This amplifier was found in a tube equipment manual from 1947. The high-fidelity circuit has pentode tubes at the output and a source with transformer.
We found this relaxation oscillator in a 1967 General Electric documentation. The frequency is given...
This circuit generates a 20 MHz sinusoidal signal from a 10 MHz crystal. It is found in the 1992...
This circuit is from a 1967 publication. The potentiometer above 4M7 is the critical component. The...