[ICOM] IC-718 / PSK31 / "phase noise"

[John Geiger]

The problem isn't with PSK31, per se, the problem is with how many operators
try to use PSK  First off, PSK isn't any better at weak signal operating
than CW or many of the other digital modes.  And PSK itself doesn't care
what power level you use.

The main problem is that most operators run PSK with the filtering in their
rig set for SSB width, so they are trying to copy a 31hz signal using a
receiver width of 3.0 khz or thereabouts.  The soundcard has no front end to
speak of in it, and any filtering done by the software is done at the AF
level, so even if you can't hear the other signals, they are still capturing
your receiver's AGC.

Put a narrow CW filter in line instead, and see how things change.  You can
make successful PSK contacts then no matter how much power other stations
are using.  Most people will say "I don't want to do that, it is too narrow.
I want to be able to see all QSOs taking place in the 3.0khz width."  That
is a viable answer, but then you have to expect your receiver's AGC to get
captured by stronger signals and reduce the receiver gain accordingly.

You can't have both-both a wide receiver range and perfect immunity from
other stations.

73s John AA5JG
(ex: W5TD, NE0P, N0EEN, KA0IFG)
Confirmed 6M addict: 6M WAS #1275, 6m VUCC #1260



----- Original Message ----- 
From: "Jim Miller" <JimMiller at STL-OnLine.Net>
To: "ICOM Reflector" <icom at mailman.qth.net>
Sent: Thursday, June 21, 2007 2:40 PM
Subject: Re: [ICOM] IC-718 / PSK31 / "phase noise"


> PSK31 doesn't want high power.