First up, I had to find a good pot (potentiometer) for the volume control. That took a bit of doing. I ended up with a 5 meg ohm pot that I bought from Digikey. Pricey little thing, but it had a 22mm (basically 7/8") long shaft, which was necessary to get through the body of the mic. It also has a very small body itself, which fits behind the element nicely.
To make this fit, I had to drill out the hole that was previously used for the ground. This started as a hole for a 6-32 screw, and I progressively enlarged it with increasing bits up to the 1/4" hole needed for the pot. For those that have never seen one of these before, I'm putting a volume knob in the hole where the mic body would have been mounted on a post in its stock configuration.
The 'Before' picture.
And the 'After' Picture.
After that, I needed to drill out one of the molding posts to make a new ground. I actually decided to drill two of them before I painted it. Just in case I wanted to ground the pot and the element to opposite sides for some reason, or the tapping of one failed. I tapped this again for a 6-32 screw.
Now it is time to wire this thing back up. A couple minutes with my multimeter told me which pins on the pot were for control and which was ground. I soldered up the circuit. For those that I don't plan on desoldering for paint, I went ahead and heat-shrinked them. I left the others bare. Everything fits pretty nicely. I'll change out the wire coming from the Amphenol connector to a white wire for 'signal' to allow easy understanding of the circuit when I rebuild that portion.
With the wiring done, I was able to screw the thing back together and give it a go. I stole the knob off my other nice mic to give it a try (I ordered some good 1/8" post knobs that should arrive tomorrow that will go on this mic).
Results with the 5 meg ohm pot are dead on and exactly what I wanted. No tone change, just volume change.
Crushed blue velvet 'silk' to protect the element.
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