Quote:
Originally Posted by radiobob
Bill:
I don't really know how the Viewsat does what it does (if anybody can figure such things out, my money would be on you), but the receiver seems to read data from somewhere. In the case where two satellites are parked in the same position, you can sometimes be watching a channel on one satellite while the display will show the other bird.
I've experimented by manually changing the name of a satellite, but when that satellite is properly tuned in, its real name pops up in the display. Also, when the "Black Belt" mux was active on Amazonas, it would show up as...Intelsat Americas 5! I don't know if some embedded data was just passing through or what.
When I get a moment, I'll play around with monitoring different transponders on different satellites and see what happens.
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Neat. Are the sats named the way YOU named them (if you have entered any of your own in there).
Anyway, there seems to be three possibilities that I can think of:
(1) That it just "thinks" it knows where it is based on where you've told it to go (ie if you change the name of the sat, this would pop up instead of what is popping up there now).
(2) It's figuring it out from the sat beacons (I don't think this is likely at all).
(3) It's figuring it out from the stream you're locked onto somehow. If so, the only PID that I've seen satellite info in is the NIT, but that info is only the longitude of the sat slot, not the name, so if it's coming up with names, it must have a table in memory of what sat is at what location, and new sats would probably come up wrong, like G16 might come up as G4 or something.
Not sure if you can receive AMC1, but I'd be curious what it says on the NBC 11840 channel. This is 4.2.2 so you probably can't view it, but you can lock it, if the polarity isn't too far off. Just curious, because this channel seems to have incorrect info in the NIT. Ie it says that it is the sat at 23.0W. The Pentagon channel on that sat says that it is at 0.0W.
The Globesat muxes on
IA5 all have correct info, but the muxes at 12115 and 12012 both say 0.0W. On AMC3, I couldn't find any signal that had correct NIT info, all either didn't have an NIT or said 0.0W.
Interestingly, I tuned in AMC15, which was mentioned in another thread, the NITs on that sat had correct info. However the interesting thing is that it listed the polarities as either "L" or "V" , which I found interesting. Ie I can see L/R or H/V, but L/V seems strange. That's one of the sats that's supposed to be capable of either linear or circular. Makes me wonder if it's half and half, or if they just have incorrect data.
Anyway, it's interesting that this receiver pops up the sat names. I've always assumed that the receiver cannot tell what sat it is on, so I'd be interested in seeing the results of your tests. Only thing that seems possible is that it uses the NIT info, and has a table that converts longitudes to names somehow. Either that or it just accepts what sat name you gave it, except that you guys are saying that sometimes it tells you that you are on a different sat, which makes me think it's the NIT thing.
interesting