[Kenwood] 930sat

[Ken Brown]

On 11/10/2013 6:27 AM, Jack Schrader wrote:
> I think I asked this once before but can’t find the replies so here goes.
>
> My 930sat has an audio problem and maybe it is only on 10-15-20m . I have not had bad reports on 40 & 75. I don’t want to venture to far into the rig and do further damage.
>
> Any suggestions?
>
>
You mention bad reports. Are you saying the problem is with your 
transmit audio and you don't notice any difference on receive audio?

Any apparent audio problem that differ between the lower bands and the 
higher bands is likely due to the sideband convention that hams use. Try 
a QSO on 10-15-20 meters using LSB instead of USB and see what happens. 
Try a QSO on 40 or 75 using USB and see what happens.

If the filter used for opposite sideband rejection has a bad crystal or 
a bad solder joint to one of the crystals, it could have a bandpass 
characteristic that is not as symmetrical as it ought to be. Maybe is 
cuts out all the bass and accentuates the high end using one sideband, 
and does the opposite in the other sideband. One of those may be more 
noticeable or objectionable than the other.
Another possibility is the BFO frequency.  If it is in the wrong place 
with respect to the filter skirts, you may have either the high end or 
the low (frequency) end of your audio being cut off. Use the opposite 
sideband and a different BFO frequency is used, at the opposite skirt of 
the filter, and it may sound better. I don't know how the TS-930 gets 
it's BFO frequencies. If it uses crystals, with trimmer capacitors, then 
maybe an adjustment is all that is necessary. Or maybe a new BFO 
crystal. I think some of Kenwoods synthesized radios such as the TS-440 
had a fully synthesized BFO, and there were some DIP switches that were 
used for the fine adjustment of the BFO, to make it match the filter. If 
the 930 has that, perhaps one of the DIP switch contacts has gone bad.

DE N6KB