[amsat-bb] Re: AO-51 now requires 67 Hz PL tone; activity reports appreciated

Eric Knaps, ON4HF on4hf at telenet.be
Thu Apr 21 07:17:54 PDT 2011


Just worked  AO-51 without 67Hz tone. I noticed that the carrier drops 
out sometimes. I guess you activate the carrier again with subtone but 
i'm not sure.

Amateur Radio Station ON4HF
Eric Knaps
Satellite manager UBA

Tel. +32472985876 (mobile)


Op 21/04/2011 15:09, Mark L. Hammond schreef:
> Hello AO-51 users,
> As you have noticed, AO-51 has recently experienced a few shutdowns
> due to a low battery voltage trip.  This is because of increasing
> eclipses (now at 20 mins per orbit and increasing), poor sun angles
> (still getting worse), and a "weak" battery.
> We are now using the 67 Hz PL tone required mode in order to turn the
> transmitter(s) OFF when not in use.   The transmitter power is down to
> about 550 mW.  We will continue adjusting various parameters,
> including transmitter power, trigger voltages, etc. in order to keep
> the battery temperatures reasonable. Keep in mind that the power
> management feature keeps the transmitter(s) OFF during eclipses, so
> you can't bring it up even with a PL tone while the satellite is in
> eclipse.
> Here is our current schedule, which will continue until further notice:
> AO-51 Schedule
> Mode V/U FM Voice Repeater (**67 Hz PL tone required**)
> Uplink: 145.880 MHz FM (Temporarily from 145.920)
> Downlink 435.300 MHz FM
> The AO-51 Command Team can use your help!
> 1-Please make activity reports to: http://oscar.dcarr.org/  This is
> very useful to all users.   Until everyone knows that the 67 Hz tone
> is required, we might see some conflicting reports.
> 2-Please help spread the word about needing the 67 Hz tone!
> 73,

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