The best coil for ICQ 250. Making a DD coil “for gold”

As many users as there are, there are as many opinions. Every self-respecting treasure hunter tries to express his opinion, advise something and offer solutions to a particular problem. But such “advice” is not always relevant and correct, either due to a lack of experience and practice, or due to the desire to create a new “manual” based on the same erroneous opinions. In order to avoid confusion and, as a result, wrong decisions, we decided to make a review and dispel all the myths and inaccuracies in the instructions and tips for using the Garrett Ace 250 metal detector. And so, let's begin.

How to select search mode for Garrett Ace 250?

This question is quite relevant, since there are a number of features that many do not know about. Let's look at everything in order.

Search mode – All metals (ALL-METAL)

This is the simplest search mode. It excludes nothing and reacts to all metals. In a word, I turned it on and went looking. Everything is simple here.

Search mode – Jewelry (JEWELRY)

The name itself indicates its purpose - searching for jewelry. In this mode, “garbage” – small ferrous metal () – is eliminated. But there are two sides to the coin. He perfectly sees crosses, coins, rings - anything that has a high metal density. But objects made of low-density metal, for example, woven chains, small earrings, will most likely fall under the discriminant and go into the “garbage”, that is, the metal detector will identify them as small black metal.

Custom Mode (CUSTOM)

This mode is selected automatically if discrimination is configured manually. That is, certain sectors of the discrimination scale are turned off or on. The advantage of this mode is the ability to disable the last sectors, those into which large objects are most often thrown. But here there is a risk of missing gray metals - silver royal coins, etc.

Relic Mode (RELICS)

The main purpose is to search for military (and not only) artifacts and sift out small “garbage”. This includes weapons such as daggers, sabers, etc. But there is also a minus in this mode. The search algorithm for this mode is tailored for objects of certain shapes, medium-sized, narrow objects, mostly of medium length. But a variety of fittings, leftovers, and construction products etc. In a word, this mode is relevant in areas where there is confirmed information about the origin of some kind of military action or ancient settlements.

Coin Mode (COINS)

This mode filters out the most garbage, leaving only coins. This is facilitated by selection for round coins, which we will discuss later. But when you select this mode, all targets specified in the previous discrete modes are eliminated. The metal detector will not see various artifacts, precious chains and earrings.

Conclusion

“So which mode is better?”, you say. There is no optimal solution for all problems; it all depends on the goals set. If you are new to this business, here’s some advice for you - set the “All metals” mode and go searching. First, you will need to dig everything to get used to the metal detector and gain experience. But over time, you will begin to distinguish beer caps from coins :).

What is selection for round objects?

While studying the intricacies of treasure hunting, most users have come across or at least heard such a thing as selection for round metals in the Garret Ace 250 metal detector. The word selection means “choice”. In our version, this is a selection of round objects focused on coins. But unfortunately, very often this “bar” includes various beer caps, medium-sized nuts (like a coin), in a word - everything that looks like a coin. This function cannot be turned on or off - it is part of the search algorithm that the metal detector uses.

Conclusion

Selection for round objects is very useful for finding coins, but at the same time “false” in terms of unwanted garbage. In a word - we dig and dig again.

How to choose a reel for Garrett Ace 250?

This question is probably the most relevant and occupies the TOP positions for queries in search engines. Some shout Nel, others say Mars, and there is nothing but controversy around. Let's put everything in its place.

ICQ comes with a standard PROformance 16 x 22.5 cm (6.5 x 9 inch) mono reel. The reel is quite good, and considering that it mono coil– has good stability. For example, consider two additional coils: Nel Tornado and Mars Tiger. We chose these reels because they are the most popular among medium-sized reels. First, let's figure out what their main differences and advantages are.

As can be seen from the figure, the mono coil has a narrow grip, which decreases with increasing depth. This is its main problem, which makes you think about purchasing an additional coil. The Nel Tornado reel is developed using DD technology and has a wider grip. This allows you to speed up the time to cover the territory by 60%, compared to a standard reel. Losses in capture are noticeable at a depth of 25 cm. Mars Tiger (also a DD coil), in turn, has less capture and, accordingly, will require more time, unlike Nel Tornado. But thanks to its oval shape, Mars Tiger makes it easier to determine the center of an object.

