home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
QRZ! Ham Radio 4
/
QRZ Ham Radio Callsign Database - Volume 4.iso
/
digests
/
antenna
/
940107.txt
< prev
next >
Wrap
Internet Message Format
|
1994-11-13
|
5KB
Date: Sat, 16 Apr 94 04:30:09 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 #107
To: Ham-Ant
Ham-Ant Digest Sat, 16 Apr 94 Volume 94 : Issue 107
Today's Topics:
bicycle antennas
Coax Loss on HF
Getting ladder line out of the shack
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: Fri, 15 Apr 1994 19:00:55 GMT
From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!math.ohio-state.edu!magnus.acs.ohio-state.edu!csn!col.hp.com!srgenprp!alanb@network.ucsd.edu
Subject: bicycle antennas
To: ham-ant@ucsd.edu
John Bate (jbate@rtp-nc.mentorg.com) wrote:
: Does anyone have any good ideas about building a bike antenna
: and the mount. I am trying get some info about a decent gain
: 2m antenna, probably 1/2 or 5/8 wave. I plan on putting a
: flag on the top to help make my bike visible so height is
: not too much of a problem.
The problem with mounting a J-pole or other large antenna on the
rear of the bike is that it makes it hard to mount/dismount the bike.
(When you try to throw your leg over the seat in the normal way.)
A flexible 1/4-wave whip works almost as well as a bigger antenna and
is much less of an obstruction. You will need a ground plane to work it
against: I have found that a standard metal bike rack works just fine.
You can put your battery (and radio) in a pannier mounted on the rack.
AL N1AL
------------------------------
Date: Fri, 15 Apr 1994 15:35:16 GMT
From: fluke!chuckb@beaver.cs.washington.edu
Subject: Coax Loss on HF
To: ham-ant@ucsd.edu
In article <gbrentCo1yHy.7nE@netcom.com> gbrent@netcom.com (Gerald J. Brentnall) writes:
>
>As Murphy's Law would dictate, the best trees and location for my 80/40
>meter dipole are at a point on my property quite distant from the ham
>shack. If I were to put the dipoles up at that point, my coax run would
>be approximately 350 feet.
>
>Does anybody have any experience with long runs of coax at hf? With good
>quality coax, I can't imagine the loss would be that great. Theory is
>one thing - anybody have any experience? Would appreciate all comments.
I just made measurments of power loss at my station with about 180' of
Belden 8217 (RG 213). I connected a 50 ohm dummy load to the end of the
coax run and measured the power output of my Icom 737 at the rig end first.
It was very close to 100W on 80 thru 10.
Next I measured the power at the far end of the coax on the same bands:
80: 100W (NO MEASUREABLE LOSS)
40: 95W
20: 80W
15: 75W
10: 66W
I would not worry about 350' of coax on 80 or 40.
--
Chuck Bowden / WB7R / chuckb@tc.fluke.com / (206) 356-6228
Fluke Corporation / MS 232E / PO Box 9090 / Everett WA 98206-9090
------------------------------
Date: Fri, 15 Apr 1994 16:31:06 GMT
From: ihnp4.ucsd.edu!swrinde!cs.utexas.edu!csc.ti.com!tilde.csc.ti.com!cauldron!ra.csc.ti.com!fstop.csc.ti.com!sbrown@network.ucsd.edu
Subject: Getting ladder line out of the shack
To: ham-ant@ucsd.edu
In article <Co7vFu.89s@cbnewsm.cb.att.com> hellman@cbnewsm.cb.att.com (eric.s.hellman) writes:
> In article <2oej7h$poq@paperboy.gsfc.nasa.gov>, lvn@cen.com (Larry Novak) writes:
> > I use a similar technique to get my coax and ground wires out of the
> > shack, but I'd hate to tell you how much plastic I cut to size and then
> > shattered trying to drill/punch/cut holes in it. I finally resorted to
> > melting holes thru it with my soldering iron! Does anyone have any good
> > suggestions about how to stop this stuff from cracking when you're
> > putting holes in it?
> >
> > Thanks,
> > Larry, K3TLX
> >
>
> Larry: use a drill bit that is ground for cutting Brass. Bits that are
> ground for steel will gall.
> You can buy them with the correct angle for brass or regrind one.
You can also buy drill bits that are ground to cut plastic. The same
dealer that you got your plastic from should be able to fix you up.
*********************************************
| Steve Brown, WD5HCY | |
| sbrown@charon.dseg.ti.com | Simplicate |
| wd5hcy@wd5hcy.ampr.org | and add |
| [44.28.0.61] | lightness. |
| wd5hcy@kf5mg.#dfw.tx.usa.na | |
*********************************************
------------------------------
End of Ham-Ant Digest V94 #107
******************************