This circuit was found in a 90s Electronic Design. The integrated circuits are from that time. Frequency multiplication can be done for odd integers.
The circuit shown is a suggestion given by an English publication from 1980. In it, a...
We found this 50 kHz 25 MHz crystal tester in a 1978 QST magazine. The FET can be the BF245 and...
This two transistor audio amplifier stage was found in a publication of the year 1968. The...