This video may help others (like me) who find themselves in posession of a 7800 but don't have that pesky power supply: http://www.youtube.com/watch?v=41e8Kr-bBpM
I'd much rather wire up a barrel-style connector so you don't have a boat anchor hanging off your 7800.
Yeah that was the original plan but I ripped a leg off the donor jack removing it from the board. This rig will do for now.