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What's happening with the old HVS-2 transmission?
During the tests I've just reported on, I thought I would take a look at the signals provided by the old and "new" HVS-2 transponders.
- The Spectrum Spy plot in the lower waterfall window shows the new transponder (C3 V) which is a smooth plot against time (vertical) with the higher frequencies being slightly stronger (redder). The upper part of the waterfall and the spectrum show the original C10 H transponder carrying HVS-2. What I note here is that there seem to be two modes operating, lust like the C4 H transponder carrying BAS and HVS-1. You can see from the Spectrum Spy scale that this is on the old frequency (11387) so I didn't forget to change that. Any idea what's going on here? Anyone looked for multiple modes?
- The CrazyScan plot clearly shows an upward tilt on the vertical polarisation (the red line) on the 11263 transponder, confirming my earlier observation. Going back to late August there is no such tilt on the spectrum when the previous service was using it, which makes me wonder about the new uplink rather than the transponder itself.
Something to ponder over breakfast!
Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv
- The Spectrum Spy plot in the lower waterfall window shows the new transponder (C3 V) which is a smooth plot against time (vertical) with the higher frequencies being slightly stronger (redder). The upper part of the waterfall and the spectrum show the original C10 H transponder carrying HVS-2. What I note here is that there seem to be two modes operating, lust like the C4 H transponder carrying BAS and HVS-1. You can see from the Spectrum Spy scale that this is on the old frequency (11387) so I didn't forget to change that. Any idea what's going on here? Anyone looked for multiple modes?
- The CrazyScan plot clearly shows an upward tilt on the vertical polarisation (the red line) on the 11263 transponder, confirming my earlier observation. Going back to late August there is no such tilt on the spectrum when the previous service was using it, which makes me wonder about the new uplink rather than the transponder itself.
Something to ponder over breakfast!
Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv
On 15/11/2022 10:18, Charlie wrote:
I've seen quite a variation in throughput on HVS-2 but had no explanation from EUMETSAT, although I didn't raise a specific query.
https://www.satsignal.eu/mrtg/lund-1-hvs.html
This may be related, or not. Some padding is added to HVS-2 to keep the buffers on TBS systems filled. Ernst has explained this before, better than I can.
Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv
I've noticed the same with HVS-2. It seems to drop back to QPSK when there is a break in the data (as there often is on there)? Note the pilot is off and no inner FEC showing.That would explain things, Charlie.
I've seen quite a variation in throughput on HVS-2 but had no explanation from EUMETSAT, although I didn't raise a specific query.
https://www.satsignal.eu/mrtg/lund-1-hvs.html
This may be related, or not. Some padding is added to HVS-2 to keep the buffers on TBS systems filled. Ernst has explained this before, better than I can.
Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv
