This analog volt-ammeter was found in an Electronics World of 1968. It makes use of a 0-1 mA analog milliammeter. Accuracy depends on the components.
The circuit whose characteristics are given in the graph uses two transconductance operational amplifiers...
This circuit was found in the Radio Electronics magazine in an article about emitter-coupled...
This circuit was obtained from an 80s factory manual. The integrated circuits used are uncommon...