Hi David!
I have this problem with my hand held antenna analyzer too. I figured out
that it was picking up AM and FM ( and maybe TV ) broadcast signals and
those were interfering with the readings.
I now use my LP-100A RF meter with about 5 watts of RF to get accurate
readings.
Yes, lugging a QRP radio and RF meter out to the antenna is not near as
handy as a small hand held RF analyzer, but at least you get stable,
reliable and repeatable results.
http://www.eham.net/reviews/detail/5981,
http://www.telepostinc.com/lp100.html
73
Lloyd - N9LB
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com]On Behalf Of D
Rodman MD
Sent: Monday, December 03, 2012 10:22 PM
To: topband@contesting.com
Subject: Topband: Delta Loop vs Antenna Analyzer
My 160m antenna died several weeks ago from a bad coax feed line and was
restored
just Sunday after the contest. I have tried several antenna analyzers and
none
seem to work with the loop antenna. I designed the antenna for 100 ohm feed
and
always wanted to put a half wavelength coax on an analyzer to measure R and
J to
achieve the best match. Calculated series transformer of 50 and 75 ohm coax
seems to match the antenna quite well as anticipated. But, no matter how I
try
with any of my many devices, I can't get the boxes to work with the loop.
The
readings are not consistent. They just don't seem to like the antenna.
Other
wire or yagi antennas work as expected. Questions about if others have
tried to
measure loops or theoretical reasons why the various devices can't read the
impedance are obvious and responses welcome. Thanks.
David J Rodman, MD
Assistant Clinical Professor
Department of Ophthalmology
SUNY/Buffalo
Office 716-857-8654
_______________________________________________
Topband reflector - topband@contesting.com
_______________________________________________
Topband reflector - topband@contesting.com
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