Date: Sun, 12 Dec 93 18:43:34 PST
From: Info-Hams Mailing List and Newsgroup <info-hams@ucsd.edu>
Errors-To: Info-Hams-Errors@UCSD.Edu
Reply-To: Info-Hams@UCSD.Edu
Precedence: Bulk
Subject: Info-Hams Digest V93 #1456
To: Info-Hams
Info-Hams Digest Sun, 12 Dec 93 Volume 93 : Issue 1456
Today's Topics:
10-Codes used by law enforcement
2m meteor skeds wanted
Daily Summary of Solar Geophysical Activity for 09 December
Life is too short WITH 2 KW!!!!!
Scratchi, January, 1960
TM732A packet hookup???
Updated Call Sign allocations
Upgrading from old tech liscense
Send Replies or notes for publication to: <Info-Hams@UCSD.Edu>
Send subscription requests to: <Info-Hams-REQUEST@UCSD.Edu>
Problems you can't solve otherwise to brian@ucsd.edu.
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: Fri, 10 Dec 1993 14:52:22
From: mvb.saic.com!unogate!news.service.uci.edu!usc!howland.reston.ans.net!gatech!destroyer!news1.oakland.edu!rcsuna.gmr.com!revjcs.gmr.com!jsimmer@network.ucsd.edu
Subject: 10-Codes used by law enforcement
To: info-hams@ucsd.edu
In article <6m4aec1w165w@opus-ovh.spk.wa.us> bmork@opus-ovh.spk.wa.us (Brian) writes:
List of 10-Codes deleted....
Note that this is the suggested use of the 10-codes. If a police department
rarely gets a 10-89 (bomb threat) they could use it for another purpose.
They can also disregared the list and make up there own 10-Code.
Joe
jsimmer@cmsa.gmr.com
>--->Brian
Mork Internet bmork@opus-ovh.spk.wa.us> . . . . Amateur Radio (AX.25)
ka9snf@wb7nnf.#spokn.wa.usa>... . .. USMail 6006-B Eaker, Fairchild, WA
99011
------------------------------
Date: 12 Dec 93 18:47:20 GMT
From: ogicse!emory!swrinde!cs.utexas.edu!howland.reston.ans.net!europa.eng.gtefsd.com!not-for-mail@network.ucsd.edu
Subject: 2m meteor skeds wanted
To: info-hams@ucsd.edu
I'm looking for skeds for the Geminids meteor shower....please e-mail
today or tonight and we can meet on 75m to coordinate.
==== Dave Pascoe KM3T ===================== km3t@mathworks.com ==========
------------------------------
Date: Thu, 9 Dec 1993 21:06:58 MST
From: pacbell.com!sgiblab!swrinde!cs.utexas.edu!math.ohio-state.edu!news.cyberstore.ca!nntp.cs.ubc.ca!alberta!adec23!ve6mgs!usenet@network.ucsd.edu
Subject: Daily Summary of Solar Geophysical Activity for 09 December
To: info-hams@ucsd.edu
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
DAILY SUMMARY OF SOLAR GEOPHYSICAL ACTIVITY
09 DECEMBER, 1993
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
(Based In-Part On SESC Observational Data)
SOLAR AND GEOPHYSICAL ACTIVITY INDICES FOR 09 DECEMBER, 1993
------------------------------------------------------------
!!BEGIN!! (1.0) S.T.D. Solar Geophysical Data Broadcast for DAY 343, 12/09/93
10.7 FLUX=098.4 90-AVG=097 SSN=079 BKI=0000 0001 BAI=000
BGND-XRAY=B1.5 FLU1=1.4E+05 FLU10=1.1E+04 PKI=2212 2212 PAI=006
BOU-DEV=004,004,004,002,002,002,002,005 DEV-AVG=003 NT SWF=00:000
XRAY-MAX= B4.9 @ 0215UT XRAY-MIN= B1.3 @ 2359UT XRAY-AVG= B1.8
NEUTN-MAX= +002% @ 0635UT NEUTN-MIN= -002% @ 2345UT NEUTN-AVG= -0.2%
PCA-MAX= +0.1DB @ 0955UT PCA-MIN= -0.4DB @ 1335UT PCA-AVG= -0.0DB
BOUTF-MAX=55354NT @ 0201UT BOUTF-MIN=55341NT @ 1747UT BOUTF-AVG=55350NT
GOES7-MAX=P:+000NT@ 0000UT GOES7-MIN=N:+000NT@ 0000UT G7-AVG=+067,+000,+000
GOES6-MAX=P:+118NT@ 1939UT GOES6-MIN=N:-075NT@ 0952UT G6-AVG=+088,+028,-048
FLUXFCST=STD:095,095,095;SESC:095,095,095 BAI/PAI-FCST=005,010,010/010,015,015
KFCST=1112 3211 1223 4211 27DAY-AP=005,008 27DAY-KP=2221 2111 2132 3221
WARNINGS=
ALERTS=
!!END-DATA!!
