got freeview only and the main tv has always had a poor reception. perfect picture then becomes blocky at around 7-10 pm every night. its a year old and a decent telly.
my old 32" upstairs works perfectly every time all the time.
all tv aerials are plugged into the wall so they use the same cables to the main aerial. baffled.com
Probably a weak signal or interference. One aerial, just using a basic splitter to send it to the two tvās? In which case youāre halving the signal strength. Could try an aerial distribution box/amplifier. Essentially a box that aerial goes into, then it duplicates the signal on a number of outputs with no loss of signal strength. But do remember, if the signal from your aerial is weak to begin with, no amount of amplification is going to help much, youāre just amplifying a poor signal and all itās noise. Better to try a higher gain aerial or preferably raise your aerial higher (oooh-err!).
Could be interference or multiple signal paths. As the sun goes down the air waves can get flooded with many signals from further afield. Possibly a transmission from another transmitter making it to you; putting you in an interference dip. Maybe the one TV is just better at separating out the signals, got a better, finer grained receiver circuit. Could be some local interference; traffic and so forth. Multiple signal paths can be tackled with a directional aerial, carefully pointed at the nearest transmitter to you. Local interference can be tackled with decent copper foil screened aerial cable (avoid that crap brown braided cable), run from aerial to tv(s).
Yes, because interference from a Radio Ham is the most likely culprit, right? Targeted at the downstairs TV only, of course, perhaps a directional Yagi antenna pointed directly at the main TV only? Muppet. FYI, radio hams get to know an awful lot about RFI, and are very unlikely to be the cause of it.
What Arfa wrote is exactly the right approach. Jaime, if you donāt get it fixed, let me know and Iāll pop over with an antenna analyser and some other bits and take a look.