11 Sep 2014

Receiving Astra 2E/F in Prague

Submitted by drhans

After Astra 2E and F replaced Astra 2D, the reception of British free to air channels got more problematic in Central and Eastern Europe. However, a good chance of solid reception still exists in Prague. I've done a test with a prime focus 1.8 dish equipped with an Invacom feedhorn and Inverto Black Pro quad LNB.

During my tests, all frequencies were receivable between 20:00 - 23:00. Even though I've tried optimizing the reception for Astra 2E, the signal is still significantly lower by 1-2 dB, compared to Astra 2F where the signal would range from 7.5 to 8.5 dB on a typical day without rain. All transponders in the UK beam on Astra 2F seem to be receivable 24/7, while Astra 2E UK beam signals change during the day and sometimes even fade out completely.

From this experience, I could conclude that for a 24/7 Astra 2E/F UK beam reception, a 200-220 cm dish would be required. On the other hand, 180 cm dish is almost perfect for fringe reception tests in this area. With careful tweaks of the LNB, I believe the signal could still be improved. I've already ordered Invacom quad LNB to give it another try.

The following signal levels (SNR) were measured using Vu+ Solo2. 

Freq. SAT DVB 8:00 13:00 15:00 16:00 17:00 21:00
10714 H 2E S 0 0 5,1 5,2 5,3 6,5
10729 V 2E S 6,3 5,6 6 6,2 6,1 7,3
10744 H 2E S 0 0 5,4 5,4 5,3 6,5
10758 V 2E S 6,3 0 5,7 6 6,1 7,1
10773 H 2E S 0 0 0 5 5,4 6,3
10788 V 2E S 6,8 6 6,3 6,5 6,4 7,5
10803 H 2E S 5,9 0 5,2 5,3 5,4 6,5
10818 V 2E S 6,7 6 6,4 6,3 6,5 7,5
10832 H 2E S 5,9 5,1 5,4 5,5 5,6 6,6
10847 V 2E S2 0 0 0 0 6,7 7,4
10876 V 2E S 7,1 6,4 6,7 6,8 6,8 7,7
10891 H 2E S 6,6 5,8 6,1 6 6,3 7,1
10906 V 2E S 7,4 6,8 7,1 7,2 7,2 8
10921 H 2E S 6,3 5,3 5,6 5,7 5,7 6,8
10936 V 2E S2 7 0 6,7 6,9 7,1 7,6
10964 H 2F S 8,8 7,7 8,1 8,1 8,1 8
10994 H 2F S 8,9 7,9 8 8,1 8,2 8,2
11023 H 2F S2 8,6 8,1 8,1 8,4 8,3 7,8
11053 H 2F S 9,2 8,5 8,6 8,6 8,6 8,3
11068 V 2F S2 9 8,5 8,2 8,7 8,6 8,2
11097 V 2F S2 9 8,1 8,5 8,5 8,7 8,3
11126 V 2F S 9 8,1 8,2 8,5 8,7 8,2

The LNB is connected through approximately 50 meters of cable and 2 diseqc switches. The picture starts to break up at SNR of 5.8 dB (FEC 5/6) on DVB-S transponders and at 7.2 dB on DVB-S2/8PSK (FEC 2/3) transponders on the Vu+. Any lower signal than this and the signal is not locked at all so it's difficult to tell the acual signal strength without a proper satellite meter. On a Dreambox 500 HD, the margins were at 6.3 dB and 7 dB respecively. What's interesting is that while Vu+ does significantly better with DVB-S signals than DM500 HD, the situation is equal, maybe even in favor of the DM500HD when it comes to DVB-S2 signal processing.

The signal then keeps quite steady till midnight, when all transponders go down in power by approximately 1 dB, resulting in no lock on most of Astra 2E transponders.