Ham Radio/Ham Radio CD-ROM (Emerald Software) (1995).ISO/news/inham01/769

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INFO-HAMS Digest            Sun, 15 Oct 89       Volume 89 : Issue 769

Today's Topics:
                      Aircraft headsets (2 msgs)
                           ARRL Membership?
   Back to Part 15 (was Re: Unrestricted access (was Re: Part 15))
                      Bandwidth grudgingly given
              Does It Matter How Thick Antenna Wire Is?
                        Heathkit name change?
                         Info wanted: IC-275
                       PL259 connector assembly
                   Thoughts from a prospective ham
                     TUVA SSR on 15M (RA0/UA9YX)
----------------------------------------------------------------------

Date: 14 Oct 89 20:12:25 GMT
From: ncrlnk!pmday_2![e-mail]  (Steve Bridges)
Subject: Aircraft headsets

In article <[e-mail]> [e-mail] (Jim Garver) writes:
>Where can I get electret mic elements that are noise cancelling?
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Well, Sporty's Pilot shop in Batavia/Cincinnati sells the David Clark
M-4 electret mike separate from headsets.  I used one to upgrade my
DC H10-30 headseat with a dynamic mike when I started flying twin-engine
aircraft.  I believe that the cost of the mike is about $75-100.

The electret mike (IMHO) does offer superior noise cancellation over
dynamic mikes.


>The boom mic headset that Yaesu has for the FT-727 is lousy for
>aircraft use and mobile with the car window open.  I see that some
>of the aircraft headset manufacturers have noise cancelling electret
>mics, but they want quite a bit for these.  Do these electret mic
>elements have a back opening to the diaphram?  I wonder how they do
>it since all the electret elements I have seen are tiny sealed cans.
>Just what is an electret mic, anyway?  Is it a condenser or a
>piezo element?

Don't know.  The M-4 mike is in a little green container.  The size of the
actual mike element is about 1/4" in diameter, and the end of a green
rectanguler box holder which fits at the end of the headseat boom.  There
are little grills on both sides of the element, one side labeled talk.

There is a small cord, labeled on one side "Nexus" and in the other side
"U-173/U".

I don't know if this will work with your Yaesu headseat.





 ____________________________________________________________________________
| Steve Bridges                               | e-mail:                      |
| NCR Corporation -- USDPG Product Marketing  | [e-mail] |
| and Support Office Level Systems            | ..!ncrlnk!pmday_2!steve      |
| 1334 South Patterson Blvd                   | (513)-445-4182               |
| Dayton, OH  45479                           |       622-4182 (VoicePlus)   |
|_____________________________________________|______________________________|

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

Date: 14 Oct 89 22:05:41 GMT
From: tank!eecae!cps3xx![e-mail]  (Usenet file owner)
Subject: Aircraft headsets

In article <[e-mail]> [e-mail] (Jim Garver) writes:
>Do these electret mic
>elements have a back opening to the diaphram?  I wonder how they do
>it since all the electret elements I have seen are tiny sealed cans.

One technique that could be used is to employ two microphones.  One mic
faces the speakers mouth, and the other faces outward.  The two signals
are fed into a difference amplifier, and since the noise is about the
same on both sides of the mic, but the speakers voice is much greater on
one side, cancellation is achieved.

In the rare case that original ideas   Kenneth J. Hendrickson    N8DGN
are found here, I am responsible.      Owen W328, E. Lansing, MI 48825
Internet: [e-mail]   UUCP: ...!uunet!frith!hendrick

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

Date: 14 Oct 89 21:52:03 GMT
From: deimos.cis.ksu.edu!harris.cis.ksu.edu![e-mail]  (Myron A. Calhoun)
Subject: ARRL Membership?

In article <[e-mail]> [e-mail] (David Hallidy) writes:
>In article <[e-mail]>, [e-mail] ( Avatar) writes:

[many lines deleted for brevity]

>This posting basically says it all in a nutshell. The sad thing is, we
>can write all day long to K1ZZ, BUT HE WON'T ANSWER....

Please don't be too hard on K1ZZ.  I wrote him once (on an
entirely UNrelated matter) and received an answer fairly promptly.

--Myron
--
Myron A. Calhoun, PhD EE, W0PBV, [phone] (work), 539-4448 (home).
INTERNET: [e-mail]
BITNET:   [e-mail]
UUCP:  ...{rutgers, texbell}!ksuvax1!harry!mac

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

Date: 14 Oct 89 22:01:33 GMT
From: tank!eecae!cps3xx![e-mail]  (Usenet file owner)
Subject: Back to Part 15 (was Re: Unrestricted access (was Re: Part 15))

In article <[e-mail]> [e-mail] (Rusty Carruth) writes:
>In article <[e-mail]> [e-mail] (Marc de Groot) writes:
>I was down at Pace (kinda like Price Club, if you know what that is)
>yesterday and saw something which really worried me.
>    "AT&T Cellular Style Walkie-Talkies"
>There was no mention of what freq they used.
>There was no mention of how much power they radiated.
>I'm worried about what freqs these things are on.

These are probably on the 49 and/or 46 MHz band.  There are 10
frequencies allocated for cordless phones.  Walkie-Talkies can use 5 (I
think) of these frequencies.  I also think they are NBFM.  They won't
bother you unless you are on 6m.

In the rare case that original ideas   Kenneth J. Hendrickson    N8DGN
are found here, I am responsible.      Owen W328, E. Lansing, MI 48825
Internet: [e-mail]   UUCP: ...!uunet!frith!hendrick

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

Date: 14 Oct 89 18:20:00 GMT
From: ux1.cso.uiuc.edu!ux1.cso.uiuc.edu![e-mail]
Subject: Bandwidth grudgingly given

> Along those same lines, I drove cross country last year on an 8500
> mile trip and found that once you are not in a Metro area, the CB channels,
> and I mean litterally all the channels, go silent.

Something must be wrong with the front end of your receiver.  Granted there
are definitely some dead spots in the country, but I live outside of the
major metro areas and the channels are still quite crowded.  It depends on
where you go.  Here in Urbana-Champaign, I hear usually 5 or 6 active CB
channels during an evening.  When visting my parents in West Viginia in a
town of 6000 people, there are often 12 or more busy channels.  Incidently
there is more two meter repeater activity there as well.

--Phil howard--  <[e-mail]>
-.-- . ...   - .... .. ...   .. ...   -- -.--
.-.-.- ... .. --. -. .- - ..- .-. .   ..-. .. .-.. .

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

Date: 12 Oct 89 06:58:58 GMT
From: att!pacbell!hoptoad!peora!tsdiag!ka2qhd![e-mail]  (Thomas A Moulton RATS Clifton NJ)
Subject: Does It Matter How Thick Antenna Wire Is?

The only time you should be real concerned about the diameter of the wire
is when the Length is Short (Like above 50 Mhz, and for sure over 500 mhz)

You see there is a factor is the electrical length that is based on the
Length to Diameter ratio, if the diameter is large the antenna will be
broader and shorter, but on HF you don't need to worry about it much...

For an HF antenna I would not worry about it, except for making sure
it is strong enough to withstand the weather...

I usually use 12 or 14 gauge Copper Weld (Copper coated steel)
and remember the wire does not have to be taunt!

Now if you were to use 2-4 wires with spacers about 3-4 inches apart you
could have a nice broad antenna for a good chunk of 80M...
(That's the wires are 3-4 inchea apart, at rf it would look like a solid
pipe...)

73
--
Life is too short to be mad about things.
Thomas A. Moulton, W2VY          Packet: w2vy@kd6th  Voice: 145.190 (r)
[phone]                   uucp: rutgers!petsd!tsdiag!ka2qhd!w2vy

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

Date: 13 Oct 89 22:08:08 GMT
From: att!cbnewsl![e-mail]  (james.p.hawkins)
Subject: Heathkit name change?

In article <[e-mail]>, [e-mail] (Bob Parnass, AJ9S) writes:
>
> Now that Zenith is selling its Heath business to Clendes Machines Bull,
> will Heathkit become Bullkit?   :-)
> --
> ============================================================================
> Bob Parnass, AJ9S - AT&T Bell Laboratories - att!ihuxz!parnass [phone]

    IT JUST DID!!!

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

Date: 14 Oct 89 19:04:50 GMT
From: att!cbnewsc![e-mail]  (Bob Parnass, AJ9S)
Subject: Info wanted: IC-275

In article <[e-mail]>, [e-mail] writes:
>
> I'd like to find out some info about the Icom IC-275:...


I own an Icom IC-275H and have been happy with it, using it
mainly for FM and listening in and out of the 2 meter band.
The dozen or so SSB QSOs I've had using it has shown it a good
performer in that mode, too.

As received from the factory, the IC275 receives 138-174 MHz.

Reception within the ham band is very good.  However,
I have noticed a difference in reception performance when
listening outside 2 meters.  You can hear the level
of the background noise go down as soon as you tune beyond
the ham band.  It's a discrete type of change so I assume
they are switching something, like a band pass filter.
I think different sythesizer circuitry may be used outside the band
also.

Outside 2 meters, the reception is sensitive enough for the
type of listening I do, but the 275H is prone to images above
148 MHz -- seemingly a bit more than my old Bearcat 300s, for
example.

I have not modified the 275H to transmit outside 2 meters so
I can't offer information about such a modification, nor about.
the computer interface either.

You might want to consider installing the high stability oscillator
option, although I have not.

My 275H receiver will change frequency about 1.6 - 1.8 kHz during the
first hour or so after initial power on.  The drift is slow, so one
would not normally be aware of it except:

    1) the discriminator meter shows off center reading,
        and more importantly

    2) the memory scan function will skip active channels
        because the "window detector" circuit thinks
        the signal is too far off frequency to be
        valid.

Fortunately, the RIT control can be easily used to compensate
for the difference.  By the way, the memory scan is very fast.

