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[TowerTalk] Pennant question

To: "''" <>
Subject: [TowerTalk] Pennant question
From: "Georgens, Tom" <>
Date: Sat, 31 Jan 2004 17:07:32 -0600
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Tower talkers -

I have a question about a pennant antenna.


At my QTH in Barbados I decided to try a pennant antenna that W1UK had made
for me.  I usually use an 800 foot beverage to the US and a somewhat shorter
version for EU.  After 4 years of not working a single EU station in CQWW
SSB, I decided to use the pennant toward EU and forget the Beverage as it
was not worth the effort.  When I put up the pennant, the SWR read 4.8:1 on
the Autek RF-1.  On the other hand, it seemed to work as I did hear a few EU
stations before the contest.  I did not have the time to experiment any

Instead, I decided to make a second pennant at home and bought two K1FZ
pennant transformers.  In CQWW CW, I had little time so I put up two
pennants instead of either Beverage.  Unfortunately, they both measured the
same high SWR on the Autek RF-1.  I just used them anyway, and they seemed
to work as expected.

I decided to bring one pennant and transformer back home to figure them out
once an for all.  I had many theories ranging from ground conductivity,
proximity to metal roof, or the towers themselves - all of which would be
different at home. I strung up the pennant in my back yard and once again,
the SWR measured 4.9:1.  The feedpoint was antenna to K1FZ transformer to 1
foot coax to RF-1.  I tried fooling with geometry of the antenna, angle of
feedline escape, etc, and very little change was noticed.  

Having very little test gear at my house, I tried one last thing.  I tried
to measure the impedance of the antenna itself.  Somewhat clumsily I managed
to get the lugs on the ends of the antenna wire in the connector of the
RF-1.  Once I removed my fingers from any of the metal surfaces, the
impedance measured 860 ohms.  This is about what I should have expected.
The RF-1 does not display the reactive component and the SWR was out of
range so I could not calculate it.  Assuming the antenna might be OK, I took
a 1K resistor and put it across the transformer input and measured the
output.  Once again the SWR measured about 5:1.  With the 18:1 transformer
ratio, I expected it to be closer to 1:1.  Interestingly, a similar
experiment yielded the same results with the W1UK Balun.

I am looking for advice.  My guess is the antenna is fine and the problem is
either my measurement technique or the feedpoint itself.  Should I be using
a balun after the transformer?  Is there some leakage or coupling path that
is fouling my measurement that I need to isolate?

Other notes, all measurements on 160 meters (80 not much different), wire is
18 gauge insulated copper.

Any suggestions are welcome

73, Tom W2SC

See:  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
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