transceiver AND a separate receiver?


->Diana L. Syriac      [e-mail]        Ham: KC1SP (Sweet Pea)      <-
->I'D RATHER BE FLYING!    P-ASEL, INST        CAP: 1LT, Freedom 690 Mobile<-
->GenRad                    AD ASTRA, PER ASPERA        <-
->MS/6, 300 Baker Ave, Concord, Mass.  01742     [phone] x2459        <-

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

Date: 4 Apr 91 13:01:40 GMT
From: [e-mail]
Subject: IAMBIC keyer - What does IAMBIC mean?
To: [e-mail]

Ted,

An "Iamb" is a rhythmic/poetic structure where the first syllable is unstressed
and the second is stressed, sort of like ta-DUM.  To whit:

To be or not to be...

ta DUM ta DUM ta DUM
or, if you prefer
diDAH diDAH diDAH

If you hold both paddles in on an iambic keyer, you will get a continuous
stream of diDAHdiDAHdiDAH...

--Charlie Ross, NC1N
[e-mail]
NC1N @ WA1PHY
[e-mail]

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

Date: 4 Apr 91 13:14:00 GMT
From: [e-mail]
Subject: IAMBIC keyer - What does IAMBIC mean?
To: [e-mail]

> Subject: IAMBIC keyer - What does IAMBIC mean?
> To: [e-mail]
>
> The subject tells it all.

And Webster says it all:
        iamb - a metrical foot consisting of one short syllable followed by one
                long syllable ...
        iam.bic - adj or n

An iambic keyer will send automatic dits when you push the paddle in one
direction, and automatic dahs in the other direction.  BUT...when you depress
BOTH paddles (squeeze), you get alternating dits and dahs, the first character
being a dit or a dah depending on which paddle connected first.  THEN...when
you release the paddles, the keyer completes the character it was making at
that time, AND THEN sends the opposite character.  If it is forming a dit when
you release the paddles, it will complete that dit and then send a dah.  You
use this feature in iambic keying.  Say you want to send an "F".  Push the
paddle to the right (most keyers are set up for dits to the right) and the
keyer will start sending a string of dits.  As the second dit is forming,
squeeze the other paddle to the left.  Since both paddles are now connected,
the keyer goes into the alternating dit/dah mode and therefore next forms a
dah.  As soon as the dah begins, let go.  The dah will complete and will be
follwed by a dit:  dit-dit-dah-dit.  Voila:  "F".   In practice, you depress
the dit paddle, tap the dah paddle, and let go:  "F".  That's only two motions
of the wrist (or fingers) versus three motions with a straight, non-iambic
keyer, where you have to go back and form the final dit.  Your timing varies
these things for the other characters.

steve - W3GRG

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

Date: 3 Apr 91 00:35:01 GMT
From: hpcc05!hpldsla![e-mail]
Subject: KNWD TS-430S PROBLEM/SOLUTION
To: [e-mail]

Re: My TS430S intermiten power output problem has been solved.
 First I would like to thank to all of you (23) who responded to
 my note of last month. Simply I was overwhelmed by the support
 and stream of notes pouring in. Another testimony that HAMS are
 true friends helping each other.

 In summary following was the distribution of problems/solutions:
 Mike connection (1 case)
 Dead MOSFET (1)
 Final POWER TRANSISTOR (2)
 RY in the RF filter deck (2)
 Bad feedthrou rivets on PA BD (3)
 Bad/coroded conntact (14)

 WELL, it didn't take a genius to make the decesion whot to try first!
 After disassembly and reassembly of power module connectors to the main
 unit I am running the unit on dummy load for 10 days without failure.

 NOW everybody in the club tells me that the standard procedures with
 any of " modern technology " ham gear is to reconnect every and each
 connector every 3 to 5 years.

  Thanks again & 73 de AA6AD

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

Date: 4 Apr 91 13:57:49 GMT
From: fs7.ece.cmu.edu!o.gp.cs.cmu.edu!andrew.cmu.edu![e-mail]
Subject: RG8U
To: [e-mail]

I SURE DID! I connected up to RG8U.DUMMY.LOAD.BELDEN_CONGO.AF.?
The packet connection was sort of erratic and BRAIDED. Belden mentioned
to me that the WX was sort of nasty in the Coaxial Islands that day,
so he slipped on his NON-CONTAMINATING jacket. His wife Dialectric had
been threatning to TERMINATE their relationship on a 1:1 basis. She
claimed that he REFLECTED too much on the past and was BRIDGING the
gap between their marrage and his ham carreer, but thats another LINE
all together. Belden bid me a hearty 73 and said he had to disconnect
since his ATTENUATION span had been growing short lately ( due, no doubt
to his marital problems with dialectric). As the last disconnect packet
slithered it's way into my TNC, I thought: "What a SILVER PLATED
opportunity this had been".


[had enough yet?]

73
\paul
WA3TLD

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

Date: 4 Apr 91 15:09:37 GMT
From: usc!zaphod.mps.ohio-state.edu!caen!news.cs.indiana.edu!att!cbnewsh![e-mail]
Subject: RG8U
To: [e-mail]

>Did anyone manage to work Belden, RG8U, during his DXpedition to the Coaxial
>Islands on April 1?
>
>
>Todd, KB6JXT

>>Hmm, I thought RG8U was in the Belden Congo. Has the ITU reassigned
>>the prefix?
>>
>>Phil

    The Coaxial Islands are part of the Belden Congo, an attempt
was made to get seperate DXCC country status, but these efforts were
attenuated by the DXCC advisory committee.


                            Al Schwarz ND2K
                            honet4!nd2k

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

Date: 4 Apr 91 16:13:11 GMT
From: news.larc.nasa.gov!grissom.larc.nasa.gov![e-mail]
Subject: RG8U
To: [e-mail]

In article <[e-mail]> [e-mail] (Charlie Panek) writes:
>>in rec.radio.amateur.misc / [e-mail] (Todd Jonz, KB6JXT) sez:
>>Did anyone manage to work Belden, RG8U, during his DXpedition to the Coaxial
>>Islands on April 1?
>>
>  Yeah, I worked him in the Poisson d'Avril contest.... Didn't you?
>  Anyone got a QSL route?

He hasn't been replying to QSL requests because he's been grounded for the
last couple of weeks.  With any luck though, he should be back on the air
with a new linear because he's got a lot to gain.
--scott

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

Date: 4 Apr 91 16:15:24 GMT
From: sdd.hp.com!uakari.primate.wisc.edu!news.larc.nasa.gov!grissom.larc.nasa.gov![e-mail]
Subject: RG8U
To: [e-mail]

In article <[e-mail]> [e-mail] (Charlie Panek) writes:
>>in rec.radio.amateur.misc / [e-mail] (Todd Jonz, KB6JXT) sez:
>>Did anyone manage to work Belden, RG8U, during his DXpedition to the Coaxial
>>Islands on April 1?
>>
>  Yeah, I worked him in the Poisson d'Avril contest.... Didn't you?
>  Anyone got a QSL route?

He hasn't been replying to QSL requests because he's been grounded for the
last couple of weeks.  He's also been off the air since coming back from the
Islands.  With any luck though, he should be back with a new linear because
he's got a lot to gain.
--scott

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

Date: 4 Apr 91 15:05:21 GMT
From: [e-mail]
Subject: Ultrasonics.
To: [e-mail]

I know of someone who once made an ultrasonic down-converter and hooked it
to a number of different ultrasonic transducers (the sort you get from
doppler burglar-alarms). Apart from hearing people with the usual garage
door openers, TV remotes etc, he discovered a new one; BATS!
They could be heard quite clearly, with a 'fluttery' swept signal.
It was quite fun to stand outside a cave known to contain bats, with the
'Batphone' on, and listen to the clicks as the bats were waking up for their
evenings hunting, then the intensifying noise as they got ready for flight.
I guess anyone experimenting with high-power ultrasonics might run the risk of
causing temporary or permanent deafness in their local bat population!

           Pete Lucas [e-mail]  [e-mail]

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

Date: 4 Apr 91 16:43:09 GMT
From: sdd.hp.com!caen!math.lsa.umich.edu!spsd4360a.erim.org![e-mail]
Subject: Ultrasonics.
To: [e-mail]

In article <04.Apr.91.16:07:10.BST.#[e-mail]>
[e-mail] (Pete Lucas, NCS-TLC, Holbrook House,
Swindon) writes:
> I know of someone who once made an ultrasonic down-converter and hooked it
> to a number of different ultrasonic transducers (the sort you get from
> doppler burglar-alarms).

I think there was an article in one of the U.S. electronics magazines
about building
such a device.

> I guess anyone experimenting with high-power ultrasonics might run the risk
> of causing temporary or permanent deafness in their local bat population!

The Heath Company now sells a device called the Dazer, that transmits an audio
(tone?) at a frequency that only dogs can hear. It supposedly "stops dogs in their tracks". Is this a myth? What frequency does it transmit on?

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Steve Hideg  N8HSC

[e-mail]

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End of Info-Hams Digest
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