Topband: CW Speaker Mystery - My Experience

[Jerry and Faye]

My guess:  This difference is likely the results of decisions made at 
the time of receiver design.  Here is the question for the designers.  
How many bits of digital do we need in the analog to digital conversion, 
and also in the digital to analog at the end. The probable conclusion is 
that we do not need to digitize anything below the noise floor of the 
receiver.  There is no information to be recovered there.  Adding extra 
bits of conversion to accurately digitize the noise floor is a waste.  - 
just my guess.

The question posed by Tree of how is FT-8 copying signals below the 
noise floor is a good one.  I suggest you measure it.  I did. You will 
be surprised.

Jerry, K4SAV


On 2/7/2026 11:19 AM, Tree wrote:
>> So is the takeaway that the older superhet top line rigs are then the
> optimum for 160-meter DX?
>
> I guess this begs a question about FT8.  Many people are copying signals
> way below the noise level with their DSP radios and FT8.  How is that
> possible if that signal just isn't there?
>
> Tree N6TR
>
> On Sat, Feb 7, 2026 at 8:08 AM Rick Kunath via Topband <
> topband at contesting.com> wrote:
>
>> So is the takeaway that the older superhet top line rigs are then the
>> optimum for 160-meter DX?
>>
>> Or is there something else about the SDR that wins out?
>>
>> Ir seems like hearing is what it is all about down here.
>>
>> And an excellent review, thank you.
>>
>> Rick Kunath, K9AO
>>
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