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Re: [TowerTalk] A3S 20 Meter troubles

To: <>, "Tom Hellem" <>,<>
Subject: Re: [TowerTalk] A3S 20 Meter troubles
From: "Michael Tope" <>
Date: Tue, 1 Jun 2004 08:18:43 -0700
List-post: <>
----- Original Message -----
From: <>

> I think that's what I'm going to have to do... I climbed the tower
yesterday and pulled the driven element level to the ground (It was a little
off) and water came out of the traps... That solved the SWR problmes however
the RX on 20 is still about the same as the dipole...  In messing with the
driven element, I moved the boom a little so now the reflector and director
are not level with the ground... So... I'll have to take it down to make the
elemnts level again... Everything seemed very clean when I put the thing
together... and now that the SWR is flat on all three bands, I'm wondering
why 20m is still sounding only as good as the dipole...
> Any Ideas?
> Thanks,
> Josh - KB0GUS


If you had water in the traps on the driven element, you could
very well have water in the traps on the parasitic elements. If so,
this could easily explain why the A3S is no better than a dipole
on 20 meters.

BTW, you mentioned in your previous email that the antenna
exhibits good directivity and pattern nulls. Does that include
front-to-back ratio on 20 meters? If the parasitic elements are
detuned from water in the traps, its quite possible that your
front-to-back on 20 meters would be degraded. You would still
see nulls off the sides when you rotate the antenna, however,
due to the pattern of the driven element (rotatable dipole).

Also, when you say that the A3S is no better than the dipole
on 20 meters, have you compared signals coming from lots of
different directions and distances?

The other thing to consider is the proximity of the A3S to
the G5RV (or any other conductor which is a significant fraction
of a wavelength on 20 meters). If the A3S is too close to the
G5RV you might be getting some interaction (this could
degrade the performance of the A3S). Does the SWR of the
A3S change significantly as you rotate it. If so, this is an
indication that it is coupling strongly to some nearby metal

73 de Mike, W4EF..............


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