This stage was found in a 1964 Electronic Design. The transistors are of the time and the shape of the signal obtained is shown in the diagram.
The transistor of this constant current source may be the BC548 or equivalent. Resistor R2 may be...
Based on the 4006 this circuit generates random signals in a frequency range that depends on L1...
The BFO or Beat Frequency Oscillator is used to receive telegraphic signals or even modulated in...