Re: Lessons Learned


Dave Kjellquist, WB5NHL
 

I find the comments about QRP PSK interesting
particularly from people with outdoor antennas and
even beams. Try a real challenge that Steve (W3HF) and
I live with -- attic antennas. My goal, watch out for
the next one Steve, is to beat W3HF.

73 Dave WB5NHL (Always 5 watts or less)

---- 070@yahoogroups.com wrote:
I find it interesting all the comments made about
QRPers. Both Jay
and Bernie tried it out this contest. Bernie even
made a comment
about gaining some more understanding of (respect
for?) what the
QRPers have to put up with.

FWIW, I have not finished compiling all the results
for the survey,
so there's still time for those of you who have not
sent yours in.
But I do notice a trend with regard to the question
on QRP operation.
About half of the respondents have tried running PSK
QRP. But I think
only one of the respondents runs QRP "most" of the
time, and I know
there's only one who runs QRP all of the time. You
can guess who that
is. :-)

Like Jay AA8QQ, I never saw any traces on 80m,
though I did find two
signals on 40. Never tried 6m, though--the only
antenna for 6 I have
is the 817's rubber duck.

I have worked aurora on cw before and was
wondering if any brave
(foolhearted?) souls have thought to try aurora on
PSK at high
power? (Don't tear me up to bad on this one folks.)

I saw lots of loud/bright sigs out there that my
computer couldn't
make heads nor tails of. It looked like some
strange type of
encryption. I kept getting weird characters where
letters should
have been. Kind of like wrong parity causes on
wired digital
comms.
No tearing here, Jay. I think you answered your own
question. The
problem with aurora is that I believe there is
significant phase
distortion in that propagation. The P in PSK stands
for phase, as it
is the phase of the signal that carries the
information. So
distortion of the phase will destroy the information
in the signal
regardless of the power level.

The best signals for aurora propagation are those
that carry
information in the amplitude of the signal, like CW
and SSB. Anything
with a phase component (PSK, or FM) will be
distorted, often to
unusability. As for the digital modes, maybe MFSK16
would work. It
would certainly be better than PSK, as that too is
an amplitude-based
signal.

What you saw is exactly what Duncan was describing
when he said that
there were many signals he could see, and were loud,
but could not be
decoded. The phase of the signal was shifting faster
than the
receiver could track it, so the bits were being
demodulated in error.
This caused the conversion from bits to letters to
be erroneous. And
this is just like the parity error problem you
compared it to.

Did you happen to notice the phase detector window
on your computer?
If the signal is clean and loud, it should be a
straight vertical
line. A clean but weaker signal will still be
vertical, but just not
as long. If there is distortion, or too much noise,
you will start
seeing lines at other angles--these are bits that
are being
demodulated that are not perfectly clean. The more
of those you see,
the more likely you are to see errors in reception.

Props stunk! I can usually work lots of EU from
here on 5 watts.
Not this
time! Only 2 EU's I heard were DL2AYL and UX0FF.
Agreed. I never heard Erika, though, on any band.
Managed to get Nick
UX0FF once, and did get one EA and one CT. But
nothing else from
central or North Europe.

Oh well, there's always next time.

73,
Steve
W3HF


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