News from a 28e revenant :O)
- Thread starter 4wd
- Start date
Nalleman
Member
- My Satellite Setup
- 1,8 Channel Master, Black Pro LNB with CM feedhorn for 28 E which is my main interest when watching TV.
Using two VU+ DUO 4K SE, a VU+ DUO 2 and an Octagon SF8000.
Fixed dishes at: 42 E (0,75 m), 28,2/28,5 E (1,8 m), 19,2 E (1,5 m), 13 E (1,1 m), 9 E (0,7 m), 5 E (1,2 m) and 1 W (0,7 m).
- My Location
- Sweden
12610 V DVB-S2 8PSK,SR 22000 and FEC 3/4 on Astra 1Lfor their transmissions in SD and 12640 V DVB-S2 8PSK, SR 23500 and FEC 3/4 on Astra 1N for their transmissions in HD (encrypted).
Nalleman
Member
- My Satellite Setup
- 1,8 Channel Master, Black Pro LNB with CM feedhorn for 28 E which is my main interest when watching TV.
Using two VU+ DUO 4K SE, a VU+ DUO 2 and an Octagon SF8000.
Fixed dishes at: 42 E (0,75 m), 28,2/28,5 E (1,8 m), 19,2 E (1,5 m), 13 E (1,1 m), 9 E (0,7 m), 5 E (1,2 m) and 1 W (0,7 m).
- My Location
- Sweden
I should add 12670 V (same parameters as on 12640 V) is also used for some channels in HD (encrypted).
Channels on both 12640 and 12670 are part of HD+ which offers lots of channels in HD and three channels in UHD. All encrypted.
Channels on both 12640 and 12670 are part of HD+ which offers lots of channels in HD and three channels in UHD. All encrypted.
4wd
Getting the picture
- My Satellite Setup
- 28e, 19e
- My Location
- Bergen, Norway \ Alpes Maritimes, France
Yep, these days got every and all channels, HD & SD,, around 3 dB +, just what's needed for 24\24 with a small rain margin.
So hope is back and (sat)spirit is lifting.
superpascu2
Member
- My Satellite Setup
- ATLAS HD100 - ASTRA 19,2 + HOTBIRD 13 + 28,2 1.2m famaval
- My Location
- Alicante
Pride Of Cucamonga
Regular Member
- My Satellite Setup
- Cheap piece of junk Spanish (Tecatel) 120cm(x110) dish, Inverto Ultra twin LNB and Sky HD box.
- My Location
- Valencia (city)
yep, makes sense to use 8PSK 3/4 FEC in Germany where signal stronger. Movistar for Spain however uses 8PSK 2/3
Is QPSK 9/10 (e.g 11778V) stronger or weaker than 8PSK 3/4?
rodscha
Specialist Contributor
- My Satellite Setup
- See signature
- My Location
- carcassonne south france,700ks south of Paris ,300k N of Barcelona
4wd
Getting the picture
- My Satellite Setup
- 28e, 19e
- My Location
- Bergen, Norway \ Alpes Maritimes, France
The 19e sidemounted lnb on the 28e UK dish, no problem. BTW, flysat lists it on A 1N.
28e, 2 transponders went dead here, 11038 V (Quest, Dmax) & 12382 H (Quest, Dmax). Any known changes ?
Attachments
rodscha
Specialist Contributor
- My Satellite Setup
- See signature
- My Location
- carcassonne south france,700ks south of Paris ,300k N of Barcelona
Pride Of Cucamonga
Regular Member
- My Satellite Setup
- Cheap piece of junk Spanish (Tecatel) 120cm(x110) dish, Inverto Ultra twin LNB and Sky HD box.
- My Location
- Valencia (city)
Fisty McB
Member
- My Satellite Setup
- See my signature...
- My Location
- County Tyrone, N. Ireland
To try and clear things up...
For a given power level & FEC, a DVB-S2 transponder broadcasting with 8PSK modulation will require a higher signal to noise (SNR) ratio to successfully decode transmissions than if it was QPSK modulation (either DVB-S or DVB-S2).
This simply means the receiver requires a stronger SNR, not that the transmitted signal power is inherently weaker!
Prior to the adoption of DVB-S2, when it was DVB-S only, only the FEC could be changed to allow whoever was transmitting on a transponder to increase the bitrate (all other things being equal e.g. Symbol rate). With the introduction of DVB-S2, three additional modulation modes were added - 8PSK, 16APSK & 32APSK though only 8PSK is used for regular broadcasts to home users, each modulation value having pros & cons as to their usability for transmission.
