A Brief History
of Zenith Royal Transoceanic Royal 1000
A Speech by Ray Andrejasich
Before a 1996 Quarterly Meeting of the Indiana Historical Radio Society
FIXTURING FOR TRANSISTOR SELECTION
The input and output impedance varied greatly in the early transistors, so test fixtures had to be designed by the engineer to sort and select devices. One fixture would be kept in the lab for reference, one went to the transistor manufacturer and the third would be kept in the incoming quality control department at the Kostner Avenue plant, where the Transoceanic was built. These were no simple go no-go type of fixtures. EACH transistor was checked by an operator. The input and output circuits of the fixture had to be tweaked for maximum gain and a scope pattern for the bandpass had to fall within marking on the face of the scope, as well as the total gain falling within a min/max specification. Then only did the transistor go to the assembly line. There was a fixture for each transistor part number! As the Tranoceanic had a battery voltage of 12 VDC, it was expected to perform down to 2/3 battery voltage, or 8 VDC. A special test fixture for the oscillator transistor 100% checked each device for frequency shift as the collector voltage was switched from 12 to 8 volts. This minimized frequency shift and dial calibration error as the batteries wore down. Later versions of the Transoceanic used a 6 volt regulator circuit for the front end, that insured no frequency drift down to half battery voltage.
Speaking of transistors, some of the big names in the fifties were Amperex, RCA, GE, Philco, T.I.,Raytheon, Sylvania, and Tung-Sol. Smaller manufacturers included Bell Labs, CBS-Hytron, Germanium Products Corporation (GPC), Minneapolis Honeywell, Radio Receptor Company, Transistor Products, Inc., and Western Electric Company. Transistor vendors used exotic names to describe their latest transistor offerings as manufacturing techniques continued to offer higher and higher frequency devices. Name like the RCA drift-field transistor and the T.I. del-mesa transistor come to mind.
EARLY TRANSISTOR RADIO OFFERINGS
|Published books state that the first commercially available transistor radio receiver was the Regency TR-1, introduced in late 1954. It is pocket sized, measuring only 3 x 5 x 1 1/4 inches, and weighing less than 12 ounces. It had only four transistors and operated from a 22 1/2 volt photoflash battery. Power output was rated at 12 mw at about 6% distortion. Now Zenith, although not first to introduce a transistor radio, did come out with their first offering, the Royal 500. At $75, it was about a week's pay for an engineerno cheap price. However, it had 7 transistors, push-pull audio output for over 100 mw before distortion, and operated from more readily available penlite batteries. I have my personal set that I continue to use to this day to listen to WIBC news at my desk.|| |
EARLY MODEL "HANDWIRED ROYAL 500 TRANSISTOR RADIOS
It had been my impression that Zenith, although not first, had come out with the second transistor portable radio. After reading the book The Portable Radio In American Life, by Michael Schiffer, I discovered that title belonged to the Raytheon Company, who introduced the 8-TP-1 in early 1955. So maybe we were third!
I don't want to reopen the argument as to who introduced the first tube portable radio, but I did ask Dr. Edmund Taylor to bring his Zenith "Companion", touted by Zenith as the world's first truly portable radio, and introduced to the public in 1924. It has 6 tubes, "A" batteries, "B" batteries, loud speaker and loop antenna all packed into a briefcase. It weighs in at 24 pounds. Dr. Taylor made an exceptional find, as an unconfirmed story has it that the set was on the market for only one year because it performance as a radio fell below expectations Zenith is said to have recalled the few hundred Companions that had been sold, destroying them and refunding the purchase price!