Thread: A-4S Issue
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Old November 22nd 08, 08:00 AM posted to rec.radio.amateur.antenna
Bryan Bryan is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 199
Default A-4S Issue

R. Scott wrote:
My A4S is acting wierd and I cannot figure it out.

20 meters its got great SWR. 15 is so so but tunable with a tuner
and stays relatively flat.

However 10 meters, the SWR stinks and I can try to tune it with a tuner
but then it goes out again. And I can swing the beam and hear the
Noise pick up and go down with the turning of the beam and when it stops
it wiggles a bit and the SWR changes. The tube and trap connections all
see secure.

Do I have a bad trap or ?????


Scotty W7PSK


I have an A3S (a similar design). It sounds to me like either...
1) oxidized connection(s) between tubing section(s): disassemble, clean and
reassemble tubing joints.
2) moisture inside a trap(s): remove trap(s), drain and "bake" the moisture
out, and reinstall with drain holes pointing DOWN.
3) a bad 15m trap (actually resonant on 10m): replace if resonant frequency
is not approximately 28 MHz.

Bryan WA7PRC