Mellow Magic Radio

Mellow Magic Regenerative Radio by Tom Kipgen, front view

A new entry into my approach now includes the tube being enclosed within the cabinet. With a magic eye tube such as the EM83 it was necessary to provide a viewing port for this classy little tube. Otherwise the twin green beacons would not be able to signal the user of signal strength (left side) or of modulation (right side). The viewing port for this one follows the outline of these screens and adds a good deal to the aesthetics of the front panel. A brand new cabinet design was developed that hints at some of the more popular styles of the 1920’s and 30’s particularly the cathedral influences of the time. The hole patterned speaker grill was replaced with an open style frame that matches the cabinet type much better.

Several adaptations in component placements had to be completed before everything could successfully be mounted in this surprisingly restricted space such as the amplifier volume potentiometer being dismounted from the amp and reconnected with 4” leads. Modifications in the framework of the cabinet itself also had to be done in several areas for the same reasons. It seems no matter how much planning and drawing is done there are always issues that arise when physical assembly is attempted and these have to be addressed and solved.

The schematic used for the set is the same as I have used in almost all of these EM83 radios and has proven to give excellent results. A standard 365 variable capacitor that actually measured 510pF was matched with a 150uH coil for the tank. The coil was wound on a torroid form from Amidon corp using 175/46 litz wire and the antenna was coupled to the tuning capacitor with a trimmer capacitor set at 40pF. I have experimented extensively with this capacitance value and it has always proven best at the 40pF setting for these particular radios.

An excellent mahogany was selected for use in the cabinet and it was carefully steamed and bent to shape before mounting on its framework. After all parts were mated and sanded down to 320 grit, a red mahogany stain that I mixe here was applied and left to dry. It was all then sealed and finished with nitro cellulose lacquer that I flatted here in my shop.

Mellow Magic Regenerative Radio by Tom Kipgen, side view
Mellow Magic Regenerative Radio by Tom Kipgen, closeup view