Found in documentation from the 1980s, this highly sensitive circuit is based on the conduction by the presence of gas from an ionization chamber. The components are from the time.
For the 7 to 10 MHz band L1 is formed by 3 turns of 22 to 28 AWG wire in a ferrite core 15 to 20...
We found this interesting timer circuit or CMOS timer in a 1988 publication. The circuit is still...
This audio mixer was found in an old American documentation. The potentiometers are 1M and the...