This circuit was obtained from a 1977 FET manual. The circuit measures inductances using a signal generator as a reference. The range is from 60 uH to 60 000 H. The FET can be a BF245.
This tone generator for CW was found in a publication by Gernsback from 1960. The circuit makes use...
This monotone alarm oscillator circuit was found in July 1975 Radio Electronics magazine. Power is...
This circuit automatically activates the relay when the phone is answered, closing the record...