Last week we heard from an experienced technician who proposed that there are two or more issues causing reboots. I agree. My set is a single issue apparently, has had reboots but never a freeze and does not care about the quality of the station's signal. It will attempt to tune in stations with zero signal strength and not reboot or cause any problem. I could not discern a pattern of any kind to reboots except that most occurred in the morning hours.
My set has not rebooted in four days, a record. It is operating, I dare say, perfectly. The only change which took the DVR from reboot death spiral to faultless operation was marrying it to the television by plugging both into the same receptacle which is not controlled by a wall switch. To repeat, the DVR and television are now plugged into the same three port adapter which in turn is plugged into a single receptacle. This strongly indicates that rf noise was the source of the original problem. The noise might be coming from the antenna amplifier or some other source, I don't know and may never know. Somehow, the television is protecting the DVR from this problem, maybe through a common mode effect or some other mechanism which is grounding out the problem noise. I know this is wild guesswork but one thing is clear, changing the location of the power plug made an immediate and possibly lasting effect to the good.
The poster who suggested that a ferrite be experimentally applied to the coax is thinking along the same lines as me. I will be looking at doing some of these things as soon as the chokes are received. As it stands now I don't need to but that is not what it is about.