Crystal oscillator (CB9504E)

This circuit was found in a 90s Popular Electronics. It can generate signals from 3 to 10 MHz.

LP5912 Q1 Ultra Low Noise LDO Regulador (COM033E)
Mouser Electronics is announcing the availability of the new voltage regulators with low dropout...
Signal Tracer (CB12463E)
This circuit is from a 1982 publication but can be assembled with BF245 for Q1 and BC548 for Q2....
Debouncer using PUT (CB8389E)
This circuit was found in documentation from the 1970s. It eliminates contact bouncing, providing...