Boris Dinkoff's Transistor Radio Page

The world's first AM pocket transistor radio, made in the U.S.A. in 1955. 
The Regency TR-1.

It contained 4 Texas Instruments Inc. germanium transistors:

Without the invention of the transistor and the development of the transistor radio, the space program to the moon and the personal computer would not have been possible.



The medium wave AM broadcasting band in U.S.A. and Canada is 540 - 1600 kilocycles, with stations spaced every 10 kilocycles (107 frequencies).


Using an AM pocket transistor radio for radio direction finding (RDF)

1.  See how the antenna coil loop is mounted inside the radio:

The NULL LINE is in the direction of the AXIS of the coil loop.  Stations in this direction will not be heard.

The MAXIMUM SIGNAL LINE is rotated 90 degrees from the NULL LINE, and is the direction of maximum received signal strength.

The most important thing to remember in radio direction finding, is that the NULL LINE is much sharper and narrower than the
MAXIMUM SIGNAL LINE.  Therefore, ALWAYS use the NULL LINE to find the direction of a station accurately.


2.  Place the radio flat down on a piece of paper on a wooden table (non-metallic), making sure the top of the paper is exactly pointing NORTH.

3.  Tune in the desired station, and then rotate the transistor radio on the paper until the signal is exactly NULLED out (zero signal received).
     Your station now lies along the null line of the radio.


4.  Plot the null line direction on a map at your location.

5.  Repeat from a different location (or have someone else who lives in a different place do this).
     The point on the map where the two null lines cross, is the location of the radio station.


AM transistor radios are one of the most useful pieces of electronic equipment.  They can be used to monitor thunderstorms and tornados, and their direction, by listening to the strength of the electromagnetic static sounds of lightning on a blank spot on the dial, and rotating the radio for the null line.

The AM pocket transistor radio.  1960 - 1975.  6 billion transistor radios were manufactured - enough for each man, woman and child on earth.

Remember - in an emergency - when FM, TV and cell towers are down in your area, AM will continue to work from stations 100 km away during the day, and easily 1,000 km away at night.  NEVER forget the lessons of December 7, 1941, September 11, 2001, the Northeast USA/Canada power blackout August 14, 2003, and Hurricane Katrina in New Orleans August 29, 2005.  ALWAYS have an AM pocket transistor radio handy with fresh batteries.

Europeans take warning!  Your FM stations WILL fail and they only have a range of 25 km or so -- you need more AM stations on the medium wave band!





1968:  The transistor radio has become an american culture icon.

By the late 1960s, Japan is producing billions of radios in a few years.
Every american has at least 1 transistor radio.

Long live AM radio!

1050 CHUM, AM radio station in Toronto, Ontario, Canada.  This was the #1 Top 40 rock and roll station in the 1960's-1970's.
The frequency of the transmitter was 1050 kilocycles, the carrier power was 50,000 watts, into a 6 tower antenna array near Lake Ontario.

The music from this station and others was heard in so many AM pocket transistor radios, including mine!