The following picture shows the "straight on" view from which the feature of the DD coil can be seen. We are talking about the fact that DD coils react to an object at the moment of crossing the center, since the active zone is located at the intersection of two turns of the winding.

If we talk about depth, then there are also many questions. Firstly, the search depth depends on the mineralization of the soil. The heavier the soil, the greater the losses. Depending on the soil, losses can range from 20 to 60%. For a clear example, we did a series of tests with different objects on black soil. Here's what happened:

Conclusion

Based on the tests and the shown circuits, we can highlight both pros and cons of both coils. The choice, as always, is yours.

What is a mask of discrimination (discrimination)?

As you know, one of the main advantages of ICQ is discriminability, that is, the ability to distinguish non-ferrous metals from ferrous metals. When searching, the metal detector indicates the expected type of metal on a scale consisting of 12 sectors. The first three are ferrous metal, starting from the 4th to the 8th are yellow metals such as gold. Well, from the 9th to the 12th - these are gray metals, for example - silver. But if you look closely, there is another range, from the 5th to the 12th sector, above which is written “COPPER”, which makes you think about how to determine, for example, the 6th or 7th sector. For this purpose, there is a discrimination mask that displays approximate response options of the metal detector.

As you can see from the diagram, under the scale that displays gold you can find many non-golden objects.

Conclusion

For beginning treasure hunters, the discrimination mask must be constantly in front of their eyes in order to compare the found objects with the signals of the metal detector. As in previous conclusions, we emphasize an indisputable fact - with time and experience, you will learn to feel the difference between copper and silver. Well, don’t forget to “carry with you” a little luck :).

Which is better: batteries or rechargeable batteries?

I see it very often on forums and social media. networks and other spaces on the Internet, disputes about the choice of power supply for a metal detector. When purchasing ICQ, simple, disposable batteries are installed by default. Some treasure hunters immediately buy batteries, while others prefer disposable batteries. Let's figure out what the pros and cons of batteries and accumulators are. I will not explain in detail the concepts of capacitance, voltage, etc., since most people are simply interested in the output. Here is a great example comparing GP alkaline batteries and Ansmann EC250 batteries.

Simple batteries:

The batteries will last for more working time within one cycle - this is a plus;
They are relatively inexpensive - this is also a plus;
You need to constantly buy - this is a minus;

Batteries:

The operating time of one cycle is less than that of simple batteries - this is a minus;
More expensive than simple batteries is a minus;
You don’t have to constantly buy – that’s a plus;

Another important fact is the charge of the battery, regardless of its type. If the charge level drops by 2 positions, false signals may appear, and the depth decreases by 10-15%. So keep an eye on the battery indicator.

Conclusion

If treasure hunting is a hobby for you, and you go out searching once a month, batteries will be enough for you. Well, if a metal detector is your second life, then you need to buy batteries. Although you will have to shell out a hefty sum of money when purchasing, the total amount you could spend on simple batteries will be many times higher. Well, don’t forget about the environment, don’t throw away batteries. All batteries must be disposed of.

Sincerely, Your Digger.

1. We cooperate directly with Nel! Direct deliveries, only certified products with a branded two-year warranty!
2. Delivery to Russian cities by mail! Dispatch in special safe packaging. Fast and reliable!
3. Return without problems! If the reel has retained its presentation and working properties, we will return the money without any questions asked!

5th generation coil. Increase in depth up to 50% compared to standard devices!

The NEL Tornado 12x13" reel for Garrett ACE will delight all ICQ owners with new features. Nel Tornado not only increases the detection depth by up to 50% compared to a standard coil (the new Tornado sensor is equipped with a built-in signal amplifier, which increases the detection range both in the air and in the ground), but also provides better target discrimination at any depth .

The design of the coil is characterized by increased rigidity. The additional rigidity of the coil ribs increases the sensitivity of the sensor by reducing the level of interference and the number of phantom triggers. The device is equipped with plastic protection. However, under favorable search conditions, protection may not be used, since the strength and quality of the coil compound allows this. The new Nel sensor for the Garrett Ace weighs 560 grams. This is weight without protection. If you want to make working with the metal detector easier and extend the search time, you don’t have to install protection. Moreover, such an opportunity exists, as we have already said above. Plus, the impact-resistant plastic from which the sensor body is made is resistant to ultraviolet radiation. There is no risk of overheating on a hot day for the Nel Tornado. The reel is 100% waterproof. You can work with it in streams and not worry about the “health” of the sensor in a rainstorm.

