Seventy years ago, transistors were new, and the March 1956 issue of Popular Electronics carried a number of projects to get the beginner up to speed with the new technology.  The magazine had five different projects (with more to follow the next month), all of which could be assembled with the parts shown at left.  The heart of all of them was a 2N35 transistor.  They were powered by a 9 volt battery, although the familiar version was apparently not yet on the market, six penlight cells could be used.  They could go in a holder, or simply connected together with soldered wires and tape.

The first circuit, where very little can go wrong, is the code oscillator shown below, to learn the “sound and touch of a ham’s second language.”

The next three projects are receivers.  The first is a crystal set with the transistor serving as audio amplifier.  The second is a solar-powered set using the transistor as detector.  And the third one goes back to nine volts to work as a regenerative receiver.

The final project is a transmitter, a slight variation on the regenerative receiver.  It is put into oscillation to generate the RF, and the frequency of the modulation is set by the time constant of an RC circuit.