This transmitter for the 40 meter or 7 MHz band was found in a magazine 73 for radio amateurs of the 90s. The circuit has a power of ½ W.
This preamp with a transistor for turntables with crystal capsules was found in a Japanese...
This variable frequency oscillator generates signals that have a recurrence frequency determined by...
This circuit with neon lamp and unijunction was found in the September 1970 Radio Electronics...