Among the design features of the coil, it is worth noting the strong fastening of the device to the metal detector using rubber rings for better fixation, as well as an elastic sealed lead that provides reliable protection from moisture, dust and dirt. You don’t have to worry at all about the tightness of the sensor, the strength of its attachment to the rod and, as a result, the stability of its operation!

In conclusion, we will say that all Nel coils undergo mandatory testing for range and depth of target detection. Moreover, the tests are carried out exclusively in conditions close to field conditions.
We wish you great finds and suggest you buy a NEL Tornado 12x13"" coil for Garrett ACE in our online store in Moscow!

Even more finds with the Nel Tornado reel in old places!

Test:

41 cm

30 cm

Characteristics:

Type: Double D
Compatibility: Garrett Ace 150, 250, 350, Euro, 400F2, F4
Size: 12x13 inches (30.5x33 cm)
Weight: 560 g
Additional protective coating for greater durability
Waterproof: 100%
Color: black/gray
Warranty: 24 months

Clean the connectors with acetone, dichlorethane or other available solvent.
Keep metal objects at a distance from the operating sensor
Wrap the wire tightly around the rod, additionally secure it with electrical tape in places where it sags
Turn off the phone while working with the coil
Install new batteries

What will you have in the kit:

Reel included Nel Tornado for Ace 12x13 (30.5 x 33 cm) - 1 pc.
Coil protection 12x13 - 1 pc.
Fastening bolt - 1 pc.
Cable clamp - 1 pc.
Rubber gasket rings - 2 pcs.
Plug plug from dirt - 1 pc.
Branded Warranty card for 2 years - 1 pc.
Branded box packaging - 1 pc.

DELIVERY in MOSCOW

Delivery of orders in Moscow is carried out daily, seven days a week, at a time convenient for you. For order values over RUB 10,000, delivery Free,
350 rub.

DELIVERY TIME IN MOSCOW

PAYMENT FOR ORDERS:

1. Cash courier. In Moscow, you can pay your order in cash to the courier upon receipt.

2. Pickup in our Store: Metro Komsomolskaya, Kazansky railway station, Komsomolskaya square d2, Kazansky shopping center pavilion 24
Opening hours: Mon-Sun from 09.00 to 21.00 (daily, seven days a week)

3. Prepayment to a Sberbank card

4. On credit: purchase on credit conditions

The search coil from the standard Garrett ACE 250 kit is self-sufficient in itself, and at first easily covers the needs of the search engine. But there comes a time when you want to increase the depth of your metal detector. Depth and speed of soil cultivation. And here for the owner of this detector, a new topic opens up, additional coils.

The Klader store has a very large selection of metal detector coils. Choice by manufacturer: from branded Garrett coils to third-party manufacturers Detech, Mars, Nel. In size: from high-precision Sniper coils to super deep coils, capable of squeezing the maximum detection depth from any metal detector. Overview, compatibility and all search coils for ACE 250.

The standard Garrett ACE 250 reel, which it is equipped with initially, has the properties and capabilities that are exactly what a standard reel should have. Excellent separation of targets into their group (metal discrimination, ACE 250 has 12 groups). The accuracy of the discriminator’s operation determines how many holes you will dig in which lies a find that does not meet expectations. The metal detector coil is directly related to this accuracy.

Work at maximum sensitivity. With a standard ACE 250 coil, you can easily increase the maximum sensitivity of the metal detector, and at the same time you will maintain search stability, without false alarms. Accurate pinpointer. On a standard coil, the Garrett ACE 250 has one of the most accurate pinpointers, features accurate localization of small targets. When using large coils on the Garrett ACE 250, you will understand this (smeared pinpoint, one of the disadvantages of large coils). And the weight of the reel, the standard ACE 250 reel, has one of the smallest weights. Such a gentle load not only preserves the integrity of the entire structure of the metal detector (from loosening), but also does not overload the hand.

