[Elecraft] [K2] Low sensitivity with variable-bandwidth filter

[Don Wilhelm]

Bill,

Yes, do the CAL FIL calibration first.  If that does not cure anything, 
then proceed with the rest of the alignment, but I doubt if that will 
help much - the K2 alignment is usually quite stable over time.
The bandpass filter and other alignments are not going to change the 
relationship between the SSB filter and the CW filter - only CAL FIL 
will do that.

If you still have a problem after the full CAL FIL, you will usually 
find a problem in the CW filter bank - like a bad crystal (but that does 
not happen often).  Reflowing the soldering on the IF crystals on the RF 
Board may help.

73,
Don W3FPR

On 6/12/2019 8:23 PM, Bill Coleman wrote:
> Yeah, this is looking more like a calibration problem.
>
> I’m listening to W1AW code practice on 14.0475. As I cycle through the filters the S-units are roughly the same through OP1, 0.4 and 0.16. But on the 1.0 bandwidth, it is often 1-2 S-units lower. If I tune about 200 Hz lower, I get the same number of bars.
>
> I’ll update you when I have a chance to do the calibration.
>
>