home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
QRZ! Ham Radio 4
/
QRZ Ham Radio Callsign Database - Volume 4.iso
/
digests
/
antenna
/
940326.txt
< prev
next >
Wrap
Internet Message Format
|
1994-11-13
|
16KB
Date: Sat, 1 Oct 94 04:30:10 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: Bulk
Subject: Ham-Ant Digest V94 #326
To: Ham-Ant
Ham-Ant Digest Sat, 1 Oct 94 Volume 94 : Issue 326
Today's Topics:
2 Meters Antenna
ALUM. ELEMENT RESTOR
Antenna in Search of a Job
Antennas are prohibited ...!!!!!!!!!
HF antenna questions from newbie ham (semi-long)
HT antenna question
Tiger Tail (HT antenna) (3 msgs)
using twin coax vs ladder line
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: 29 Sep 1994 12:31:11 GMT
From: ihnp4.ucsd.edu!dog.ee.lbl.gov!agate!howland.reston.ans.net!math.ohio-state.edu!jussieu.fr!univ-lyon1.fr!cri.ens-lyon.fr!news@network.ucsd.edu
Subject: 2 Meters Antenna
To: ham-ant@ucsd.edu
I've built a meters antenna ,described in a french review ,a double delta loop.
______
\ /
\ /
\/
[] <---- BOOOM
/\
/ \
/____\
(figure for "1" element )
My antenna for the test had got 6 elements ,and the result is impressive .
That's why if someone else had already built something like this ,I would be interressed by his opinion and may be measures.
If you want further informations send me a mail.
------------------------------
Date: Wed, 28 Sep 1994 15:41:00 GMT
From: ihnp4.ucsd.edu!pacbell.com!sgiblab!swrinde!howland.reston.ans.net!news.sprintlink.net!holonet!colossus.holonet.net!iat.holonet.net!kbsbbs!tom.alldread@network.ucsd.edu
Subject: ALUM. ELEMENT RESTOR
To: ham-ant@ucsd.edu
JC>Tom Alldread (tom.alldread@kbsbbs.com) wrote:
JC>: Greetings to All:
JC>: I recently purchased a 15 year old 20/15 metre 9 element
JC>: Wilson beam with a 40 foot boom. The aluminum is pretty dull
JC>: looking and I wonder if anyone on this conference has any
JC>: recommendations as to the best way to restore the elements back to
JC>a nice glossy finish?
JC>: Very Best Regards and 73 to All,
JC>: Tom, VE7TMA
JC>Hello Tom:
JC>Please understand, I am not bloody minded when I ask the following
JC>question, but I hope you can educate me:-
JC>Why would you want to do this?
JC>I ask this question for the following reasons:
JC>1. Even if is possible to gloss it up (I have no idea one way or the
JC>other), it is only going to revert back to dull-looking after
JC>erection.
JC>2. Assuming it is going to be on a tower, I doubt that you would be
JC>able to tell the difference anyways. (Perhaps this for esthetics?)
JC>3. Perhaps your objective is to ensure good contact at the joints of
JC>the antenna. If this is the case, there is a product called
JC>"NOALOX" (I think) that assists in conductivity and prevents
JC>aluminum to aluminum seizure. It is sold by Home Hardware (give me
JC>a few days and I should be able to get you the HH product number).
JC>In any case, let me know
JC>73 and live better digitally
JC>James of Rockland
JC>VE3XJ
Greetings James:
Thank you for your reply. This antenna was installed on a salt
water beach and thus was in the salt spray zone. The joints look like
they need to be cleaned up to ensure a good connection and while I am at
it I thought I would try to restore the overall appearance as well. I am
aware that the aluminum will oxidize again but my existing antenna that
has been up 7 years looks quite a bit better than this one. I already
have some NOALOX but it is nice to know that I can get some more from
Home Hardware as I had to get my present tube from an electrician.
Thanks for the info James.
73
Tom
Very Best Regards,
T.M. Alldread
---
* CmpQwk #UNREG* UNREGISTERED EVALUATION COPY
------------------------------
Date: 29 Sep 1994 21:09:58 GMT
From: haven.umd.edu!umd5.umd.edu!jbytof@uunet.uu.net
Subject: Antenna in Search of a Job
To: ham-ant@ucsd.edu
A friend just purchased a surplus 30' parabolic antenna from
General Dynamics in San Diego. It had been used to test
radar imaging technology, I believe.
He wants to start a business providing program uplinks to
geosyncsats. What equipment is required and how much
would it all cost?
Thanks,
Jeff Bytof
rabjab@golem.ucsd.edu
------------------------------
Date: 30 Sep 1994 19:27:09 GMT
From: lll-winken.llnl.gov!noc.near.net!jericho.mc.com!fugu!levine@ames.arpa
Subject: Antennas are prohibited ...!!!!!!!!!
To: ham-ant@ucsd.edu
In article 000DD789@gsusgi2.gsu.edu, cisrmp@gsusgi2.gsu.edu (Roderick Padilla) writes:
-->I live in a subdivision that WILL not accept any kind of outdoors antennas. I
-->need to know the best solution to install 2M antenna without going "ilegal".
