Re: AVO Multimeter survey
Avometer Model 4
Fault with 1,200v range/s identified and (partly) fixed! Required an Avo 8 and more fiddling. Phil's comment led me to focus on the main switches.
Set up Avo8 to monitor resistance across main terminals and jabbed the rear of the rotary AC selector ring near to the 1,200v area. Pressing the bakelite of the multi-contact ring caused slight fluctuation of the ohm reading, then removing one of it's fixing screws dramatically increased the ohm reading. An improvement! Once the AC HV contact screw had been removed and the wire sat on paper (as per picture) the 1,200v (DC) range worked properly.
Sintered Bakelite in the contact rings, Batman! I believe the rings might be detachable but have nothing of this sort to hand and for all i know the conductive sintering damage could include the facia surface. Too much intervention for an uncertain result, perhaps.
A fault to be aware of. Indicative of abuse, but not necessarily conclusive..? Occasionally bakelite does suffer with this deterioration, i am told.
Dave
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