Tesoro 11" widescan µMax coil opened up, falsing problem:

[Pinpoint]

I have recently opened up a coil of mine because it was falsing even with the slightest touch, no matter what setting (I can't afford to send it back and forth, postage would cost almost as much a new coil!). Upon opening it up, I see that there's a wire sticking out from the middle, I moved it around and that's not the source of the problem. I tap the sponge and it falses then, or even if I tap other parts of the coil.

Does anyone know what could be causing this problem, and what the solution might be?

Here's a photo of coil opened up:

[kt315]

I see that there's a wire sticking out from the middle, I moved it around

the wire is going to Faraday shield of another housing part, that is not on the photo.
your problem may be a breaking cable at low part near to housing.

[Pinpoint]

the wire is going to Faraday shield of another housing part, that is not on the photo.
your problem may be a breaking cable at low part near to housing.

Interesting. The bottom half of the coil relative to the photo, is mainly where the falsing seems to be coming from, I think you may be right. Is it safe to pull the rest of the foam/coil off the housing?

[Pinpoint]

This thread gave me some clues:
http://metaldetectingforum.com/showthread.php?t=13360

Others seem to have the same problem as me.

[kt315]

this photo gives you the clues

[Qiaozhi]

Interesting. The bottom half of the coil relative to the photo, is mainly where the falsing seems to be coming from, I think you may be right. Is it safe to pull the rest of the foam/coil off the housing?

Solder the wire to a short spring (10mm to 15mm long) of about 15mm diameter. When you refit the bottom half of the coil shell, the spring will make electrical contact. Garrett Crossfire coils use an electrostatic sheet either side of the coils, and this is how they get a good connection.

[Pinpoint]

Solder the wire to a short spring (10mm to 15mm long) of about 15mm diameter. When you refit the bottom half of the coil shell, the spring will make electrical contact. Garrett Crossfire coils use an electrostatic sheet either side of the coils, and this is how they get a good connection.

Thanks for advice , but that didn't help.

[Pinpoint]

Upon further inspection, tapping around the bottom of the coil, the falsing mainly seems to come from a specific area, I've marked it in red. The area marked in blue is where the coil cable goes into the housing:


Can this be fixed? Should I try to get to the problem by removing the foam around the area marked red?

[kt315]

pinpoint, can you measure inductivity of coil? by acetone you can delete the foam. get it from your moom, they use liquid for nail varnish deleting, it contains acetone.

[Pinpoint]

pinpoint, can you measure inductivity of coil? by acetone you can delete the foam. get it from your moom, they use liquid for nail varnish deleting, it contains acetone.

This acetone, could it damage any part of the coil?

I don't know how to measure inductance, I have a multimeter, don't know if that will do. Looking it up now.

[kt315]

This acetone, could it damage any part of the coil?

I don't know how to measure inductance, I have a multimeter, don't know if that will do. Looking it up now.

I mean you will not run the acetone of big dose. do by a sodden brush deleting gradually. you need in LC meter, not ordinary cheap multimeter.

[Pinpoint]

Yeah, I won't be able to test the inductance in that case, but I'm keen on removing part of the foam, I'm sure I know the source of the problem.

[kt315]

Yeah, I won't be able to test the inductance in that case, but I'm keen on removing part of the foam, I'm sure I know the source of the problem.

have you an electronics service around? there are always nuts'n'bolts guys with LC meter wishing help you.

[Pinpoint]

have you an electronics service around? there are always nuts'n'bolts guys with LC meter wishing help you.

You don't want to know what happened last time I took something to an electronics service near my area. Thankfully Sido fixed it.

Though yes, it would be good if I could take it to an electronics guy without having to send it somewhere. I'm still thinking.

[Pinpoint]

The more I look into it, the more I think post #5 is the issue, I think you are right kt315. I know this sounds stubborn, but is there any way to push the coil cable through the housing?