said by IowaCowboy:
Another question I have is if I cut power to the DTA for an extended period of time (when set is not in use as TV will only be occasionally used, such as during severe weather warnings which have been increasingly common around here including a tornado last year that tore through the southern half of the city last year), will the DTA lose its provisioning and have to be reactivated. I am thinking of plugging it into a power strip along with the TV and powering it on when the TV is going to be used (want to cut phantom loads as our electric rates in this part of the country is through the roof).
One of the DTAs that I have is connected to a portable TV and will frequently have its coax RF input and power disconnected for some period of time. I find if it has been only a week or two, then it will usually start working again by itself as soon as it is reconnected. It only seems to need reactivation if it's left disconnected for an extended period of time, maybe a month or more. Then I just call the number that is displayed on the TV to reactivate it.
This post I found from May 2011, says that the DTAs have a 720 hour (30-day) countdown timer, reset by a daily authorization "keep-alive" signal, that determines when it gets deactivated: »Re: When & how often does comcast update the dta?