On Thu, 24 Jan 2008 09:33:26 -0600, Rick Hiller wrote:
>My concern is the ZERO R value -- for even occurring, but also that
>it occurs over such a very wide range of frequencies
Like most (all?) analyzers at this price level, the MFJ has problems in
the presence of strong RF. Go to http://www.fcc.gov/mb/audio/amq.html
and enter the lat/lon coordinates and a distance of 20 miles to find AM
broadcast stations likely to generate high field strengths. You'll get
them listed by power level, distance, and antenna type. DA means
"directional antenna", DA-N means "DA at night only," DA-2 means
"different patterns day and night." If it is directional, you can also
click on the "Electrical Field Strength pattern plot" and see the
directional pattern!
If you're lucky, your problem may be a station that gives you high field
strength during the day only. Otherwise, you're hosed, and you'll need
to rely on SWR measurements made using your transmitter as the source.
Adding a filter in series with the analyzer is NOT a solution -- the
impedance of the filter would be added to the impedance of the antenna.
73,
Jim Brown K9YC
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