We found this preamplifier for the 10 and 11-meter range in an old documentation for radio amateurs. The integrated circuit used is uncommon today.
This circuit of 1965 documentation makes use of a tunnel diode to retard a pulse without...
This circuit triggers an LM380 oscillator, producing an audio tone with light falling on the LDR....
This UAA170 application circuit was taken from Siemens' own integrated circuits manual from 1976....