AO-51 (2158Z) Mid Atlantic pass.
Good downlink but no other stations heard on the last pass (2154Z - 2202Z) of AO-51 as it passed south to north up the middle of the Atlantic at max elevation of 3 degrees.
10w from IC910H to 4 x 9 turn (WIMO) Helix. BBQ dish and K5GNA downconverter.
Cheers,
Dave G1OCN AMSAT UK 5766 IO80SM Portland, Dorset.
Well, I just finished the 03:00z pass, setting due North through the trees. I did manage to make one contact (thanks WA6FWF!), but man, I've got work to do.
S-band downlink was pretty crummy. Lots of QSB - more than I remember on other modes, and more than I would have expected given my AO-40-capable, circular polarized 24x30 inch grill with preamp and all that. I know I've had better results in VS before. But the big surprise is that my shiny new 18 turn helix seems to perform much worse than the thrown-together 9-element quagi I had up for LU on field day. No full quieting, and real spotty when I did get in. I guess the only good news is that I was able to work the bird a lot lower in elevation than on LU for some reason. Go figure.
Next pass in about an hour, out to the west. Will give it another shot.
Greg KO6TH
----Original Message Follows---- From: "Dave Aitch" dave@g1ocn.com To: amsat-bb@amsat.org Subject: [amsat-bb] AO-51 (2158Z) Mid Atlantic pass. Date: Tue, 10 Jul 2007 23:10:46 +0100
Good downlink but no other stations heard on the last pass (2154Z - 2202Z) of AO-51 as it passed south to north up the middle of the Atlantic at max elevation of 3 degrees.
10w from IC910H to 4 x 9 turn (WIMO) Helix. BBQ dish and K5GNA downconverter.
Cheers,
Dave G1OCN AMSAT UK 5766 IO80SM Portland, Dorset.
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Greg,
The first couple of morning NS passes yesterday, I found that everything worked fine, though there seemed to be a bit more QSB on the audio. Downlink signals were good, though suffering from relatively low elevation geometry. On the uplink, as I saw before on LU, it required power for full quieting ranging from 80 watts out of the brick on the horizon, to what must have been a watt at most at TCA. There is a very detectable threshold, unsurprisingly with FM, though things are not normally quiet enough on mode VU to experiment and find it. On the previous mode LU operation, I was able to use that threshold, and of course the sparse number of operators, to net in my uplink frequency, BTW.
Last night, I had a "down the throat" SN pass around 0110 UTC. Signals were excellent, and at TCA, my S-meter was absolutely pinned, even with the 10 db attenuator switched on. AO-51 is LOUD on mode S. What I did find, and N8BBQ made a similar comment, was that there was much less QSB on the evening pass. AOS to LOS, it was really like a terrestrial repeater. (Plug for SATPC32. It handles the rapid Doppler perfectly!) I did notice a bit of noise, which for lack of a better term I will say sounded a bit _like_ terrestrial intermod. It was very low level, but I want to look for that on some future passes. I also need to get WA4SXM's book out and look at the antenna locations, as there is definitely a difference in performance depending on aspect, much more so than on VU.
Alan WA4SCA
Hi folks,
Final update on the subject for a while (at least until the next LS session). 03:53 pass this evening, nice and high off to the west. Good strong signals on S-band, but still with a lot of QSB towards the end. The trees in that direction surely have something to do with it, but I'm not wiggling the needle on my R-7000. With AO-40 out at 30,000 miles, I can accept that, but not from a LEO. I think I need a new feed.
But the good news is that my Shiny New Helix is working. Nice chats with KD6IRE and WA6FWF. Good quieting, like I had with the 9 element Quagi. I can't tell which is better now, though it seems like the helix wasn't quite so picky about being on frequency for the uplink. Is that a sign of better or worse signal, or am I imagining things...?
Greg KO6TH
----Original Message Follows---- From: "Greg D." ko6th_greg@hotmail.com To: amsat-bb@amsat.org Subject: [amsat-bb] Re: AO-51 (2158Z) Mid Atlantic pass. Date: Tue, 10 Jul 2007 20:34:55 -0700
Well, I just finished the 03:00z pass, setting due North through the trees. I did manage to make one contact (thanks WA6FWF!), but man, I've got work to do.
S-band downlink was pretty crummy. Lots of QSB - more than I remember on other modes, and more than I would have expected given my AO-40-capable, circular polarized 24x30 inch grill with preamp and all that. I know I've had better results in VS before. But the big surprise is that my shiny new 18 turn helix seems to perform much worse than the thrown-together 9-element quagi I had up for LU on field day. No full quieting, and real spotty when I did get in. I guess the only good news is that I was able to work the bird a lot lower in elevation than on LU for some reason. Go figure.
Next pass in about an hour, out to the west. Will give it another shot.
Greg KO6TH
----Original Message Follows---- From: "Dave Aitch" dave@g1ocn.com To: amsat-bb@amsat.org Subject: [amsat-bb] AO-51 (2158Z) Mid Atlantic pass. Date: Tue, 10 Jul 2007 23:10:46 +0100
Good downlink but no other stations heard on the last pass (2154Z - 2202Z) of AO-51 as it passed south to north up the middle of the Atlantic at max elevation of 3 degrees.
10w from IC910H to 4 x 9 turn (WIMO) Helix. BBQ dish and K5GNA downconverter.
Cheers,
Dave G1OCN AMSAT UK 5766 IO80SM Portland, Dorset.
_______________________________________________ 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
_________________________________________________________________ http://im.live.com/messenger/im/home/?source=hmtextlinkjuly07
_______________________________________________ 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
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participants (3)
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Alan P. Biddle -
Dave Aitch -
Greg D.