This circuit was found in a 80's Popular Electronics. The sensor can be any phototransistor. The circuit is indicated for an audio link modulated in pulses.
This circuit is interesting for experiments and can be part of the bench in the form of a module. The...
This RF wattmeter was found in an American 1980s documentation. The components are common and the...
The configuration shown allows to obtain a high voltage gain for FETs. FETs can be BF245 or...