masterphon: Three Dial Set

 ASPECTS AND DIFFERENCES: 

 

Masterphone Model: Three Dial Set:

 

The first set of pictures uploaded by, Alan Larson, and the second set of pictures uploaded by, Bruce Morgenstern, show some very interesting and distinct differences in the chassis and wiring. There are also, some very interesting aspects in the radio that can also be observed.

 

 

TUBES:

 

This model has a set of Van Horne “Cushion X” tubes. All five tubes are named “VAN HORNE   CUSHION X” on the cushions. Two of the tubes are labled “Series 3” and three of the tubes have no labels and no markings.  One could reasonably conclude these tubes were installed at the manufacturing stage as there is a complete set in the radio. One could also be certain the tubes are 5VAX’s. Cushion tubes were developed and used as a way to alleviate “Microphonics”.

 

 

 

 

INTERSTAGE TRANSFORMERS:

 

The Hegehog interstage transformers have been moved to the underside of the chassis board, thus, the wiring had to be rearranged and other wiring was also rearranged for neatness, overall appearance and more than likely improved performance. There are no screw holes on the top of the wood chassis board to indicate that the Hegehog transformers were moved from the top to the bottom after manufacture. NOTE: One of the Hegehog transformers was replaced with Ritco. 

 

 

 

WIRING:

 

A quality, all in one, battery wire and cable loom was added. ---The wiring arrangement to the chassis battery terminals was also changed. The wires that went to the C- and C+ terminals were moved to the A- and A+ terminals and the C- and C+ terminals are jumpered. It is likely that this was done to accommodate the change to, Van Horne Cushion X tubes.

 

 

CHASSIS MANUFACTURER:

 

The Chassis Manufacturer of Set #199660, according to the picture showing the Manufacture’s label, was manufactured by “TRESCO Davenport, Iowa”, Tri-City Radio Electric Supply Co.”  and was pinned to the chassis. In mid 1925, Steinite acquired the remnants of the Tri-City Radio Electric Supply Co. “TRESCO” of Davenport, Iowa. Tri-City / Tresco models manufactured during this period were identified by with the Atchison, Kansas address. A label or manufacturer identification could not be found anywhere on this model that would indicate who manufactured it. Where the, TRESCO, label would have been there is also no indication that it has been removed. A reasonable assumption, could be made, that this model was manufactured by the Van Horne Tube Company, Franklin, OH.

 

RF COILS:

 

The manufacturing industry term for these coils are “Spider web or Diamond Weave coils” The indications are these coils were not manufactured by the, Chas Freshman Co. Inc, New York. Attached is an excerpt from an advertisement in the, Radio Digest Nov 1, 1924,  “Each and every Freshman Masterpiece Coil bears a serial number and trade mark-our guarantee of electrical and mechanical perfection”. A serial number or trade mark could not be found on these coils. It is possible these coils were manufactured   by either, F.W. Stickles Co.  Springfield, Mass. or Pfanstiehl Radio Company, Chicago Ill, as prominent companies, manufacturing this type of coil. 

 

 

SPEAKER:

 

This unit is operational and has decent sound using an Atwater Kent Model H horn speaker.

 

Bruce Morgenstern

 

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