In 1957 Zenith Transistor Radios Are Prolific

1957 was a banner year for Zenith. They introduced a number of new and well performing radios including the first all-transistor Transoceanic portable radio which was labeled the Royal 1000. The Royal 500 received several upgrades for 1957. First, the new radios were no longer "hand-wired" but were built using printed circuits. Second, a vernier tuning system was added in response to the tuning criticisms of 1956. Also, circuit redesigns were incorporated to improve the overall performance of the radio. In 1957, Zenith introduced the new additional colors of white, pink, and beige. Several times a year, a pink one will show up on Ebay and command a premium price because of its rarity. The 1957 Royal 500 continued to sell for $75.00.

I have only one of the 1957 Royal 500 7 transistor radios. It is the maroon color and has the chassis designation 7ZT40.

The next 1957 radio in my collection is one Zenith's most outstanding performers. It is the Zenith Royal 750. This series of radios are commonly referred to as "lunch box" radios since they have a carrying handle and are close to the size and weight of a lunch box. The Royal 750 carries the chassis designation of 8AT41. The radio is an 8 transistor unit that has a tuned RF amplifier section for greater sensitivity. The radio uses 6 standard "C" cells for power. The radio has a nice 4" speaker rated at 275 milliwatts of undistorted audio power. The radio sold though dealers for $79.95.

Here is a top and front view of my Royal 750. It plays just like new. These radios will play 2-3 years with a new set of Duracells.


In 1957, Zenith introduced the Royal 300. This radio is considered by some to be the most stylish handheld portable Zenith manufactured. The Royal 300 features a large thumbwheel tuning knob on the right side of the radio rather that the vernier tuning found on most other Zenith models.Here are the three Royal 300's in my collection. Ebony, maroon and pine forest green were the main three colors of this model. There were a very limited number of Royal 300's produced with a white cabinet. These are very rare. I have never seen one up for sale. An interesting feature of this radio's cabinet are 3 small feet on the back to prevent the back from becoming scratched. This radio has 7 transistors. It is basically the same chassis as the 7 transistor Royal 500. There were two chassis designations— the 7AT42 and the 7AT42Z1. There are significant differences between the two. The 7AT42Z1 employs a negative ground whereas the 7AT42 employs a positive ground. Both of the models use a mixture of PNP and NPN transistor types. This radio is a sensitive pleasant sounding set. This radio sold originally for $59.95.

I have Royal 300 radios in the three basic cabinet colors.

Probably the biggest and most exciting 1957 radio introduction by Zenith was the Royal 1000 Trans-Oceanic multi-band portable. John H. Bryant, AIA, and Harold N. Cones, Ph.D. authors of The Zenith Trans-Oceanic The Royalty of Radios tell of the Royal 1000's development and its importance to Commander Eugene F. McDonald, President of Zenith. Some interesting history on this radio is found on page 36 of their book regarding Commander McDonald's liking the design of a recently purchased German Leica camera and his strongly suggesting that the black leather-brushed chrome "look" be incorporated into the new Royal 1000's design.

The Royal 1000 features 8 bands that are tuned using rotating drum and slide-rule dial. The radio weighs 13 pounds with batteries. The radio operates from 9 "D" cells—8 cells for radio power and 1 for the dial lamp power. The 9 transistor chassis is designated as the 9AT40. Most Zenith transoceanics play just like new if they have been well maintained. Also, the 9AT40 chassis was manufactured using hand-wired point-to-point construction.

Here are two pictures of my Royal 1000 Zenith Trans-Oceanic Radio. The radio certainly has the "Leica" camera styling. The four-page news release of November 5, 1957 stated that close to $300,000 had been spent on the radio's development. Money well spent because the portable has outstanding looks and performance. The radio uses "D" cells and will play forever with a set of new batteries. Click here to view a short Zenith advertisement about the transistorized Transoceanic radio.

Important Note: Since most Zenith portables have very long battery life, it is important to keep up with battery useage. Even today, battery corrosion can be a major problem.