NOTE: The Effective Sunspot Number for 08 DEC 93 was 37.0.
The Full Kp Indices for 08 DEC 93 are not available.
SYNOPSIS OF ACTIVITY
--------------------
Solar activity was very low. Flare activity was minimal.
A new region may be coming into view near N07, but it is as yet
unnumbered.
Solar activity forecast: solar activity is expected to be
very low.
STD: A full-disk Yohkoh x-ray image has been appended to this
report which shows the increased emissions near N07 and a
narrow southern-hemisphere coronal hole which has not yet fully
rotated into view around the west limb.
The geomagnetic field was quiet. Yesterday's storm abruptly
gave way to the very quiet conditions seen now.
Geophysical activity forecast: the geomagnetic field is
expected to be quiet to unsettled.
Event probabilities 10 dec-12 dec
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF Green
Geomagnetic activity probabilities 10 dec-12 dec
A. Middle Latitudes
Active 15/15/15
Minor Storm 05/05/05
Major-Severe Storm 01/01/01
B. High Latitudes
Active 15/20/20
Minor Storm 10/10/10
Major-Severe Storm 01/01/01
HF propagation conditions were near-normal over all
regions. However, global MUFs are depressed between 20 and 30
percent below normal. Similar conditions are expected to
persist over the next 72 hours, through 12 December inclusive.
There are still reports of VHF openings in the Australian
regions. FM reception was reported in Brisbane and Pakenham on
frequencies as high as 100 MHz. These openings are likely the
result of persistent sporadic-E.
COPIES OF JOINT USAF/NOAA SESC SOLAR GEOPHYSICAL REPORTS
========================================================
REGIONS WITH SUNSPOTS. LOCATIONS VALID AT 09/2400Z DECEMBER
-----------------------------------------------------------
NMBR LOCATION LO AREA Z LL NN MAG TYPE
7627 S15W51 108 0000 AXX 00 001 ALPHA
7629 S21W26 083 0090 CAO 09 014 BETA
7630 S09W27 084 0080 CAO 09 012 BETA
7631 N15W17 074 0000 AXX 01 001 ALPHA
7632 N07E72 345 0000 AXX 01 001 ALPHA
REGIONS DUE TO RETURN 10 DECEMBER TO 12 DECEMBER
NMBR LAT LO
NONE
LISTING OF SOLAR ENERGETIC EVENTS FOR 09 DECEMBER, 1993
-------------------------------------------------------
BEGIN MAX END RGN LOC XRAY OP 245MHZ 10CM SWEEP SWF
NO EVENTS OBSERVED
POSSIBLE CORONAL MASS EJECTION EVENTS FOR 09 DECEMBER, 1993
-----------------------------------------------------------
ISOLATED HOLES AND POLAR EXTENSIONS
EAST SOUTH WEST NORTH CAR TYPE POL AREA OBSN
53 S30E72 S30E72 S08E30 S04E44 011 ISO NEG 010 10830A
SUMMARY OF FLARE EVENTS FOR THE PREVIOUS UTC DAY
------------------------------------------------
Date Begin Max End Xray Op Region Locn 2695 MHz 8800 MHz 15.4 GHz