Which reel is best for the Garrett ACE 250? The choice of coil depends on the type of finds and the place where you are going to go with your Garrett ACE 250 metal detector. To increase the depth, of course, you need to use a large coil. This addition will not only increase the depth of target detection, but will also significantly speed up the speed of surface processing. But for beach searching with the Garrett ACE 250, the size of the coil is not important, and a very large size will even interfere. On the beach, finds do not lie deep, and are often in sufficient concentration to allow several to fall simultaneously under one pass of the coil. For a beach cop with a Garrett ACE 250, it is better to choose a medium-sized reel (up to a maximum of 13 inches), but with a DD type (Double-D, DD). It will allow you to gain an advantage on small targets, and provides some compensation for the influence of mineralization (for example, sea sand).

With all the advantages of large reels, the size also has disadvantages. With a large reel, the pinpoint works less accurately, and sometimes you won’t be able to pick up a small coin with one pick. Larger coils consume more power. The large coil is susceptible to external electrical noise, which can add false alarms. A large reel has a weight corresponding to its size. Which affects the overall balance of the metal detector design, and hand fatigue (especially at the end of the searching day).

The most optimal solution for the Garrett ACE 250 is a combination of two coils. One is a regular, medium-sized one, for example the same standard Garrett ACE 250 coil. The second is a deep coil, which is used specifically for deep search and quick reconnaissance of the area.

Garrett ACE 250 Coil Compatibility

Coils for Garrett ACE 250, by default suitable for all series of Garrett ACE metal detectors. The same coil connector to the metal detector control unit, the same mount on the metal detector rod. Garrett ACE 250 coils are also suitable for Garrett ACE 150, Garrett ACE 350, Garrett Euro ACE metal detectors.

All coils for Garrett ACE 250

The Klader store has the largest selection of coils for the Garrett ACE 250 metal detector. There are branded Garrett coils from the manufacturer. There are coils for Garrett ACE 250, third-party manufacturers. Detech reels, Bulgarian manufacturer. From our experience, Detech coils on the Garrett ACE 250 are one of the preferred ones. Excellent workmanship and reliability in the field. Let's make a special mention of Detech coils. Stable operation of the coils, without false alarms and maintaining the original compliance of the metal discrimination scale.

Cheaper reels for Garrett ACE 250, third party Mars and Nel. Domestic coils for the Garrett ACE 250 are most often purchased to dramatically increase the depth of the metal detector.

1080 878 Search with a Garrett ACE 250 metal detector http://site/wp-content/uploads/2013/11/cda775a0bad3-1259x1024.jpg 01.11.2013 23.03.2018

I decided to wind the reel “on gold”. According to my estimates, it should be a small DD coil operating at double the frequency. If the native coil on the ACE 250 gives approximately 6.5 kHz, then I will try to develop 11-12 kHz on a “homemade” one.

Let's try to see at what frequency the ACE 250 is currently operating:

I did this. I wound a test probe coil. This is said loudly, because winding took... 10 seconds. Here it is:

There are only 5 turns in the test coil (I took one core from the so-called “twisted pair”). The picture also shows a connecting cable (“twisted pair” 2 m long) and a connector (“jack” in green electrical tape) - it is needed to connect the test coil to the computer sound card. The connector/jack/plug contains two limiting diodes KD103, connected back-to-back, they are designed to protect the microphone input of the sound card from interference and overvoltage (based on the results of the first application, it turned out that diodes do not need to be installed, see below).

Next, I needed to temporarily turn my computer into a virtual laboratory. I went to this site and picked up an oscilloscope and a frequency meter - they are listed first on the site, I’ll show you what they look like below.

I turned on the ACE 250 with its original 6.5x9″ coil and placed the coil on a test coil-probe, which, in turn, connected to the computer’s sound card at the microphone input (i.e., I pulled out the audio cable coming from the webcam and plugged in my own). On the screen of the virtual oscilloscope, I saw that the probe, despite its simplicity, picks up the signal emitted by ACEY. You can calculate in milliseconds exactly what frequency is generated by the ASI coil, but it’s better install Wirth. frequency meter and look at it.

The virtual frequency meter showed a frequency of 6700 Hz.

conclusions: the test coil-probe is working, the virtual instruments also coped with their task. Judging by the shape of the signal on the oscilloscope, the probe has sufficient sensitivity, in addition, we can conclude that protective diodes (KD103) are not needed: no signal overload is observed on the oscillogram, although the probe was located close to the emitting coil. The probe shown works either from the microphone input of the sound card or from the linear one (I have it integrated into the motherboard).

