In use telephone indicator (CB8665E)

This circuit was found in a 90s Electronics Now. The circuit can use a TIC106 for the SCR.

Crystal Test (CB13253E)
This circuit tests quartz crystals of frequencies between 100 kHz and 10 MHz. The circuit is from...
Transformerless 12V x 50mA Power Supply (CB4564E)
We found this circuit at a January 1991 Modern Electronics. The magazine no longer exists, but the...
Simple AM radio ZN416E (CB8203E)
The ZN416E integrated circuit is uncommon today. It consists of a complete radio, like the one...