Stromberg-Carlson No. 29, 9-Tube Superheterodyne Receiver
Radio Service Data Sheet
May 1932 Radio-Craft

May 1932 Radio-Craft

May 1932 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.

Stromberg-Carlson No. 29a, 9-Tube Superheterodyne Receiver Radio Service Data Sheet, May 1932 Radio-Craft - RF CafeHere is another addition to the growing collection of radio service data sheets for vintage radio sets. Most people will have no need for them, but for the few who have one of these old sets and want to restore or service it, this information can mean the difference between owning a non-working conversation piece or a functional piece of America's history. This Radio Service Data Sheet for for the Stromberg-Carlson No. 29, 9-tube superheterodyne receiver appeared in a 1932 issue of Hugo Gernsback's Radio-Craft magazine. Note that its name derives from "number of its design feature." All 29 are delineated, including Optosynchronic (Visual) Tuning, and a Mono-vision Dial and Tuning Meter. The photo thumbnails are just two of many for a very fine example of a Stromberg-Carlson No. 29a claiming to be in its original finish, with no rework having been performed on the cabinet or electronics.

A full list of all radio service data sheets is at the bottom of the page. See also Tom Bavis' website for an extensive collection of Stromberg-Carlson photos, datasheets and Sam's Photofacts files.

Stromberg-Carlson No. 29, 9-Tube Superheterodyne Receiver

 - RF Cafe

What is probably the first receiver to derive its designation from the number of its design features is the "29" receiver of Stromberg-Carlson Telephone Manufacturing Co., Rochester, N. Y. These features, as furnished by the factory, are listed below (where their position in the circuit is not evident from the wording, a more detailed description of the nomenclature is given) :

1. Optosynchronic (Visual) Tuning, with sensitive meter for accurate setting of the station-selector dial;

2. Mono-vision Dial and Tuning Meter, for quick, accurate tuning;

3. Large Baffle Area Cabinet, for full, smooth range of musical and voice tones;

4. Manual Volume-Control, for pre-setting to desired audio volume and for increasing sensitivity on extreme distance;

5. Level-Action Automatic Volume-Control, to maintain the predetermined volume over an extremely wide range of signal strength;

6. Detectomatic (Duo-Diode) Detector, for most efficient demodulation action;

7. Adjustable Automatic Clarifier, to allow hand adjustment of high- frequency reproduction to meet receiving conditions: (R15-C27);

8. Antenna Aligner, for obtaining maximum results with any particular size of an antenna;

9. Image Suppressor, for giving a very high discrimination (over 100,000 to 1) against "cross-talk"; C1-C2-C3, L1-L2-L3

10. Isolated Oscillator Tube and Circuit, for correct control' of sensitivity;

11. Bi-Resonator Radio-Frequency Tuning System, for better selectivity; C1-C2, L1-L2;

12. Tri-Resonator Intermediate Amplifier, providing high selectivity;

13. Triplex Audio System, employing screen-grid first audio, and push-pull outut;



Posted April 14, 2023
(updated from original post on 5/18/2016)

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.