Topband: Ant Analyzer Assistance request -- funky readings

[Jim Brown]

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