Do search coils go bad?

chowder

Jr. Member
Nov 3, 2013
36
16
Western New York
Detector(s) used
White's M6 and White's MXT Pro
The coils don't go bad, it's not like there's an expiration date. With that said, they can be damaged cause the plastic on the bottom has scratches/holes from rough ground, the cable could have a break or the pins could be broken/bent/loose. I've bought a couple of coils off eBay, but always asked the seller a huge amount of questions, studied the pictures for damage to the coil and looked for a return policy. It's a pain, but if you use PayPal; you can always get eBay involved if the seller rips you off.
 

Fletch88

Silver Member
Mar 7, 2013
4,841
2,367
Valdosta, GA
Detector(s) used
Garrett ATPro- 8.5x11, 5x8, CORS Fotune 5.5x9.5
Tesoro Silver microMax- 8 donut, 8x11 RSD, 3x18 Cleansweep
Minelab Excalibur ll- 10" Tornado
Minelab CTX 3030
Minelab Xterra 305
Primary Interest:
All Treasure Hunting
They can go bad but it's very rare. I've bought 15-20 coils used and only have had one that bad. I was able to contact seller and return coil and get my money back.
 

airscapes

Hero Member
Nov 13, 2013
973
555
Philadelphia PA
Detector(s) used
DFX 950, U13,6"Exc & 4x6 Coils, Coinmaster GT 4x6 & NEL Hunter coil, TRX Pin Pointer, CZE-T200 FM Transmitter, Sangean DT-400W and ER6i in-ears.
Primary Interest:
All Treasure Hunting
Yes they go bad, and the 4x6 go bad alot! I am on my 6th one from whites.. 4 were bad from the get go. It is very difficult to make one of these coils and get it correct then to make it stay correct is even harder.
I just opened up a 950 to try and fix something loose and it is better but still not good as new. I would not buy a used coil from ebay, from a forum sponsor, dealer, someone selling on the forums or craigs list where I can test it. There is more in there than just wire.. there are capacitors and adjustable pots and a null wire that is moved around to get the 2 windings in proper phase then glued in place.
Opening/Fixing and Assembling an XLT 950 coil

Once you get a look inside you know why the say NEVER BANG your coil against anything or use your MD as a cane to stand up. The epoxy they use does not adhere well to the foam or the plastic and with age just pops off. When I removed the foam carrier from the shell there was NO damage to the foam or the shell the epoxy just came right off clean as a whistle.
 

Last edited:

flyadive

Bronze Member
Jun 11, 2012
2,192
1,535
NJ
Detector(s) used
Whites
Primary Interest:
Metal Detecting
If you have a coil protector on your coil then you must remove it and clean! Better yet throw it away, you don't need it ! Fine particles of dirt get between the coil and protector and your detector will go crazy.
 

chowder

Jr. Member
Nov 3, 2013
36
16
Western New York
Detector(s) used
White's M6 and White's MXT Pro
If you have a coil protector on your coil then you must remove it and clean! Better yet throw it away, you don't need it ! Fine particles of dirt get between the coil and protector and your detector will go crazy.

I was prospecting in sand. Didn't even occur to me the sand was able to get in between the coil and protector. Took the detector out to do some coin shooting and detector was just going crazy. Took the protector off and sure enough...sand was found. I put a nice bead of silicon around the seam to fill cracks. It will be a pain to take off, but I should not need to anytime soon.
 

gabbyhayes

Jr. Member
Feb 9, 2014
35
6
Sask.
Detector(s) used
ACE 250 AT PRO GTI 2500
V3i SURF PI PRO
CTX 3030
Primary Interest:
All Treasure Hunting
Coils can go bad and they do. They are electronic and though all the components are passive, like anything else they can fail. (Some coils are starting to include active components( Transistors etc.) inside like the Deus and the CTX 3030)
More often though, they drift off frequency from the ideal. Hence they loose sensitivity which usually translates into loss of depth.
When they go out of tune they can also overload more easily because the null is no longer perfect or as close to perfect.

I always use coil protectors and if you are concerned about sand or dirt getting between the coil and the cover all you need is some silicone to seal the cover to the coil.....or just remove the cover occasionally to clean.
Think of a cover as a glove. Just as a glove protects your hand from injury the cover protects the coil from injury. A cover is very cheap insurance! I'd rather spend $5-$10 on a cover that I replace every few years than $200-$300 on a coil.
 