------ ---- ---- ---- ---- -- ------ ------ --------- --------- ---------
08 Dec: 0146 0151 0156 C1.0 SF 7629 S22E01
0429 0433 0435 B3.9
0548 0558 0604 B6.2
0921 0925 0928 B3.4
0930 0941 0948 C1.8 SF 7629 S22W04
1012 1018 1023 B6.9 SF 7627 S24W21
1129 1134 1136 B5.6
1215 1218 1220 B6.3
1223 1226 1231 B4.8
1458 1503 1508 B7.9 SF 7629 S22W08
1756 1800 1803 B3.5 SF 7629 S21W08
1819 1823 1827 B3.0
1937 1941 2013 B8.3 SF 7630 S10W11
B2053 U2053 A2056 SF 7629 S21W09
REGION FLARE STATISTICS FOR THE PREVIOUS UTC DAY
------------------------------------------------
C M X S 1 2 3 4 Total (%)
-- -- -- -- -- -- -- -- --- ------
Region 7627: 0 0 0 1 0 0 0 0 001 ( 7.1)
Region 7629: 2 0 0 5 0 0 0 0 005 (35.7)
Region 7630: 0 0 0 1 0 0 0 0 001 ( 7.1)
Uncorrellated: 0 0 0 0 0 0 0 0 007 (50.0)
Total Events: 014 optical and x-ray.
EVENTS WITH SWEEPS AND/OR OPTICAL PHENOMENA FOR THE LAST UTC DAY
----------------------------------------------------------------
Date Begin Max End Xray Op Region Locn Sweeps/Optical Observations
------ ---- ---- ---- ---- -- ------ ------ ---------------------------
NO EVENTS OBSERVED.
NOTES:
All times are in Universal Time (UT). Characters preceding begin, max,
and end times are defined as: B = Before, U = Uncertain, A = After.
All times associated with x-ray flares (ex. flares which produce
associated x-ray bursts) refer to the begin, max, and end times of the
x-rays. Flares which are not associated with x-ray signatures use the
optical observations to determine the begin, max, and end times.
Acronyms used to identify sweeps and optical phenomena include:
II = Type II Sweep Frequency Event
III = Type III Sweep
IV = Type IV Sweep
V = Type V Sweep
Continuum = Continuum Radio Event
Loop = Loop Prominence System,
Spray = Limb Spray,
Surge = Bright Limb Surge,
EPL = Eruptive Prominence on the Limb.
SPECIAL INSERT: CURRENT X-RAY EMISSIONS FROM THE JAPANESE YOHKOH SPACECRAFT
===========================================================================
08 December 1993, 20:10 UTC
North
.....,,,,,,........... .. .. .... .
.........,,,::::;;;;;::,,,,,,,,......... ...,,,,....... .
..........,,,::;;;;;;::::,,,,,,,,,,,,,,,,,,.... ...,,,,,..... ..
........,,:::;;-;;:,:,,,,,,,,,,....,,:;,,,...,,,...,.,,,,,,::,,,,,,,....
.....,,,,::;;---:,,,,,,,...,,,,........,.,.,,,,,,,,,,,,,,,,:::;;;;;::,,...
...,,,,:;--+++-;::,,,,,,,,,,,...........,,,,,,,,,.....,,,,,,,,,:;;;;;::,,. .
..,,,::;;-+++;:;;;;:::::::,,,,,,...,,,,,.,,,,,,,,,...,,,,,,,,,,,:::;+-;--;,...
.,::;--++++-;;::::::::::,,:,,,,,,,,,,,,.,,,,,,,,,...,,,,,,,,,,,,,,:;+21||-,,...
,;;;--+|!!-::::,:::::,,,:,,:::::,,,,,,,,,,,,,,,,,,,,,,,,,.......,,::;!*3!+:,,..
