1996 - 2016
BSEE - KB3UON
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
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|January 1955 Radio & TV News|
[Table of Contents]
These articles are scanned and OCRed from old editions of the Radio & Television News magazine. Here is a list of the Radio & Television News articles I have already posted. All copyrights are hereby acknowledged.
This Regency TR-1 transistor radio and leather pouch will probably have been sold on eBay long ago by the time most people see it, but there seems to be an ample supply available for collectors if you are willing to either pay a small fortune for a well-preserved copy like this one, or accept some wear and tear on a lesser copy. Not surprisingly, there is a website dedicated to only the Regency TR-1 transistor radio and its history from development through retail sales. As reported in this January 1955 issue of Radio and Television News, The TR-1 was the world's first commercially available, fully transistorized portable radio. A complete schematic and functional description is provided. It used four germanium transistors and operated on a 22-1/2 volt battery, which provided about twenty hours of listening pleasure. The unit weighed eleven ounces and cost $49.95. It had just been released to the public the previous year.
This all-transistor broadcast receiver weighs less than twelve ounces and is the first available for consumer use.
The first pocket radio to use transistors instead of tubes has been produced by Regency of Indianapolis and is being marketed currently in the N.Y. and Los Angeles areas.
Slightly taller than a teacup, "Model TR-1" uses four transistors and a germanium diode in a compact super-heterodyne circuit. Within its case, measuring 3" x 5" x 1 1/4", the unit contains its own battery power supply, a built-in bar antenna, and a tiny PM speaker.
This first commercial all-transistor set owes its successful design, in part, to the high performance transistor developed by Texas Instruments Incorporated of Dallas, who are the first people to mass produce a low cost, high gain, high frequency germanium transistor.
The transistor is a grown junction n-p-n type. Used in the new pocket radio, it provides power gains of 34 decibels and 40 decibels in the intermediate frequency and audio stages, respectively. Such figures have previously been attainable only in the laboratory.
As shown in the schematic below, the circuit employs only four transistors and one germanium diode. Laboratory models of similar sets have hitherto used almost twice as many transistors. The first transistor, TI223, serves as a frequency converter (local oscillator and mixer). Stations are tuned in by a miniature two-ganged capacitor. The i.f. stages employ two transistors, TI222 type and three tiny i.f. transformers. Audio detection is accomplished by a germanium diode. The audio signal is developed across a miniature 1000 ohm volume control and thence fed to the fourth transistor, TI210, which serves as an audio amplifier. Sufficient power is developed by this stage to drive the diminutive PM speaker.
Slightly taller than a teacup, the new set has no tubes, provides good reception on broadcast band.
Featured in this set is the advantage of long battery life. Because the power consumption is only a fraction of that required for a comparable vacuum tube unit, it was possible to eliminate one battery as well as to reduce the size of the one remaining and still extend its life. This, in turn, effected a reduction in weight and is expected to reduce battery replacement cost.
Another advantage claimed by the manufacturer is the elimination of tubes and the problem of tube replacement. While the hot filament or cathode in a vacuum tube is continually consumed during operation, no similar phenomenon occurs in transistors. Except for physical damage, transistors will last indefinitely.
The new radio was designed by the firm of Painter, Teague and Petertil, industrial designers. Miniaturization of components was achieved by a number of organizations. The speaker was produced by Jensen of Chicago. The tuning capacitor was made by the Radio Condenser Company of Camden, N.J. The Vokar Corporation of Dexter, Mich. contributed the i.f. transformers. The volume control was made by Chicago Telephone Supply Corporation of Elkhart, Indiana. Centralab of Milwaukee engineered a very small ceramic capacitor.
Components were assembled by a semi-automatic process using printed wiring and dip soldering techniques.
SanfoTd Electronics is handling distribution in New York, while West Coast distribution is being undertaken by Gough Industries, Inc. of Los Angeles.
Posted January 26, 2016