This General Electric circuit is from the 80's. The PUTs used in this meter are not common components today.
Found in a 90s Radio Electronics, this circuit can be used in high voltage experiments, ionizers,...
This VFO circuit generates signals from 2 Hz to 50 Hz. We found it in Popular Electronics from...
This circuit, published in the 1980s, can be applied to operational amplifiers of almost any type....