[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

RE: AMSAT has a SECRET!



> Yes, there is automatic computer tuning and all that.
> I KNOW some people will respond with that.  Sure, there
> is.  But if you don't have equipment that will do that,
> you will spend a lot of time spinning the dial I am afraid.

Yes there is computer tuning. But I don't think the update speed of the
current doppler tracking software is sufficiently fast or accurate enough
for the prediction type AFC's (as opposed to feedback AFC's such as on
AO40RCV) on the LEO's at TCA.

Even Mic up/down tuners used in feedback AFC's will suffer limitations due
to the switch debounce circuitry limiting the speed at which you can tune.
Feedback AFC's also generally need a 'push start'.

I'm sure there's better samples, but a couple of months ago I put up some
scratchy UO-11 and AO-16 S-Band wav files on my site where you can hear the
rate of doppler. The second one has me attempting to manually keep the
tuning centered on a PSK-1.

http://www.g6lvb.com/images/uo11-cut.wav

http://www.g6lvb.com/images/ao16-cut.WAV

You're right - it'll be fun...

73 Howard G6LVB



----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home