Note: Dates refer to Zenith model years. Typically Zenith brought out new models by Thanksgiving to be available for the holiday sales. As such the 1935 line was announced and on sale in late 1934. This has confused a number of people about exactly when various models were introduced.

The years from 1930 to 1935 marked both the emergence of Zenith as a dominant force in the market and a revolution in the technology involved.

The thirties also marked an explosion in models and varients plus a bit of sanity in the numbering schemes that would reach fruition in 1936. Model numbers were specific to years and from 1934 on the chassis type (number of tubes) could be identified in the chassis number

For 1930, the big news was screen grid UX and UY tubes as model numbers counted off the fifties and sixties. Some confusion often occurs here because of Zenith's use of numberical suffixes to the model number for various power supply options. For instance a nine tube model 64 became a model 642 if equipped for 110v 25 cycle operation in the Notheast. Similarly a 563 was designed for direct current neighborhoods (often in inner cities).

The difference between the fifties and the sixties seems to be the loop antennas used in the latter as both were entering the tube-count-race with "double push-pull audio amplification". Manual automatic tuning similar to the pushbutton tuning in automotive radios was a selling point of the upper level models.

Chassis numbers from 1930-1934 all were in the 20xx series and were assined in order of development. During the four year period, less than 60 chassis number were assigned so it was adequate

The basic nine tube chassis was continued for 1931 in the 70 series with new electric remote control replacing the mechanical unit of the previous year for the model 74 only. The big news was a new, less expensive Zenette or Zeneth line of six tube chassis cathedral tabletops. To mark the difference, these were known as models A, B, C, a "richer appearing" D, L, M, and W. Spinet base was optional.Models often were suffixed with "H" which indicated the first use of Superhetrodyne circuits instead of TRF.

1932 marked a real change: Zeniths were now sold "complete with Zenith Quality Tubes" and all radios hadsuper-heterodyne circuits of ten tubes. The new line consisting of models 82, 822, 89, 892 (Hypermetrons) and 90, 91,& 92 (with automatic tuning) plus the continued (and still lettered ZENETTEs in superhet form only. There was also a 1932 model 103 "Ultra"

1933 marked an explosion of models and chassis that demonstrated to Zenith that they should never do that again.

Zenettes were no longer a separate line but were combined with the lesser models in tabletop and free-standing consoles represented by model numbers in the 200's. Experimentation was done in band selection with regualar broadcast being combined with Long Wave (-5 suffix to the model number as in 210-5) or short wave (to 18 Mc). Most were 7 tube chassis though a few like the 288 which claimed to be able to tune to 25 Mc had eight tube chassis.

The pitch for 1933 "All Star Line" was the new 7-prong "Cathode Type" tube that "so far can be had only in a Zenith radio".

Top of the line were the ten tubed chassis in the 400 series that featured variable tone control with visual volume and tone indicators plus Shadowgraph tuning, the forrunner of the yet to come tuning eyes.

For 1934, the "little7"news was the revision of chassis numbers to an ordered sequence of four digits indicating the number of tubes and the model line number. If there were less than ten tubes,the first digit would be a 5 and the second the tube count, if more than ten, then the first two were the tube count and the second two were the model line. Model numbers were assigned in sequence but by tube count so each year the count got higher.

In 1934, Zenith models were briefly called "Challengers" and model numbers skipped from the 400s to the 700s since the 500s and 600s had been used for the Interoceans though there may have been two models in the 600 seies (616 and 618).

Models with 5, 6 ,7, 8, & 9 tube chassis were available which is probably what prompted the change to sane chassis numbers.

Model numbers were in the 800 and 900s (and some carried over 700s) with chassis of 5, 6, 7, 10, and new 12 tube five band radios to exploit the shortwave craze in America during the mid thirties.

The big news (though not well received at the time due to its high price - $750 "...AND WORTH IT") was the model 1000Z/chassis 2501 Stratosphere with 25 tubes in two chassis (mostly 45's) and three speakers. Earliest units had markings on the dial to 60 Mc though later production scaled this back to a saner 40 Mc.

The first of the Big Black Dials that would be a Zenith mainstay until 1942, it was really a design of a passing generation, its 16 tube successors of 1936 were much better radios though not half as valuable today.

An interesting sidelight in Zenith advertising for 1935 was the reference to " ...twenty years makers of fine radios". This must refer to the first radios built by Mr. Mathews prior to enlisting in the Navy. The company's official historic brochure "The Zenith Story" - undated but evidently produced in late 1954 or early 1955 mentions 1915 as the year he began building radios.

This was used again in advertising over ten years later - a 1949 advertisment for the new G-500 TransOceanic mentions " Over thirty years of know-how in Radionics". 1919 is certainly supportable.

1935 also contained listings for several radios carrying 1100 series model numbers though little is known of these radios.