Astatic D-104 Rebuild & Update To Condenser Microphone

Note: The wire I call "purple" is actually "black" per Astatic diagrams.
The rebuild of a vintage, probably 1960 or before, Astatic D-104 microphone. The microphone casing is practically "indestructible" but the element in the head has gone bad in most all cases. A few good examples still exist. However, these microphones can be easily updated with inexpensive condenser type microphones available on the Internet. Also, in this video I demonstrate how to use the existing pot in some of the microphone bases to control gain of the microphone.