Posted: 8/24/2011 6:45:24 PM EDT
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Anyone here work sat comms?
I've been trying but am not having any luck. I have this Arrow Antenna - Arrow Satellite Antenna and am using a Kenwood TH-D7A with full duplex capability. Maybe I am not doing the Dopler correctly, but I think I am; one of the primers I saw said we only really need to worry about it on the 70cm side and have tried to find sats that have the uplink side 2m so it won't mess with my outgoing signal. I do have another HT that I will use for receive when I get the cable so I am not bouncing back and forth from 2m to 70cm and back to adjust for dopler and forget and TX on the wrong side. Any recommended sats? Some things I read say that AO-51 is about dead, but then something I saw last night said that even though the batts are LOW it is still working quite well. I just tried SO-67 and didn't get anywhere. Suggestions? Thought? 73's Greg |
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Try this list for starters.
The main Amsat page will link you to a lot of info. I've done a tiny bit of sat work years ago on 2M and 10M, and a lot of satellite RX work in the past. I assume you've got the RX side working? Make sure you can get the satellite's beacons on RX first, once you have that down you can start playing with TX and look for your signal on the downlinks. |
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Quoted:
Thanks. Actually, it hadn't even occurred to me to just try RX before I tried two way. Makes perfect sense; I'll give that a try. Any more thoughts? After you get RX working, I'd try for the FM satellites first, then go from there. Also, there are lots of satellite tracking programs, but for a quick and dirty start there's web based sites like this and this (this one is especially good, as you can easily put in your location and get a list of all ham satellites for 24 hours over your location, with downlink frequencies.) On a lark I tried picking up some beacons last night, but was 0 for 3. If I find a known working satellite I'll post it in this thread. |
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OK, I've done a little bit of research to get up to speed, and I would recommend AO-27.
It's a FM satellite with a downlink on 70cm. There's a pass here tonight I'll try to copy and let you know how it goes. You can try the same, too. EDIT: FYI, the pass tonight will cover about half of the US (basically everything west of the mississippi) and starts around 02:15 or so UTC (so 7:15PM here in AZ and on the west coast, not sure where you're at.) FM downlink for AO-27 is 436.7950 MHz, you might want to start at 436.800 MHz since it'll be doppler'd up frequency as it approaches, then drop it down 5 KHz for best signal as the pass progresses. Also, this link is the latest satellite status for the week. Everything I see says SO-67 was working, so maybe you were off on schedule? |
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Appears that I am not quite far enough west of the River as it doesn't show as being workable for me.
I am REALLY close to 43N 93W. SO-50 should be workable in about 20 minutes; I'll go try that. Radio programmed: Duplex on VHF side: SO50up, 145.850 (no shift) pl on 67.0 UHF side: SO50down, 436.795 (no shift) no tone We'll see. |
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Quoted:
OK, I've done a little bit of research to get up to speed, and I would recommend AO-27. It's a FM satellite with a downlink on 70cm. There's a pass here tonight I'll try to copy and let you know how it goes. You can try the same, too. EDIT: FYI, the pass tonight will cover about half of the US (basically everything west of the mississippi) and starts around 02:15 or so UTC (so 7:15PM here in AZ and on the west coast, not sure where you're at.) FM downlink for AO-27 is 436.7950 MHz, you might want to start at 436.800 MHz since it'll be doppler'd up frequency as it approaches, then drop it down 5 KHz for best signal as the pass progresses. Also, this link is the latest satellite status for the week. Everything I see says SO-67 was working, so maybe you were off on schedule? AO27 has a complex schedule; sometimes it is data-only; sometimes it has a very weak output signal. It NEVER operates until it is in full sunlight! 27 is an old bird and its batteries are depleted. The operators keep it on a very strict power budget. |