General Electric K−40A Radio Service Data Sheet
July 1933 Radio-Craft

July 1933 Radio-Craft

July 1933 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.

General Electric K-40 Tabletop Radio - RF Cafe

General Electric K-40A Radio (RadioMuseum)

Here is the Radio Service Data Sheet for the General Electric Model K−40-A tabletop radio, as featured in a 1933 edition of Radio-Craft magazine. When posting vintage documentation, I attempt to find photos of an actual radio. My first stop is eBay, since often some of the best detailed images of the outside and inside show up there. Next are RadioMuseum and RadioAttic. Some models are popular restoration projects and others even extensive searching turns up nothing at all - not even a drawing or an old advertisement. Notice how even the less sophisticated vintage radios like this General Electric K−40 usually have nicely crafted wooden cases. As mentioned many times in the past, I post these online for the benefit of hobbyists looking for information to assist in repairing or restoring vintage communication equipment.

General Electric K-40A Radio Service Data Sheet

General Electric K-40A Radio Service Data Sheet, July 1933 Radio-Craft - RF CafeGeneral Electric K-40A Radio Service Data Sheet Instructions, July 1933 Radio-Craft - RF Cafe*Impossible to measure on ordinary voltmeter; on 25 cycles the voltages will be lower than those on 60 cycles. Voltages are measured to cathode. These figures are for set adjusted to maximum volume; line potential, 115 V., 60 cycles A.C., or D.C.

Note the use of a voltage doubling connection of rectifier V4; on A.C. the power output is greatly increased. Undistorted power output on A.C., 0.55-W.; on D.C., 0.15-W. Power consumption, 50 W, at 115 V, A.C. Since the frequency range is 540 to 1,710 kc., it is possible to receive police broadcasts on wavelengths below 200 meters.

Check power line characteristics and the position of Sw. 2 before connecting the set to the power line; disconnect the set before touching the chassis.



Posted July 31, 2023
(updated from original post on 12/11/2015)

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.