We have the devices. (I recently noticed that the virtual frequency meter shown could not work with WINDOWS7 (x64), so I advise you to use the virtual spectrum analyzer Simple Audio Spectrum Analyzer to measure frequency specan22 from this site, the program also works under WINDOWS-10). Now you can move on to the practical part, namely: wind a small coil (one half of the future DD coil) and connect it to the generator part of the ASI circuit, reaching a resonance of 12 kHz.
I wound this coil from twisted pair wires.

There are 9 turns of this cable, devoid of an outer sheath, i.e. 9 x 8 = 72 turns, respectively, soldered end-to-end. I connect the coil output through a 1.1 Ohm safety resistor to contacts 1.4 of the connector (bought for 5 UAH). In order to prevent the ASI input from being excited, I temporarily solder a 10 Ohm resistor to pins 2.3 (to which the Rx coil will be connected). Here is the diagram:

I plug in the connector and turn on the ACE 250 - it beeps twice and turns on as usual, without noticing the change. The oscilloscope showed the presence of generation of the “newly appeared” Tx coil (the signal was recorded with a test coil-probe):

And the frequency meter showed the expected frequency:

The sound card was a little capricious - it didn’t want to recognize the test probe coil as a microphone, so I had to trick it by soldering a 10 kOhm resistor and a 0.47 µF capacitor to the coil, see pictures:

I made the receiving coil with 11 x 8 = 88 turns (I found a “twisted pair” of a slightly thinner diameter, so the coils seem the same, although the Rx has 22% more turns).

Now we have both halves of the DD coil, let’s check the possibility of “combining” the coils.

I connected the Tx coil to the ACE 250 (see the previous message for the diagram for starting the Tx coil from the ACE 250 generator), and connected a multimeter to the output of the Rx coil in the alternating voltage measurement mode. By moving one coil relative to the other, you can easily get three zeros after the decimal point in alternating voltage on the receiving coil, i.e. “Mixing” the coils is done without problems. I outlined the relative position on the underlying piece of paper in order to roughly transfer the configuration to the future “bed”.

The coils turned out to be “plump” - when they are round, they have a diameter of exactly 10 cm from edge to edge, they can easily be turned into oval ones:

For the sake of beauty, I introduced a multimeter into the frame, but mixing with it does not work. However, if you remove the measuring device by 30 centimeters, then by mutual movement of the coils you can easily achieve “zeros” on the display (i.e., an imbalance of less than 0.001 V).
Of course, I will make the DD coil using oval coils: the sensitivity will be lower than on round coils, but judging even from these pictures, the area of “transmission” of the ground with oval coils is 50 percent larger.
The main estimates have been made, installation will begin soon.

Don’t think that I’m using waste cheap materials, in fact, it’s the other way around - these are the best materials. The coils are made of wire in thick polyethylene insulation with a twist, which helps to reduce the interturn capacitance and, ultimately, gives a high quality factor Q, which means a well-pronounced inductive effect and a large circulating current in the generator coil Tx, high quality factor is also useful for the receiving coil Rx . The coils are “loose”, i.e. there is no mechanical tension in the wire - this gives increased thermal stability. (When heated, the polyethylene will “move”, where outward, where inward, and the total area of the coil will remain unchanged, which means L = const, R will change when heated, you can’t get away from the formulas, but it will change less than with simple coils, since initially there is no mechanical tension). There are others positive effects(for example, the absence of aging of the wire insulation due to magnetostriction - it is because of this that the varnish on conventional winding wires wears out). The coils are wound without any tricks, in one minute, on an ordinary coffee can. It is also important that in the assembled structure, in addition to the wire, there will be no radio components (and remember entire boards with radio components and trimming resistors (!) in coils from “brands”). Even higher parameters can be obtained by using a twisted pair cable for computer networks, in which each core is made of stranded wire - but I did not find this on sale, and this one was just on hand.
Very modest expenses had to be incurred for the manufacture of the connecting cable (connector - 5 UAH, 4 pieces of stranded oxygen-free copper wire in fluoroplastic insulation and a silver-plated copper screen - 4 x 2 m. x 1 UAH = 8 UAH. The fifth wire is intended for connecting the static shielding of the coil with the “ground” of the ASI block - also in fluoroplastic insulation, multi-core MGTF - 2 m x 1 UAH = 2 UAH. Heat-shrinkable tubes were only meter long - another 4 UAH). As a result, the cable together with the connector cost 19 UAH.

