This circuit is from a Radio Electronics from February 1966. The circuit is of a type that was found in many applications at the time as output from radios, televisions and other equipment.
This configuration, which requires a symmetrical power supply for the 741, can be implemented with other...
We found this circuit in a 1980s Motorola documentation. The circuit makes use of common operating...
The instrument is a common multimeter on the lower voltage scale. The FET can be BF245 or MPF102. The...