-->
-->/Roderick Padilla
-->wp4-boc
Can you have an American Flag sticking out from your house/garage?
That "pole" holding the flag could be a nice Daimond Dual Bander
or medium sized 2m vertical.
---
------------------------------------------------------------
Bob Levine KD1GG 7J1AIS VK2GYN formerly KA1JFP
levine@mc.com <--Internet email Phone(508) 256-1300 x247
kd1gg@wa1phy.ma <--Packet Mail FAX(508) 256-3599
------------------------------------------------------------
------------------------------
Date: 29 Sep 1994 15:57:57 GMT
From: ihnp4.ucsd.edu!dog.ee.lbl.gov!news.cs.utah.edu!cs.utexas.edu!howland.reston.ans.net!swrinde!news.uh.edu!usenet@network.ucsd.edu
Subject: HF antenna questions from newbie ham (semi-long)
To: ham-ant@ucsd.edu
I just got my Tech license ( :) ) and will take the test to upgrade on
10/8 ( 5 wpm will be a shoo-in, 13 is possible but doubtful). I have a
borrowed QRP rig, and am planning the antenna that I'll use with it. I
would like to initially do a lot of CW until my speed gets up enough to
upgrade, and then switch to HF phone. I have the following questions,
posed in no particular order:
1) Under what circusmtances does one use a 1:1 balun as opposed to a
4:1? Why don't I see ads for 3.5:1 or some other ratios?
2) Do most antenna tuners include baluns? If so, the balun would not
really be in the antenna system at the point where the unbalanced feed
line meets the balanced antenna. Is this a problem? Does it make any
kind of meaningful difference?
3) Some antenna ads mention "lossy" traps. Are traps
inherently "lossy," or is the amount of loss introduced a function of the
attributes of the trap?
4) If I had a transmatch, would I ever need traps in a dipole?
5) If one has an antenna which purports NOT to need a tuner, will
the use of a tuner in such a system detract from the performance of the
antenna? Enhance it? Make no difference either way?
6) We live in the country, with a good deal of open space around (14
acres). Nevertheless, my wife is lobbying *heavily* against stringing
wires around the house. I have seen (and so has she) ads for the
Cushcraft R5 and R7 vertical multibanders. Would either of these be an
appropriate choice for a first antenna? Why? Why not? Any caveats?
7) I may be able to talk Joy (we've been married (to each
other) for 35 years--this has a tendency to lull one into thinking one
knows one's spouse, but there'a always that nagging doubt--know what I
mean?) into letting me string a single long wire (150' to possibly 400').
It would terminate in pasture, and would average about25'above ground.
Would this be useful? If so, how should it be fed? (Rig has unbalanced
output only.)
Any other advice you can offer, on or off line, would be most helpful and
most appreciated.
David F. Jenkins | Lurk and learn,
Decision and Information Sciences | Post and burn.
University of Houston | (S. Carpenter)
KC5JRR
------------------------------
Date: 29 Sep 1994 15:01:57 GMT
From: ihnp4.ucsd.edu!dog.ee.lbl.gov!overload.lbl.gov!agate!spool.mu.edu!darwin.sura.net!coil!venus.nist.gov!onyx.nist.gov!proctor@network.ucsd.edu
Subject: HT antenna question
To: ham-ant@ucsd.edu
Hello all,
Before I bought an HT, I had assumed that the rubber duck antenna was a helical
wire with the bottom end attached to the ground of the bnc, and the center of
the bnc was connected somewhere up on the helix where the antenna looked like
50 ohms. All was fine in the world until I bought my HT, checked with an
ohmmeter, and found that the ground of the bnc was not connected to anything
(at DC anyway). There went my theory, and all of my other beliefs became
suspect :-)
It appears that the rubber duck is simply an end feed antenna. Of course, the
"electrical lenght" could be 1/2 wavelenth, which would work fine without
ground radials, but the impedance would not be anything like 50 ohms either.
Several manufacturers sell 1/4 wavelenth whips for HT, which would look like 50
ohms (or close enough) with suitable ground radials, but again, without the
radials this would be far from 50 ohms. Then to make things worse, there are
those 5/8 wl collapsable antennas that "perform like a rubber duck when
collapsed".
Maybe I'm showing my ignorance, but is there a way to make these end feed
antennas look like 50 ohms? Or maybe the finals of an HT are designed to be
abused, and manufactures will have you put almost anything on it and assume the
finals will grin and bear it.
Can anyone enlighten me on HT antenna design?
Thanks,
Jim - KE3HO
--
James E. Proctor
National Institute of Standards and Technology
If you put your left shoe on your right foot, will it be on the right foot?
My opinions are my own. I have the receipt to prove it.
