As the volunteer who wrote the code that does it, I can tell you with certainty that when AO-92 is switched to L-band it turns off in 24 hours automatically (or sooner if the satellite goes into safe mode, resets, or is commanded to UHF). The time was chosen just because of the uncertainties. Would L-band work? Would anyone use it? Will the power use be prohibitive (analysis said it was ok, but...) The time is hard-coded in. It would have been nice to be able to change it by command, but the entire design of the original Foxes were based on a lot of uncertainty. There was not much time to change after some certainty was gained after the first launch or 2, so that capability is not available. Fox-1e is an improvement over the previous Foxes. HuskySat was an improvement over that. (Despite the opposite launch order). And Golf will be a big improvement over both, in all cases because of what we learned from the earlier satellites and the extra time available.
As to the day that it is switched, that's outside of my pay grade :-)
73,
Burns WB1FJ
On Wed, Jul 22, 2020 at 4:56 PM David Worboys via AMSAT-BB < amsat-bb@amsat.org> wrote:
Following on from Patrick’s post (below), I just got home and checked to find that the first AO-92 pass for me is at 23:13 edt tonight which, as I have to get up at 3.15am for work, is a definite no-no!
What is the reason for L/U to be only switched on for just a 24 hour period and during the work week? Is it automatically switched back or does the command station do it? If that latter, can it be left on for say, 48 hours to give operators a better chance of working L band or moved to a weekend slot? What with the non activity last week I think its been about three weeks since the last time I could use Mode L and whilst I appreciate that there are a lot of people who want to use that mode, opening up the ability would give a greater number of operators the opportunity.
If the 24 hour period is the maximum available to preserve the health of the satellite then I understand but I would be interested in knowing the rationale!
Many thanks
73
David KG4ZLB
On Jul 22, 2020, at 1:30 PM, Patrick STODDARD (WD9EWK/VA7EWK) via AMSAT-BB amsat-bb@amsat.org wrote:
Hi Andrew!
I am all for a variety of satellites. When we had AO-51 in the 2000s, I found the pieces to work its V/S FM repeater as I started working satellites. Doppler at 2.4 GHz made tuning those downlinks an almost constant thing on those passes, but it was fun. We have the sort of transponder you mentioned in your post with AO-92's L/V FM repeater right now. We are only permitted to use the 1.2 GHz band for satellite uplinks, not downlinks.
Many satellite operators now have the 1.2 GHz uplink capability with the IC-9700, but the only time AO-92 L/V is available appears to be inconvenient for many who might want to try it right now (Tuesday evenings and Wednesday mornings in North America). We were told that the switch from a Sunday UTC activation (Saturday nights and Sunday mornings in North America) last year was not going to be a permanent change. I think there would be more new call signs heard on AO-92 L/V with those IC-9700s and other radios, if that mode was available at a more convenient time for those who have work or school commitments during the week. It isn't like we lack V/U or U/V FM satellites right now.
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ Twitter: @WD9EWK or http://twitter.com/WD9EWK
On Wed, Jul 22, 2020 at 4:46 PM Andrew Lazenby via AMSAT-BB < amsat-bb@amsat.org> wrote:
Hello EveryoneI recently joined Amsat because I felt like a bit of a hypocrite for complaining about things, and not doing my part to change them. One thing that does bug me is the HEO satellites having microwave uplinks and downlinks. I think that will greatly limit the clientele that will be able to use these. I have head many older hams gripe about LEO satellites and reflect back on how back in the day there would be passes up for hours! Many of them where using drifty transverters with terrible noise figures, turning antennas with tv rotators and no preamp! The argument that I have heard
to
move to mircowave uplinks and downlinks is lower noise, but if it worked with them back then, then what's changed? Something else to consider is that the microwave spectrum is under fire from commercial interest more and more. Why not consider like a U/L or
L/U
transponder? That would bring the envelope a little closer to where the average ham could operate with out investing in some serious equipment, while keeping the dream of HEO alive for the large percentage of
satellite
operators, and not just a handful? Forgive me if Im wrong, but I just wanted to put my 2 cents in the pot.
If
we all would learn to work together as much as we fuss we would be making some tracks. Thanks everyone, Andrew N4LAZ
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Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb