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.
A New Pocket Radio
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
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
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.
Complete schematic diagram of the new Regency TR-1 transistorized
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.
Sanford 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