[Elecraft] K4D R29 beta ESSB and CESSB - Rolls off low end TX frequency response when COmp at 1 or higher.

[rocketnj at gmail.com]

Hi All,

 

Just received a K4D from a friend. I have it connected and just getting used
to the radio. 

 

We operate ESSB (4 kHz LSB) on the lower end of 80 meters where there is
ample room without causing interference. When you rag chew for several hours
it is much more pleasing to listen to.

 

I upgraded the radio to R29 beta and set TX to ESSB and TX BW to 4 kHz.
First thing I noticed is the low frequency rolloff point is fixed and not
adjustable. The TX bandwidth seems to use the same low frequency cutoff.

Second thing I noticed is the CESSB compressor seems to be programmed in
both ESSB and normal TX mode as a mid band compressor, boosting the
midrange, which then makes the audio sound very flat. This happens as soon
as compression is 1 or higher.

 

This is fine for normal SSB TX to add punch and help crack pileups but in
ESSB mode it should affect the complete TX passband. I guess I have gotten
used to a couple of other brand SDRs that do use CESSB and don't attenuate
the lows and highs when engaged.

 

I'd like a feature request that the CESSB compression work over the whole
range of TX audio in ESSB mode and also have the low frequency and high
frequency cutoffs on TX in ESSB be adjustable, just like the RX filters are.
The CESSB implementation for normal SSB is fine.

 

73

Dave wo2x