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the Altec does not use a VU meter.
I see.
It isn't even calibrated as a VU meter. Many limiters used a plain VU meter, and (as WoB says) didn't worry that the dB marks were a bit off. But a real VU reads 6dB below max at half-scale; the 436 meter shows about -12dB. This is (supposedly) correctly calibrated to the 6BC8's GR curve.
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100uA movement
It actually wants a 0.2V sensitivity. An older high-quality 100uA movement might be 0.2V naked (2K internal resistance). I was startled to find that modern high-price plastic mA meters have sensitivities above 1V.... I guess magnets have got more expensive over the decades? Or do we just not care any more?
You could trim the "34" resistor higher, but go as high as 1V and you are starting to upset the sharpness of threshold.... oh, heck, the 436's low 2:1-4:1 compression ratio is so un-sharp that it hardly matters. And I have seen reputable mods using larger resistors.
Put in a modern cheezy 1mA meter, shunt with 220 ohms, diddle so the needle sits near full scale. 1/3rd scale is ~~~~-9dB, half-scale is ~~~-12dB, 1/8th scale is ~~~-20dB.
It won't sound right without the green paint. Many people won't know the difference if you use the
OLD (2-banger) John Deere Green. (There's a song about it...)
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how bout these...
An amazing cosmetic match. Probably the same case-mold.
Leave it marked "milliTorr", confuse your friends. The current is near enough. "9mV" is suspiciously low, but as WoB says, you'll trim the shunt so idle is near full scale. Then 300mT is lightly trimmed, 20mT is brutally crushed, etc.
.... it is odd that this meter is
shown with needle at full scale, while others are shown reading zero (as you'd expect if the photographer didn't have meter-test gear on stage). Maybe it is right-zero? Maybe you can fiddle the springs to bring it to the left side, but the springs are very easy to tangle. Maybe best to leave it as is, let the "normal" position be zero-left, and the "more squash" range be to the right.
