[Elecraft] RE: Audio Improvements on a K2

[Ron D' Eau Claire]

 > Ron:
>I had changed the BFO settings while using
> Spectragram including settings on FL1.
>
> Is FL1 used the xmit mode and when I changed factory recommended
> settings, all went wrong?
>
> After changing back to recommended settings, my voice sounds *near*
> normal and the mic works again.  Can I tweek current setting on FL1 to
> optimize sound?...
> TIA &  73,
> Clif W7ECS

Hi, Clif:

Yes, OPT1 is used for SSB transmit when you have the SSB module installed.
The OPT1 filter is the one built onto the SSB module and you cannot change
its bandwidth.  When you installed the SSB module, you assigned the OPT1
filter to the FL1 position. When you switch to FL1 you will see "OPT1"
instead of a bandwidth.

(By the way, people have asked if there is an OPT2 and Wayne or Eric
answered, "Not Yet..." Hi!  They apparently called it OPT1 to allow for the
possibility of other special filters in the future.)

So FL1 (OPT1) is ALWAYS used in SSB transmit, no matter which filter you
have selected to use in receive, AND the BFO settings for FL1 are ALWAYS
used for transmitting, no matter which filter you have selected. So you want
to set up FL1 using the OPT1 filter for the best TRANSMIT audio.

I found it best to start with the frequencies Elecraft recommends. As I
mentioned in my earlier post, after I set up my K2 for the "best sounding"
audio as heard on another receiver, I found that spectrogram showed my
bandpass well centered between 300 and 2100 Hz. That may not be exactly the
case for every filter.

I recommend that you use the Elecraft BFO frequencies and adjust them by
listening to yourself in another receiver to please your ear. A good final
check might be to use spectrogram to see how the bandpass looks, but I would
not rely on it alone. Indeed, I have set up my BFO frequencies using only
spectrogram and while the plot looked good, my voice did not sound good. For
me, my ability to interpret the spectrogram display was not 'precise' enough
to see the best BFO frequency to use. My ear did a much better job.

That done, you might want to use slightly different BFO settings for
receive. You can choose OPT1 in FL2 position, then change the BFO settings
to please your ear on receive. That will NOT affect the transmit signal
since only the FL1 BFO settings are ALWAYS used on transmit regardless of
which filter position you have selected for receiving.

Indeed, I think it was Wayne who suggested a while back using several
different BFO settings on the OPT1 filter in FL 2, 3 and 4 positions to
provide a sort of rudimentary "passband tuning" affect.

I hope that helps!

73,

Ron AC7AC
K2 # 1289