On 10/24/2016 5:09 PM, Jeff AC0C wrote:
There is an entire PSK and JT69 band segment of younger users who
have managed to pilot those systems to success without a crutch like
FSK.
PSK31 and JT65/JT9 operators have been browbeaten to keep their power
levels very low - many of the "thought police" claim anything more than
5W is intentional interference - while the normal RTTY operator will
run his full transmitter output. With an untrained/poorly trained
operator is it much easier to generate a "clean" AFSK or PSK signal
when the transmitter is configured for "no ALC" and 20% of the PA's
saturated output.
Untrained/poorly trained operators tend to run AFSK "all knobs to the
right" with the attendant clipping in the microphone preamplifier and
"wave form sharpening" caused by *excess* IF gain and overly fast ALC
ALC time constants in many rigs.
Even "DOOK" in 2-Tone and the similar AFSK modulation in fldigi will
be excessively wide, distorted and generally "dirty" if the transceiver
mic preamp is running into hard clipping (sound card output connected
directly to the mic jack with no attenuator) and the mic gain is run
up so the IF and final amplifier are saturated.
73,
... Joe, W4TV
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