Wiring of microphone circuits
b. Sometimes the trouble is only intermittent and must be traced by
jiggling the cable. Start at the plug and work back a foot or so at a time
to the microphone housing. The following is a good general procedure to use
in checking for microphone housing and for microphone and cable troubles.
(1) First check the plug and receptacle. All types are encountered
in microphone input circuits. Some simple two-conductor microphones use the
familiar jack and jack plug.
(2) Some use a metal shell that is insulated from the outer conductor
which has a single pin in the center. For the latter type, the receptacle
is a matching female plug with a spring-loaded connector that grips the
center pin tightly, and has a knurled metal ring connector to hold the outer
conductor firmly in place.