The Turn Of The Century Electrotherapy Museum http://www.electrotherapymuseum.com Physician's Equipment Co Short Wave Diathermy Machine 27000 KC (27 MHz) (Many thanks to Jim and Graham for this machine) This power supply was... ...removed from this box to take these photos. Power transformer, tubes, caps, and coils... Main coil is Oscillator, side coils couple to this for surgical and pad outputs, vertical coils couple to this for inductance cable connections Bottom view.  Nice and simple! Side view. Front panel. "Spark Gap" :)