Last edited:

ivan salis

Gold Member
Feb 5, 2007
16,794
3,809
callahan,fl
🏆 Honorable Mentions:
1
Detector(s) used
delta 4000 / ace 250 - used BH and many others too
i have had 2 coils "go bad" as you say -- both were replaced by the manufactor since it happen fairly early into my ownership of the detector...
 

flyadive

Bronze Member
Jun 11, 2012
2,192
1,535
NJ
Detector(s) used
Whites
Primary Interest:
Metal Detecting
I lost more targets from a coil protector due to fine particles of dirt ! It's cheaper to replace the coil rather than miss one good target.
Period
 

gabbyhayes

Jr. Member
Feb 9, 2014
35
6
Sask.
Detector(s) used
ACE 250 AT PRO GTI 2500
V3i SURF PI PRO
CTX 3030
Primary Interest:
All Treasure Hunting
I lost more targets from a coil protector due to fine particles of dirt ! It's cheaper to replace the coil rather than miss one good target.
Period
That statement is absolutely ridiculous. How would you ever know you had lost targets????
 

Snowmaniac153

Jr. Member
Apr 30, 2015
27
22
So Californa
Detector(s) used
Garrett AT Pro, Garrett carrot, bazooka gold trap
Primary Interest:
All Treasure Hunting
How bad are scratches on the bottom of the coil? I have a few light scratches on the bottom of mine.
 

Keppy

Gold Member
Nov 19, 2006
8,318
2,870
N.E. Ohio on lake Erie
Detector(s) used
** WHAT ONE I FEEL LIKE ON HUNTING DAY *****
Primary Interest:
Other
I have one coil that has chips & small chunks out of it and it still works like new .. It is the coil that comes on garret's ACE detectors...
 

flyadive

Bronze Member
Jun 11, 2012
2,192
1,535
NJ
Detector(s) used
Whites
Primary Interest:
Metal Detecting
I know I'm missing targets when my friends walk in my footsteps and pick up awesome finds. The detector would gradually become erratic slowly and unnoticed until you say to yourself " what the heck is wrong with this machine" , you change the batteries and it gets worse, then after removing the protector .. Like brand new! And I did it more than once because someone said to use the stupid cover.
Once I tripped on a large rock and used the coil to stop my fall ! It chipped and all I did was use some ABS cement and it still works like new. It is a whites spectrum XLT.
 

pistolpete59

Tenderfoot
Jul 29, 2015
5
2
Primary Interest:
All Treasure Hunting
Coils sometimes need recalabrating say after being dropped or a bad knock
 

airscapes

Hero Member
Nov 13, 2013
973
555
Philadelphia PA
Detector(s) used
DFX 950, U13,6"Exc & 4x6 Coils, Coinmaster GT 4x6 & NEL Hunter coil, TRX Pin Pointer, CZE-T200 FM Transmitter, Sangean DT-400W and ER6i in-ears.
Primary Interest:
All Treasure Hunting
Coils go bad, they can look NEW and even BE NEW and be bad. The coils LOOKS simple but in reality it is a bit complicated. I just received a used machine that came with 3 coils, one is completely unusable and sells for $249, it also look immaculate..
 

Snowmaniac153

Jr. Member
Apr 30, 2015
27
22
So Californa
Detector(s) used
Garrett AT Pro, Garrett carrot, bazooka gold trap
Primary Interest:
All Treasure Hunting
@pistolpete58, how does one recalibrate a coil?? Do at home or is that a send it in type of thing?
 

airscapes

Hero Member
Nov 13, 2013
973
555
Philadelphia PA
Detector(s) used
DFX 950, U13,6"Exc & 4x6 Coils, Coinmaster GT 4x6 & NEL Hunter coil, TRX Pin Pointer, CZE-T200 FM Transmitter, Sangean DT-400W and ER6i in-ears.
Primary Interest:
All Treasure Hunting
Manufacture opens it up and adjust a pot or move a wire that aligns the transmit and receive fields, or more than likely, they just replace it.. Fixing was possible with the old clam shell type coils but with the epoxy molded I don't believe they can be repaired.

Some pics of an XLT 950 coil
EEShells pulled apart.jpg FFwinding after reglue.jpg GGNull wire.jpg
 

G.I.B.

Gold Member
Feb 23, 2007
7,187
8,537
North Central Florida
🏆 Honorable Mentions:
1
Detector(s) used
CTX 3030 / GTI 2500 / Infinium LS / Tesoro Sand Shark / 1 Garrett Pro-pointer / 1 Carrot / Vibra Probe 580 (out on loan) / Lesche M85 / Mark1 MOD1 EyeBall
Primary Interest:
Other
The coil on my Infinium went bad. It's defaulted into finding nothing but pull tabs and can slaw on the beach.

I don't know how to fix it.
 

Top Member Reactions

Users who are viewing this thread

Top