[criageek]

Hi Mars - Now that I give it more thought I realize the design of my bucking transformer is pretty specialized for my needs and probably wouldn't work as-is for someone else.  That being said, if we can zero in on your requirements and parts to be used I can easily modify the design for your needs.  For the 3 prong power cord I could design in an opening for one of these:
   

As for ideas to keep the transformer from warming when idle, I could only think of two other ideas:

1)  Unplug the radio when not in use.
2)  Install a switch in the bucking transformer case and use it as the power switch for the radio.

I didn't like either of these ideas so I went the route of going through the radio's power switch.  But it would be easy enough to include a switch in the bucking transformer if you wanted to go that way.

I love doing this kind of thing so don't hesitate if you want me to get one designed and printed.  Here's one I built to use as a stand-alone unit.  Some radios don't have room for either a bucking transformer or a voltage dropping resistor, so I can plug them into this (there is an outlet on the back) when I want to play them.
   

Rich