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

[David Decoons]

Hi Morgan,

I appreciate your opinion and I agree on the crowded band comment. If you read my message I did say we only use ESSB when band conditions allow. In the extra SSB portion on 80 meters there is enough elbow room. Using ESSB vs AM uses less bandwidth but allows for very comfortable listening.

My report is since the radio supports ESSB, I am reporting my observations of what the CESSB implementation is doing. For ESSB operation the radio should be able to have TX bandwidth low cut down to 50 Hz and the compression should be for the entire TX bandwidth instead of a mid band compressor.

I did use the radio last night on 40 meters with normal SSB bandwidth and comp at 6. I received excellent signal and audio quality reports from many EU stations. Band conditions were excellent.

I will continue to keep the Flex radio for my 80 meter rag chew and use the K4D for my DX use for now.

Sent from my iPad

> On Apr 6, 2022, at 5:56 AM, Morgan Bailey <mbaileycrna at gmail.com> wrote:
> 
> 
> ESSB---Folks, if you want to be a broadcaster with high fidelity, then use AM. SSB is for COMMUNICATION of information and as such making it a fidelity race will occupy more bandwidth than is necessary to communicate. The bands are already crowded, Imagine everyone one in a contest with 1500 watts of ESSB with 4KHZ bandwidth. What a waste of available spectrum. As long as I do not sound like some woke disney donald duck character and have clear audio at 2.3khz, I am good to go and freely give up the 1.7khz to another station's bandwidth. 
> 
> 73, Morgan NJ8M 
> 
> BS + MS + $2.98 = COFFEE
> Real Life Experience = Priceless, says the man who set his back yard on fire with a breadboard tuner loading a 160 meter inverted L with 1000 watts. LOL
> 
> 
>> On Tue, Apr 5, 2022 at 10:29 PM <rocketnj at gmail.com> wrote:
>> 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
>> 
>> 
>> 
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Elecraft at mailman.qth.net
>> 
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to mbaileycrna at gmail.com