[Elecraft] tinning audio

[Ron D'Eau Claire]

Dan, I will assume that you are using a K2 with the SSB module in it. 

If it sounds "tinny" on receive, it probably sounds "tinny" on transmit
too. First check that out by having someone listen to you or recording
your voice on an auxiliary receiver. You can get some idea of what your
voice sounds like on the air by putting the rig in SSBA-BAL mode and
speaking into the mic while listening to yourself in the phones. You
must use a mic that is "live" when the PTT button is NOT pressed. If you
press the PTT doing this, you will shut off the audio. Also, Gary
Surrency commented to me recently that this is NOT a very good test of
the on-air signal quality. The audio characteristics of the K2 in this
mode disguise the true sound of the signal. The best check is to have
someone listen to you on another separate receiver while you transmit.
Then you can adjust your FL1 BFO frequencies in CAL FIL mode slightly to
make your voice sound the best. Keep in mind that the BFO frequencies
provided by Elecraft in the SSB Module booklet are recommendations, but
they are NOT necessarily the best for you to use. After running some
extensive on-air tests to get the best audio quality, of my BFO settings
is over 100 Hz off from their recommendation. 

That gets your OPT1 (SSB) filter in the FL1 position set correctly for
transmit. No matter which filter you select for receive, filter FL1 will
ALWAYS be the one you transmit with. It's automatic. You can't make the
K2 transmit on anything but FL1 in SSB. 

That means that you can set up FL2 - 4 for different characteristics
when receiving without affecting your transmitted signal in any way. If
you want more bass in the receive audio, you can adjust the BFO
frequencies in FL2, 3 or 4 to put the bandpass closer to the carrier
frequency. IF you want more highs, you can adjust the BFO frequency to
move the bandpass further away from the carrier frequency and emphasize
the highs more. You can set up all three of the other filter positions -
FL2 , 3 and 4, with different BFO settings and get a sort of "poor man's
Bandpass Tuning" that will let you choose a filter setting that cuts
down QRM and gives you the most pleasing audio from a variety of
signals. 

One thing you CANNOT do with the OPT1 SSB filter is change its
bandwidth. That is fixed. All you can do is shift the bandpass by
changing the BFO frequency in CAL FIL mode. Use Spectrogram to see what
you are doing when you adjust the BFO frequency. If you haven't tried
Spectrogram, there are excellent instructions for obtaining and using
Spectrogram on the Elecraft web site under Builder's Resources. 

Of course, you can use the CW filter for receiving in FL 2, 3 or 4 too.
That way you can adjust the bandwidth. I use my SSB module mostly for
digital modes, so I have two of the filter positions set up using the CW
filter in narrow bandwidths when receiving digital signals. 

Ron AC7AC
K2 # 1289



What can I do to my radio; a mod or a adustment of the BFO/FIL1-4; to
improve the audio coming out of the speaker?  During Field Day I had a
problem trying to distinguish an OM or YL voice clearly,  then I found
some clarification on FL1 to make it sound more like them, instead of a
muffled voice.

I am not asking for too much bass or treble in the voice, but that it
would sound like a natural and not a computer voice with static on it.

Anyone have any suggestions?

dan