Maybe you can have your buddy bring over his receiver, like you said, or if he doesn't want to do that, bring yours to his home, and see if you see any difference, if his works great at your home (or yours works crappy at his home), then you know it's the receiver, if his has the same issues hooked up to your wiring (or yours is perfect at his home), then you know it's in the wiring, the buildings around you, or some other non-receiver factor. If you try yours at his home, and it works great, try and see if he has any attenuators etc in the ota line, maybe he has one and didn't think of mentioning it, also make note of how many splits are off of it (if any) and the approx length compared to your setup, if you have any splitters (or diplexors if applicable) for your OTA, that too can cause many issues, if they are defective or cheapos.