Disturbing that nowhere in the manual does it give the polarity of the power supply. Looking at the schematic, it has both major electrolytics with their negative sides to ground -- that's the only clue. The large-area sections of foil on the PCB are ground, the P/S jack's housing is soldered to ground, so jpdylon's assertion that the jack's center is positive is correct.
I went to Radio Shack, another $20 added to the price tag of the transmitter for this:
http://www.radioshack.com/product/in...ductId=2049714 . I snipped the end off of it and soldered the bare wires directly to the PCB, bypassing the plug. No confusion for later.
As jpdylon alluded to, I'm having a helluva time getting the thing tuned. Four separate adjustments that all interact with each other, sort of like trying to crack a 4-digit combination safe. Hopefully there's a combination that works, and hopefully it can be found!