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.
The XR2206 is not a common component today, but if you have one you can build this function...
May 2017 - Mouser Electronics already has inventory with ROHM BD570xx integrated circuits for...
This amplifier uses hybrid modules Sanken and can provide powers of 10 W or 20, depending on the...