TV picture breakup or sudden shrinkage when an AC compressor kicks in is a symptom of sudden severe voltage drop. It is not RFI related. Hevac1's suggestion is good, although I think some assumptions are being made in this thread. What size is the air conditioner ? What is the condition of the household electrical service ? A small window air conditioner on the same 120V leg, with old, inadequate wiring can create similar symptoms.
