Five Inch TV Sets of 1939
145 Little Peconuic Bay Rd.
Cutchogue, NY 11935
The April, 1939 issue of Radio and Television Retailing proclaimed that "The opening of the New York World's Fair on April 30 will go down in history as one of the most important dates in the communications industry." A number of manufacturers placed television receivers on sale to coincide with the "coming out" of TV at that event.
Most of these sets were out of the price range of the average family, especially with the economy still in recession. The best known of them was the RCA TRK-12, which cost $600--the price of some new cars! But there were also some (relatively) low-cost sets available with tiny 5-inch screens.
The Andrea IF5 ($190.00), RCA TT-5 ($199.00) and GE HM-171 ($250.00) were three of the most inexpensive factory-built TVs that one could purchase at that time. Westinghouse produced a 5-inch set, the WRT-700, which appears to be copy of the RCA. Andrea offered the KTE-5, a kit version of the IF5. Meissner, Garod, and National also produced 5-inch kit sets.
Some years ago I had an Andrea KTE-5 working and it gave a reasonable picture with an external TV booster. And yet that design has only one stage of video amplification, two video IF stages and no RF amplifier. Pre-set channel selection is by a two-position switch. Of the three sets, the Andrea is the only one with two audio stages and a speaker. And it does have much better power supply filtering than either the GE or the RCA.
The RCA is probably the most common of the pre-war 5-inchers and it surely has most stylish cabinet. But it, too, came without an RF stage. A five-position switch preset to select channels 1 through 5 accomplishes tuning. It does have three stages of IF amplification with extremely elaborate interstage band-pass coupling circuits such as were used on the 1936 RR359 test sets. The other manufacturer's sets are far simpler with typical interstage IF transformers. Interestingly, RCA greatly simplified these IF coupling circuits in the postwar 621 and 630TS.
The GE is tuned by three push buttons, which can be preset to receive any three of the original low-band channels. (There were seven channels allocated at that time from 44 to 108 MHz.)
Again, there was no RF amplifier. But the GE has four IF stages which should provide plenty of gain. And this set is the only one that has two stages of video amplification. Now I am really eager to get mine operational. Many years ago, I restored a HM-225 and it really worked well.
These are easy sets to restore but bear in mind that they have dangerous "brute-force" high-voltage supplies. Unlike post-war TVs, they can supply significant current at 2000+ volts. Stories have been told of servicemen having been electrocuted while working on those pre-war sets.
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