default transponder on sky

[mickc]

I have 2 sky boxes,one an old Grundig which works fine,default transponder 11778v/27500/2/3.
The other is a Thomson,and persistantly loses the default transponder 11778v/27500/2/3.
I know the cabling/lnb are ok as I've tried the box on another dish system, and the fault still persists.
My "easy"? question is,can I use another transponder as the default? and will the box still "update" using it?

 

[iceman]

when you say "persistantly loses the default transponder 11778v/27500/2/3" what exactly do you mean?
what happens when it "looses" the default transponder?

 

[PaulR]

Whereabouts are you?

If you're not in the UK then it's possible that you haven't got a large enough dish for reliable reception. I don't know for sure but possibly the Grundig has a slightly more sensitive tuner than the Thomson, although, as Thomson took over the Grundig assets, they shouldn't.

 

[mickc]

when you say "persistantly loses the default transponder 11778v/27500/2/3" what exactly do you mean?
what happens when it "looses" the default transponder?

When I observe the "signal strength" or default transponder it shows NO strength or quality,if I observe it a while it appears to come and go at random,yet if I put in ,say,12207v/27500/2/3 it will show strength/quality immediately and stay on,but if I use it as the default transponder as soon as it "sees" 11778v it then reverts back to 11778v as the default transponder.

Problems I get are when changing channels. I get NO SIGNAL displayed on some,and others I have to wait quite sometime before it will display a picture.
I live in the U.K. in the west midlands,and currently have this box connected to a 1 Metre dish,so signal is no problem.
Can I use another transponder as the default? and will it update? or is the box U/S?
Any suggestions/help much appreciated.

 

[Analoguesat]

The Thompson may be suffering the usual capacitor failure in the power supply. It causes all sorts of weird & wonderful problems.

Pop the top off the box and see if theres any obvious bulging of the tops of thecaps in the psu area.

 

[iceman]

When I observe the "signal strength" or default transponder it shows NO strength or quality,if I observe it a while it appears to come and go at random,yet if I put in ,say,12207v/27500/2/3 it will show strength/quality immediately and stay on,but if I use it as the default transponder as soon as it "sees" 11778v it then reverts back to 11778v as the default transponder.

Problems I get are when changing channels. I get NO SIGNAL displayed on some,and others I have to wait quite sometime before it will display a picture.
I live in the U.K. in the west midlands,and currently have this box connected to a 1 Metre dish,so signal is no problem.
Can I use another transponder as the default? and will it update? or is the box U/S?
Any suggestions/help much appreciated.

The default transponder 11778V is embedded in the SKY software and changing default transponder manually only lasts till the box can detect sufficient signal from this transponder in which case it will always automatically revert to 11778V.
The problem you described is caused from low signal level on the reception of this transponder.
There are few different issues that might be responsible for this low signal level...But in your case, it is highly likely that the problem is what Analoguesat suggested above.
If the capacitors on the power supply fail, this effects the outgoing voltages (13v-18v) to the LNB through the tuner, resulting in all sorts of strange reception issues.
If you are OK handling electronic equipment,open the box cover and observe the capacitors on the PSU...failed ones usually have a bulge on the top..;)

 

[mickc]

Had a quick look as suggested,cannot see anything visually amiss.
P.S. I'm a retired electrical engr,so I'm able to recognise the components you suggested.
Incidentally,when signal is present,It's easily 90% on both strength and quality,sometimes it's just the quality that disappears,sometimes both.
Silly question,why does it only appear to affect this transponder? others I've tried seem very stable.

 

[iceman]

Had a quick look as suggested,cannot see anything visually amiss.
P.S. I'm a retired electrical engr,so I'm able to recognise the components you suggested.
Incidentally,when signal is present,It's easily 90% on both strength and quality,sometimes it's just the quality that disappears,sometimes both.
Silly question,why does it only appear to affect this transponder? others I've tried seem very stable.

If its a voltage issue caused by faulty PSU it should be affecting other trasponders in the same band & polarisation.

 

[denis1501]

The default transponder 11778V is embedded in the SKY software and changing default transponder manually only lasts till the box can detect sufficient signal from this transponder in which case it will always automatically revert to 11778V.
The problem you described is caused from low signal level on the reception of this transponder.

Thankfully with the new HD EPG this problem has disappeared. I changed my default transponder to 12110, H 10 days ago and the box has not automatically gone back to 11778, V despite there being a strong signal on this transponder in the evenings!
This new software rocks for us fringe folk!

 

[PaulR]

You still haven't told us where you are. This might be pertinent.

 

[iceman]

You still haven't told us where you are. This might be pertinent.

But he has already told us he is from the West Midlands UK.

 

[mickc]

Thankfully with the new HD EPG this problem has disappeared. I changed my default transponder to 12110, H 10 days ago and the box has not automatically gone back to 11778, V despite there being a strong signal on this transponder in the evenings!
This new software rocks for us fringe folk!

I'll try this later and report back.
I've put my old grundig back at present,I'll try it out on that first.

 

[denis1501]

It won't work on the Grundig m8, it only works on HD boxes that have the new HD EPG.

 

[PaulR]

Ooooops

Sorry evryone.

 

[mickc]

It would appear there is a problem with this box.
Looks like purchasing a replacement,as nothing I've tried will rectify the fault.