This circuit was obtained from a 1965 Radio Electronics. The semiconductors used admit modern equivalents. The high voltage coil is an automobile ignition coil.
This is the circuit for the transmitter described in the previous project. T-he 4tube circuit has...
This preamplifier is intended for the use with magnetic pick-ups. Power supply must have voltages...
The low power transistors of this siren can be BC548 or BC558 according to NPN or PNP. The output...