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Old 20th Nov 2017, 7:51 pm   #1
mark_in_manc
Octode
 
Join Date: Nov 2011
Location: Manchester, UK.
Posts: 1,875
Default AVO Model 40 Multimeter

Split from this thread: https://www.vintage-radio.net/forum/...d.php?t=140392

I have one of these apart at the mo, and this thread is timely! I took mine apart to cure a cut-out which wouldn't latch; I fixed that, and now find it won't zero on 100,000 ohm range, and is entirely dead on 1000 ohm. 10,000 ohm range seems to work OK. All AC and DC voltage and current ranges seem OK too.

I don't really need it to work for R measurement - but it's so nicely made that now I have it apart, I feel obliged to fix it before putting it back together. I've had a look at the circuit diagram above. If anyone knows the component layout it would save me a bit of tracing out. A resistor attached to the 10k ohm switch position looks rather burnt, for a start - I'll need to study the diagram to work out what value it might once have had.

Circuit diagram: https://www.vintage-radio.net/forum/...7&d=1311627688

cheers
Mark

Last edited by AC/HL; 20th Nov 2017 at 10:58 pm. Reason: Thread split
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