Stewart-Warner Model 03-5A1 to 03-5A9 (Chassis 03-5A) Senior Varsity Radio Service Data Sheet
November 1939 Radio-Craft

November 1939 Radio-Craft [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.

I have been scanning and posting Radio Service Data Sheets like this one featuring the Stewart-Warner Model 03-5A Senior Varsity Radio receiver for many years now. There are still many people who restore and service these vintage radios, and often it can be difficult or impossible to find schematics and/or tuning information. The thumbnail image of the Stewart-Warner Model 03-5A Senior Varsity Radio came from the RadioAttic.com website.

Stewart-Warner Model 03-5A1 to 03-5A9 (Chassis 03-5A) Senior Varsity Radio Service Data Sheet

Alignment Procedure

An output meter and an accurately calibrated signal generator are required.

(1) Connect the output meter across the voice coil; or, using a con­denser in series, connect between the plate of the 35L6GT output tube and "B-" as shown on the voltage chart. The more sensitive type should be connected across the voice coil.

(2) Connect the ground lead of the signal generator to the "B-" lug (shown on the voltage diagram) through a 0.25-mf. condenser and keep it connected in this manner throughout the entire alignment procedure. Failure to do this may have serious results, as one side of the power line may be grounded in the signal generator, or bum may be encountered.

(3) Turn the volume control to the maximum volume position and leave it in this position throughout the entire alignment pro­cedure.

(4) To Calibrate the Dial - Remove the chassis from the cabinet and set it on a fiat surface (insulated from ground). With the gang in full mesh, the last dial division (just below 55) on the low-frequency end, should be exactly 4% inches above the table surface. If this is not the case, release the set­screw in the collar which connects the gang condenser shaft with the tuning unit, and holding the gang in full mesh, turn the dial until the last division is exactly 4% inches above the table surface. Now re-tighten the setscrew in the collar. The 4% inch division on the ruler (when measured vertically from table

Posted April 12, 2017