This oscillator for the fifth overtone of a crystal was found in a Radio Electronics magazine from May 1970. Transistors are RF types, and the transistor determines the maximum frequency achieved.
The circuit shown has a voltage gain of 500 times and can use equivalent FETs like the BF245. The...
Found in a 1968 Novel Electronics Circuit, this circuit compares two light intensities using...
We found this circuit in an old publication from Argentina. The relay must be of the sensitive type,...