------------------------------
Date: 29 Sep 1994 15:45:47 GMT
From: ihnp4.ucsd.edu!dog.ee.lbl.gov!agate!howland.reston.ans.net!europa.eng.gtefsd.com!news.umbc.edu!haven.umd.edu!cville-srv.wam.umd.edu!ham@network.ucsd.edu
Subject: Tiger Tail (HT antenna)
To: ham-ant@ucsd.edu
>Hello all,
>
>Before I bought an HT, I had assumed that the rubber duck antenna was a helical
>the bnc was connected somewhere up on the helix where the antenna looked like
>50 ohms. All was fine in the world until I bought my HT, checked with an
>ohmmeter, and found that the ground of the bnc was not connected to anything
>(at DC anyway). There went my theory, and all of my other beliefs became
>suspect :-)
>
>It appears that the rubber duck is simply an end feed antenna. Of course, the
>"electrical lenght" could be 1/2 wavelenth, which would work fine without
>ground radials, but the impedance would not be anything like 50 ohms either.
>Several manufacturers sell 1/4 wavelenth whips for HT, which would look like 50
>ohms (or close enough) with suitable ground radials, but again, without the
>radials this would be far from 50 ohms. Then to make things worse, there are
>those 5/8 wl collapsable antennas that "perform like a rubber duck when
>collapsed".
>
>Maybe I'm showing my ignorance, but is there a way to make these end feed
>antennas look like 50 ohms? Or maybe the finals of an HT are designed to be
>abused, and manufactures will have you put almost anything on it and assume the
>finals will grin and bear it.
>
>Can anyone enlighten me on HT antenna design?
Take a hank of wire about 18" in length and clip it around the base of the BNC
such that it's making contact. This will be your counterpoise. Antennas West
sells this as the "Tiger Tail." they get $7.50 for it! That's ALL it is!
It will improve performance - it MUST do so. Only other thing I can recommed
for improving an HT antenna would be to tune the inductance out of it by
adding some capacitance somewhere - although a capacitance hat would make it
dangerous and difficult to carry around...\
--
73, _________ _________ The
\ / Long Original
Scott Rosenfeld Amateur Radio NF3I Burtonsville, MD | Live $5.00
WAC-CW/SSB WAS DXCC - 130 QSLed on dipoles __________| Dipoles! Antenna!
------------------------------
Date: 30 Sep 1994 21:13:56 GMT
From: ihnp4.ucsd.edu!usc!elroy.jpl.nasa.gov!lll-winken.llnl.gov!taco.cc.ncsu.edu!ccmc9.cc.ncsu.edu!user@network.ucsd.edu
Subject: Tiger Tail (HT antenna)
To: ham-ant@ucsd.edu
In article <36enfb$63i@cville-srv.wam.umd.edu>, ham@wam.umd.edu (Scott
Richard Rosenfeld) wrote:
>
...stuff he was replying to deleted...
>
> Take a hank of wire about 18" in length and clip it around the base of the BNC
> such that it's making contact. This will be your counterpoise. Antennas West
> sells this as the "Tiger Tail." they get $7.50 for it! That's ALL it is!
> It will improve performance - it MUST do so. Only other thing I can recommed
> for improving an HT antenna would be to tune the inductance out of it by
> adding some capacitance somewhere - although a capacitance hat would make it
> dangerous and difficult to carry around...\
>
I tried a Tiger Tail on my Kenwood TH-78A handheld
(both with the standard rubber duck and with a quarter-wave whip)
and it didn't seem to make any difference.
This subjective impression is not based on extensive or
intensive testing. Your mileage may vary.
I'd be pleased to read reports from others on the Tiger Tail,
especially objective measurements of its effects.
Regards,
-- Russell Herman (KE4ERB)
russell_herman@ncsu.edu
------------------------------
Date: 30 Sep 1994 18:13:26 -0400
From: america.com!not-for-mail@uunet.uu.net
Subject: Tiger Tail (HT antenna)
To: ham-ant@ucsd.edu
I have constructed the counterpoise (abt 19") and found no difference
in my transmitted or received signal. Thinking I didn't do it right I
purchased the Tiger Tail. No noticed difference in my signal. My HT
is an Alinco DJ580T with an aluminum case. Mabe the case is the
counterpoise in my case and the wire counterpoise makes no difference.
Anyway, The touted signal improvement with the Tiger Tail are Hogwash
as far as I am concerned. Mabe someone else has had better luck.
_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ _/
_/ _/
_/ Internet = beau@enterprise.america.com _/
_/ VHF Packet = kd4gfy@kb4t.#dabfl.fl.usa.na _/
_/ _/
_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
------------------------------
Date: 30 Sep 94 18:21:00 GMT
From: news-mail-gateway@ucsd.edu
Subject: using twin coax vs ladder line
To: ham-ant@ucsd.edu
I am new to ham radio. I entered as a no-code tech. and now are planning to
upgrade to General. I am building an hf antenna and another ham told me
about seeing an antenna a long time ago that was using two coax lines to
feed vs. open line. Can anyone shed any light on this? Would it be better
than open line feed and how you would make the connection to both the
antenna and the radio?
73 Bill N1QEU
bcantin@foxboro.com
------------------------------
End of Ham-Ant Digest V94 #326
******************************