[Elecraft] RE: K3 Filter Questions

[Joel R. Hallas]

Dave,

It is unlikely, but possible that your 250 Hz filter is defective. My
original 400 Hz filter had a center frequency offset beyond the 250 Hz
correction limit (as an 8-pole, supposed to be 0 Hz offset). 

If you can center the signal in another filter's bandbass (use CWT to be
sure) and then switch to the narrow filter and it is no longer there, but
noise is, tune the receiver (first try shifting the DSP) and see if you find
it nearby. If it's way off you may need to configure it as if it were a
wider filter (say 1 kHz) and have the DSP set to 1 kHz, so it will get
through. 

I have had an opportunity to evaluate quite a few K3 filters lately, and
this is the only one I've seen that was obviously off frequency -- in my
personal K3 -- naturally <g>!

Needless to say, Elecraft replaced the filter immediately and that fixed the
problem.

<snip>
1. When I turn my 250 Hz filter on in config, and then select that 
filter (which is FL5 here)I can hear noise coming through but no cw 
signals come through. I can see the signals on my PowerSDR/LP-PAN 
setup and CW Skimmer. Signal comes through all the rest of the 
filters O.K. Yes, I opened the radio, and all the filters are installed.
<snip>

Regards, Joel
Joel R. Hallas, W1ZR