When I bought my 275H, the reference oscillator was aligned
perfectly for operation when the rig was first powered on.
I realigned the oscillator after a 1 hour warmup instead.

I compared the Kenwood TS-711A, the Icom 275A/H, the Yaesu
FT726R, and FT736R before buying the Icom and would make
the same choice over again.
--
============================================================================
Bob Parnass, AJ9S - AT&T Bell Laboratories - att!ihuxz!parnass [phone]

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

Date: 14 Oct 89 18:25:00 GMT
From: ux1.cso.uiuc.edu!ux1.cso.uiuc.edu![e-mail]
Subject: PL259 connector assembly

>     Amphenol lists two different adapters for the PL-259 in thier catalog:
>
>     UG-175 -- RG-55,58,141,142  (.209" I.D.)
>     UG-176 -- RG-59,62,71,140,210  (.257" I.D.)
>
>     They list nothing for RG-8/X specifically. In the back of my mind I
>   seem to recall that Radio Shack had an adapter that would handle RG-8/X
>   but I could be mistaken. My Belden catalog lists RG-8/X as having an
>   O.D. of .242", so it looks like the UG-176 adapter should accomidate
>   it.

Yes, the UG-176 works.  RG-8/X has basically the same O.D. as RG-59.

--Phil howard--  <[e-mail]>
-.-- . ...   - .... .. ...   .. ...   -- -.--
.-.-.- ... .. --. -. .- - ..- .-. .   ..-. .. .-.. .

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

Date: 12 Oct 89 07:08:05 GMT
From: att!pacbell!hoptoad!peora!tsdiag!ka2qhd![e-mail]  (Thomas A Moulton RATS Clifton NJ)
Subject: Thoughts from a prospective ham

Please do not let what you see on the NEWS-groups discourage you, this is
a totally different world from being on the air.

If you were to listen (watch) the evening NEWS you would then not want to
venture outside, all they do is talk about the BAD things...

There are many areas of the bands that are a bit boring after a while, but there
is a lot out there to enjoy!

Also remember that more often than not people like to flame and argue at
each other on news groups...

I would compare this news group to others and I think you might see that
there is a fair percentage of good stuff here...

And as with any ongoing discussion there are many horses that get beaten
to death... like the code wars... you were not seeing us at our best...
it's a very emotional topic...

besides a very very small percentage of hams are represented here...:>

73, Tom, W2VY
--
Life is too short to be mad about things.
Thomas A. Moulton, W2VY          Packet: w2vy@kd6th  Voice: 145.190 (r)
[phone]                   uucp: rutgers!petsd!tsdiag!ka2qhd!w2vy

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

Date: Sat, 14 Oct 89 14:12:15 EDT
From: [e-mail]
Subject: TUVA SSR on 15M (RA0/UA9YX)

Date: Fri, 13 Oct 89 10:29 EDT
From: Ed Schwalenberg <[e-mail]>
Subject: TUVA SSR on 15M (RA0/UA9YX)
In article <TUVA SSR on 15M (RA0/UA9YX)> from <[e-mail].
Symbolics.COM> on <Fri, 13 Oct 89 10:29 EDT>:

>   I contacted a station on 15M last night (10pm ET) from the TUVA soviet
>republic.
>   It was RA0/UA9YX on 21295 kHz.
>   This is the first time I've heard this area of the Soviet Union on Ham
>Radio.
>   Perhaps others may be interested.  (B T W Tuva is the geographical centre of
>   Asia)
>There was a very funny show on PBS (I think it was Nova) about Richard
>Feynmann   of the Feynmann Lectures on Physics. He decided to try to visit
>Tuva, because as far as he could tell no Westerner had ever been there.
>Unfortunately, in the pre-glasnost era, that proved impossible.

I was curious about the "TUVA SSR" and so looked it up in Encyclopaedia
Britannica.  Here is what I found:

Correct name:  Tuva Autonomous Soviet Socialist Republic
(or Tuva A.S.S.R.).  Note that it is *not* a Union republic but part of
the R.S.F.S.R., or Russia (loosely speaking) , which is itself a
federated republic.  All Union republics have the (theoretical) right of
secession; autonomous republics do not.  A.S.S.R.'s are administrative
divisions based on nationality, somewhat different from oblasts.

Some history of the Tuva A.S.S.R.:
Part of the Chinese Empire until 1911
1914:  Russia took country under its protection after fomenting a
       separatist movement
1921:  Independence declared: Tanna Tuva People's Republic
1944:  Annexed by the U.S.S.R., made an autonomous oblast of the
       R.S.F.S.R.
1961:  Status raised to A.S.S.R.


Richard B. Langley                E-mail:  [e-mail] or [e-mail]
Assoc. Prof.                      Phone:   [phone]
Geodetic Research Laboratory      Telex:   014-46202
Dept. of Surveying Engineering    FAX:     [phone]
University of New Brunswick
Fredericton, N.B., Canada
E3B 5A3

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End of INFO-HAMS Digest V89 Issue #769
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