Ach, is Planefinder now also blocking that for private a/c? That's frustrating.
I just have a cheap Mode-S receiver to pick-up whatever's broadcasting; since they issue their ICAO Mode-C identities it's straightforward for the software to determine the reg .
Ards is located in a 'basin' which restricts range in the northern hemisphere but reception to the south is good over the Lough.