In the case of the transponders that at 28 degrees east been converting to DVB-S2 since the start of the year, they mostly (but not all) converted from DVB-S FEC-5/6 to DVB-S2 8PSK FEC-2/3. The SNR required for the former is 6.5db while the latter is 6.6db - essentially no real difference as far as reception goes.
DVB-S2 8PSK transmissions are used on geostationary satellites across the Clarke Belt, serving across the world, for over 15 years now. It's a very mature & well tested mode of transmission.
For a given power level & FEC, a DVB-S2 transponder broadcasting with 8PSK modulation will require a higher signal to noise (SNR) ratio to successfully decode transmissions than if it was QPSK modulation (either DVB-S or DVB-S2).
This simply means the receiver requires a stronger SNR, not that the transmitted signal power is inherently weaker!
Prior to the adoption of DVB-S2, when it was DVB-S only, only the FEC could be changed to allow whoever was transmitting on a transponder to increase the bitrate (all other things being equal e.g. Symbol rate). With the introduction of DVB-S2, three additional modulation modes were added - 8PSK, 16APSK & 32APSK though only 8PSK is used for regular broadcasts to home users, each modulation value having pros & cons as to their usability for transmission.
In the case of the transponders that at 28 degrees east been converting to DVB-S2 since the start of the year, they mostly (but not all) converted from DVB-S FEC-5/6 to DVB-S2 8PSK FEC-2/3. The SNR required for the former is 6.5db while the latter is 6.6db - essentially no real difference as far as reception goes.
DVB-S2 8PSK transmissions are used on geostationary satellites across the Clarke Belt, serving across the world, for over 15 years now. It's a very mature & well tested mode of transmission.
Pride Of Cucamonga
Regular Member
- My Satellite Setup
- Cheap piece of junk Spanish (Tecatel) 120cm(x110) dish, Inverto Ultra twin LNB and Sky HD box.
- My Location
- Valencia (city)
good info, thanks. would DVB-S2 QPSK have lower signal strength than DVB-S at the same FEC?
Why aren't all DVB-S2 transponders at 28.2E 8PSK?
rodscha
Specialist Contributor
- My Satellite Setup
- See signature
- My Location
- carcassonne south france,700ks south of Paris ,300k N of Barcelona
In the case of the transponders that at 28 degrees east been converting to DVB-S2 since the start of the year, they mostly (but not all) converted from DVB-S FEC-5/6 to DVB-S2 8PSK FEC-2/3. The SNR required for the former is 6.5db while the latter is 6.6db - essentially no real difference as far as reception goes.
Except that the received signal changes from 76%to 30%.... so,no change in reception????
I know 30% now means nothing when rain comes ,or when low propagation sets in.
Before it worked almost all the time....no big change?
Except that the received signal changes from 76%to 30%.... so,no change in reception????
I know 30% now means nothing when rain comes ,or when low propagation sets in.
Before it worked almost all the time....no big change?
Nalleman
Member
- My Satellite Setup
- 1,8 Channel Master, Black Pro LNB with CM feedhorn for 28 E which is my main interest when watching TV.
Using two VU+ DUO 4K SE, a VU+ DUO 2 and an Octagon SF8000.
Fixed dishes at: 42 E (0,75 m), 28,2/28,5 E (1,8 m), 19,2 E (1,5 m), 13 E (1,1 m), 9 E (0,7 m), 5 E (1,2 m) and 1 W (0,7 m).
- My Location
- Sweden
Look in the table I posted. There you can see the difference in C/N needed to get a picture depending on which technique used.
The strength of the transmitted signal is the same but the signal needed for the receiver to produce a picture is higher when using 8PSK.
Attachments
4wd
Getting the picture
- My Satellite Setup
- 28e, 19e
- My Location
- Bergen, Norway \ Alpes Maritimes, France
Ain't it just the same that I get here (dept. 06, not that far from Mediterranean & Italy border)? A general diminished level for anything from 28e spot beams (SD, HD, whatever FEC) > change of beam area coverage > less signal to grab for us fringies vs a few years ago. No changes to the Europe beam, looks strong enough to melt the LNB as before.
Nalleman
Member
- My Satellite Setup
- 1,8 Channel Master, Black Pro LNB with CM feedhorn for 28 E which is my main interest when watching TV.
Using two VU+ DUO 4K SE, a VU+ DUO 2 and an Octagon SF8000.
Fixed dishes at: 42 E (0,75 m), 28,2/28,5 E (1,8 m), 19,2 E (1,5 m), 13 E (1,1 m), 9 E (0,7 m), 5 E (1,2 m) and 1 W (0,7 m).
- My Location
- Sweden
Labour won't stop the change to a new technique even if it's makes it harder for those outside the intended coverage area to watch the programs intended for the UK.