Zenith Model Number Scheme

A Guide to Zenith Model Numbers

The Black Dial Era (1936-1949)

by Blake Deitze

This article appeared in the Winter 1996 issue of The Reproducer, the journal of The Vintage Radio & Phonograph Society, and is reprinted here with permission of Blake Deitze.

Two important points need to be covered for a better understanding of the model numbering scheme. First; the big round "airplaine" dial that was introduced by Zenith came prior to 1936. This article will deal with the "Big Black Dial" radios and the numbering scheme which was introduced in late 1935 for the 1936 model year. It is my belief that the year used to date a radio should track with the "model year" and not with the actual production date. I offer an analogy: An automobile may be produced in 1995, but will for ever more be referred to by "its" model year (1996). Second and equally important; Zenith included every vacuum tube in the tube count including: ballast, regulators, and cathode ray (magic eye) tubes.

Beginning in 1936, Zenith introduced a new model numbering scheme. Given the model number, a repairman could easily determine the number of tubes, the type of chassis, power requirements, model year, the type of cabinet, and ever where in the line-up the radio was found. Lets start by examining the left or leading side of the model number using a "Walton Radio" as an example (12S232).

The first digit(s) will be the number of tubes, 12 in this case, 11 on the chassis plus an "eye" tube. The number of tubes will be between 4 and 16 (the 25 tube Stratosphere, first produced in 1935 remained as the model 1000 throughout production).

The second segment of the model number revels the chassis type and the power requirements. Research indicated that there were 17 initial categories, each represented by a single letter. Many of the letter designations were used to describe Zenith's line of automobile radios, which I do not intend to discuss in this article. Listed below are the letter designations that were used to describe the Zenith home radios:

A - 110 volt AC, All Wave	M - Automobile (subcatagories inc: F, H, L, M, N, W, X)
B - 6 volt farm set	P - 110 volt AC, broadcast and police bands
D - AC/DC chassis, 110 volt	R - 110 volt AC, broadcast only
F - 2 volt farm set	S - 110 volt AC, broadcast police and shortwave
G - 110 volt AC/DC plus battery	T - 110 volt AC
H - 110 volt AC with FM	U - 110 volt AC, broadcast, shortwave and ultra- shortwave
J - 110 volt AC or 6 volt DC	V - 6 volt farm set with synchronous vibrator
K - Battery type farm or portable	X - 32 volt farm set
L - Standard broadcast plus shortwave

The last 3 digits get a bit more complex. The last two or three identify the cabinet type, and the relative placement in the line-up ($costs$). If the letter designation is followed by a two digit number (IE. 6V27), the radio was built for the 1936 model year. Some collectors will force a zero at the beginning, (IE. 6V027), this however is not correct and may lead to confusion later on. If the letter designation is followed by a three digit number the radio was built in later model years. If the leading number is 1 (IE 5S128) the radio was built for the 1937 model year. In our example of the 12S232, the radio was built for the 1938 model year. This scheme holds true for radios built through 1942, when Zenith halted civilian radio production to enter the war effort. Zenith did not produce radios for the general public again until late 1945, and were sold as 1946 models. An interesting side note, Zenith did continue to produce civilian hearing-aids throughout the war years.

The two trailing digits of the model number describe the cabinet and the relative placement in the cost line-up. The higher the last two digits within their range, the higher the position in that years model line, or more simply the higher the retail cost of the radio. As for the cabinet, the ranges for the cabinet styles are as follows:

00 - 30 indicates a table model

40 - 49 indicates a chairside model

50 - indicates a console model

In our example, the 12S232 would be a 12 tube table model built for 1938. The chassis would have 3 bands including broadcast, shortwave and police and was 110 volt AC powered. The collector would also note that the cabinet number falls very high in its range (00-39) indicating a rather expensive cabinet design.

Should you ever come across a Zenith radio which uses this model numbering system and it has a suffix letter after the model number itself, you have obtained an export model. The suffixes included: