This circuit shows how to make an adaptation on an AM receiver to receive CW and SSB signals. The circuit is from an 80's documentation. The diode is commonly used.
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...