Welcome to the Coiltek Manufacturing’s frequently asked questions page (FAQ).

This page is designed to provide quick answers to many common questions we get asked from around the world. We hope that it will help you in your prospecting endeavors and lead to quicker results when you have any issues. We intend this to cover a broad range of prospecting queries and not only concentrate on the Coiltek product.

From time to time we will be updating this page with more questions as they arise and encourage you to contact us with your suggestions which could help others with their detecting experience.

1. How long is the warranty for my Coiltek product?
2. Is the warranty transferable?
3. What do I do to claim warranty?
4. Can my Coiltek coil be repaired? Where do I send it?
5. Can I repair any part of my coil like cracked plastic or the plug?
6. Can a coil just stop working? How can I prevent my coil from failing?
7. Can water damage my coil? What coils are waterproof?
8. My coil is noisy / touch sensitive, what can I do?
9. Can I get an extension lead for my coil?
10. If the cable is too long for me can I shorten it? Does this improve its performance?
11. Can I run my Coiltek coil without a skid plate? Does it void my warranty?
12. What are the benefits in using an Anti-Interference coil?
13. I live overseas, where can I get your product?
14. How should I store my coil when not in use?
15. Is round better than elliptical?
16. What goes deeper, an 18” round or 18” Elliptical coil?

1. How long is the warranty for my Coiltek product?
At Coiltek Manufacturing(CTM) we provide a full 12 month warranty on all of our manufactured coils and accessories (some products may vary). This warranty starts from the date of purchase by the customer. This is applicable worldwide. This warranty covers any manufacturing errors like cracks in plastics or performance issues like no response which are from manufacturing faults – usually these are noticeable within the first few hours of use. The warranty does not cover normal use or misuse of the product. The warranty does not cover ‘touch sensitivity’ or noise in coils which develops after several hours of normal use.

For a coil/product to continue to perform well it must be treated with care and not be used in a way that will jar or incur any sudden impact. This sudden impact may result in developing a noisy product. CTM, at its sole discretion, will determine the nature of the returned item and decide whether it is a warranty issue. Each individual case will be reviewed on its own merits and the more information you can provide the easier it will be for us to make a quick decision.

2. Is the warranty transferable?
No, the warranty is only applicable for the original owner.

3. What do I do to claim warranty?
When wanting to claim warranty within Australia, you can either return it to your place of purchase or send it direct to COILTEK MANUFACTURING, P.O. Box 91, Salisbury South, South Australia, 5106. It is essential you include your proof of purchase docket and a short note informing us of the problem which has occurred. Also include your return address and phone number as we may need to contact you regarding the product.

If you have purchased a product outside of Australia you must return it with your proof of purchase to your local dealer who will handle the warranty claims. Ensure you include your return address and phone number whenever returning a product.

4. Can my Coiltek coil be repaired? Where do I send it?
If you are within Australia then in most cases yes. With the standard plastic housed coil we can cut open the coil and replace certain parts however we cannot rewind the coils as they are poured with epoxy so any damage which occurs to the windings are usually terminal. A fully potted coil, (epoxy filled), is more difficult to repair and usually only allows us to re-terminate the cable with a new plug.

Replacing cables and plugs are usually quite easy and can sometimes make the coil work well for many more years. However, not all coils can be repaired successfully depending on the extent of the damage and the age of the coil. We individually assess each repair so as to ensure we make the correct diagnosis. There is a repair charge plus freight if the coil is outside of its warranty period. If you wish for your coil or any product to be repaired or reviewed you can forward it to us and we will assess the situation. Please include a note with your contact details and comment regarding the products behaviour.

If you are outside of Australia then usually it is quite expensive to return the coil to us and if out of warranty can sometimes mean a new coil purchase. Please contact your local dealer for more information.

5. Can I repair any part of my coil like cracked plastics or the plug?
Usually yes especially if you are in the middle of a planned trip and cannot get the coil back for repair. If there are cracks in an older coil them the use of Araldite or a two part epoxy will help prevent them getting any worse. Regular inspection of your product can ensure you get on top of any damage early and help you use it for longer. At your earliest chance we recommend you forward the coil back to us so we can properly repair your coil for your next trip. If you need to repair a plug, then basic soldering skills are necessary. You will need to either buy a new plug or reuse the existing one and re-terminate the wires to the correct pins. By looking at the existing plugs configuration you will see where the wires terminate. This is crucial for correct operation of the coil.

