[Elecraft] No FL2, 3 or 4 SSB Filters Above 40 Meters

[Don Wilhelm]

Ken,

It certainly sounds to me like you need to do a complete alignment of the IF
filters in SSB mode.

There is nothing band dependent for the FL1 thru FL4 filters (for any mode),
but from your description, I think that you have the LSB filter/BFO
relationship set near where it should be but the USB IF filter/BFO
relationship needs attention.  The KAT2 could not cause a problem as you
have described.

If you want or need the full explaination of the filter alignment process,
take a look at my website www.qsl.net/w3fpr article on K2 Dial calibration -
Step 3 covers the filter alignment.  You will find links there to additional
information if you should need it.

Just a sanity check on the terms you used - for the K2, the bandpass filters
are the L and C adjustments on the RF board and are adjusted only for
maximum signal through them, and the IF (crystal) filter adjustments are
done through the CAL PLL procedure in the menu.  I trust you simply used the
term bandpass filter when you meant the IF filter - They may be
interchangable on some transceivers but for the K2 they each refer to
different circuity.

To do a good alignment job, I recommend that you use a wideband noise
generator and some type of audio spectrum analyzer program (Spectrogram or
Spectrum Lab are typical) running on a PC.  Connect the audio output of the
K2 (external speaker) to the line in or mic in of the computer's soundcard.

73,
Don W3FPR

----- Original Message ----- >
> Hope someone has come across this one. I use CW mostly so I just noticed
> this. All three filters BF2, 3 and 4 do not seem to be working above 40
> meters. OP1  (FL1) is working OK. "BF" settings are all ok and the filters
> are set to the defaults. Built this K2 in December and all was well. Put
in
> the SSB board in January and still all was well.
>
> Switching to LSB for example on and using FL2, 3 and 4, 20M produces an
SSB
> signal that cannot be tuned in on LSB or USB.
>