[Harp-L] bullet mic hum

["john" <jjthaden@xxxxxxxxx>]

     Man have I enjoyed playing through the bullet mic pictured disassembled here  http://www.flash.net/~jjthaden/bulletMicInnards.jpg.  You'll see it's got an Astatic element in a Shure green bullet body, along with a military-spec 4 megohm pot I got from a junked oscilloscope, bridged by two 47 picofarad capacitors in parallel (sort of a Rod mod).  The brown braided wire is the mic hot lead to the cable.  White wires go from the pot to a grounding screw inside the casing and to the element.
     Problem is, if I grab the mic body, it hums badly; if I touch only the cable connector, it's quiet as can be.  The connector is fused directly into the casing, so this has got me confused.  Could the grey metal of the casing be a bad enough conductor that the potentiometer and element are essentially ungrounded?  Should I try to run a wire from the grounding screw directly to the cable connector ground?  Could the hum have increased as the casing paint job wore off?  Could the fix be as easy as a coat of paint?
     I'd sure be obliged for some hints on how to fix this problem.
Thanks!
-John Thaden (ublokr)
rocklittlerock.com