Eutelsat 7E: mapping feed transponders

campag5242

Feed Hunter
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2,582
Lyngsat & kingofsat both seem to list feed TPs verbatim using details reported by users, & without trying to correct for measurement errors in reported user data. Same goes with this site. Nor can I find "official" lists of feed transponders.

The most common variable is frequency - this is made up of a systematic error ie an LNB's local oscillator centre-frequency (LOF offset) / set-top-box's LOF drift (both temperature-dependant), plus random sampling error. I assume a multi-million $ satellite's electronics are temperature & (special & general) relativity compensated, so as to emit rock-solid frequencies.

Enhancing https://www.sat-universe.com/showthread.php?t=309092 to auto-calibrate LOF offset & show frequencies to a resolution of 10 kHz, I am starting to see patterns: frequencies might be be aligned to 250kHz boundaries. (I have a physics background so am a stickler for such things).

Helpful in making sense of what might appear to be random feed frequencies is the spectral bandwith which a feed uses for given SR: bandwidth in MHz ~= 1.2 * SR in ksps. This determines the spacing of tightly-packed, adjacent feed TPs eg the commonly use SR around 7200ksps are spaced by 9MHz, 9875 by 12MHz, 14400 by 18MHz etc.

My best estimate for the first 72MHz of spectrum allocated to feeds on 7E, 10955.5-11027.5MHz (both H&V), follows in the next post.
 
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campag5242

Feed Hunter
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2,582
72MHz of spectrum on 7E: 10955.5-11027.5MHz, both H & V:

24MHz TPs
10967.50 19200
10991.50 19200
11015.50 19200

18MHz TPs
10964.50 14400
10982.50 14400
11000.50 14400
11018.50 14400

12MHz TPs
10961.50 9875
10973.50 9875
10985.50 9875
10997.50 9875
11009.50 9875
11021.50 9875

9MHz TPs
10960.00 7200
10969.00 7200
10978.00 7200
10987.00 7200
10996.00 7200
11005.00 7200
11014.00 7200
11023.00 7200

6MHz TPs
10958.50 4938
10964.50 4938
10970.50 4938
10976.50 4938
10982.50 4938
10988.50 4938
10994.50 4938
11000.50 4938
11006.50 4938
11012.50 4938
11018.50 4938
11024.50 4938
 

campag5242

Feed Hunter
Messages
2,582
The 2nd 72MHz band in the Eutelsat W plan is centered on frequency 11075.00MHz. Thus we get 9MHz BW / SR7200 TPs with 0.5MHz fractional frequencies 11043.50MHz & upwards, whilst the other common SRs are *whole* MHz inside that 72MHz band.

The 3rd 72MHz band in the Eutelsat W plan is centered on frequency 11158.33MHz. That puts 9MHz / SR ~7200ksps feeds at 0.83MHz fractional frequency, others 4938/9875 etc at 0.33MHz.

The above have been confirmed by European Space Agency published launch event viewing info eg https://www.esa.int/ESA_Multimedia/Transmissions/2017/01/SmallGeo_Hispasat_Live_launch , & by on air chat: https://www.sat-universe.com/showpost.php?p=2037149395&postcount=3659
 

vtcc

Registered
Messages
100
The 2nd 72MHz band in the Eutelsat W plan is centered on frequency 11075.00MHz. Thus we get 9MHz BW / SR7200 TPs with 0.5MHz fractional frequencies 11043.50MHz & upwards, whilst the other common SRs are *whole* MHz inside that 72MHz band.

The 3rd 72MHz band in the Eutelsat W plan is centered on frequency 11158.33MHz. That puts 9MHz / SR ~7200ksps feeds at 0.83MHz fractional frequency, others 4938/9875 etc at 0.33MHz.

The above have been confirmed by European Space Agency published launch event viewing info eg https://www.esa.int/ESA_Multimedia/Transmissions/2017/01/SmallGeo_Hispasat_Live_launch , & by on air chat: https://www.sat-universe.com/showpost.php?p=2037149395&postcount=3659
Hi Please see your pm
 
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