Low RX SNR

I'm having trouble peaking up my Tooway system.  My reseller is unresponsive to emails and phone calls, so I'm on my own.

I'm on an island in the Adriatic, in the centre of Blue 1.  From installation I've had a maximum of 13.5dB, but recently this has dropped.  I did a re swing of the dish and the best I can now receive is 10.5dB.

I found when I was up the ladder the the earth lead has disintegrated in the high UV here.  Can that cause TRIA problems?

There are lots of mention of Peaking up but no descriptions of how to do it.  I don't have a meter, so use the TRIA tones with a portable wifi device showing the INSTALL page readings to help and very small changes to the bolts, but still can't get above 10.5.

I don't know why the RX SNR has changed.  Any advice would be appreciated.

Hi Eric,  Thanks for your detailed response.  I think I've been abandoned by the company so will be sorting this myself!  On the subject of the beam, I also do not understand the drop, nor why I can't, with careful adjustment, get it up.  However since last week AND not having touched the dish, today it is up to and steady at 11.2dB, so there is something going on that I can't understand.  The dish is solid and does not move.  It is high summer, with a daily max of 35C.  I even wondered if it was due to metal expansion?

As for the earth cable, I also have never seen that kind of failure.  The dish was installed by a company installer.  When he put it up, on the gable end of a stone building, I asked about the earth, and the need to connect it to "Ground" but he said it wasn't necessary.

Yes, we get a lot of thunderstorms, but have had no nearby strikes.  The dish is below the roof top and well below the mains electricity pole on the end of the house, which does have ground protection.  So while the TRIA is (or was) bonded to the dish frame, the frame is just bolted to the wall, without any further bonding.  The rubber sleeve/heat shrink is still in place at both ends |(moisture ingress protection?) and the damage is limited to the vertical wire run close to the frame.  It almost looks as though it has been eaten?

As the coax is in its own, separate conduit from the outside wall to the internet distribution box in the hall, where the satellite modem is, I'm not sure how main current would get into the sheathing?  I think I need to check the coax at the TRIA when I do the replacement work.

I haven't touched the earth, as I am aware of the potential for it to carry current, and will turn the system off and unplug, as you suggest before replacing it.  The danger is magnified when you are at the top of a ladder!!

I don't have a PME.  This is southern Europe, where there is no earth on the incoming power, instead every property has it's own, sometimes, with mine, the earth from the consumer unit goes via the meter box to the underground steel rising water main.

Norman