[CQ-Contest] 10/15 interaction

Jim Brown k9yc at audiosystemsgroup.com
Thu Nov 6 12:46:44 EST 2014

On Thu,11/6/2014 7:18 AM, Randall K Martin wrote:
> I'm contemplating purchasing a high power band pass filter (4O3A) to 
> prevent the interaction. I

Study my survey of the measured performance of the major brands of 
bandpass filters. It ran in NCJ a year or two ago. 

Since my measurements were published, 5B4AGN implemented more 
sophisticated versions of his bandpass filters that provide better 
adjacent-band rejection. See his yahoo group website for details, and 
for how to purchase.

Also, try to learn why you're having problems -- is it possible that the 
amp is creating a spur on 15M?
What kind of amp is it? Is it carefully tuned?  If a solid state amp, 
are you using a tuner?

If the amp is clean, you can probably do just fine with one of the 
better 200W filters (or filter sets).

73, Jim K9YC

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