--- Jim Jarvis <jimjarvis@verizon.net> wrote:
as Bill also observed.
>
> A year ago, I raised the psk31 question..and I raise
> it again...
> Is it fast enough, stable enough, phase noise
> tolerant enough, to be
> of use on topband? Surely casual psk'ers can't
> play. qrp & small
> antennas won't prove squat. We need guys with big
> antennas, full power,
> and phase-noise clean tx's to explore the mode.
> Will phase anomalies in
> the auroral zone wipe it out, or just limit it a
> bit? Unexplored.
Jim and everyone,
It has been my experience that PSK31 is a real piece
of crap, just a toy. Standard Baudot RTTY is way
better than PSK31 for real DX'ing. PSK31 for rag
chewing, RTTY for digging in the dirt!
If you want to push the envelope, look at WSJT. The
JT6M mode is optimized for 6 meter meteor scatter but
has wide application for terrestial work as well. It
is a medium to fast bit rate FSK that is somewhat
tolerant of the phase shift crap we experience during
disturbed conditions, but is very suited to amplitude
QSB conditions.
The JT65 modes, A, B, and C are slow bit rate FSK and
do very well with any amplitude QSB but are somewhat
degraded by fast phase shifting. These three modes are
very much more sensitive than JT6M. A is the most
sensitive, but also the most susceptible to
phase/frequency errors and C is the opposite.
There will be two major obstacles to overcome in any
attempt to use these modes on 160. The first is
technical. The modes are time and frequency dependant.
You must both be on the exact same frequency (+/- 100
Hz or so), tuning not allowed usually although
possible if you are experienced. And you must both be
time sync'd to within 1 second or so. The QSO partners
do not need to have real time co-ordination via LL or
Intenet but it sure helps when getting started and
ramping up the learning curve.
The second obstacle is political. The 160 mode police
will have a coniption fit if you try this. The CW guys
think their end of the band is scared (I do to!) and
many will try to jam you (I wouldn't do that, but
expect a nasty gram in your inbox). Imagine their
surprise when they discover it's really hard to jam
JT65 modes! The phone guys are even worse. Anything
they don't understand will get jammed just for fun.
SSB is bad news for some of these modes.
If you can find a frequency that everyone would be
happy with, I would jump at the chance to experiment.
However I would never ever suggest that these modes be
used for serious DX'ing or during prime time! I think
it would be exciting to discover just how far into
daylight you could push propagation on 160.
73,
Larry - W7IUV
DN07dg - central WA
http://w7iuv.com
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