[Ron Ramirez]

Wow, TWO 39-55 sets? Lucky you! Congratulations on your acquisition.

The radio will operate without the four tubes used in the Mystery Control section of the set. However, keep in mind that you will need to replace the motor run capacitor (59), because the off-on-volume control is operated by a motor - whether you use the Mystery Control remote or not. Also replace electrolytic (66) in the stepper circuit. In fact, you should go ahead and replace all of the paper and electrolytic capacitors, including those in the Mystery Control section, as well as any off-tolerance resistors; even if you do not plan on using the Mystery Control right away. This way, you won't have to go back into the set later on.

Cap (59) is shown as a conventional electrolytic on the schematic. It isn't! It should be replaced with a non-polarized unit rated at 30 volts or better. You might find an ideal replacement, a new motor run capacitor, at a motor rewinding shop.

Two tube vendors worthy of your consideration:

http://www.findatube.com/
http://www.vacuumtubesinc.com/

Both offer used as well as new tubes, and they stand behind what they sell.