The cable turns out to be the best of all possible (without exaggeration): each coil will be connected to the ACE 250 unit with two shielded cables, the signal will not be transmitted through the screens, the “ground” connecting the “ground” of the ACE 250 unit with the static screen of the DD-coil goes through a separate wire from pin 5 of the connector (see diagram). All wires of the connecting cable are MGTF. (The radio amateur will immediately notice that the “ground” is separated by a “spider” - thus, all interference coming from the environment in different phases and amplitudes will be mutually subtracted at point 5 of the connector).
(For reference: all spacecraft cable routing is done only MGTF wire).

So the dug graphite came in handy))). It weighs about 20 kilograms, apparently from an electrolysis bath, there are 3 holes on top for connecting the cable.

Both coils and the "bed" are shown here. The bed / slipway / substrate is fiberglass, 3 mm thick, mounting the coils on it means that there will be no work on the bottom of the future DD-coil - in fact: put the Rx, Tx coils on the bed, bring them together, fix them with epoxy with fiberglass and EVERYTHING .

In the morning I went to the garden, sawed off a piece of graphite from my “super stash” and took further steps along the coil.

I took a 10 mm drill, drilled a hole and a little dispersed it in a graphite cube, and collected the resulting powder. I wrapped the Rx spool with cotton thread to improve adhesion with PVA glue. I mixed glue with graphite powder in a ratio of 50 to 50 and coated the Rx coil with this mixture. He put the oiled coil on the place designated for it on the “bed” and left it to dry. I won’t coat the Tx coil with antistatic at all.

The Rx coil, coated yesterday with “antistatic”, has dried out. I checked the resistance of the graphite screen:

I cut the screen (you can see the red stripe from the insulating tape) and started working on the connecting cable.
After I made the connecting cable (stretched 4 shielded wires and one simple wire into a heat-shrinkable tube) and soldered everything (both coils and the shield wire, see diagram above), then connecting the connector to the ACE 250 and making sure that everything works (the frequency dropped to 11 kHz), reduced the coils to an imbalance of 1 mV and tested a DD coil with a golden earring on the table in comparison with the original coil from the ACE 250.
Outcome. For a buttoned gold earring it became 17 cm, but it was 13, for an unbuttoned one: it became 7 cm, but it was 5. The longitudinal size of the “asa” coil, 6.5x9″, is 22.5 cm, and mine, size 5x5.8″, is only 12 cm.
It is interesting that the scale of discrimination has shifted significantly in the area of ferrous metals (expanded), and starting from the USSR nickel, it has remained the same and in its place, 5 kopecks. USSR and 50 kop. Ukrainian. - they respond with “bellton”, but the nickel is Ukrainian. from stainless steel it moved one cell to the right (scale cell 2). Pinpoint works. I also noticed that for 25 kopecks in Ukrainian, 50 kopecks in Ukrainian and a nickel of the USSR, the sensitivity, in comparison with the native reel, fell, but for gold it increased, i.e. the gold “stuck out” against the background of the walker, as intended.

If you click on the left frame - this is the first step in filling the coil with epoxy with fiberglass - you can see the “ground” drain from the screen. It is a bare copper wire, 10 cm long, fused in places with a soldering iron into a graphite screen.

In the meantime, I repaired the original “Asin” coil, there were nicks, and with the remaining black putty (epoxy with SAMSUNG laser printer powder) I glued a couple of fiberglass patches to the sensor. My baby is moving towards the finish line, I’ll soon take him out for a walk and breathe some sea air, although I didn’t get it right with the epoxy - it dries slowly. Please note that the Rx and Tx coils were not actually impregnated with epoxy before the wires - this is as intended - this also saves weight, but the main thing is maintaining the highest electrical quality factor Q. We get an armored body made of epoxy resin with fiberglass, but the coils themselves are dry, The epoxy didn't reach them.

Below is a comparison of the main parameters of a new homemade “gold reel” and a small native coil from ASI (I show two screenshot specan22 programs).

The reel was more or less successful, after checking the new reel made on a nearby beach (it showed 10 cm on the primer in the sand, which made me very happy), I immediately wanted to go to the beach and have a real run with it.

