I replaced my ageing Miglia TV Mini/Eye TV 3.6.9 with a new EyeTV Hybrid/EyeTV 4, both running on a 64 bit iMac/ Catalina 10.15.2 and connected to a TV aerial amplifier. I am in the UK.
Previously, I had no trouble with reception, although I was having a problem with scheduled recordings ending prematurely. With the new setup, TV reception is appalling on most channels - slow to start up, picture jumps forward and breaks up, audio likewise. The exceptions are the BBC HD channels, which come through perfectly. What is going on?