This meter was soon superseded by the more accurate
and virtually identical model
72. which does not have the 1Amp
fuse but otherwise much the same.
There are four thick film resistor circuits housing the majority of the resistors which form the universal shunt, voltage dividers etc
The meter movement was OK but failed to
give any indication on the DC voltage ranges. I found one of the
section of the voltage divider thin film resistor was open circuit and
another was considerably lower than it should be and a previous owner
had already soldered a replacement for another open circuit section of
the same thick film circuit. I also have a model
an open circuit meter so I exchanged
the meter and scaleplates to get a working instrument. This one will
remain as a donor for spare parts.
Three of the thick film circuits
are on the underside of the printed circuit board
moulding for the meter and batteries has holes for additional sockets
so that it can be used for the other meters in the range. This model
was soon superseded by the more accurate
and virtually identical model 72. The 1A fuse was omitted in the Model
You will find more information here about these instruments and other similar models. AVO produced a range of the smaller multimeters such as this which are described here
AVO produced the "70 series" range of analogue pocket meters with 2000 Ohms/Volt sensitivity and 3 inch scale lengths at the beginning of the 1970's. The following is from a 1972/3 trade catalogue.
For further information have a look at my pages on similar AVOmeters here