This circuit was found in Radio Electronics magazine from June 1958. The maximum distance depends on cable losses. More stations can be added.
This circuit can produce signals up to 100 kHz depending on C1 and R1 adjustment. The output has a...
Found in Radio Electronics this circuit uses a fotodiac to drive a triac. The circuit can use...
This circuit was obtained in an American documentation translated in the 80's. The circuit can be...