This intermediate frequency amplifier step using 2 junction FETs has a gain of 20 dB. The pass band is 4 MHz. FETs are for general use, with several types that serve in this circuit as BF245.
This circuit was found in a 1975 documentation. Current general-purpose transistors can be used,...
We found this circuit in a publication for radio amateurs in 1974. The bipolar transistors can be...
This conventional humidity or water alarm circuit was found in an English documentation from 1974....