6. Can a coil just stop working? How can I prevent my coil from failing?
Sometimes this can happen depending on the age of the coil or how it has been stored. The most crucial part to protect on the coil is its cable, especially where it enters the coil housing. If the cable happens to break at this point it is not fixable in the field and must be returned for repair. If your coil is a fully potted coil like the UFO and there is a break at this part of the coil then the coil is not repairable as there is no way into the coil due to the hard epoxy which covers the termination area. You can tell if this has happened because you will get a constant loud signal and by moving the cable left to right at the point where it enters the coil you could hear the signal stop and then come back. This means there is an open circuit. We recommend you turn off your detector quickly and avoid using the coil until fixed or replaced.

To prevent coils being damaged ensure your coils are stored carefully and no moisture enters the coil. Always check the strain relief area where the cable enters the coil for cracks or signs of wear. Regular inspection can help prevent things going wrong in the field.

7. Can water damage my coil? What coils are waterproof?
Definitely yes, only if the water gets to the internals of the coil. If you have a fully water-proof coil then water will not damage the coil but if you have a coil which is not water proof then submersing the coil is not recommended. Water will short out any contacts and make the coil extremely noisy. The shielding of the coil will be compromised and if the water damage is vary bad, can completely right off the coil. For a complete view of what our coils do and which ones are water-proof check out our Coil Comparison Chart. For quick reference here is a list of water proof coils we manufacture, the rest are only water resistant:
1” Pinpoint probe
12x8” Platypus coil
17x10” Mini UFO coil
15” All Terrain coil
24x12” UFO coil
40x20” Drag coil

8. My coil is noisy / touch sensitive, what can I do?
Sometimes coils can develop a thing called ‘touch sensitivity’. This is when the detector is in operation and the coil comes in contact with the ground via sticks, rocks or grass. When it hits these object a sharp ‘ping’ sound is heard which can sometime resemble a small, close to the surface target. A quick recheck over the area shows no sign of a repeatable target.

Coils which are fully potted with epoxy can usually display behaviour like this due to a shielding nature and are best run just off the ground. This is also due to the coil being extremely sensitive to ground conditions.

Sometimes atmospheric conditions can cause this due to high electronic activity within the atmosphere. This can come from storms, windy days especially hot ones and salty ground conditions. Trying to eliminate the noise of the coil can be difficult and can sometimes mean an Anti-Interference coil will be better for this area.

Coils which are not potted but housed in a plastic top and base can sometimes have increased noise due to an expanded case. When you press on the plastics there will be a noticeable bulge in the housing. This is mainly noticeable on older coils or coils which have been in a high heat situation like the car boot on a 35degC day. The air which is trapped in the coil housing expands and because the plastics slightly soften with the heat it tends to create bulging areas. We have noticed an increase of noise and touch sensitivity with coils which develop this attribute. To rectify this follow the steps below:
1. Place the coil on a flat table like surface and undo the strain relief where the cable enters the coil.
2. With one hand press down firmly on the top of the coil concentrating mainly on the bulging area and with the other hand slightly wiggle the cable where it enters the coil. Sometimes you can hear the air being pushed out of the coil housings.
3. Continue to press down on the coil so it does not relax and suck in any air and place a little silicone around the cable entry point and clamping area then re-tighten the strain relief top into position.
4. The coil housing should now feel firmly against the inner part of the coil which can reduce noise and touch sensitivity.

If this problem persists and the coil is unstable we recommend you return it for repair.

9. Can I get an extension lead for my coil?
Yes, we can make an extension lead for almost any coil. There are certain lengths which limit performance and for DD or Anti-Interference (A.I.) coils there is a link which needs to be removed from the coil plug for the extension cable to work efficiently. The diagram for the link remove modification will be supplied upon request when purchasing an extension cable. Maximum lengths suggested are:
• DD or A.I. CABLE – 4 metres (total length including existing cable length)
• MONO CABLE – 10 metres (total length including existing cable length)

NOTE: at the maximum suggested length there potentially can be some performance loss due to resistance in length of cable.

