This circuit for very low frequencies was found in an American documentation from the 90's. Transistors are for general use and the frequency depends on C1 and C2.
Equivalent transistors, such as the BC548, can be used in this circuit that we find in...
Found in a 90s documentation, this circuit makes use of D1, a switching diode that is uncommon today....
This is the suggested transmitter circuit for the CB16880E. The emitting LED must be a...