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Re: Topband: Radial directivity

To: topband@contesting.com
Subject: Re: Topband: Radial directivity
From: "Dan Zimmerman N3OX" <n3ox@n3ox.net>
Date: Sat, 30 Dec 2006 15:08:16 -0500
List-post: <mailto:topband@contesting.com>
Good news, factual news, and bad news.

I put up my 60 foot vertical yesterday in place of the 40 footer.  I'm
still base loading but will probably hoist an inverted L for special
occasions.

The good news is that the 60 footer + full radial field seems to be
about 6dB (!) stronger than the 40 footer (more than expected, but
maybe I was getting more nearfield + coil losses than I thought: I've
halved the necessary inductance for base loading and there's less
clutter around the loading coil and antenna base now.).  I put a fresh
battery in the test transmitter and it's exactly in the same place,
and any tuning shift in its antenna (a small, sharply resonant loop)
would make its signal weaker, so I think I really got 6dB.

The unexplained news;  now I don't see any variation between adding
the new radials and the old backyard field.  The 1dB drop when adding
the new radials seems to have disappeared, but they don't seem to help
in that direction either.

The bad news: I just transmitted into my step attenuator and let some
smoke out, so I think I'm done doing FS measurements until I can take
it into the lab and check it and repair it if necessary, so I guess
I'm not going to do directional tests today.  I'll hit you guys up in
Stew Perry and we can do some real tests ;-)

73,
Dan
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