This circuit was found in an American 1980s documentation. The transistorized step is the receiver's last IF and the diode is the receiver's existing detector.
This alternating voltage voltmeter was found in a 1967 magazine. The magazine no longer exists, but...
September 2017 - Intersil's ISL850x Synchronized Buck Regulators can be ordered from Mouser...
January 2017 - Texas Instruments' new TPS7A19 Low Voltage Dropout (LDO) linear regulators are now...