:;-++|||1+;::::::::::,,,::::::::,,,,,,,,,,,,,,,,,,,,,,,,,,,...,,,,,,::-11|::,,,
;-+|!122|;:::::::::::::,:::::::::::,,,,,:,::,:,,::,:::,,,,,,,,.,,:,,,,:-+;:::,,
+-+!1441-;::,,:::::::::,::::::::::::::::;:::::::::::::,,,,,,,,,,,,,,,,,:;--;;::
-+|!24*1-;::,:::;:::::::::::::::::;;;::;;;;;;;:::;:::::::::::,,,,,,,,,::-++--;;
;-||!34|;;:::::::;:,,,,:::::::::::;;;;;;;;---;;;;;;;:;::::::::::,,,,;;::;!++++-
+|||!1!-;;:::::,,,,,,,,,,:;;;;-;:::;;;;:;;;---+--;;;;;;;;;;;;:::,,,:::::;!|++++
;;--+++-;;::,,,,,:::::::::::::;:::::::;;;-+|!2321|--;;;;;;;;;;::,::::::;-!!!|+-
,:;;-++-;;:,,,..,::;:;;;:::::::;:::::;;;-+212*#@4!+--;;;;;;;;;;:::::;;;-+21!|++
,,::;-+-;;:,,,..::;;;-;;::::::::::::;----+!13#@#1!||+++++--;;;;:::;;;;-+221!|+;
.,::;;-+--::,,..:;;--;::::::::::::;-----||!1231|!1111!2441|+-;;;;;;;;+|!*32!|+;
.,,:;;;--;:,,...,:;::;:::::::::;-;-----|!24***42112223*@@*2!|+-----;--+1221|+-;
..,,::;;-;,...,,::;:;;;;;;;;;;;;----;;++|!12#@#*21332###@@#4!++------+!11!!+--;
..,,,,:::;:,..,,:::::;;;:;;;;;;;;;;;;;;;;-+|12221112*#@@@@#3!++------|!!!|+--;;
...,,,::::;,..,:::::;;;;-;;::;:::;;;;;;--+++|!!11123*#4321||++-----+||++---;;:
....,,,,,::,..,,,:::;;;;;:::::::;;;;;;-----++++||||!!!|||++-----++++++---;;;:
........,,,,..,,,,,,::::,:,:::::::;:;;;;;--;;;---------------+--+----;;;;;:
...,,,,,,,,,,,,:::::::::::;::;;;;;;;;;;;;;;;;;--++------;;;;;::::
...,,,,,::;;:::::::;;;;;;;;;;;;;;;;;;;;;---+------;;;;::::::,,
.....,,,::::::;;;;;;;;;----;;;;;--++++++----;;;;;::::,,,,,
......,,::,,,::;;;;;;;;--+++++----;;;:::::,,,,...
. ........,,::::::::;;;;;;;;;;;:::,,,,......
. .....,,,,,,,,,,,,,::,,,,,..... .
.................. .
South
KEY: East and west limbs are to the left and right respectively. Emission
strength, from minimum to maximum are coded in the following way:
[space] . , : ; - + | ! 1 2 3 4 * # @
Units used are arbitrary, for illustrative purposes. Get "showasc.zip"
from "pub/solar/Software" at the anonymous FTP site: xi.uleth.ca
(IP # 142.66.3.29) to view these images on VGA screens.
** End of Daily Report **
------------------------------
Date: Fri, 10 Dec 1993 13:41:59 GMT
From: pacbell.com!sgiblab!sdd.hp.com!col.hp.com!news.dtc.hp.com!hplextra!hplb!hpwin052!hpqmoea!dstock@network.ucsd.edu
Subject: Life is too short WITH 2 KW!!!!!
To: info-hams@ucsd.edu
Gregory Lapin (lapin@casbah.acns.nwu.edu) wrote:
: Do QRP operators live longer than QRO operators?
Probably.
It just depends how careful each is when working on live equipment
<8*)X
(Boffo-the-clown smiley is easy, but without the revolving bow-tie
squirting water, seems to lack something)
You can still get a painful burn from an overrun 2N3866
Cheers
David GM4ZNX
------------------------------
Date: Thu, 09 Dec 93 13:53:12 PST
From: netcomsv!netcomsv!micromed!brett@decwrl.dec.com
Subject: Scratchi, January, 1960
To: info-hams@ucsd.edu
dm_johnson@dave.enet.dec.com (Dennis Johnson) writes:
>
>
> Greg,
>
> Myron should not have to explain intent until true offense, not pc offense,
> has been indicated. By your intent we should disallow reproductions of bible
> text because they slur certain pc categories.