10. If the cable is too long for me can I shorten it? Does this improve its performance?
Yes, shortening a coil cable is fine however there will be a minimum distance required from the control box and headphones. If you are too close to these parts then there can potentially be an increase in noise through your detector. We really only notice performance issues when the coil cable is too long. The increased resistance of the length of cable affects the coils ability to transmit and receive within the frequency of the detector. The standard coil cable length is perfectly adequate for the detector to perform its magic and we have noticed no performance increase when shortening the cable below this length.

11. Can I run my Coiltek coil without a skid plate? Does it void my warranty?
Yes. However it is always recommended to use a skid plate to avoid any unwanted damage to the coil base especially with the plastic housed coil type. The fully potted coils are made so they can be run without a skid due to their durability. Running a Coiltek coil without a skidplate does not void warranty.

12. What are the benefits in using an Anti-Interference coil?
An anti-Interference (A.I.) coil has unique abilities which set this coil apart from the others. Its main purpose is to eliminate any external interference which the metal detectors are susceptible to. The interference can come from Salt Lake hunting, electric fences, power lines, phone towers, metropolitan areas, airports, solar activity etc. By using a coil of this type you can use your detector with little or no interference noise unlike a DD or MONO.

The next benefit is that the performance of the A.I. coil is only approximately 5% down on a DD coil of similar size. Therefore you can be assured that you are getting excellent depth and sensitivity where ever you use this coil type. This coil type has already been used with great success on and around salt lakes and directly under power lines in a gold bearing area. It has helped many obtain more targets in these areas as in the past no detectors could hunt in these locations with any great success. We have many people using these coils as a general hunting coil. We believe it is an essential tool to have in your detecting kit.

13. I live overseas, where can I get your product?
We currently have an extensive network of dealers and distributors around the globe. Please see our International dealers page for one closest to you or contact us and we can advise you the best place to purchase.

14. How should I store my coil when not in use?
Storing coils properly is essential to ensure good life from your product. The main area to protect is of course the cable, especially where it enters the coil. Most of the failings we see are at this point mainly due to constant use or pressure being placed on the entry point.

When storing the coil make sure that the strain relief area has no pressure placed on it by way of other objects laying on top or being placed in tight areas. The more the cable bends in this section the more the risk of it breaking wires internally. We suggest protecting this area by means of cardboard packers or bubble wrap wrapped around the strain relief. Remember that the last thing you need happening is a coil failing in the field when you have travelled a great distance to get there. Always check you full kit before you leave!

15. Is round better than elliptical?
This answer depends on what ground you hunt and what you prefer to swing. However here are some points which might help you decide what you would like to use. With the round coils you have a broad search field being emitted and this can help with depth but with the larger round coils (18” and above) can reduce your sensitivity to the sub gram targets. The round coils have the ability to cover lots of ground but can be hindered somewhat if the terrain becomes overgrown or covered in large rocks. They can pinpoint well but do take some time to find their ‘sweet spot’ but many operators are very confident with these coils.

The elliptical has a narrow search field but can compensate for this as it is longer from tip to heel. It has a better ability to maneuver through tight detecting areas and can also pinpoint a little better due to the tight field at its ends. They have a great ability to cover lots of ground as they are usually longer than the equivalent round which can save time. Also because they are quite narrow compared to the round they provide a better target separation which means when you encounter two targets close together the coil can help identify to the operator that there are two targets in the ground. The Elliptical is a very popular coil for its all round ability.

By assessing your hunting area and knowing the approximate depth you wish to search to will help you choose what coil to use for that area.

16. What goes deeper, an 18” round or 18” Elliptical coil?
To answer this question we must understand that these two coils are not equivalent in size or shape even though they both are 18” coils. The round coil provides a much broader magnetic field which improves its depth capabilities. So the 18” round will have better depth than the Elliptical but the Elliptical will have better sensitivity to the smaller targets due to its tighter magnetic field at the tip of the coil. To make this question more even we must compare an 18” round coil to something like a 24x12” Elliptical coil. The two coils would be quite close in depth capabilities. The 18” round has a broad magnetic field and the 24x12” Elliptical has a long magnetic field area. This long area helps the coil’s field penetrate into the ground as the broad field does for the round. The elliptical coil would have slightly better pinpointing ability than the round due to its shape. So the answer to the main question is that the round 18” coil will go deeper than the Elliptical 18” coil.