I run the audio from my IC-765 through a Timewave DSP-599zx and then through
an Autek QF-1A audio filter. I've found the DSP noise reduction to be
rarely worth the trouble, but there have been a couple of times when a weak
SSB signal was more readable with the Random Noise function on than without
it. While the background noise level is certainly reduced, the SSB signal
is a bit distorted by the DSP. Static crashes appear to be only slightly
attenuated, but I've not measured the difference - it's certainly not much.
By the way, my comments apply to the 599zx with the latest available chip
level.
The DSP is completely useless for typical electric fence noise pulses. The
noise blanker in my IC-765 takes out the pulses almost completely (mine go
from 20 dB over S9 down into the background noise) and I don't get grunge
from strong stations on the band while the blanker is on, as I did with the
Kenwood 850 and 950 SDX. No experience with line noise at this QTH.
Frankly, I find that the old Autek QF-1A peak filter is much better at
digging out weak CW signals than the 599zx and its narrow bandwidth filter.
There are times when a bit of ringing on the resultant audio actually helps
in copying the signal.
K8AC in Angier, NC
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