This simple 1-transistor audio preamplifier appeared in the June 1968 Radio Electronics magazine. The transistor is a general-purpose type of the time. The gain is 14 dB.
The resonant circuit depends on the crystal frequency that can go up to a few megahertz. The...
This circuit is from the 1983 Intersil Databook. The display is plasma and must be excited by a...
This is a typical common emitter amplifier stage configuration. The transistor can be used...