Re: EUTMETCast DVB-S2 Unable to lock


David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

Thank you very much everyone!
Your help has been very useful and instructive.

I played around with the azimuth, with the tuner set at 1512.500MHz, to see what signal I could get.
The receiver locked on 4 different satellites. I could easily observe distinctive peaks of signal power around each location.
I swept about 60 degrees around South. Three were on the edges of that angle window, one was close to the theoretical direction estimated via www.dishpointer.com + landscape reference.
This method is a good start, but I found it difficult to visualize a central axe on the dish to aim at those references in one view.
So I assumed it was reasonable to end up with a couple a degrees off (5-10) to the actual observed power peak with signal lock.

The fact this "locking" position is a bit to the right of the supposed Hotbird 13°E position corroborate my idea that I found the correct satellite.

With this on field observation, I am now thinking that I would probably not see a significant power drop between Eutelsat 9A and Eutelsat 10A considering they are 1° apart from each other and there was clearly no such signal peak at this frequency in a 15° angle window around.

Here is my new signal lock:
RX1: Active, Locked
EUMETCast DVB-S2 T1 1512.500 MHz, DVB-S2 8PSK 3/4, 29.996 Msps, CCM, 11.8 dB

RX Status 1, Configuration 2
============================
1. Tuner Status Locked
2. Demodulator Status Locked
3. Transport Status Not Locked
4. Demodulator Frequency Offset 2348 KHz
5. Demodulator Es/N0 11.7 dB
6. Signal Input Level -28.0 dBm
7. Demodulator BER 0.00 e-7
8. Bad Frame Count 0
9. Bad Packet Count 0
A. Demodulator Link Margin 3.5 dB
B. Modulation Order and Code Rate DVB-S2 8PSK 3/4
C. Link Adaptation CCM
D. Pilots On
E. Frame Type Normal
F. Roll Off 35%
G. FPGA Loaded

Although I realized afterward the 22KHz was ON during my azimuth scan, with a tuner frequency set at 1512.500MHz, I saw the demodulator frequency offset dropping when I desabled the 22KHz, SNR increased, and the signal status remained on "locked". So I guess this is not a problem.

Transmission Standard is correct (DVB-S2), modulation is correct (8PSK), code rate not exactly (3/4 instead of 3/5), but it was varying a lot in the beginning.
I believe I am now very closely pointing at Eutelsat 9 or 10.

Unfortunately, as you can see the Transport Status is still Not Locked, while I do receive some packets.

RX1 Transport Statistics
=======================
No. MPEG MPE MAC Mismatch MPE CRC Errors

1. 110522 49138 45634 3504
2. 3384 3382 3362 20
3. 23900533 23900533 0 23900538
4. 5134 5129 5099 30
5. 13 0 0 0
6. 17 43 0 5
7. 1752 1743 1740 3
8. 1493180 8950 0 8948

RX Transport Filter Table
=========================

Slot. PID Ethernet Address Status IP Multicast
1. 100 CC-F6-7A-04-CA-B8 Enabled Pass
2. 300 CC-F6-7A-04-CA-B8 Enabled Pass
3. 301 CC-F6-7A-04-CA-B8 Enabled Pass
4. 500 CC-F6-7A-04-CA-B8 Enabled Pass
5. 509 CC-F6-7A-04-CA-B8 Enabled Pass
6. 511 CC-F6-7A-04-CA-B8 Enabled Pass
7. 600 CC-F6-7A-04-CA-B8 Enabled Pass
8. 601 CC-F6-7A-04-CA-B8 Enabled Pass

What does the Transport Status actually means?

Greetings,
Quentin
============================================

Quentin,

In the report, Transport Status should be Locked.

You should be seeing the RX status alternate between:

EUMETCast DVB-S2 1513.000 MHz, DVB-S2 16APSK 2/3, 32.993 Msps, ACM, 12.1 dB
EUMETCast DVB-S2 1513.000 MHz, DVB-S2 8PSK 3/5, 32.993 Msps, ACM, 12.0 dB

As both the bit rate and 8PSK are wrong, I think you may still be on the wrong satellite. If the signal is weak, perhaps there will be no 16APSK data received.

As you say, the signal is marginal, so it may take some time to find and optimise it!

Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv

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