>
> Dj
HELLO??
You sure you guys have the right newsgroup?
--
brett@micromed.com (brett miller)
------------------------------
Date: Sun, 12 Dec 1993 01:57:37 GMT
From: agate!howland.reston.ans.net!vixen.cso.uiuc.edu!moe.ksu.ksu.edu!osuunx.ucc.okstate.edu!ki5zw!corey@ames.arpa
Subject: TM732A packet hookup???
To: info-hams@ucsd.edu
does anyone know how to make a packet cable for the
kenwood TM 732A? I would sure appreciate some information
on this...
Thanks in advance...
Corey Croci AB5IM
corey@ki5zw.ampr.org
------------------------------
Date: 12 Dec 93 10:36:52 GMT
From: ogicse!uwm.edu!vixen.cso.uiuc.edu!moe.ksu.ksu.edu!abc.ksu.ksu.edu!news@network.ucsd.edu
Subject: Updated Call Sign allocations
To: info-hams@ucsd.edu
Hello all! I was wondering if anyone happens to have an updated copy of the
call sign allocations taking into account all the world's changes over the last
several years....the copy I have access to is a older copy, and still has
the two Germany's separated. If anyone has this available, or knows where it
might be available via FTP, please let me know, via either e-mail or posting
to this group...Thanks!
73 DE N0YAX
------------------------------------------------------------------------------
Jeremy L. Utley | jlu@cygnus.cis.ksu.edu
Computing & Infomation Sciences | cbr600@matt.ksu.ksu.edu
Student | cbr600@ksuvm.bitnet
Kansas State University | bxth85a (Prodigy)
A.S. Comp. Sci. & Acctg. | N0YAX@N0OER.#NEKS.KS.USA.NA (Packet Radio)
------------------------------------------------------------------------------
------------------------------
Date: 9 Dec 93 08:33:53 EST
From: sgiblab!swrinde!gatech!howland.reston.ans.net!math.ohio-state.edu!magnus.acs.ohio-state.edu!cis.ohio-state.edu!pacific.mps.ohio-state.edu!ohstpy.mps.ohio-state.edu!miavx1!miavx3.mid.@pacbell.com
Subject: Upgrading from old tech liscense
To: info-hams@ucsd.edu
In article <CHLG0M.9ux@hub.cs.jmu.edu>, blaziec@hub.cs.jmu.edu (Christopher Blazie) writes:
> I earned my technician liscense about 8 or 9 years ago. I became
> relatively inactive in amateur radio for quite a while, and now
> I'm getting back into it. When I had my novice liscense, one had
> only to take the written exam to become a tech; the written exam
> was the same as the general-class exam. So, when a technician
> wanted to upgrade to general, all he/she had to do was pass the
> 13wpm code test. Now, of course, things have changed...I've heard
> that those of us who had a tech liscense were grandfathered into
> the new system, i.e. we can still take take the 13wpm test and be
> upgraded.
That is correct. As long as *you* can prove you held
a valid Technician license prior to 3/21/87, the only
requirement (to upgrade to General) is 13 WPM.
> However, when I recently received a new liscense in the
> mail (just a replacement for the old one, which was lost), there
> was no designation that I could see that would set my lisense
> apart from any other (newer) tech liscense.
There is no different designation. An expired license,
issued prior to 3/21/87 is acceptable proof. A copy of
that license must accompany the upgrade 610 as well.
> Can someone shed
> some light on the new regulations? I've heard bits and pieces,
> but not enough to get a clear idea of what the rules are.
>
> Thanks!
>
> - Chris/KA3PUF
>
Go for it Chris ... but don't stop 'till you hit Extra!
