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1994-11-13
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Date: Fri, 28 Oct 94 04:30:21 PDT
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: List
Subject: Ham-Ant Digest V94 #358
To: Ham-Ant
Ham-Ant Digest Fri, 28 Oct 94 Volume 94 : Issue 358
Today's Topics:
### Advice needed for loss in BNC<->SO-239 connector
AP8
Best wire for dipoles? (2 msgs)
Copper J-Pole measurements (2 msgs)
How's the Wire ... Man?
Looking for comments on helically wound HF antennas
Needed: J-pole measurements
PCB antennas
Want to put up half of a TH6DXX
what IS a bevrage antenna? (2 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: Thu, 27 Oct 1994 22:12:28 GMT
From: mack@ncifcrf.gov (Joe Mack)
Subject: ### Advice needed for loss in BNC<->SO-239 connector
In article <3864u4$6ae@nova.np.ac.sg> s2202629@np.ac.sg (Teh Aik Wen) writes:
>I'm at present trying to homebrew an antenna. It's the first time I'm doing
>it, and parts aren't exactly the easiest for me to find, especially since
>I'm not very sure what I'm looking for. (Yes, I'm very new, and I don't have
>a xceiver or anything for that matter).
>
>Whats the antenna for? Thats a different story altogether.
>
>Anyway, I've been trying to make this antenna featured in Sept'94 CQ.
>(Anyone else doing it/has done it, care to email me?). I didn't read it
>carefully enough, and bought a BNC connector instead of a SO-239 for the
>antenna. Not difficult I thought, just go look for a 'single-hole,
>rear-mount SO-239 socket'. But I didn't seem very successful in finding it.
>
>What I did find however was a connector that was a BNC to SO-239.
>
>I was wondering, how much 'losses' would I face if I went ahead and used the
>BNC, followed by this connector? Reason why I want to do this is because I'm
>having difficulity in finding the SO-239 (single hole, rear mount).
>
>Just a note, the 'other side' of the SO-239 socket was supposed to be a
>lenght of RG-58/U that is some 2" and then connected directly to the twin
>lead (that makes up the antenna).
>
>Thanks.
>
The problem is not of losses but mechanical. I don't know what your antenna
is, but if you can do it, then you've done it. Joe NA3T, have fun
welcome to hamming
------------------------------
Date: 28 Oct 94 02:09:40 GMT
From: w5robert@blkbox.COM (Robert Wood)
Subject: AP8
Any reason on the AP8 10mhz adjustment being shorter for
the CW setting than the phone setting??? Is this a misprint??
--
73
Robert Wood
WB5CRG w5robert@blkbox.com
------------------------------
Date: 27 Oct 1994 07:11:05 -0400
From: jimn0oct@aol.com (JimN0OCT)
Subject: Best wire for dipoles?
In article <1994Oct24.120528.101@lmpsbbs.comm.mot.com>,
burke_br@adcae1.comm.mot.com (Bruce Burke) writes:
Well, let' see.....
Stranded vs. solid: solid will stretch more. If not useing an antenna
tuner, this could be a problem, as your resonant frequency will decrease
as the wire stretches.
Insulated vs. non: Insulated protects the outer layer of copper (which the
RF uses) from corrosion. It's also my opinion that insulation changes the
specific impedance of the wire, changing the 468/MHz equation somewhat.
Never used copperweld, have heard good and bad things. Real bear to
solder and bend.
Good luck!
73, jim
------------------------------
Date: 27 Oct 1994 13:40:06 -0700
From: rdcole@crl.com (Ron Cole)
Subject: Best wire for dipoles?
Mike Staples (fa419@cleveland.Freenet.Edu) wrote:
: For 1/2 wavelength wire dipoles in the 10 - 80 meter range, whats the best
: type of wire to use? Solid? Stranded? Insulated? Non-insulated? Also, what's
: "Copperweld" and what does "hard drawn" mean?
I would use the Copperweld because of the strength of the steel core.
There is a stranded antenna wire being sold that looks good to.
It featuers a large strand count thst is woven in a roap like
manner, it strong and flexiable, expensive somthing like 20 to 40 cents
per foot. I first saw this wire used as trailing wires for HF radios on
Aircraft. Check for the Ad's in 73 and QST.
----------------------------------------------------------------------
Ron Cole Internet:rdcole@crl.com ICBM:29 31.03 N
N5HYH CIS:70325,102 98 25.55 W
CE KZEP/KHBL AX25:N5HYH @ K3WGF.STX.NA
----------------------------------------------------------------------
------------------------------
Date: 27 Oct 1994 23:47:14 GMT
From: Luke Hamaty <70324.1010@CompuServe.COM>
Subject: Copper J-Pole measurements
I just built a J-pole recently using 3/4" pipe (thin wall) for the
main radiator and 1/2" for the stub. The radiator pipe (!) is
58-1/2" and the stub is 19-1/2". The connector pipe is 1-1/2".
