2 trps on Astra 2A or Eut 28A?

hvdh

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Since a few days (maybe more), 11307V and 11343V of Eutelsat 28A show a very fast-jumping dB value here.
I'd think the transponder they have in common is not healthy, since neighbouring frequencies have much more stable dB values.
Or am I having a local problem?
 

timo_w2s

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Since a few days (maybe more), 11307V and 11343V of Eutelsat 28A show a very fast-jumping dB value here.
I'd think the transponder they have in common is not healthy, since neighbouring frequencies have much more stable dB values.
Or am I having a local problem?
Nothing unusual here in the UK. Looks pretty stable. Could it be local interference somewhere between 11307 and 11343MHz?
 

hvdh

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Instead of the F16 and T-55, I checked these transponders on the TBS6925 and Laminas, and it shows the same instability.
Don't think it's related to the IF either, because the same frequency on Astra 19E, or 850 MHz higher (same IF) have no problem.
The constellation diagram shows a skewness I can't recall seeing before...
 

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timo_w2s

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Hmm odd, by how much do the db vary? On my Technomate I can't see the percentage moving, it's just showing the same as when I last checked the levels.
 

hvdh

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Jumping between 11.7 and 12.1 dB, several times per second (probably limited by the F16's refresh time of the value).
Other transponders are stable with now and then + or - 0.1 dB.

Maybe it's just interference (unintended) of a misaligned uplink, for another satellite. Anyway, it's not impacting reception.
Thanks for the help timo_w2s!
 

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timo_w2s

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Just bumped upon this Eutelsat "Reference Document 2013 - 2014", issued a few weeks ago.
Especially Chapter 1.3 is interesting.
For example, Eutelsat 28A is estimated to stay in stable orbit until Q3 2018.
I'm not 100% sure though, if stable orbit also means non-inclined.
http://www.eutelsat.com/files/contributed/investors/pdf/AGM2014/Eutelsat_DRF2013-2014_UK_Web.pdf

Yeah, further down the list (page 18) they list older satellites as already "inclined" with no date so that would seem to suggest stable means non-inclined? But I suppose this just means Eutelsat may use the bird at another location once SES are ready to take the full load (once 2G arrives?). Either way it would suggest there isn't such a great panic yet about shifting transponders off 28A as some people seem to think.

I see they also say that they have long term leases from SES on 4 transponders on Astra 2E and 4 on 2F. Doesn't seem very many to me (considering 28A is listed as having 24 transponders).
 

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That satellite table has some fascinating stuff in it - look at Eut 3D - expected service life 26 years! :-ohmy
 

hvdh

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Yeah, further down the list (page 18) they list older satellites as already "inclined" with no date so that would seem to suggest stable means non-inclined?
A similar, older list of June 2013 seems to confirm that.
Eutelsat 33A is mentioned there with stable orbit until Q3 2014, and indeed this satellite became Eutelsat 31A, then started building inclination.
 
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