The idea of this circuit found in a Radio Electronics from January 1966. The idea of the circuit is to improve the reception of audio signals, mainly telegraphy, working as a filter.
The idea of this automation can be extended to other applications that involve the control of...
What differentiates this circuit from the previous one (CB15613E) is the non-need to use a...
Found in Elektor Electronics from the 90s, this circuit produces the tone of 1 750 Hz for calling VHF...