My mom and my grandpa both get their local channels over the air because their market is not available via DirecTV. Both their TVs only have a single coax input, so now that I hooked their Magnavox digital to analog converter up, the over the air channels look great, but the DirecTV signal is now fuzzy. I assume the box must be interfering. I tried setting the box to use channel 4, but that didn't help. I also saw the RF passthrough option in setup, but I figured that there is no way they would remember to go in there every time they wanted to switch between the antenna and directv. My only solution I could think of is to put in an A/B switch and separate out the over the air antenna signal from the directv signal. Of course, buying a newer tv that at least has composite AV jacks would work too, but neither of them are looking for a new tv right now.