Hi Domenico, Bob & all
it's a nice idea but I am thinking also that, the relay between AO-7 & FO-29 needs UHF Uplink and UHF Downlink as well ! Therefore, we need two UHF systems (TX-RX) working simultaneously for Full-Duplex operation. And even if the AO-7 Uplink is 3.7 MHZ lower than FO-29 downlink, we need two antennas in the same band and probably a repeater-style *Hi-Q duplexer* in order to avoid the desense. Or just a UHF antenna and a circulator dr Domenico ? Difficult components for the most of us!
However, it's a great challenge. For example @ 18:30 UTC the overlap took place between the 2 footprints over W.Asia. From E.Canada, Atlantic Ocean, Europe, Asia upto E.Siberia it was possible a QSO... !
Amazing distance for LEOs ! Can you imagine that ?!?!?
Yes, I know.. it's difficult, yes. But a great-great challenge for the hibernal months ! And the AO-7 is working 24/7 for the next months - out of eclipse. Great opportunity !
73 de Mak, SV1BSX
----- Original Message ----- From: "i8cvs" domenico.i8cvs@tin.it To: w7lrd@comcast.net; "AMSAT-BB" AMSAT-BB@amsat.org Sent: Thursday, August 28, 2008 5:03 PM Subject: [amsat-bb] Re: bird to bird fun
----- Original Message ----- From: w7lrd@comcast.net To: "AMSAT-BB" AMSAT-BB@amsat.org Sent: Thursday, August 28, 2008 12:07 AM Subject: [amsat-bb] bird to bird fun
Hello All Here's an interesting endeavor. The downlink on AO-7 mode B is 145.950 which is the uplink for FO-29. So you could hear yourself (or anyone else on the FO-29 downlink at 435.850, when both are in view. I think there was something like this back in the days of the RS birds. Why bother? Well we have to do something to keep our interest going while waiting for the next HEO. Plus it's fun. 73 Bob W7LRD Seattle
-- "if this were easy, everyone would be doing it"
Hi Bob, W7LRD
Since OSCAR-7 mode B and FO-29 mode-J have both inverting transponders using SSB it happens that to be received as usually in USB over the FO-29 downlink we must transmit as well USB into the OSCAR-7 uplink.
Since the noise translated by OSCAR-7 mode-B is very high probably a try on CW will be convenient.
As Rick WA4NVM pointed out with OSCAR-7 mode-B and OSCAR-8 mode-J it was a common practice.
73" de
i8CVS Domenico
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