I have been building a small (but growing) off-grid solar power system for my home as a bit of an experiment. Part technology geekery, part environmentalist, and part prepper, it has been going well. More details on the system later. One of my first goals was to make sure that our DirecTV system would function without mains power and the first part of that is the dc power required by the dish to operate. If you have DirecTV (I would guess that most other DBS systems are similar) then you probably have one of these that the installer wedged behind your media center out of site.
It provides 21V DC power to the dish. The label:
Not wanting to take the TV service down for the whole house while I experimented, I ordered one off Ebay for less than ten bucks. Inside, it really couldn’t be simpler, just a power supply and a magical little Coax component.
The power supply looks quite decent. And all it does is provide 21V to the magical part.
With the coax power inserter in hand, I hooked up the 12V DC feed from my solar system to one of these:
A simple DC to DC step up voltage converter I picked up somewhere along the way. This unit has a hefty heat sink on it and is way bigger than needed for this application, but would prove out the solution. And sure enough, it worked like a champ. I ended up ordering one of these:
Which is more appropriate to the demands of the load. It was $12 on Amazon and provides plenty of current for this application. AND it fits in the original, installer-provided power supply case with the magical coax bit.
I attached it to the bottom of the case with a piece of adhesive velcro and sealed it back up. Other than my lack of cable tension relief (I do need to fix that at some point) you can barely tell that this no longer runs off AC. After several weeks in service it is still working well.