Did you try using the View Wide Band Decode feature? That gives you two
different copying algorithms and I have found that the wide band one is
great for signals with a little flutter. Actually, I have found the wide
band decode usually copies the things the main window does not so they are a
great pair.
But you have to watch the screen all the time because the info you want will
scroll away in a hurry. :)
Randy
> -----Original Message-----
> From: owner-writelog@contesting.com
> [mailto:owner-writelog@contesting.com]On Behalf Of Dave Hachadorian
> Sent: Monday, January 08, 2001 9:02 PM
> To: writelog@contesting.com
> Subject: [WriteLog] Sound Card Demodulation questions
>
>
>
> 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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>
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