These are the lengths of just the pipes, NOT counting connectors.
Use a 3/4-1/2-3/4 tee. I solder all tee connections, and put caps
on the open pipe ends w/o solder. A spacer to keep the stub and
radiator helps, too. Connect the center of the feedline to the
long element 2-1/2" up from the bottom of the inside of the J, and
the feedline shield across from that. You don't need a balun
unless you are a purist. You can loop the coax if it makes you
feel better. Use another piece of 3/4 pipe in the bottom of the
tee for mounting.
The dimensions are from an article in one of the digests a year or
so back. They were for 3/4 pipe, but worked perfectly as I
describe above.
Hope that helps! 73 de KQ4OQ
------------------------------
Date: Thu, 27 Oct 1994 21:16:49 GMT
From: roberson@HDFS3.UCSD.EDU ( Brad Roberson )
Subject: Copper J-Pole measurements
PLEASE, I beg of you, DO NOT SEND INFO ON TWIN-LEAD J-POLES. While I appreciate
the mail and suggestions that is not what I want to build. I am looking
along with another individual now who has seen my posts, for the following:
1. J-Pole antenna project
a. must be constructed from 1/2" copper water pipe
b. must contain formulas for measurements
1. length of 1/4 wave stub
2. length of 3/4 wave stub
3. spacing between stubs
4. coax placement
Please, Please, PLEASE, I don't want numbers, but FORMULAS.
...---... ...---... ...---... -.. . -. ----. -. -.. ...
*---------* Applied Computing Devices, Inc. _**_
| RESCUE |_*_ BRAD A. ROERSON IIIIIIIII-|____\
| 95 |---\_ roberson@acd4.acd.com /-------| 91 |<
=(O)-------(O)-' Honey Creek Volunteer Fire Department +-(O)-----(O)-+
------------------------------
Date: Thu, 27 Oct 1994 20:19:42 GMT
From: gdo@aloft.att.com (Glenn D. O'Donnell)
Subject: How's the Wire ... Man?
Hi everyone,
Our local club is looking to buy mass quantities of coax so our members can
take advantage of the bulk rate. We're looking at various varieties of cable
and we all feel warm & fuzzy about Belden.
One of our members got a copy of "The Wirebook" from "The Wireman". The
book is a fantastic collection of information about transmission lines and
such. It is also, of course, the catalog for "The Wireman". Their cable
looks almost too good to be true! Therein lies my skepticism.
Is their cable REALLY that good? Who makes it? I find it hard to believe
that they would make it themselves. The overhead for such an operation must
be huge.
Please respond via email since I usually don't get a chance to read the
newsgroups. I will summarize my findings on these newsgroups.
adTHANKSvance and 73
de Glenn O'Donnell, N3BDA
gdo@aloft.att.com
--
Glenn D. O'Donnell, N3BDA Internet: gdo@aloft.att.com
AT&T Bell Laboratories Amateur Radio: n3bda@n3dpu.#epa.pa.usa.na
Allentown, PA Home QTH: Palmerton, PA (Grid FN20eu)
------------------------------
Date: 27 Oct 1994 00:08:26 +0200
From: stickler@cc.Helsinki.FI (Patric M Stickler)
Subject: Looking for comments on helically wound HF antennas
I am looking for the most effective antenna to install in the attic of
an apartment building, or rather in an attic-like access space, where
the maximum working area is around 6' by 4' and 2.5' high. I have been
considering some sort of helically wound antenna (or slinky-type) for
40m, but would like some comments on expected efficiency, etc. as
opposed to some other scheme (IsoLoop-type).
Any suggestions/comments will be greatly appreciated.
Patrick Stickler
OH2LUV, KC4YYY
------------------------------
Date: Wed, 26 Oct 1994 20:53:53 GMT
From: roberson@HDFS3.UCSD.EDU ( Brad Roberson )
Subject: Needed: J-pole measurements
Thanks to all of those who replied to my post regarding J-pole information,
but everyone has missed what I was truly looking for. What I had was an
article from a magazine produced by Wayne Green (can't remember the name)
but the article actually had the measurement, i.e. the distance of spacing
between the legs, the lengths of the elements, and the placement of the coax.
All of these are approximations but they are a good start. These four
formulas are what I am looking for. If anyone has this article (published
approx. 2 1/2 years ago) or another similar one with formulas. Thanks
N9NDS
*---------* Applied Computing Devices, Inc. _**_
| RESCUE |_*_ BRAD A. ROERSON IIIIIIIII-|____\
| 95 |---\_ roberson@acd4.acd.com /-------| 91 |<
=(O)-------(O)-' Honey Creek Volunteer Fire Department +-(O)-----(O)-+
------------------------------
Date: Wed, 26 Oct 1994 20:25:51 GMT
From: zlau@arrl.org (Zack Lau (KH6CP))
Subject: PCB antennas
Alan Denby (alden@ozemail.com.au) wrote:
: Hi there HAMs etc,
: Does anyone have any information or a reference on methods of building
: VHF and UHF antennas on circuit board material. I want to use
: photographic techniques to etch the boards, preferably on standard
: fibreglass boards. Do I need to use teflon? I'm not tring to build
: microstrip circuits or filters just antennas. DIrectiaonal beams and
: co-linears and phased arrays are what I had in mind.
