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Dee Flint wrote:
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I'd be willing to argue that point in favor
of the computer.


Actually, you would lose such an argument.

I don't think so, at least under most common operating conditions.


Define "common operating conditions".

For a contester, common operating conditions often include murderous QRM.
Yet contesting is common. I've always maintained that one can construct
various scenarios such that there is one where the particular mode under
discussion is "the best".

For ragchewers, common operating conditions often include manually sent CW.

There are many hams who have
proven that they can decipher better than the computer. The computer
hardware or software requires the following characteristics in the
received
transmission to work:

1. A strong signal

Signal to noise ratio would be important, to be sure, however with the
proper application of some limited computing power I'm sure one could
construct a detector that would work with seriously low SNR. It is
amazing what DSP's can do now days..


Yes and there are some very fine software programs already available. But
even so they fail before the "EAR" fails, assuming a trained and experienced
operator.

2. No distortion on the signal such as occurs from aurora, meteor
scatter,
etc.

Again, I've seen spectral displays that clearly show CW transmissions
that could *not* be heard.


So I've seen displays of many types of signals that cannot be heard. That
is an entirely different issue from distortion. When the auroras start
playing, PSK (as an example) is so distorted that no matter how strong the
signal, the computer cannot decipher it. If a CW signal is distorted but
loud enough to hear, the human ear/brain combo can still decipher.

3. The code sent is nearly equal in quality to that sent by a computer.
Some one using paddles may achieve that but if they are sending with a
manual key or bug, that is highly unlikely.

Sending code is not in question. Surely a computer is able to open and
close the keying faster than a transmitter can possibly transmit.
Also, remember that the faster you key, the higher bandwidth your
signal will require and the higher the SNR will theoretically need to
be for it to be decoded at the receiving end.


Receiving is the issue. If the received code was manually sent, the
computer often fails.

I have frequently been able to copy better than the computer and my code
skills are quite modest. The only time it beats me is when the code
meets
the above three criteria and is too fast for me to copy.

I would contend that the software you are using is not utilizing the
inputted signal at it's full potential. I've seen audio processing
techniques that could pull out inaudible signals that where more
complicated than CW would be.


I''ve tested everyone I could find. I'm one of those people who gets
pleasure out of trying all the new gadgets & software I can find and afford.
I've also seen inaudible signals pulled out of all kinds. That's quite
feasible when the bands are in good shape. Add a little thunderstorm
activity, geomagnetic disturbances, solar flares, etc and the machine can't
decipher them. It's not a matter of signal strength but a matter of signal
quality.

I would also ask if you where copying random characters or where you
able to "fill in the gaps" by using the context? The latter would be a
very different problem for a computer to solve.


Yes it is a different matter. Humans definitely have the edge on "fill in
the gaps".

I'll be willing to bet that there won't be much improvement over CW in
the raw "get the message though under bad conditions" power with the
new digital modes using the same bandwidth as CW. Simple is
under-rated in my book.


I'm not sure I understand what you are saying here. Did you leave
something
out?


I'm saying that if you pick any digital mode, restrict the bandwidth to
that of the CW signal with the same data rate, keep the SNR the same
with the same error rates, CW will be about as good as you can get.
Not bad for an operating mode that has been around as long as CW.


Ok, I understand. Actually many digital modes are, by their nature,
narrower than CW already. You would have to open up the filter to get to
the same bandwidth. Again the key item is quality of signal. For example,
aurora induces phase shifts on PSK (phase shift keying) and makes it
undecipherable. It also induces phase shifts in voice and CW. It gives the
voice & CW signals a buzzy, raspy sound. Yet you can often understand voice
when PSK is undecipherable. CW, when there is a phase shift, sounds like a
series of buzzes but can still be copied if you are used to it.

And yes CW does a fine job and will continue to be advantageous under
certain conditions.

Dee, N8UZE