Lost EPG/BBC HD after retune of working system

g0ukb

New Member
Well last night at 22:00 all was well with my Foxsat HDR, fully-functioning Freesat EPG, BBC HD channels and everything else seemed fine. But I was bored so flicked through the channels and found a few (e.g. Kerrang) a bit weaker signal than before and pixellating.

I wondered if a retune might fix it and exactly the opposite - Freeview retune failed to find a satellite. So tried a factory reset and still no good. Manual tuning finds 200+ stations and most of the usual ones except BBC HD and no Freesat EPG.

I suspect I need the dish realigned but I'm baffled as to why the system had the stations and EPG. No changes to the dish or cables, just an attempt at a rescan and I no longer have them - curious?

Any ideas?
 

grahamlthompson

Well-Known Member
Well last night at 22:00 all was well with my Foxsat HDR, fully-functioning Freesat EPG, BBC HD channels and everything else seemed fine. But I was bored so flicked through the channels and found a few (e.g. Kerrang) a bit weaker signal than before and pixellating.

I wondered if a retune might fix it and exactly the opposite - Freeview retune failed to find a satellite. So tried a factory reset and still no good. Manual tuning finds 200+ stations and most of the usual ones except BBC HD and no Freesat EPG.

I suspect I need the dish realigned but I'm baffled as to why the system had the stations and EPG. No changes to the dish or cables, just an attempt at a rescan and I no longer have them - curious?

Any ideas?

Most likely reason is you have lost contact with the Freesat home transponder. (11428 H). The epg is delivered over all channels so apart from the fact that you will have lost channel 407 you wouldn't notice except you won't get updates to the epg channel line up. When you did a freesat tune the box needs to download the postcode database to set up your local channels, if it can't the retune fails. Look in your manual tune channels for FASHION ONE, if you haven't got this channel which is also on the freesat home transponder then you have your explanation
 
OP
g0ukb

g0ukb

New Member
Yep, spot on - no Fashion One and manually trying to tune 11428H gives no signal strength and consequently no channels.

Apologies for the dumb question but why do I get loads of other transponders and suddenly not get this one? Do I just need to realign the dish (checked it today and it doesn't appear able to move much), but if I do so won't I just lose different transponders? Anyway my simple mental model sees transponders as just different frequency radio channels each carrying a set of information - surely if I'm aiming at the satellite why would I only get some not all?

Thanks for your help.
 

grahamlthompson

Well-Known Member
Yep, spot on - no Fashion One and manually trying to tune 11428H gives no signal strength and consequently no channels.

Apologies for the dumb question but why do I get loads of other transponders and suddenly not get this one? Do I just need to realign the dish (checked it today and it doesn't appear able to move much), but if I do so won't I just lose different transponders? Anyway my simple mental model sees transponders as just different frequency radio channels each carrying a set of information - surely if I'm aiming at the satellite why would I only get some not all?

Thanks for your help.

The Freesat home transponder is from Eutelsat 28A which is located at a slightly different point to the Astra satellites. Eutelsat is nominally at 28.5E with Astra 2 nominally at 28.2E. A further complication is that the 28.2 group use a non standard lnb skew. To get both requires a compromise lnb skew setting.

Try other 28A transponders close in frequency and horizontal polarisation to 11428 H

http://en.kingofsat.net/freqs.php?&pos=28.2E&standard=All&ordre=freq&filtre=Clear

Note the exact current orbital location of all the satellites.

It's also possible that you have a local source of interference blanking the single transponder. Your previous info about some weaker transponders points to alignment. This may be as simple as tweaking the lnb skew while looking at the home transponder.
 

Trev

The Dumb One
On my sky dish the distance between the face and the throats of the two LNBs is about 220mm The separation of the LNBs is about 50mm this setup gives me 19E/28.2/28.5E. So with 50mm giving 9 deg., o.3 deg (28.2/28.5) = about 1.6mm. The horizontal beam with of a sky dish is somewhere about 3-3.5 degrees at the 11GHz 3db down points with an on axis gain of about 34dB, so the sat separation of 0.3 degrees should make little difference to relative signal strength.

In practice I have found very little, if any difference by altering the skew from the default on the LNB as supplied (unless you go really silly with it). Having said that, I do have my LNB mounting boom skewed a bit clockwise and the 28E LNB is skewed a few degrees more than the 19E one, but this is more to satisfy theory rather than being established by empirical means.
 

grahamlthompson

Well-Known Member
When Channel4 launched it's initial HD service on Freesat from Eutelsat28A there was a whole spate of failed to get the channel posts. Most turned out to be skew problems.
 

Trev

The Dumb One
It's going to depend on where the OP is relative to the downlink beam spread, isn't it?
What is?

GLT said:
When Channel4 launched it's initial HD service on Freesat from Eutelsat28A there was a whole spate of failed to get the channel posts
Quite right, I was one of them. Can't remember what my prob was, but my observations on skew is a result of trying it to see if I could improve my H/V strength/quality differences. I found that the skew made little difference unless I changed it by about 10 degrees or more.
 

Black Hole

May contain traces of nut
How critical the skew and alignment are will depend on the signal strength, and therefore the receiver's location relative to the footprint. If you are in a strong reception area, you can be quite lax with the alignment.
 

Trev

The Dumb One
Yep, I'll go along with that. I live on the south east coast, so I suppose that gives me a good positioning in the footprint





Sent from my Nexus 10 using Tapatalk 4 Beta
 
OP
g0ukb

g0ukb

New Member
Well, all sorted now! But at a cost - the real culprit was a silver birch tree which had been gradually obscuring the line of sight. Given the position and angle of the dish it was not easy to be sure this was the problem until on the ladder with an iclinometer; it had looked like the dish might just be in the clear. Anyway I decided to shell out for a professional reinstall with the dish in a new position because it would have been very difficult for me to install myself given the very limited sight lines and ensuring missing the neighbour's roof line.

I'm still amazed that the previous much attenuated signals worked with about 80% quality strength but perfect reception on all the main channels (including BBC HD) but was sufficiently poor to stop a retune.
 

grahamlthompson

Well-Known Member
Well, all sorted now! But at a cost - the real culprit was a silver birch tree which had been gradually obscuring the line of sight. Given the position and angle of the dish it was not easy to be sure this was the problem until on the ladder with an iclinometer; it had looked like the dish might just be in the clear. Anyway I decided to shell out for a professional reinstall with the dish in a new position because it would have been very difficult for me to install myself given the very limited sight lines and ensuring missing the neighbour's roof line.

I'm still amazed that the previous much attenuated signals worked with about 80% quality strength but perfect reception on all the main channels (including BBC HD) but was sufficiently poor to stop a retune.

Signals from wide beam transponders are weaker in the first place. Although the power output is comparable it's spread over a much wider beam. Imagine a torch you can focus. A narrow beam will give a small bright spot because all the energy is concentrated into a smaller area. A wider beam will be dimmer but viewable over a wider area.

As a result signal strengths from the tight UK spotbeams as used by Astra 1N and especially 2E are very strong in the UK but much weaker as you travel outside the primary footprint.

Tune to a 28A channel (say 704) and look at diagnostics, now repeat for a 2E transponder, try Channel 4 HD.
 
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