Topband: Reactance problem

[Larry Molitor]

At 06:21 AM 3/13/02 -0500, W2pm@aol.com wrote:
>  I have found after extensive work with it that the MFJ259B is quite 
> sensitive to BC band and/or any other "strong RF" coming in off the 
> antenna in question.

Most likely this is the problem. I suspect that a new AM station came up or 
an old one increased power level. In my case, the real part of the 
impedance is not effected much, but the reactive part can never be nulled 
out and the magnitude is somewhat proportional to the level of RF present.

In my case also, filters have proven ineffective. The offending AM stations 
are all spread around the top of the band and are just too close for a 
filter to work. The MFJ unit is not alone in this problem. Even my HP 
spectrum analyzer and network analyzer go belly up when connected to one of 
the low band TX antennas. After many years of looking for a solution, the 
only one I've found seems to be moving to where there are no local AM 
stations within 100 miles!

73,

Larry - W7IUV