Bosch Models 60 and 61 Radio Service Data Sheet
August 1931 Radio-Craft

August 1931 Radio-Craft

August 1931 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.

This Radio Service Data Sheet for the Bosch Models 60 and 61 was published in the August 1931 issue of Radio-Craft magazine. Features like automatic volume control (AVC) were considered deluxe niceties available to the consumer willing to pay extra for it. I could not find a photo of the Bosch Model 60 or Model 61.

Bosch Models 60 and 61

The Bosch Model 60 receiver incorporates an automatic volume-control tube, V8; a "mute switch" SW4 (which should be closed, during the operation of tuning, to short the voice coil of the dynamic reproducer; thus eliminating the sounds incidental to tuning in programs, the automatic volume control's panel-meter being the resonance indicator) and connections for a phonograph .pickup, The pickup circuit is conĀ­trolled by an automatic switch, SW2, which, in the tuning dial's "0" position is designed to replace a 1,000-ohm resistor and its bypass condenser by a pick-up of approximately 1,000 ohms, At the same time, a ground spring makes contact with condenser C4; shorting it out of circuit and eliminating the need to deĀ­ tune the R.F. portion of the receiver.

Bosch Models 60 and 61 Radio Service Data Sheet, August 1931 Radio-Craft - RF Cafe

The trimmer condensers are located on the condenser gang. The antenna coupling condenser C1A is adjusted from the side of the chassis, when the set is installed, in the following manner: tune in a somewhat weak station at some point between 40 and 60 on the dial; reduce the volume until the station can be barely be heard; and then turn the adjustment knob of C1A until the signal is received with maximum volume.

 

 

Posted October 5, 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 219 Radio Service Data Sheets as of November 15, 2017.