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1994-11-13
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11KB
Date: Fri, 4 Feb 94 04:30:11 PST
From: Ham-Ant Mailing List and Newsgroup <ham-ant@ucsd.edu>
Errors-To: Ham-Ant-Errors@UCSD.Edu
Reply-To: Ham-Ant@UCSD.Edu
Precedence: Bulk
Subject: Ham-Ant Digest V94 #23
To: Ham-Ant
Ham-Ant Digest Fri, 4 Feb 94 Volume 94 : Issue 23
Today's Topics:
antenna pattern
Antenna stacking problems
How to tune a J pole?
J-Pole Design Needed
mininec source code
RG-58 and Discone ant. problem at VHF (2 msgs)
TEST (2 msgs)
Testing (4 msgs)
Send Replies or notes for publication to: <Ham-Ant@UCSD.Edu>
Send subscription requests to: <Ham-Ant-REQUEST@UCSD.Edu>
Problems you can't solve otherwise to brian@ucsd.edu.
Archives of past issues of the Ham-Ant Digest are available
(by FTP only) from UCSD.Edu in directory "mailarchives/ham-ant".
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: 3 Feb 94 22:07:30 GMT
From: news-mail-gateway@ucsd.edu
Subject: antenna pattern
To: ham-ant@ucsd.edu
Does anyone know of a reference or have a closed form expression to
predict the pattern from an offset-fed parabolic dish? Thanks
end
the views expressed here are the author's
C. Harper harper@huntsville.sparta.com or kd4qio@amsat.org
KD4QIO
SPARTA Inc (205) 837-5282 x1216 voicemail
4901 Corporate Drive (205) 830-0287 FAX
Huntsville AL 35805
"we have met the enemy and he is us." w. kelly
------------------------------
Date: Mon, 31 Jan 1994 21:00:20 GMT
From: adobe!swirsky@decwrl.dec.com
Subject: Antenna stacking problems
To: ham-ant@ucsd.edu
In article <1994Jan31.191526.18186@nosc.mil> price@nosc.mil (James N. Price) writes:
>
>3) The TH-7 "works" in that signals get louder in the right direction, but
>overall it sounds rather dead--not much noise, a bunch of weak signals.
>Kinda like listening to 15 mtrs on a 40 meter dipole. Again, the
>side-by-side on 15 meters had same results--his 3-el tri-bander at 50 feet
>was "hearing" better than my TH-7 at 60 feet. (And my location is, if
>anything, better than his).
>
James:
Your comment "..like listening to 15 meters on a 40 meter dipole"
made me wonder: Would a "real" 15 meter dipole work better on
15 than a 40? I've always assumed (but never experimented) that
a dipole antenna works just as well on its third harmonic.
Have you had experience comparing a 40 and 15 meter dipole
at the same location? Maybe I'll experiment this weekend.
Thanks.
Robert "AF2M" Swirsky.
------------------------------
Date: 2 Feb 1994 16:17:33 GMT
From: library.ucla.edu!europa.eng.gtefsd.com!howland.reston.ans.net!vixen.cso.uiuc.edu!sdd.hp.com!hpscit.sc.hp.com!icon!hpchase.rose.hp.com!cmoore@network.ucsd.edu
Subject: How to tune a J pole?
To: ham-ant@ucsd.edu
I have a commercial J pole antenna for 2M that I bought many years ago.
I no longer have any information on it, and I don't recall what the tuning
procedure is. Both the long and short sections can be adjusted in length.
How should I tune it? Adjust one for minimum SWR, then the other? Adjust
them both at the same time?
Thanks for any help
Chris Moore
N6IYS
cmoore@mothra.rose.hp.com
------------------------------
Date: 31 Jan 94 15:51:26
From: metro!news.cs.su.oz.au!harbinger.cc.monash.edu.au!yeshua.marcam.com!news.kei.com!eff!usenet.ins.cwru.edu!lerc.nasa.gov!news.larc.nasa.gov!larry.larc.nasa.gov!partos@@munnari.oz.au
Subject: J-Pole Design Needed
To: ham-ant@ucsd.edu
Darryl: I don't know about coax, but it is easy to make a J-pole from
TV twin lead. The design has been posted on here several times. I made
one and it works fine. I'll dig up the design snd E-mail it to you.
73's Dick
--
|----------------------------------------------------------------|
| Richard D. Partos KE4AZJ Norfolk, VA |
| Internet: r.d.partos@larc.nasa.gov |
|----------------------------------------------------------------|
------------------------------
Date: 2 Feb 1994 09:43:48 -0800
From: apple!apple.com!apple.com!not-for-mail@decwrl.dec.com
Subject: mininec source code
To: ham-ant@ucsd.edu
mack@ncifcrf.gov (Joe Mack) writes:
>In article <steve-260194134849@brainiac.hi.com> steve@hi.com (Steve Byan) writes:
>>Is anyone aware of an ftp site that has the source for mininec?
>>
>Dear Steve,
> I think (only think remember ) that mininec was written by a guy
>with the second name of Beazley , who advertises in QST, under the name
>of his software company and I doubt if the source code is avaiable.
> Mininec is a little antiquated now. I like yagiopt (by the same guy)
>for yagis, for other antennas I don't know what's the best.
Aiiiya!
MININEC preceeds Brian Beezley, K6STI. Brian improved many things,
especially the user interface aspects, and made it into a commercial
product (another adaptation of MININEC is ELNEC by W7EL). However,
the original MININEC was developed with your tax dollars (unless you
are young, in which case it was your parents' tax dollars :-) and
is public domain.
