Why Does My Noise Cancelling Mic Only Work When I Pinch the Wires?

[wwiaftm]

to start off let me state the problem... I have a bike to bike radio that has a microphone and speakers. At speed of over 20mph it is very poor quality. I have cut the wires and tried to solder in a noise canceling mic. the mic does not pic up anything but If i pinch the wires

------finger------
(wire - one inch of space - wire)
------finger------

the mic works perfectly! if i connect the wires together it does not work.

one wire is insulated one is not and rides beside the insulated one.

things i have tried...

pinching to connect the wires with my bodies resistance works
covering both wires in flux works until the flux dries
sheilding the wires separately or togther does not work
i was told to try a resistor of .3 - .5 ohm this did not work
multiple mics give the same result
wiring in the old mic works fine still

any help would be helpful because i am stumped!

 

[vk6kro]

Is it possible that when you squeeze these wires, you are putting pressure on a poor joint nearby?

Some 3 MM plugs are notorious for this. They can be made by pressing two pieces of metal together and these sometimes make a poor contact.

You can get better plugs if this is the case. Look for the ones that have the center pin coming through to the area where it gets soldered, not the ones that have this pin joined to another piece of metal.

 

[wwiaftm]

I did try clamps in many places last night. Across the wires, and each wire individually, neither of these seemed to work. The plugs are original and the wire is cut in the center with plenty to work from. It does not seem to be loose or bad connection problem as I have tried soldering and clamping in different places many times. Thank you very much for the thought but it still won't work.