False readings on coils

Hi all

I went out yesterday and did a little detecting i got a couple of Nuggets 2 x 2 grams I'm very happy with that, but I was getting a lot off false reading , when I was nocking the coil on the ground or bumping it on rocks . So I moved the connector were connects to the box and it gave me bad false readings or a bad reading .

So at home I had a look at the wires on the connector and I found one wire was so bad it was hanging on by one strain . .

Is this common on old coils, it was a minelab 11" DD ? ( I think about 3-4 years old )

Shane

Gday Shane

Damage to the ends of the coil lead is fairly common, sometimes it can happen by the coil end of the lead snagging on branches or sticks while being used, sometimes by the coil being stored with other gear on top of it causing strain to the area where it enters the coil.

On the plug end to the control box the lead gets damaged by the plug being pulled out by the wire leading to it rather than holding on to the metal part of the plug and pulling it out that way, the lead to plug connection is easier to repair than the other end.

This damage can happen to any coil old or new if it is not looked after and the first symptom of the damage is what you described by the coil falsing as it moves about and touches other objects, this same thing will happen if the windings have become loose internally with coil sounding off as it is touched against things because the windings inside slop about banging on the inside of the coil body, this is fairly common with older coils that have seen a fair bit of use and abuse.

As you have found a loose wire in the plug end of the lead I would say that is where the problem is and it should be relatively easy to rectify,

cheers

stayyerAU

Hi stayyerAU
I just hope I have fix it or I have to tell the wife I need more money for new coil

Shane

Each coil I have has its own lower shaft and the cable is taped at intervals straight up the shaft.

I found not only did it cut down on falsing in the scrub from bumps, it also stopped damage by snagging and made it a damn sight quicker and easier doing coil change overs.
Most coils will sound off if touched or wobbled at the plug end, but I've also found as they age a lot will sound off all along the cable.