Used by radio amateurs to accompany telegraphic transmissions, this circuit generates an audio tone. The power comes from the transmitted RF signal itself.
We found this circuit in the February 1987 issue of Radio Electronics magazine. It is based on an...
This circuit is from an Argentine publication from the 1970s but can still be assembled with...
We found this circuit in a publication from the 90's. The circuit is used with sinusoidal...