The original version was in BASIC (hee, hee, ha, ha) and the listing
and theory etc are available in a 130 page document you can get from
NTIS of the Commerce Department. Call NTIS at (703) 487-4650. Ask
the government employee on the other side of the landline that you
want document ADA181682. The price is $27. Modulo shipping, which is a
couple of bucks. They can also Fed-ex it to you for an extra $15.
Yes, they accept plastic.
Beezley has an interesting bug report in, I think it was, the February
1994 (most recent) issue of QST.
Has anyone else ordered from NTIS more than once? Really weird --
they use your telephone number as the key their data base. They
must have me tagged as an antenna nut by now, having bought the
two NEC2 tomes (no other way to describe it :-) and more recenty,
the MININEC document, from them.
73,
Kok Chen, AA6TY kchen@apple.com
Apple Computer, Inc.
------------------------------
Date: 2 Feb 1994 17:57:37 GMT
From: koriel!newscast.West.Sun.COM!abyss.West.Sun.COM!pongo!myers@decwrl.dec.com
Subject: RG-58 and Discone ant. problem at VHF
To: ham-ant@ucsd.edu
In article <Pine.3.89.9401291735.A26656-0100000@comp> Peter Laws <plaws@comp.uark.edu> writes:
>> A guy I know recently installed a Discone Antenna (R-S brand) and 50 ft of
>> RG 58 for his scanner. Problem: The rubber duck on the handheld unit, 20
>
>There's your answer right there: RG58 and UHF don't mix very well. I
>don't have the RS $3 Catalog near me, but I think you'll be surprised at
>the dB loss at UHF. And I don't recall the discone design having much,
>if any, gain.
>
>On my indoor discone, I use the RG8/M from RS which has less loss at the
>higher frequencies. You'll find a lot of folks who'll recommend RG6 for
>scanner use, too. (I don't use it 'cause it's ~70 ohm and I like to use
>my discone for my 2m HT).
If you want low-loss coaxial cable in a 50 ohm system, use Belden 9913.
This is a partial-air dielectric coax, with about the same form factor
as RG-8.
--
* Dana H. Myers KK6JQ, DoD 466 | Views expressed here are *
* (310) 348-6043 | mine and do not necessarily *
* Dana.Myers@West.Sun.Com | reflect those of my employer *
* This Extra supports the abolition of the 13 and 20 WPM tests *
------------------------------
Date: Fri, 4 Feb 1994 00:47:40 GMT
From: agate!howland.reston.ans.net!vixen.cso.uiuc.edu!uwm.edu!msuinfo!netnews.upenn.edu!netnews.cc.lehigh.edu!ns1.cc.lehigh.edu!c002@network.ucsd.edu
Subject: RG-58 and Discone ant. problem at VHF
To: ham-ant@ucsd.edu
In article <Pine.3.89.9401291735.A26656-0100000@comp>, plaws@comp.uark.edu (Pete
r Laws) writes:
>> A guy I know recently installed a Discone Antenna (R-S brand) and 50 ft of
>> RG 58 for his scanner. Problem: The rubber duck on the handheld unit, 20
>
>There's your answer right there: RG58 and UHF don't mix very well. I
>don't have the RS $3 Catalog near me, but I think you'll be surprised at
>the dB loss at UHF. And I don't recall the discone design having much,
>if any, gain.
>
>On my indoor discone, I use the RG8/M from RS which has less loss at the
>higher frequencies. You'll find a lot of folks who'll recommend RG6 for
>scanner use, too. (I don't use it 'cause it's ~70 ohm and I like to use
>my discone for my 2m HT).
>
yes....rg58 has a 10.0dB lose at 400MHz and rg6 has a 4.4 dB lose there..
the best is rg58 at 4.1dB lose at 400MHz.buuuut it cost MORE!
just wanted to throw that is!
DAvid
--
:)****************************************************************(:
** ** The Flying HAm **
** David Roseman ** c002@lehigh.edu **
** ** **
** Cole's Law: ** Les Boules Qui Roulet **
** Thinly sliced Cabbage ** Toutes Les Poules!! **
------------------------------
Date: Thu, 3 Feb 1994 23:24:34 GMT
From: agate!usenet.ins.cwru.edu!howland.reston.ans.net!cs.utexas.edu!oakhill!victorc@network.ucsd.edu
Subject: TEST
To: ham-ant@ucsd.edu
This is a testing.
------------------------------
Date: Thu, 3 Feb 1994 22:27:45 GMT
From: agate!library.ucla.edu!europa.eng.gtefsd.com!howland.reston.ans.net!cs.utexas.edu!oakhill!victorc@network.ucsd.edu
Subject: TEST
To: ham-ant@ucsd.edu
This is a testing.
------------------------------
Date: Thu, 3 Feb 1994 20:51:38 GMT
From: agate!howland.reston.ans.net!cs.utexas.edu!oakhill!victorc@network.ucsd.edu
Subject: Testing
To: ham-ant@ucsd.edu
------------------------------
Date: Thu, 3 Feb 1994 20:52:11 GMT
From: agate!howland.reston.ans.net!cs.utexas.edu!oakhill!victorc@network.ucsd.edu
Subject: Testing
To: ham-ant@ucsd.edu
------------------------------
Date: Thu, 3 Feb 1994 20:56:47 GMT
From: agate!howland.reston.ans.net!cs.utexas.edu!oakhill!victorc@network.ucsd.edu
Subject: Testing
To: ham-ant@ucsd.edu
------------------------------
Date: Thu, 3 Feb 1994 20:50:51 GMT
From: agate!howland.reston.ans.net!cs.utexas.edu!oakhill!victorc@network.ucsd.edu
Subject: Testing
To: ham-ant@ucsd.edu
Testing.
------------------------------
End of Ham-Ant Digest V94 #23
******************************