mast mount preamp needs power hmmmm?

[newhallone]

I was given a Winegard 8700 preamp but not the power supply. Their website has one for 16 bucks but I figure I have enough junkbox stuff to make one. The specs are 15V DC.
I have an archer supply that puts out 14V ac. I have lots of trannys around I could use. I could make a full wave rectifier. I'm just not sure what to use for filtering and a blocking cap on the tv side. Any ideas?