Today, I headed to Sligo with someone, so for my own curiosity I took my TV-top aerial and checked the signal throughout most of the journey using a handheld meter (info here) to see what areas pick up the best reception. When I connected the attic aerial directly to the meter, no LEDs lit apart from the power LED, so it seems like that as long as a single LED lights, there is decent DVB-T reception, especially since there’s a large difference between the gain of a TV-top aerial with no amplifier and a full size aerial with amplifier.
When we drove past our local TV booster mast, the meter showed up a single LED when I pointed the aerial towards it, so some of the following results may not be accurate if the meter was detecting a strong analogue channel from a local booster mast in the area.
Kilcar - While travelling on the road passing the town, I got a single LED when pointing the aerial at the bay. So anyone with a view of the bay or even the hills of Sligo should have good DVB-T reception.
After leaving Kilcar where the two roads merge, no LEDs lit until I started seeing the bay again. I got peak reception while passing the Blue Haven (2 to 3 LEDs). Quite surprisingly, I have also been able to pick up DAB radio in the Blue Haven car park on both the BBC and commercial muxes when I carried out a previous test with a portable DAB radio. However, as I don’t have a portable DVB-T receiver at this time, I am unable to determine whether Freeview reception from the north is possible there or anywhere else along the coast.
Killybegs - Throughout the town, I got 1 to 2 LEDs. After leaving Killybegs all LEDs went out once I could no longer see the bay and there were only a few spots where a single LED lit. One LED lit while going down the Mountcharles bypass and remained lit until the climb prior to the Texaco filling station.
Donegal - After the roundabout entering the bypass, 1 LED lit once we started passing the first houses on the right. This remained lit all the way to the next roundabout and then disappeared after the roundabout. From here to the Ballyshannon bypass, 1 LED lit up intermittently except in valleys.
Bundoran - We took the bypass heading to Sligo and went through the town on the way back. On the bypass, 1 to 2 LEDs remained lit on the meter. While travelling through the town, 1 LED remained lit through most of the town, so it looks like anyone there may be able to get reception with just a TV-top aerial almost anywhere in the house.
Cliffony - Only 1 LED was lit before entering the town, went out throughout it and lit up again while leaving the town.
Grange - Like Cliffony, no signal LEDs lit throughout the town. The first LED lit while midway up the climb leaving the town on the Sligo side.
Drumcliff - 1 LED intermittently lit throughout the town.
Rathcormack - 1 LED lit throughout the town, increasing to 2 leaving on the Sligo side.
Sligo - 1 to 2 LEDs while taking the main road through Sligo until we reached the roundabout that leaves for Galway. 2 to 3 bars at the borders of the town.
Assuming the signal LEDs all meant DVB-T reception above, it looks like that anyone living between Donegal and Sligo that is not in a deep valley should have no problem picking up DVB-T. As I mentioned earlier, a good test is to see what UHF channels 60 & 63 are like (which broadcast from Truskmore), since if these two channels come in fine, this gives a very good chance of getting DVB-T.