This 6W amplifier with 4 tubes was indicated in an American documentation from 1947 to operate with recorders. The circuit uses a source with a transformer.
The search coil of this detector consists of 140 turns of wire 18 in an 8 inch diameter form. The...
This circuit was obtained from a 1966 General Electric documentation. It can serve as a basis for...
The quiescent current of this alarm is in the order of microamps and the same is true for the...