Re:[Harp-L] Bad JT-30 Ground

[G <gigs@xxxxxxxxxxxxxxx>]

Date: Tue, 05 Dec 2006 23:46:18 -0500
From: "Ryan Hartt" <rhartt1234@xxxxxxxxxxx>
Subject: [Harp-L] Bad JT-30 Ground
To: harp-l@xxxxxxxxxx

>I've got a JT-30 that a buddy of mine customized a million years ago. It
>had an XLR and he added a screw on and a volume control and I used it for
>years and I put it away for a long time and just brought  back out.
>Apparently it has a bad ground? It hums. When I touch the collar of the
>screw-on connector the hum goes away. I opened it up and the ground wire
>is screwed into the back of the mic so I guess the ground problem is in
>the volume control connections. Any suggestions for a quick and easy fix?
>I'm not exactly Mr. Electronic Handy Man, especially is small spaces.
>Thanks
>Ryan

Hello Mr Electronic Handy Man.
  A small brown (ceramic?) capacitor marked 151 (15pF?), soldered between
the volume POT's two contacts where the mic and cable signal wires are
connected, should mitigate the humming.  Earlier Hohner Blues Blasters with
the MC151 element had this setup.
-- G.