[Elecraft] INRAD will be soon making custom RX filters for the K2?

[Vic K2VCO]

Fred (FL) wrote:
> Did anything ever become of the idea of "INRAD will be
> soon making custom RX filters for the K2"?
> 
> I saw this concluding remark, in an article on
> Elecraft site, about K2.
> 
> Maybe it was a rumor, wishful thinking, or
> didn't make sense to INRAD.

INRAD did make a few 400Hz CW filters for evaluation purposes. I have 
one -- but not in my K2!

The filter had great characteristics when measured on stand-alone 
equipment. But I (and others) didn't succeed in installing it in the K2 
without there being too much leakage around the filter.

I tried using a cut-down ssb board to switch it in and out. Way too much 
leakage, so then I simply connected it to the headers used for the ssb 
board. I even made little hoods for the coax jumpers to eliminate that 
leakage path. Not good enough.  And of course, without switching it was 
only possible to have one bandwidth (although I did set it up for 
discrete passband tuning).

The problem was likely due to grounding issues. I did try various things 
suggested by Wayne, Eric and George, W2JVN (who was the owner of INRAD 
at the time), but I could not get good enough ultimate rejection to make 
it worthwhile.
-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco