AO-51 now requires 67 Hz PL tone; activity reports appreciated
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,
Hello,
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. 73, Eric.
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,
participants (2)
-
Eric Knaps, ON4HF -
Mark L. Hammond