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Sky signal break up on ITV (not HD)

freddyuk

Standard Member
For some considerable time we have had loss of picture on ITV 1 channel. Some other channels are affected but ITV actually becomes unwatchable. The signal strength is 100% and signal quality is 80-90%.
I have an Octo LNB so 8 inputs into 5 boxes so we can check each signal and box the see if it is the cables or not. It seems ITV is bad on all the inputs even though signal is good. I have tweaked the LNB but how much over 100% can you go!!
When we had Channel 973 as ITV we could use that which was clear of the problem but that channel has now gone. There are regional channel options and some work better than others so we have to search for one that is watchable
What is going on?? I am out of ideas to fix this.
 

TJT1

Distinguished Member
I have tweaked the LNB
Just how do you 'tweak the LNB'? In other words, what the heck did you actually do to the LNB/dish?
 

freddyuk

Standard Member
I checked the skew angle? It makes a difference here in Ireland. I have a 60cm dish. it has been aligned for over 15 years. I noted the LNB was not tight in the bracket so skew was centred. I have sorted this and set the LNB with negative (clockwise) skew. I checked signal strength on all boxes and it is 100% with quality at 95%. I cannot use this method to get any more accurate and I can get perfect service in UK with far less quality and strength.
Do I start moving the dish? ITV1 is still going blocky. Other channels are good.
 

davemurgatroyd2

Distinguished Member
I have tweaked the LNB but how much over 100% can you go!!
The percentage readings in receivers are absolutely meaningless for an accurate reading. The software is set for a particular signal level against which the signal measured is compared. Their only purpose is to allow adjustment of dishes/lnbs by maximising the signal level and quality.

Exactly what channels are affected besides ITV?
 

TJT1

Distinguished Member
Do I start moving the dish?
Don't do that to start with.
Dishes tend to flex/move on their mounts slightly. Get someone to push one edge of the dish to flex it slightly and hold it flexed. See if Quality improves. (Don't overdo the push and permanently distort the dish though) If it does, the dish could be off. Repeat the 'flex' on the other side of the dish observing Qual. Repeat by flexing the dish up or down and repeat the Q checks. If no improvement in Qual can be had, then it would appear that the dish is pretty much aligned properly.
You can do pretty much the same by flexing the boom a bit, but keep well out of the beam (and for the edge flexing checks).
I noted the LNB was not tight in the bracket so skew was centred. I have sorted this and set the LNB with negative (clockwise) skew. I checked signal strength on all boxes and it is 100% with quality at 95%.
Did you check on both vertical and horizontal tp transmissions?
 

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