Upon pressing the switch, the circuit generates a pulse whose duration depends on C. The transistors can be BC548 and the power can be between 1 and 6 V. The circuit is from a 1975 publication.
Originally created to feed the filaments of a 12AX7 as an audio preamplifier to eliminate the...
The BFO or Beat Frequency Oscillator is used to receive telegraphic signals or even modulated in...
This circuit is a variation of the previous one, containing a modulation input. The components are the same....