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EQUINOX - have your coke and reject it too!

March 08, 2018 02:23pm

Derek McLennan
Derek McLennan

EQUINOX and the dreaded coke problem…

Gold coins, micro-gold nuggets (0.7g) and cut quarters, located in the ground under coke, are no problem when you wield the new EQUINOX! I hate hearing coke, as it breaks your concentration and you always end up thinking “what have I missed.” This is the main reason I moved onto the Minelab multi-frequency machines. Hopefully this blog will put you at ease with a commonly asked question on Facebook and various forums – “Does the EQUINOX hear coke?”

Both Sharon and I have worked over many months with Minelab during the development testing on the issue of coke and the fine-tuning of the new Multi-IQ technology. Coke contains carbon which is conductive and therefore can be detected with a metal detector. This usually happens when the coke is encountered on the ground surface, or just under it. Coke/carbon also shares Target ID responses with some very fine gold. This coke problem can lead to a lack of confidence in finding tiny ancient gold coins and gold micro-jewelry, especially with users of single-frequency VLF machines.

Minelab EQUINOX and coke

There are many different types of coke. During testing, Sharon and I collected various pieces from all around the UK, all with differing target responses. We then worked intensively with Minelab to make the EQUINOX as ‘coke free’ as possible… if, of course, this target response suits your particular detecting environment and expected finds.

The problem with coke is that it can produce different target responses depending on what type of composition it is, what shape it is, how deep it is, how large it is and how wet it is! As I said, many months of testing have eliminated almost all coke responses, without using coarse discrimination, or broad filtering; albeit there were a couple of varieties from the UK that still gave a distinct response. However, such is the stability of the Target Identification numbers (TID), any coke that could typically be heard, would come in at a solid TID 1 and very infrequently and scratchy at TID 2. As such, the rejection of these two TID numbers would eliminate ALL coke.

Now, the reason that most single-frequency VLF machines cannot successfully notch out coke is because they do not operate in simultaneous multi-frequency and do not have accurate TIDs. The numbers for coke generally fluctuate massively due to the various conditions, size and depth of the coke. Therefore, they hear coke as a loud target response and many users tend to simply put up with it and not discriminate it out. Otherwise, they would have to notch out a wide range of TIDs and hence miss a fairly large range of good targets. Newcomers to detecting will be interested to learn that coke does mask good targets when they are located under or beside it. You will simply hear the coke noise and not the good target. The masking of targets, when combined with the ongoing concentration-destroying signal responses you get from coke, leads to massive frustration when using single-frequency detectors. You tend to register the sound and TID numbers as coke and move on without digging, but not when you use the EQUINOX.

Minelab EQUINOX and cokeThe EQUINOX is the perfect machine to combat the coke problem anywhere it is encountered throughout the world. This is especially important within the UK and Europe, due to the historic uses of coal and the spreading of it upon the fields. However, some very fine gold (sub-gram nuggets or micro jewellery) can still also be unintentionally discriminated out. This is also true for certain TIDs that would give an iron response to tiny fragments of ferrous material, which would be discriminated out by most users not running All Metal.  BUT, with the EQUINOX you have the ability to adjust the settings and hear the coke and tiny iron responses (-3 to +2 TID) if you wish to search in an area that does not have a multitude of coke, but does have the type of fine gold targets mentioned above. A relevant point from the EQUINOX Instruction Manual is: “Field 1 Multi-IQ, even with Target IDs 1 and 2 accepted, will reject more coke than Field 2 using Multi-IQ.”

Note: while the Field Modes excel at rejecting coke, dedicated beach hunters and gold prospectors should use the Beach and Gold modes designed for those respective purposes.

Minelab EQUINOX and coke

To date, we have found many examples of low conductors, including a Victorian gold half sovereign in a coke infested field, an Edward 1 hammered penny and also micro jewellery (sub gram gold and silver earrings) on the beaches in Hawaii – these were all found with the default factory settings, using only an increase in Sensitivity or a reduction in Recovery Speed to gain a little more depth. So, from all of our testing, we can confidently say to you, “Go forth and use your EQUINOX straight out of the box, whatever the environment you play in.”  If you have not yet made the leap from single-frequency to true simultaneous multi-frequency, perhaps now is the opportune time. Catch you all later on from the wet, windy and mysterious detecting islands of Hawaii or the wet, windy wilds of bonny Scotland! Slàinte 

Join our Dug That EQUINOX Facebook group here and Equinox the competition out of the park!


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Great report Derek.
Posted By: Andre16 on April 23, 2018 04:58pm