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PSK modems and noise



I'm setting up a system here to use the 1200 baud pacsats, and am
particularly interested in people's "real world" experience. 

The ARRL manual suggests that "PSK coded signals can be detected and decoded
even when the signal is buried in noise" and also that simple antennae
(J-pole) are the way to go.

Is this realistic? My G3RUH modem seems to need a signal well above the
noise (by ear anyway) in order to "lock" in - and the pacsat signals are a
lot below that level. So, should I be going for higher antenna gain or a
masthead preamp (I use a J-pole and have probably about 2db of feed line
loss), or is the PSK modem not performing as well as I've been led to
believe? I can certainly hear by ear signals far weaker than the PSK modem
wants to lock in to.

In other words, how noisy/noise free do the pacsat signals need to be for
reliable access?

Any thoughts would be appreciated
73
Steve, vk5asf




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