Re: Avometer Model 40 Special (7.5mA FSD)
AC current ranges OK (I think i have only ever encountered one of these transformers which had a problem, and that was a Model 8 with a dry joint to the 10A winding)
If for example (on any range) the needle is energised to 2/3 FSD, it takes 6 oscillations in total to settle. If memory serves correct this is more than it should be- i would expect about 3. The movement is in very good balance, so i will see if i can detect any excess slop back and forth in the sprung jewels. (I bet there isn't any)
The screws and contact leaves on the battery box have suffered from electrolyte damage, verdigris being slightly contagious any parts that i have spares for i will likely replace especially if etch-cleaning them in lemon juice shows deep pitting.
As we are in 1947 the self-tappers holding the leaves to the battery box are cad plated steel, so that might be a brass nut and bolt job if they have swelled too much.
The rivets for the leather handle being a little flappy i have drizzled superglue around them as this seems to be able to stabilise them in the bakelite, and the excess glue can be removed mechanically. Where the bakelite surface shine has been abraded through on the case i have treated it with baby oil (previous success with mildly spalled bakelite, first coat takes a few hours to soak in.) Apart from anything else, my theory is that the case should be dry beforehand, and the oil prevents moisture ingress (& distortion) in future.
Dave
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