This receiver was found in a Popular Electronics from the 90's. Its different configuration shows a tuning circuit after the tube that works as an aperiodic amplifier. Observe supply voltages.
Any high-gain Darlington transistor can be used on this touch circuit. The load can be formed by...
This circuit is from an April 1991 Radio Electronics magazine. The circuit uses power MOSFETs and...
We found this circuit in a 1980s Linear Technology documentation. The components are from the...