Crystal variable oscillator (CB9506E)

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

3 to 20 MHz XTAL Oscillator (CB13870E)
We found this oscillator in a publication for radio amateurs from the 70s. The circuit generates...
Rhythmic Sequential (CB18165E)
We found this circuit in a 1982 publication, but all the components used are still common in our...
Symmetric 12 V x 80 mA Power Supply (CB13356E)
We found this circuit in a 1976 technical documentation, but it can be assembled with modern...