Hello All,
Just decoded my second set of telemetry from DO-64. So far I have heard the 145.870 beacon every pass. Unlike during the first 3 months when it was heard 1 pass in 10.
A question for the designers - are the two beacons separate transmitters or just separate feeds to the one transmitter? The 145.870 is far more reliable.
73 de David VK5DG
Hi David,
yes, we have received your telemetry, thanks a lot for that! the 145.870 and 145.930MHz are separate transmitters (which are only combined just before the antennas), they are connected to the same databus from the On Board Computer. The drop out issue is not an issue with one of the transmitters itself, but is related to the databus mentioned above, and it occurs when large volumes of data are transferred. (And it is not dependent on which transmitter is on). Delfi-C3 is currently in basic mode, in which the datavolume no the bus is relatively low since no payload data is gathered from the payloads, in fact, the payloads are switched off, causing the dropout issue not to occur (and it also does not occur in transponder mode). This is why the downlink is still on when the satellite is over your qth down under hi:)
73 on behalf of the Delfi-C3 / DO-64 team,
Wouter Jan Ubbels PE4WJ
On Fri, Oct 17, 2008 at 12:57 AM, David Giles vk5dg@aapt.net.au wrote:
Hello All,
Just decoded my second set of telemetry from DO-64. So far I have heard the 145.870 beacon every pass. Unlike during the first 3 months when it was heard 1 pass in 10.
A question for the designers - are the two beacons separate transmitters or just separate feeds to the one transmitter? The 145.870 is far more reliable.
73 de David VK5DG
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
I really enjoy reading about the specific construction and operation of the satellites! I really hope that the builders of this satellite, and also older sats, can find reasons to express their experiences and insight into these sats, so that we can learn about how they work(or don't work), satisfying the scientific portion of my brain. Sats are fun to operate when they're working, but I also find them just as much fun, or maybe more, when their quirks and modes-of-failure are analysed publicly on here. The archived, relatively recent discussions regarding AO-7, AO-16, and AO-40 have provided me with such joy to read!
Please continue this trend.
73 all Auke
----- Original Message ----- From: "Wouter Jan Ubbels" wjubbels@gmail.com To: "Amsat-Bb@Amsat. Org" amsat-bb@amsat.org Sent: Friday, October 17, 2008 1:28 AM Subject: [amsat-bb] Re: DO-64/Delfi-c3 telemetry
Hi David,
yes, we have received your telemetry, thanks a lot for that! the 145.870 and 145.930MHz are separate transmitters (which are only combined just before the antennas), they are connected to the same databus from the On Board Computer. The drop out issue is not an issue with one of the transmitters itself, but is related to the databus mentioned above, and it occurs when large volumes of data are transferred. (And it is not dependent on which transmitter is on). Delfi-C3 is currently in basic mode, in which the datavolume no the bus is relatively low since no payload data is gathered from the payloads, in fact, the payloads are switched off, causing the dropout issue not to occur (and it also does not occur in transponder mode). This is why the downlink is still on when the satellite is over your qth down under hi:)
73 on behalf of the Delfi-C3 / DO-64 team,
Wouter Jan Ubbels PE4WJ
On Fri, Oct 17, 2008 at 12:57 AM, David Giles vk5dg@aapt.net.au wrote:
Hello All,
Just decoded my second set of telemetry from DO-64. So far I have heard the 145.870 beacon every pass. Unlike during the first 3 months when it was heard 1 pass in 10.
A question for the designers - are the two beacons separate transmitters or just separate feeds to the one transmitter? The 145.870 is far more reliable.
73 de David VK5DG
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
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)
-
Auke de Jong -
David Giles -
Wouter Jan Ubbels