For having done some tests with an HF channel simulator, and parallel tests
from real live signals I personaly don't have any doubt about the fact that DSP-
based decoders really outperform decoders with conventional analog filters
(like the PK232, PTC2, etc)...
This was pointed out a few years ago by K6STI in articles about RITTY(for
example the importance of the ATC, an the big difference it can make)
But I also confirm what Phil has mentionned here
>I also suspect that the processing power of your PC, and maybe even the
>soundcard, might be a contributing factor in some cases.
For the processing power, I don't know, but for the soundcard I am sure!
-A good soundcard with low noise line input (like you can find on "home studio"
quality soundcards) can make a difference with Cheap soundcards having just
a microphone input. One obvious reason, is the substantial amount of noise
added to the signal, when using the microphone input...
-Many amateurs never thought about the calibration of their soundcard...By
experience I know that a baddly calibrated sound-card card can really make the
best decoder deaf like a stone (*).
Of course many other factors, starting from the receiver itself may also play a
role, especialy when approaching the theoretical limit, but in general if your
PK232 outperforms MMTTY, I think that you should first look at the a/m points.
CU in the SP-test - 73's Patrick
(*)For more details, refer to the MMTTY manual chapter "getting things to
work"
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