Topband: Tuned cw speaker

[kq2m at kq2m.com]

I don't know if this is related to Tree's question or not but I suspect 
it is.

In 1986 I went to operate CQWWSSB at Terry Baxter's (N6CW) old spot at 
VP2VCW.
I brought an analog tape recorder and taped several hours of my 10 and 
15 meter runs in the contest.

After the contest and after I submitted my log to CQWW, I was astonished 
to see how many times the analog
recorder clearly picked up callsigns and qso information that I 
struggled with or missed entirely while operating.
The reverse was also true - occasionally, but less frequently, my ears 
picked up callsigns and qso info that was
inaudible on the recorder tape.

A few years later when I was in Seattle, WA and I was taking pictures of 
sunsets with my digital camera,
I was amazed to see how much less colorful and dull the sunsets were on 
than what I remembered seeing
with my eyes. The opposite was true when I had taken pictures of sunsets 
in 1988 from Aruba (P40V) where the analog film showed wavelengths of 
color that I never saw.  Frankly, the sunsets were more striking on 
analog film than my eyes could see, but the opposite was true with 
pictures of sunsets taken on my digital camera one year later in 
Seattle.

I don't know the disparity between I heard and did not hear with audio 
at HF frequencies was/is related to the disparity I saw between the 
colors of the sunset in pictures taken with my analog camera vs. what I 
saw with my eyes, but they are all waves of energy being propagated in 
different modes and then interpreted in our brain.

Maybe someone can enlighten me as to what I was experiencing and why 
such differences between what I heard/saw and what the equipment picked 
up?  And is this in fact similar to what Tree described?  It sure seems 
that way.

Tnx & 73

Bob, KQ2M



On 2026-02-07 11:14, Tree wrote:
>> My take: for a SDR, if no signal was converted during the A to D 
>> stage,
> there will be no signal to "dig out" during the D to A stage
> 
> I find this very interesting.  I can't say I totally understand the 
> issue
> well enough to have an educated opinion.  If it is indeed true that 
> going
> into the digital domain eliminates the effectiveness of a "CW Speaker" 
> - I
> think that is fascinating and makes me wonder what else is being missed 
> by
> the human ear.
> 
> Tree N6TR
> 
> On Sat, Feb 7, 2026 at 8:17 AM Ron Spencer via Topband <
> topband at contesting.com> wrote:
> 
>> I think Dave and Adrian's conclusion is correct. My take: for a SDR, 
>> if no
>> signal was converted during the A to D stage, there will be no signal 
>> to
>> "dig out" during the D to A stage. No amount of signal processing or 
>> noise
>> reduction will help since there is nothing there. Nothing is buried in 
>> the
>> noise floor.
>> 
>> 
>> 
>> Ron  N4XD
>> 
>> 
>> Sent using https://www.zoho.com/mail/
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