Found in American documentation from 1968, this circuit uses both diodes and a neon lamp to generate a 4-step ladder. Observe the signal voltage.
This configuration from a 1976 technical documentation shows how to use a varicap in a direct...
This circuit was found in a Popular Electronics of the 90s. It operates a third brake light that...
We found this circuit in a 1977 Radio Handbook. The circuit applies to any JFET and the frequency...