Jack antenna has (often) two power sources.
THere is a wall plate somewhere. this draws house power likely off one of the house fuses in the house fuse box.. It may have a fuse internal to itself as well. This is the same as the famous Winegard Wall plate.. 12 volt outlet, light, switch and antenna connection.
THe SURE LOCK device may well work off a wall wart type power supply (120vac) I do not knwo if it can draw off the 12 volt as an option.. ONly one I looked at had a wall wart.. And the blasted source switch/wall plate was Hidden by the wall wart. Pure luck I found it. That I recalled where it was when someone else was working for it was not luck,, You see most Non-pro technicians work for BEER, I work for Coffee, it enhances memory