Have you checked your downconverter with some sort of frequency standard to make sure it is where you think it is? Also, are you tuning for the +/- 50 khz of doppler shift? Both of these are common pitfalls with Mode S on AO-51. The downlink is very strong, Sunday night I copied the downlink thru the shack window with my downconverter and corner reflector.
Good Luck, Drew KO4MA
----- Original Message ----- From: "Michael Tondee" mat_62@netcommander.com To: amsat-bb@amsat.org Sent: Thursday, September 14, 2006 8:01 PM Subject: [amsat-bb] Not hearing S-band on AO-51
I've been trying to get a handle on my S-band receiving setup for a couple of months now. It seems when the bird has been in V-S mode that I've had one problem or another that hasn't allowed me to test it. I don't have an L-band antenna up at the moment so I thought I would at least listen to some passes the past couple of evenings to see how my receive would work. I have a AIDC 3731 downconverter and a small BBQ-grill dish on my Az/El rotator system. The IF of the downconverter is at 123 Mhz. I built another converter that was featued in the AMSAT Journal awhile back. The purpose of this converter is to further reduce the 123 Mhz output to 6 meters where I can feed it into my TS-2000X. Unfortunately I haven't heard anything with this setup. I've had some near overhead passes and once my dish gets above about 30 degrees or so it is pointing at clear sky. I thought maybe my homebrew converter was to blame so I dug up an HT that will receive directly on 123 Mhz. Still nothing. I can hear the noise level increase and decrease if I cut power on and off to the downconverter so I assume it's working. Could I be wrong in that assumption? The other thing is that it's been kind of rainy and overcast here the past couple of evenings. Would this affect my reception? I don't know what I should be trying here. It's pretty new to me. I know a BBQ grill dish isn't the best antenna but it seems to me it should work ok considering people hear the bird with this same downconverter and a small corner reflector plus an HT. Any ideas or suggestions out there? TNX and 73, Michael, W4HIJ AMSAT # 36017 _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb