Sudden loss of signal

Irreverent · 04-05-2020 6:14pm #1

Hi all. I am having a problem all of a sudden with a loss of terrestrial signal. There are three aerials on the roof with two diplexers on the pole. In the attic there is a Triax power unit of some sort with one in / one out. The out cable is then fed into a 1 in / 2 out distribution unit. I have a DVB-t tester and there is no signal from the cable going into the distribution unit or the cable going into the power unit.

Any ideas what the issue mint be? There are no power indicators on the Triax unit so I can’t tell if it is doing anything. Only recently bought the house so still fumbling around a bit with the setup.

The aerial is alarmingly high on the roof so don’t fancy getting up at it.

Elvis Hammond · 04-05-2020 8:05pm

The power supply would be the place to start; I suppose I'd check for damage to its plug & cable, & make sure the socket is providing power, then either test the 'in' side with a multimeter, or swap it for a known working unit.

Irreverent · 09-05-2020 2:47pm

Elvis Hammond wrote: »

The power supply would be the place to start; I suppose I'd check for damage to its plug & cable, & make sure the socket is providing power, then either test the 'in' side with a multimeter, or swap it for a known working unit.

Thanks for the response on this. I have replaced the power supply. I am getting full signal almost now on RTÉ 2 but on RTÉ 1 virtually no signal. Would this be an aerial issue do you think? Cables are all fit well with F connectors so no issue there and does not seem to be any short in the cabling.

Elvis Hammond · 14-05-2020 3:17pm

Could be an aerial problem, or something outside anyway. I suppose the setup would be up there a good few years now: I assume it's a UHF & VHF aerial that would have been for Irish analogue TV, & another UHF aerial for UK TV?

Irreverent · 15-05-2020 7:58am

Elvis Hammond wrote: »

Could be an aerial problem, or something outside anyway. I suppose the setup would be up there a good few years now: I assume it's a UHF & VHF aerial that would have been for Irish analogue TV, & another UHF aerial for UK TV?

So you would think but it actually looks like 3 UHF aerial in this picture all pointed in different directions, none big enough to pick up UK freeview. I presume one is pointed at Mt Leinster, another at a mast somewhere in Waterford city. No idea what the third one is doing.

The Cush · 15-05-2020 8:43am

Irreverent wrote: »

So you would think but it actually looks like 3 UHF aerial in this picture all pointed in different directions, none big enough to pick up UK freeview. I presume one is pointed at Mt Leinster, another at a mast somewhere in Waterford city. No idea what the third one is doing.

I wonder if 1 or 2 of them were used for the old UK TV deflectors? It's possible that one or both of the masthead amps/diplexers has failed if they've been up there that long.

Getting up there and removing the old hardware may be the only option, and when up there replace the Mt Leinster aerial and cabling back down to the attic to rule out any potential present of future issues with it. A replacement contract aerial like those is about €15-€20.

i'm assuming Mt Leinster is recommended for your location, check here - http://coverage.2rn.ie/index700.php

ei9go · 15-05-2020 11:48am

In Waterford, the deflector in Dunmore east was on group C/D and the one on the Comeraghs just inverted the Group B polarisation. Both Mount Leinster and Waterford fill in are Group A but the Waterford Fill in is on vertical polarisation.

I had a recent issue when i put an aerial in a friends attic when Virgin switched off the analogue multiroom.

Aerial pointed at the Waterford Fill in vertical polarisation, 2km from transmitter. Perfect picture. Then after 10pm picture break up, signal level the same but quality collapsed.

After much head scratching, finally noticed that the TV had selected Mt. Lenister when tuning in and it was a propagation effect that happened presumably as the temperature dropped at night.

Elvis Hammond · 15-05-2020 1:55pm

Irreverent wrote: »

So you would think but it actually looks like 3 UHF aerial in this picture all pointed in different directions, none big enough to pick up UK freeview. I presume one is pointed at Mt Leinster, another at a mast somewhere in Waterford city. No idea what the third one is doing.

Assuming the horizontal aerial is for Mt. Leinster, one of the others must have been for UK channels. The other vertical one could have been for RTE from a relay site that didn't carry TV3, either because reception was better, or just to save trying to fit in a VHF aerial for Mt. Leinster. (Although a lot of the mast height is wasted with it being lashed so low down the chimney.)

Irreverent · 15-05-2020 7:15pm

Thanks all for your comments. I think I’ll try and lower the pole and remove all the old hardware as suggested. I have a red Group A aerial that I bought before and never used so will stick that up.

Mt Leinster is my suggested transmitter although it is 45 km away. I can get w good reception in the upstairs bedroom off a rabbit ears so hopefully the signal should be ok.

The Cush · 15-05-2020 8:12pm

Irreverent wrote: »

Mt Leinster is my suggested transmitter although it is 45 km away. I can get w good reception in the upstairs bedroom off a rabbit ears so hopefully the signal should be ok.

45km distance wouldn't be an issue for a powerful main transmitter like Mt Leinster.

Sudden loss of signal

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