This circuit is a variation of the common grid dip meter, having been found in a 1975 publication on FETs. The FET can be of any type and the coil depends on the frequency to be detected. The double variable may be of the type found in AM receivers. Transistors like the BF245 can be used instead of the original. The instrument is 200 uA.

 

Datasheets


N° of component