This RF monitor or field strength meter can use instruments from 100 uA to 1 mA full scale. The diode is germanium type.
This circuit was found in an Electronics World of 1968. It can be applied to any modern triac and...
This circuit is from a documentation from the 70s. The transistors are types of germanium of the...
Obtained from a 1996 documentation, this circuit uses common components and has a voltage gain of 200...