OT: Power connection question

[Ry]

So I found an old tube 1/4" reel-to-reel in a thrift store.  It looks to be in wonderful condition with an old, weak microphone included.  It's a 3M Revere with an internal speaker and a preamp out jack.  The only problem is that it didn't come with a power cord and the jack is non-standard.  I'm looking for some help in determining how to wire power to it.  I can't seem to get into the machine to trace out the connections between the power transformer and jack.  It has a three prong power jack, the left most and middle prongs show continuity on my meter.  The right prong is isolated from the other two.  Am I safe just connecting one of the left two jacks to one side of an AC supply (white, for instance), and the right most to the other (black)?

Sorry if this seems obvious, I'm always really nervous about this sort of thing.

[Ry]

I got ansy and wired it up as I described.  It sounds like a wet fart.  Oh well, for ten bucks, I now have a big power transformer (claimed to be 100W, but I seriously doubt it) and a handful of tubes to play with