ZENITH in 1933

This page is about 1933 Zenith radios

This page is preliminary and the links are not working yet. In time I will be adding content to the links. Thanks for reading!

1932-33 was an interesting time for the Zenith radio Corp.
Franklin D. Roosevelt was elected President of the United States and the country was in the very depths of the Great Depression.
Even though things were grim for most companies and people, Zenith managed to pay off all bank loans and had a surplus of over $600,000! This was quite impressive considering the economy was so bad.

The company had introduced a line of small, cheaper models under the name "Zenette" which helped greatly. But, they were trying to figure out what worked and what didn't in those hard times. So, there was a flurry of experimentation due to the abundant cash reserve.

The sheer number of 1933 models is impressive! The model numbers fall into the 200, 400, 500 and 600 range. There are about 125 or so models listed in various publications all in the 1933 line. Considering the previous year had around 25 total, this is quite the explosion!

The main 1933 "All Star" line up was made up of 14 models in the 200 and 400 model range. The 500 and 600 range as well as some 200 and 400 models were not advertised. In fact, Zenith tried selling radios under the name "Interocean Radio Corp" which sometimes had the name "Sky Rover" on the front.

Zenith also tried selling some radios to other retail stores such as Sears Roebuck, Gambles (Gamble Skogmo) and others such as B.F. Goodrich Tire retailers which sported the particular company's own brand name (Silvertone, Coronado and Mantola respectively).

many of the 1933 models would appear to be "one off" or maybe only a few produced. I'm speculating here, but from what I have seen, Zenith was known for inserting a newer model chassis into an older model cabinet. They probably had several extra cabinets left over from previous model years and attempted to use the excess stock up. Others were certainly produced in numbers as they do show up from time to time.

This time period of Zenith and the radios produced rather fascinates me. These models are amongst my absolute favorite radios Zenith made!

On this page, I will showcase the 1933 models I have found and also provide info on some speculations. After all, hard documentation is very limited on this line of models and they are often hard to pin down.

Advertisements in Radio Retailing of the 1933 Zenith radios

The first ad appeared in the July 1932 issue of Radio Retailing. It only hinted about the 1933 models touting their virtues.



Unfortunately, I don't have the August issue available to me to know what it had for Zenith. September had a 2 page ad anouncing the use of the type 59 output tube in all Zenith radios.



The 59 is a unique 3 grid power output tube that can be wired in three ways.
First of all, it can be wired as a Class A triode by tying the last two grids to the plate.
Second, it can be wired as a zero-bias Class B triode by tying the first two grids together with the third to the plate. Lastly, it can be wired as a Class A Pentode in the conventional form by tying the 3rd grid to the cathode.

In most models, Zenith wired the 59 as a Class A triode. A few used it as a Class A Pentode. Zenith did not use them in Class B.

The ad mentions a Class "AAA" circuit. I have discovered that this is a rather obscure class of operation which is now called Class A2

Class A2 output stage is biased pretty much the same as Class A, but in order to achieve a higher output power, the stage is overdriven causing the control grids to go positive.
Normally this would cause distortion, BUT, the higher power 59 Driver stage can provide enough power to the positive going grids to effectively avoid distortion.

There is an article in the February 1933 issue of Radio Craft magazine which describes the Class AAA audio amplifier

The article can be found here on RF Cafe


The September 1932 issue also announced Zenith's new 1933 line in the "New Merchandise" section as seen here.



The ad in the October issue was different as well as being on the front cover of the magazine.
A "Challenge" which I really wonder how well Zenith would have fared in that?



The October issue also had the Specification listing of most 1932-33 radios on the market at that time. It shows the 14 main Zenith models for the 1933 line.



November's ad explained the multi-windowed dial escutcheon and controls.



December's ad explained the extended coverage Zenith added to their radios due to the fact the FRC (FCC) was considering extending the band.
The band was extended to 1600 KC in the mid 1930s, but didn't get extended to 1700 until 1993.



January, Zenith advertised the Automatic Tuning feature found on a few of the 1933 models such as the 245, 420 and 440.
Interestingly, the 245 was the lowest priced model Zenith ever sold with this feature. Also, the 1933 line was the last Zenith used mechanical automatic tuning. The feature was discontinued on the 1934 line and automatic pushbutton tuning had to wait until the 1939 line.



There were no further advertisements in Radio Retailing for the 1933 Zeniths. Although, April 1933 contains an ad for the model 460 Automobile radio.
June 1933 introduces the 1933-34 models 705, 706 and 750.


Thank you for reading!

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