Freesat installation gone wonky, opinions and advice please

We spent the weekend at the holiday flat where we have a basic Goodmans SD Freesat box connected to a bogstandard dish with a bogstandard mono-LNB. The install was done two years ago by a local independent installer.

Sadly, all is not rosy in our Freesat garden. In good weather on Saturday, a selection of channels was missing (ITV1 and ITV2 among them, but strangely not ITV2+1 ... I'm guessing this is down to a particular mux missing). When the weather turned foul, everything went down. The installer menu shows about 30% signal in good weather and flat zero in bad weather.

It is a fairly exposed seaside location. What is more likely to have happened - corrosion or moisture ingress to the cable or LNB, or might the dish have been battered by maritime winds sufficiently to have moved out of place? I'm just curious really, as whatever's wrong with it I think we're going to have to get the installer back to do a repair.

Any thoughts? And with a satellite rig, why would some channels vanish more readily than others?

[Kymmy]

Chris remember that the channels are not done via a singla sat but many which are constanly in motion inside a virtual box and also the transponders point in slightly different directions, both of these things mean that some channels can be a lower signal strength than the other.. Always best to tune in the sat/point the dish using the lowest signal possible, if you suspect the cable then replace, the LNB's are normally sealed so shouldn't be an issue there..

Also have you properly orientated the LNB in it's holder for your latitude?..

No idea, it was done by a professional installer...

All I can say is, it worked fine when installed 2 years ago, and has deteriorated to the point where even in good weather it's dodgy to say the least.

Ta for the info about the multiple satellites - I suspected this was the reason but wasn't sure.

[Kymmy]

Chris, not sure if it's relevant but I also seem to have a few dodgy channels atm.. So it's likely to be a sat issue (either low power or a sat has creeped outside or towards the edge of the box) than a local issue.. That's the thing in that if the dish was set up when for example the sat was in one corner of the virtual box then months down the line it might have creeped over to the oppisite corner

[fireman328]

Possible it is corrrosion due to salt spray on elements of array for aerial

It's a dish. Could corrosion on the f-plug connecting the cable to the LNB be an issue though?

[Kymmy]

Could be an issue, the F plug isn't just conducting a signal but also upto 17v (polarization voltage) that can cause a major reaction between varying metals withthe salt acting like an electrolyte.. You could always replace the plugs or at very least give them a good clean... This would though effect mst of the channels and not just a few

So, in fine weather, with the rig receiving some satellites better than others, the likliest diagnosis would be a misaligned dish? It's very exposed and has been fairly battered by wind over the last couple of years.

[fireman328]

Originally Posted by Chris

So, in fine weather, with the rig receiving some satellites better than others, the likliest diagnosis would be a misaligned dish? It's very exposed and has been fairly battered by wind over the last couple of years.

I think you need a pro to see what is happening on the roof.

[Kymmy]

There's three possible reasons all leading to a weakened signal..

1# Sat's gone on low power due to some technical reason whilst the techies look at it (from remote of course)
2# The sats or the dish are slightly misaligned
3# There's a problem with the local equipment that's lowering the signal strength..

[Turkey Machine]

Originally Posted by Chris

So, in fine weather, with the rig receiving some satellites better than others, the likliest diagnosis would be a misaligned dish? It's very exposed and has been fairly battered by wind over the last couple of years.

Either way, you'll likely need somebody out. Alignment to the 28.2 / 28.5 satellites would ensure you receive the best of both signals. If it's still poor, the cable might need refreshing, or the LNB might need changing.

[alferret]

LNB's dont cost much and are relatively easy to replace http://www.argos.co.uk/static/Produc...%3ESKY+LNB.htm
There is a site that explains the degree of rotation\skew of the LNB on the arm in relation to the dish (dependant on where you are in the UK) http://www.uk-satellite-tv.co.uk/tec...lp_154117.html

As its an exposed point when you get the signal back to a high enough quality make sure all securing bolts\nuts\screws are tight as strong winds, moisture, hot\cold can cause some movement.

Also & I'm sure if this would work you could cover the LNB and some of the arm with a clear strong food bag and tie-wrap it to to the arm to stop ingress of salt water into the LNB. There should be no degridation of signal received to the LNB.

Erk, thanks for bumping the thread Alf ... I'd forgotten to phone the in-laws to tell them it needs looking at (it's their flat, so thankfully not my repair bill!). And good advice, I'll go armed with tie-wraps and bags when we're back over there in the summer.