creative misuse of tool

[xjwmx]

I had a headphone and one side quit working. That side measured open at the plug. Knew the problem was either at the plug or at the other end of the cable, but which? How to avoid hacking the plug unnecessarily or taking the headphone apart at the other end necessarily? How to tell which end had the problem?

Ha. My little portable meter has a feature where if you hold it near an AC circuit it beeps if the circuit is live. I connected a clip to the lot leg of a 110V plug and plugged it back in the socket. Held the meter close to the wire...beep...it's gonna work. Connected the other end of the clip to ground on the headphone plug and put the meter at the other end of the headphone lead. Beep...expected. Connected the clip to the tip on the headphone plug...beep...expected. Connected the clip to the ring on the plug. No beep, which told me the problem was at the plug... You don't have to worry about the 110V frying the headphone because there's no actual circuit being made.

 

[Downeaster]

Ever heard of a TDR? Time Domain Reflectometer. Used to detect breaks in long cables, will tell you how far from the TDR the break is.

Used one in the Navy a couple of times to find breaks in antenna cables that were hundreds of feet long.

 

[Jim]

1+ on the TDR. It was invaluable when working on electronic warfare radar recievers and jammers. You could even narrow down to a few inches where someone clamped an antenna cable with too small a clamp and pinched the cable.

 

[59Tebo]

+2 on the TDR, De. I never used one in the telephone biz (some friends in cable maintenance use them all the time), but I have used an OTDR. That's an Optical Time Domain Refractometer, on about a zillion miles of fiber cable. Splices showed up on the graph as a tiny little bump (we did really good splices). When there was a break in the fiber, the graph would "spike" to infinity, and give you the footage right to the break.

 

[xjwmx]

Well, I ain't go no time demained reflect-o-meter.