The purpose of this circuit is to check the linearity of SSB amplifiers. The circuit was found in an old documentation for hams. The diode is a general purpose detector type.
Several circuits similar to this one can be found on our website. This is from an internet...
This circuit generates a rectangular signal whose frequency depends on the electrolytic...
This circuit locks when the sensors are opened. The relay can be 6 or 12 V depending on the power...