This amplifier for signals in the 2 m range that corresponds to 150 MHz was found in an American documentation from the 1980s. The FET can be a BF245.
This circuit using an operational amplifier was found in old American documentation. It can be...
If the circuit oscillates, emitting sound, it is because the transistor is good. This simple...
Like the previous circuit, this is used in the analog part of the telephone lines. The same...