This is the circuit of a modified Heathkit kit. The circuit was found in a Radio Electronics from December 1965. The author of the circuit included improvements to the original circuit.
With the circuit in the figure, it is possible to control the amount of heat generated by the...
We found this circuit in an old European documentation. Transistor TR1 can be BC548 and TR2 can be...
This small telephone transmitter uses a telephone capsule as a microphone. The L1 coil has 4 to 5...