Voltage amplifier with the 37 tube (T392E)

Found in a modern design book with tubes, this stage with the triode 37 has a plate current of 3.7 mA.

Polarity Reversal Protectors (CB4137E)
The circuits shown below consist of diode protections against accidental polarity reversal in the supply...
Frequency Doubler (CB25778E)
We found this circuit in the November 1994 issue of Electronics Now magazine. It doubles the...
MW Receiver (CB4616E)
The circuit presented is a simple MW tuner that can be plugged into the input of any audio...