Universal AvoMeter (AVO Meter) 4

Fourth version of the Avometer, 34 ranges with the "Divide by 2" button added.

This doubled the sensitivity of the meter when pushed.

Bakelite front panel with an aluminiunm case.

Ranges;

DC 0.12, 1.2, 12, 120, 1200 volts - sensitivity 6/3 mA
DC 12, 120 mA, 1.2, 12 A
AC 12, 120, 1200 volts 
  sensitivity: 6/3 mA on 120, 1200 volts, 120/60 mA on 12 volts
AC 120 mA, 1.2, 12 A
R     1k, 10 k ohm (12.5, 125 ohm center)
        100k, 1M ohm (1.25, 12.5k ohm center) with external power   

Here you find 82 models, 79 with images and 41 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from Avo (Brand), Automatic Coil Winder and Electrical Equipment Co., Avo Ltd; London