Modulator Amplifier (V1574E)

This circuit is from a 1938 tube manual. Transformers are the critical components. Component values are given.

Digital Voltage Indicator (CB25335E)
This indicator with the integrated circuits CA3162E and 3161E was published in the July 1990 issue...
REF6000 Precision High Voltage Reference (COM094E)
September 2016 - It can be purchased at Mouser Electronics the new REF6000 precision voltage...
Simple Timer (CIR865E)
This simple two transistor timer can be used to measure short time intervals. The power supply...