[R-390] R-390a Image problem?

[Gord Hayward]

> I also have a 50KW broadcast station in my area. It causes problems on 
> both of my R-390A's, 51S-1 and R-392. The cross over distortion is 
> mostly heard in the broadcast bands. I built a highpass filter with 
> about a 3MHZ roll off. Put it in series with the antenna lead, going 
> into the multicoupler and it works great. Ended the problem, can still 
> receive broadcast bands with the filter inline because they are so 
> strong. 


We had a problem like that on field day one year.  (This wasn't on an 
R-390)  The cure was a can.  We build a helical resonator to suck out 
the AM station.
It was about 160 turns of #12 magnet wire on a 12" sonotube in a 45 gal 
drum.  I like titanic engineering.  The next year I used the R-390 
without the can.  No
problems at all.

Cheers, Gord VE3EOS.

-- 

Gordon L. Hayward, Ph.D., P.Eng.,
Associate Professor, Biological Engineering,
School of Engineering, University of Guelph,
Guelph, Ontaro, N1G 2W1.