I recently bought a Freecom USB DVB Digital Freview TV tuner stick.
It seems to pick up all the channels in the scan but I can only get Sky news, sky three, uk tv history, sky sports news and sometimes E4 to tune in properly--(and after a while they sometimes lose signal) and all the other channels are either VERY JUMPY (i believe this is a lack of signal, as the green light (on stick) either flashes or is just orange) or no signal at all (black screen, orange light on stick).
I'm using the large aerial on my house (not the crappy stubby aerial that came with it which couldn't even pick up channels in the scan), and I'm in a pretty much normal area which has no problems with signals.
Do you think this the stick is faulty? I know a few people who have one and have many signal problems with it.