I enjoyed using Writelog for the first time this past weekend
in a two-radio setup for the RTTY Roundup. The program ran
smoothly despite my lack of experience.
The old computer I used had only one com port available, so I
used that for FSK on one of the Radios.
For the other radio, I had to use AFSK. Selecting "low tones"
put the transmitted audio in the middle of the TS-850's LSB
passband, and the two 500 Hz filters seemed optimally placed.
I also selected "low tones" on the FSK radio/soundcard channel,
just to keep the tuning on both radios the same.
I saw K5ZD's comment that "If he could hear the signal, the sound
card would print it." That was not quite my experience here. The
print was generally quite good (1171 QSO's!), but there were times,
especially on the Europeans, where it would just not print. Some
of these signals were quite loud, but you could hear the flutter
on them. It's a 3 hop polar path to EU from here. The soundcard
also had a little trouble with backscatter stations from California.
So here, finally, are my questions.
1. Would the sound card have done a better job if I had not selected
"low tones?"
2. Does using the "AFC" feature slow down signal acquisition, or make
it less sensitive?
3. Is there significant variation between sound card manufacturers,
or CPU speed, in decoding sensitivity?
4. Is there a general consensus among serious RTTY contesters that
Writelog's sound card decoder is as sensitive as the old HAL military
units?
5. Did I overlook some other issue that would have improved
sensitivity?
This stuff is all pretty new to me, so thanks for your patience.
Dave Hachadorian, K6LL
Yuma, AZ
K6LL@juno.com
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