73 >< Carl
K8NHE
------------------------------
Date: Fri, 10 Dec 1993 13:12:06 GMT
From: netcomsv!netcom.com!greg@decwrl.dec.com
To: info-hams@ucsd.edu
References <jchappel.79.755364937@sanders.lockheed.com>, <gregCHrsuv.3Jt@netcom.com>, <jchappel.80.755465269@sanders.lockheed.com>
Subject : Re: Scratchi, January, 1960
In article <jchappel.80.755465269@sanders.lockheed.com> jchappel@sanders.lockheed.com (Joel Chappell) writes:
>
>Greg - This is so typical of liberal behavior. Yes it was the best without
>really flaming yer butt....
Well, gawwwlleeee. My butt's hottern' a leaky ol' still. What is this,
the 'Hampshire Hillbillies?
> Now when faced with the truthful part that I
>wrote, and that is; this is a bit of amateur radio history and was
>written more than 30 years ago (as pointed out to you by others), you jump
>to another smart remark and try to raise color as an issue.
Color *IS* the issue, you ignoramus. Look up 'race' in the dictionary.
>Typical liberal way to squirm away from the truth...
Whatsa matter, the PC label didn't work so now you have to tag a 'liberal'
label on what you can't get your mind around?
> I doubt that Myron had any other motive
>other than to replay a bit of that history for us.
I already said that. Over, and over, and over... ...but you're so busy
making mental Dymo labels that you apparently aren't able to read. Hope
you read engineering specs a little better.
> What do you really know
>about amateur radio Greg? Do you have a ticket?
Use the call-sign server. I did, and found I've been an active ham
longer than it suggests you have. You can find the same information,
at least if you can read the FAQs well enough to glean it. By the
way, how is your ad hominem argument relevant?
>I have not seen your callsign here.
Then you don't read the net much. No, unlike you, I don't have to put
all kinds of irrelevant stuff in a .sig file.
> What do you know about life in the USA 40 to 50 years ago?
Are you asking for a transcript?
>What do you know about the person who originally wrote the Scratchi
>letters? What do you know about his motives? How many other Scratchi
>letters have you read?
I'd invite you over to see my collection of old ham literature (I've been
one of those wierd collectors of the stuff since before it was popular.
Used to pick up QSTs at the local thrift stores.)
> The answer is nothing, not much, zero..zip.
While you're looking up 'race,' look up prejudice. Your refusal to read
what's written, to label everything and move on, to answer your own questions
before hearing the answer demonstrates an inclination towards prejudice.
One wonders how you've managed to have any success as an engineer. Then
again, it is defense...
> No, you
>just jumped in with your new age PC crap and raised a lot of issues without
>doing the research.
Actually, I raised one issue.
> Too many folks use this political correctness to white
>wash the truth Greg....and that's what I object to.
So why don't you stop painting the truth with a white-wash label you
call 'political correctness,' and let it stand for what it is... or
isn't?
> And they use it to
>rewrite history books and change our social values.
Yep, gotta keep them damn historians from writing all them history books
all the time. The ones we had wuz good enough. Then along comes all these
liberals, wantin' to change our social values. Out marching through
Alabama...
> Now in typical liberal
>fashion you have me stereo-typed as some sort of bigot.
You've established yourself quite nicely without need of any stereotypes.
> Why I might even be
>black for all you know,
If you are, you aren't very good at it.
> or a member of some ethnic group
...which wouldn't stop you from being racist.
> ....but you're so
>cocked sure about what I found funny about Scratchi..and it can't be good.
I have no idea what you find funny about it. I know what I find funny,
and not funny, about it. Seems like that in addition to knowing what
I know you think that you know what I know and what I think you know,
you know?
>Well Greg..you have no idea what I believe, what I know, what I've done..how
>well I do it...
You're right. I can only infer from your demonstrated ability to reason
in a straight line.
