CW tone generator (CB21673E)

This telegraphy circuit generates an audio tone from a pure RF carrier. We found it in a publication by Gernsback from 1960.

20 MHz Oscillator (CB17506E)
This crystal oscillator generates a 20 MHz signal. Equivalent transistors such as BF494 and 2N2222...
CMOS Amplifier +1 and -1 Gain (CB15751E)
The interesting circuit shown in the figure, can have its gain digitally controlled and present two...
Photomultiplier tube trigger (CB8868E)
We found this circuit in a 1970’s Philips documentation. The circuit uses components from that time....