[Elecraft] K3 sub rx matched filters

[Vic K2VCO]

Don Wilhelm wrote:

> Supposedly, the 8 pole filters do not have to be matched (they do not 
> have offset numbers associated with them), but in practice, they may 
> have a small offset and some ''tweaking" of the offset values may be 
> required to eliminate the "wush, wush" sound when using diversity.

For what it's worth, I have only a 2.8 kHz filter in my KRX3, and 2.8, 1.0 and 0.4 kHz 
filters in my main receiver. Offsets are 0. I use diversity a lot and haven't had any 
problems.

Normally I have the bandwidth adjusted to 400 Hz or less when trying to work weak CW 
signals. I often find that intelligibility is improved with diversity (on 40 meters I use 
a dipole as the main antenna and a vertical as the second rx antenna). It's hard to 
describe, but the signal seems to stand out better.

It might be due to the reduction in QSB gained by polarization diversity, or something 
else, having to do with noise. I'm not sure.

On 160 I use a 200' wire thrown on the ground as the second rx antenna (main is a 
vertical). There is some improvement, but nothing like 40.

On 20, I have a 4-el tribander at 40'. It is *always* better than the vertical by many dB, 
so I don't bother with diversity.
-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco