Brunswick Model 31 Combination Radio and Panatrope
Radio Service Data Sheet
February 1930 Radio-Craft

February 1930 Radio-Craft

February 1930 Radio Craft Cover - RF Cafe[Table of Contents]

Wax nostalgic about and learn from the history of early electronics. See articles from Radio-Craft, published 1929 - 1953. All copyrights are hereby acknowledged.

Brunswick Model 31 Combination Radio and Panatrope advertisement in "Talking Machine" magazine - RF Cafe

Brunswick Model 31 Combination Radio and Panatrope advertisement in "The Talking Machine World" magazine.

The Brunswick Model 31 Combination Radio Panatrope was billed as the world's first all-electric phonograph (as opposed to the mechanical crank-up models), combined with an AM radio. It was designed with the assistance of RCA, many of whose components were integrated into the unit. A video of a restored Panatrope is embedded on the page below the data sheet. I couldn't find an official etymology for "panatrope," but the prefix "pan" means "all-inclusive," and "trope" means "turning," like the turning of a phrase. However, given that the Panatrope is a "turn"table, perhaps that was an intentional distortion of the meaning to fit the device which it named, ergo, a record player that had all available functions. That's my best shot at it. This Radio Service Data Sheet for the Brunswick Model 31 Combination Radio and Panatrope appeared in the February 1930 issue of Radio-Craft magazine. It includes schematics and very detailed alignment instructions. A video of one in operation is embedded below. 

Brunswick Model 31 Combination Radio and Panatrope Radio Service Data Sheet

Brunswick Model 31 Combination Radio and Panatrope Radio Service Data Sheet, February 1930 Radio-Craft - RF Cafe

In this receiver a radio-record switch, Sw2, cable and input transformer, T4, are used, in order that the low-impedance of the pick-up may be matched with the relatively high input impedance existing in the primary of T1.

Referring to the parts layout sketch, units TC1, TC2, TC3 and TC4 are trimmer condensers in shunt to the tuning condensers but not shown in the schematic circuit. This receiver is in three sections: The R.F. chassis, the "SPU" (socket-power-unit) chassis and the dynamic reproducer. Field current for the latter is supplied by the SPU. Note that operation of the receiver should not be attempted unless either the field coil of a dynamic or a 600-ohm resistor is connected across the terminals for the two "field" leads; this resistor must be capable of carrying 100 ma.

To facilitate service, the RF. chassis and SPU chassis are bolted to a single mounting board which, in turn, may be removed from the cabinet by removing retaining bolts at the rear of the mounting board which, in turn, may be removed from the cabinet by removing retaining bolts at the rear of the mounting board.

For hum, two filament shunt resistors, R9, R10, with variable center taps, are provided on the SPU chassis. R9 is adjusted first and then R10. If R10 appears unresponsive, try other '27s at V4 and V5. Abnormal hum may be due to one or more of the following causes...

Restored Brunswick Panatrope

 

 

Posted October 27, 2023
(updated from original post on 6/9/2016)


Radio Service Data Sheets

These schematics, tuning instructions, and other data are reproduced from my collection of vintage radio and electronics magazines. As back in the era, similar schematic and service info was available for purchase from sources such as SAMS Photofacts, but these printings were a no-cost bonus for readers. There are 227 Radio Service Data Sheets as of December 28, 2020.