Greg
------------------------------
Date: 12 Dec 93 17:25:21 GMT
From: ogicse!emory!kd4nc!ke4zv!gary@network.ucsd.edu
To: info-hams@ucsd.edu
References <CHsMuy.DJH@boi.hp.com>, <1993Dec10.154257.16572@ke4zv.atl.ga.us>, <btobackCHw3wH.99J@netcom.com>
Reply-To : gary@ke4zv.atl.ga.us (Gary Coffman)
Subject : Re: Receive broadcast FM on 2m mobile antenna?
In article <btobackCHw3wH.99J@netcom.com> btoback@netcom.com (Bruce Toback) writes:
>In article <1993Dec10.154257.16572@ke4zv.atl.ga.us> gary@ke4zv.atl.ga.us (Gary Coffman) writes:
>>Note, a center of roof mount will still work better than the cowl
>>mount, but [the combined AM/FM/comm antenna] is better than
>>on-glass or magmount expedients.
>
>I have wondered about that. I was about to buy an on-glass dual-band antenna
>because a sunroof pretty much precludes center-of-roof mounting, and I saw
>that the claimed antenna gain figures for such antennas were quite respectable.
>However, assumed that the gain claimed included the loss associated with
>the mount. Is this not the case? How much loss is associated with the
>on-glass mount, assuming that the inside portion is properly grounded?
Ok, this definitely falls into the "your mileage may vary" category.
I've been very unhappy with the results of using on-glass mount antennas
while some others have claimed satisfactory results. Let's look at the
theory of these antennas a bit to see if we can pinpoint potential problem
areas.
On-glass antennas are fed at a voltage node by a capacitive coupling
made up of the antenna foot, the auto glass, and a small box attached
to the inner side of the glass. Now to have the antenna end be a voltage
node, the antenna has to be an even multiple of 1/4 wave electrically
at the frequency of interest. This is usually done with a physical
halfwave rod which also has the charm that it doesn't require a groundplane
to function properly. Since the auto glass isn't well characterized, and
every individual installation is likely to be different, the inner box
usually has an adjustment to vary the capacitance for a particular
installation. This is usually a "flapper" capacitor bent closer or further
from the glass with a nylon cam. The antenna rod is usually slightly longer
than a halfwave so it can be shortened by the capacitance to resonance,
a series LC circuit.
Now since this is a high impedance point, we'd normally expect the
tuning to be quite sharp, but it usually isn't. In trying to find out
why not, we discover one of the problem areas of on-glass antennas.
That's the usually poor decoupling of the coax shield from the antenna
currents. This results in a hot shield, RF in the cabin, and a poor
resultant antenna pattern. The reason there is poor decoupling is that
the "matchbox" is equipped with a wire and little metal tab that's
supposed to "ground" the shield to the auto body. Unfortunately, this
doesn't do much good. That's because (1) we're using an antenna that
doesn't work against ground so this isn't a virtual short at VHF/UHF,
and (2) because the radio usually isn't well grounded to the body either
in today's plastic dash cars so that the return likely is via the power
wiring to the battery and then to the body. So we've got a nasty
ground loop that includes the coax shield and the window frame.
The resultant antenna pattern is unlikely to be omni, unlikely to
have it's major lobe in the horizontal plane, and certainly will
have less gain than a 5/8 wave antenna mounted securely through
the center of the top.
The other concern with on-glass antennas is physical. They do tend
to fall off or get knocked off more frequently than a thru-hole
mounted antenna. As an example of both problems, I was using an
Avanti on-glass antenna on 2 meters in a Chevy Monza. One night
as I was driving down the interstate the rod fell off. I didn't
notice, and the fellows with whom I was talking didn't notice. That's
because the coax in the cabin continued to be the primary radiator.
Note that the dashboard tach always noticed when I was transmitting
by jumping to 6000 RPM any time I keyed down, whether the rod was
in place or not.
As I said in the beginning, your mileage may vary, but I'm not
going to bother with on-glass ham antennas anymore. I either
drill the hole, or use a magmount expedient.
Gary
--
Gary Coffman KE4ZV | I kill you, | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems | You kill me, | uunet!rsiatl!ke4zv!gary
534 Shannon Way | We're the Manson Family | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244 | -sorry Barney |
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End of Info-Hams Digest V93 #1456
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