[Elecraft] on air SSB filter alignment

[W3FPR - Don Wilhelm]

Howard,

You said the receive audio curves 'look great' - but are they at the proper
frequencies?

What is the audio frequency shown in Spectrogram at the -3dB points of the
USB passband?  In my experience, the low end should be somewhere near 300
Hz.  Also be certain that this is the passband for the FL1 filter - that is
the only BFO setting used for transmit - you can set FL2 thru FL4 anywhere
you want for receiving.  Also be certain FL1 is set to OP1 and not the
variable filter.

If you have the 2.3 kHz filter bandwidth, set markers (pointers) in
Spectrogram at 300 and 2600 Hz and center the passband between those
markers. (300 and 2300 markers for the older 2.0 kHz filter).

Could it be that you are 'netting' the K2 to a certain frequency rather than
listening to the other signal and tuning for the best audio? - if you are
relying on a particular net frequency shown on the K2 dial, it could simply
be that your dial calibration is off.  See my website www.qsl.net/w3fpr or
the mirror at http://home.earthlink.net/~w3fpr for detail information on
setting the K2 dial calibration.

To adjust 'on the air', you should use a second receiver, being careful not
to overload it, and feed the K2 into a dummy load.  If you can record the
output of the receiver you can better evaluate the voice response.
Determine whether the audio is too high or too low and then use the receive
Spectrogram display to shift the passband a bit up or down as required and
repeat the testing process - continue until satisfied.

73,
Don W3FPR

> -----Original Message-----
>
> Other hams say my USB sounds tinny, lacking in bass,
> on 20 meters, that's the band I'm on these days.
>
> On spectrogram, the received audio curves look great.
>
> What is the process for "on air" adjusting of the
> filters for better transmit audio? Is this process
> archived somewhere?
>
>
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