Do you know any amateur radio enthusiasts in your area? This is a known issue with HAM radio (in the 2-30MHz bands). Its also suspected of being a problem with ADSL.
If you don't know any HAMs, there is probably a club near you.. contact them for advice on EMC (they will understand). BUT, be careful... ..
Cure? Its complicated....
Firstly, fit RF chokes on the TV power lead, and quite possibly the RF/sat lead. A choke need be as simple as an iron 'ring' which you can wind the mains cable around (obviously need to remove the plug then refit it, depending on the power lead interface). OR, you might be able to find a snap-on choke- it looks like a rectangular which opens lengthways, you put the cable in and fold the open half over.
If this doesn't make any difference, then it is the TV itself which is radiating, and you need to contact the manufacturer. NOT the retailer, but the manufacturer. And OFCOM. The manufacturuer, as it is there responsibility to ensure that their equipment meets EU EMC/EMR regulations (CISPR22, and EN55022:2006). OFCOM, to raise awareness of the EMC issue (but make it plain that you do not want them to investigate - that costs £50 unless you know 'how' to get it done for free!).
The caveat about HAMS: This is NOT mean to be disrespectful in anyway, but some HAMS have a real bee about plasma (the Mar 2011 issue of RADCOM has the 'results' of a survey on Plasma interference on ham radio) - many believe that plasma TV should be withdrawn from the market, and applaud manufacturers who instead of fixing the problem replace the set with an inferior LCD/LED model
. Drop me a PM if needed and I'll get a copy to you. The 'conclusions' are interesting...
Out of interest, what model Panny is it? I have the P42G20B, and have suffered no issues.
More than happy to help you work this out - DONT BIN THE PLASMA!
The views expressed here are mine alone, and do NOT reflect those of my employer, present or previous.