Crystal variable oscillator (CB9506E)

Found in Radio Electronics from the 90s, this circuit can vary the frequency in small values around the crystal frequency.

Operational Astable (CB14826E)
This is the conventional configuration of an astable multivibrator with operational, found in a...
Triple 5 V Numitron power supply (CB8673E)
This 1969 Electronics World power supply has 5 V to power digital circuits and a 170 V output for...
Telephone Equipment Regulator (CB6030E)
The Texas TL783 integrated circuit is a three-terminal high voltage regulator with a wide range of...