This circuit covers the bands from 1.8 to 150 MHz, with plug-in coils whose characteristics are given next to the diagram. The FET can be a BF245. We found it in old documentation.
This other high stability thermocouple amplifier uses an 80's operating. The circuit can be used...
This circuit is from a 1982 publication. It is a sequential effect of accelerated and intermittent LEDs....
Found in a Popular Electronics from the 90s, this circuit presents the difficulty of obtaining the...