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Old January 7th 07, 07:48 PM posted to rec.radio.amateur.policy
[email protected] N2EY@AOL.COM is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 877
Default One way to promote learning of code ...

Carl R. Stevenson wrote:
wrote in message
ups.com...
Cecil Moore wrote:
John Smith I wrote:
... technology, ain't it wonderful? Welcome to the new millennium!


My SCS PTC2e multimode controller will copy PACTOR2
DX signals from Europe that I cannot even hear and
don't even budge the S-meter. It also copies CW at
faster speeds than I can copy.


A fascinating piece of gear! IIRC, it does a bunch of other modes,
too.


Of course it needs to be hooked to a computer, too. Not too many
years ago having a shack computer would have been a big
investment, but now the SCS unit probably costs more than the
computer it's hooked up to.


That's a problem ... the fact that those boxes are proprietary means that
the manufacturer can charge more than they ought to cost ...


Agreed - but there's another issue, which I'd like to read your
comments on.

If I understand the meaning of Part 97 rules on amateur use of digital
modes,
we're allowed to use almost anything we can come up with as long as the
FCC specified bandwidth/shift/rate criteria aren't exceeded, and the
mode is "documented".

The "specified bandwidth/shift/rate criteria" in PArt 97 needs work,
IMHO, but
that's not the issue I'm after right now.

What I wonder about is the "documentation" part.

If a ham wanted to start from scratch and design/build/operate a
"modem"
(hardware, software, or
some combination) for Baudot RTTY, PSK31, Morse Code, AX.25 packet, or
many
other modes, the first step would be to get a copy of how the encoding
is done. For the
modes I mentioned, and many others, that encoding is easily available.
Any ham who
wants to can design/build/operate such a device, as long as they have
the know-how
and are willing to make the investment of time and money. I remember
seeing the first
amateur non-mechanical RTTY keyboard in ham magazines almost 40 years
ago - they
were designed from the specification for 60 wpm Baudot RTTY.

But where is the specification for PACTOR2 easily available? Doesn't
the proprietary nature
of the modems violate Part 97?

How much are current PACTOR2 capable boxes going for, anyway?


Last time I looked - $600

As for hearing signals you can't - that's really a matter of having
more filtering and a better detector.


I think that Cecil's point was that there is no detector that can be used
to detect Morse by ear that can compete with a near optimum system
that uses digital modulations, FEC, etc.


That all depends on the definitions.

There are conditions where Morse Code is perfectly usable but some
digital modes
are rendered useless by things like phase distortion.

If you use a receiving system that is not optimized for the mode, such
as using an SSB filter when listening to Morse Code, SNR suffers. The
SCS modem is optimized for the mode, while Cecil's rx may not be
optimized for Morse Code.

As for speed - well, consider this:


You could almost certainly win the Tour de France and set world-record
times for each leg - if they'd let you ride your Harley to do it....;-)


And he'd certainly lose hands down if he entered a race against motorcycles
using a bicycle


Well, Cecil might. It depends on the race, the riders - and the
motorcycles. Replace the Harley with a lesser motorcycle and the
bicyclists could certainly win!

... your point is? :-)


Simply that inventions don't necessarily replace people, skills, or
earlier inventions.

And that the journey can be as important as the destination. Otherwise
there would be
very few motorcycles.

73 de Jim, N2EY