People have made dish feeds using G-10/FR-4 board. The biggest
complaint is the low power handling capability--25 watts or
so and you fry your dish feed. Teflon doesn't have the
mechanical rigidity of fiberglass.
--
Zack Lau KH6CP/1 2 way QRP WAS
8 States on 10 GHz
Internet: zlau@arrl.org 10 grids on 2304 MHz
------------------------------
Date: 27 Oct 94 19:59:22 GMT
From: henniger@cisco.com (Mickey Henniger)
Subject: Want to put up half of a TH6DXX
Hi!
I live in town, and have a regular lot, neighbors, and a TH6DXX.
The TH6DXX barely stays within the property lines with its 22 ft
boom and 33 ft width. Not wanting to get roasted by the neighbors,
I had the idea of using only half of the antenna:
The elements are:
Reflector 20/15 -----------------------------------------
|
|
Reflector 10 ------------------------------
|
|
Driven Ele 20/15/10 ---------------------------------------
|
[I want to cut here-------------> |
|
Director ------------------------------
|
|
|
Director ---------------------------------
|
|
Director -----------------------------------
Can anyone think of problems with dropping the directors?
I put this half-tenna in the air about 15 feet and the SWR is fine
on 10 and 15 meters, but is significantly off on 20 meters, actually
resonating at about 13.7 mhz.
How will the gain be expected to change?
Will it have any resonable gain over a dipole?
Any experiences? opinions?
Mick
(ac6eu)
------------------------------
Date: 26 Oct 1994 19:39:00 -0400
From: c002@ns3.CC.Lehigh.EDU (David M. Roseman)
Subject: what IS a bevrage antenna?
>
>Well, years ago the Atlanta (Georgia) ARC had their own beverage (sic)
>antenna for Field Day made out of beer cans soldered together. Worked
>great on 40m as I recall. Operating ability went down as the vertical
>went up though :-)
>
oh hahaha, very funny! :)
nice one tho..
DAvid
|-----------------------------------------------------------------------|
| David Roseman | c002@lehigh.edu |
| SysOp of NODE 3 BBS | The Flying HAm - BBS |
| Running OBV/2 Software | KBR-9318 - CB |
| | N3SQE/SVARC - Ham |
| HAmmy in IRC | N3SQE@N3IQD.FN20GO.PA.USA.NA - Packet |
|-----------------------------------------------------------------------|
------------------------------
Date: 26 Oct 1994 20:21:00 GMT
From: domonkos@access4.digex.net (Andy Domonkos)
Subject: what IS a bevrage antenna?
David M. Roseman (c002@ns3.CC.Lehigh.EDU) wrote:
: what IS a beverage antenna anyway? and what is it comprized of? LEDs?!
: thanks
: David
: |-----------------------------------------------------------------------|
: | David Roseman | c002@lehigh.edu |
: | SysOp of NODE 3 BBS | The Flying HAm - BBS |
: | Running OBV/2 Software | KBR-9318 - CB |
: | | N3SQE/SVARC - Ham |
: | HAmmy in IRC | N3SQE@N3IQD.FN20GO.PA.USA.NA - Packet |
: |-----------------------------------------------------------------------|
....I know it has nothing to do with coffee... :-)
Andy N3LCW
------------------------------
Date: Thu, 27 Oct 1994 17:02:18 -0400
From: frederick.mckenzie-1@pp.ksc.nasa.gov (Fred McKenzie)
References<R691SQJ.darrylb@delphi.com> <freyderCyA455.6Lz@netcom.com>, <CyAB8H.3nt@pica.army.mil>
Subject: Re: RS Speaker Mics [WAS Re: Radio Shack Antennas?]
In article <CyAB8H.3nt@pica.army.mil>, mellis@ramcad.pica.army.mil (Mark
Ellis) wrote:
> FYI, that's all. I'm looking for a used Icom or whatever fits the
> HTX-202 plug, but I keep missing hamfests.
Mark-
For your info, the Icom speaker-mike may not key the HTX-202 unless you
change a resistor inside. The Radio Shack unit uses about 2200 Ohms,
while the Icom unit uses something around 10K to 50K Ohms for the P-T-T
function. As a result, the Radio Shack unit will work with Icom, but not
vice-versa.
The Radio Shack unit reportedly works with Yaesu. It's possible that a
Yaesu unit will work with the HTX-202.
I never noticed the cheap construction with my R/S speaker-mike. Mine
works quite well, and is probably a little better on the IC-2AT, than the
Icom unit, because of having a slightly larger speaker.
73, Fred, K4DII
------------------------------
End of Ham-Ant Digest V94 #358
******************************