The first vacationers appeared on the city beach of Kerch, so I chose a quiet corner outside it. This place was examined a couple of days earlier with two coils (6.5x9″ and NEL Tornado), however, my homemade baby suddenly began to pull out USSR pennies and Ukrainian nickels. It was clear with Ukrainian stainless steel nickels - previously, if you turned off the first square of the discrimination scale, the device saw them, but did not voice them, because it considered them ferrous metal, and the new coil operating at a frequency of 11 kHz “stretched” the left side of the metal scale (as at Ace 350 Euro) and began to squeak “color” on the stainless steel. But the USSR kopecks really became an indicator of the quality of my reel, because some jumped out from a depth of 15 cm and were clearly missed by me earlier when I was using my original and “Tornado” reels. Despite its small size, the reel showed quite a large coverage, similar to the usual one from the native Asevskaya 6.5x9″ reel (along the center line the coverage was 18 cm for a 10 kopeck coin lying on the sand surface), so I did not have to compact steps when searching.

Then I came across an openwork silver chain. I'm not sure that I could find it with the original Acev coil (I'll have to check).

Found a silver chain somewhere here.
I liked the sharp sound and sharp reaction to the target, probably characteristic of this type of coil.
The clouds began to thicken, a cold breeze blew, and in order to avoid getting caught in the downpour, I drove home.

Modest discoveries made during testing. The gold medallion was raised two days earlier using my native ASE reel, I’m showing it because I also tested my “gold reel” on it.

The frequency response of the coil is shown in comparison with other coils (practical screenshots specan22 programs of some reels for ASI in comparison with this new-made “gold reel”).

I started the article in December 2013, but I carried out the final test of the reel’s reaction to small gold only at the beginning of June 2014, together with a friend.

And you can see this coil in comparison with the factory coils for the ACE 250.

And the work of the reel on the beach in 2017 is shown.

— — — — — — — — — — — —

In March 2015, I received questions. I in no way think that there are stupid questions, but I think that there are stupid answers.

Let's start with the first question.

1. Connecting the headphone jack to which contacts, or does it matter?

Answer: doesn't matter. Solder the “jack”, plug it into the input of the computer’s sound card and the probe will begin to receive frequencies emitted by the coils of metal detectors, and the computer, turned into an analyzer, will “figure it out” and show the frequency. a slightly different diagram of the probe and details of the work in the program are given specan22.

2. How are the wires on the coils soldered? 8 in one or in colors with each other? How did you get 2 exits?

Answer:

This is the future Tx radiating coil (the second Rx coil will be made according to the same principle).

In the main text (see above) I write: “There are 9 turns of this cable, devoid of an outer sheath, i.e. 9 x 8 = 72 turns, respectively, soldered end-to-end.

Let's describe it in more detail.

First, I wound 9 turns of cable on a coffee can (the diameter is approximately the same as a liter glass jar), then I removed the coil, grabbed it in four places with white electrical tape and began to unsolder it. Those. Before I started working on turning it into a single coil of 72 turns, I had 8 separate coils of 9 turns each (or 8 “beginnings” and 8 “ends” lying opposite each other - I separated them with a conventional red line), which I had to connect it into one coil.

Let's now look at this particular picture of the coil, although it is not very good for demonstration.

We take the first “start” vein we come across - for me it’s a green vein (it dives into the coil in the upper half of all “starts” and is indicated by a red arrow), now we find this green vein among the “ends” at the bottom of the coil (i.e. our green vein made 9 turns and finally emerged among the “ends” - I also marked it with a red arrow) and we solder this “end” to the “beginning” of any other vein (if you click on the frame and look closely, you can see that the end of the green vein is soldered with the beginning of some next vein and an insulating tube with an asterisk is put on the splice). Then we find the end of the second vein and connect it to the beginning of a third vein. We will have to do such operations, on record, 7 times, i.e. make 7 splices of cable cores until there is only one “end” left, which has nowhere to solder - in the picture it is a white core with a green streak.

As a result, we get a single coil of 72 turns, the “beginning” of which is a green vein and the “end” is a white vein with a green vein.

I recently saw this picture and took it to my website - this is how you need to join the ends together to get a single coil, it is clear that there are different colors for the beginning and end of the coil.

3. There are 2 outputs from the coil. Which one should I solder on the connector? Or does it matter?

Answer: Each coil has 2 outputs, in order to test the future Tx coil for frequency generation and measure it, the coil needs to be connected to pins 1, 4 of the connector, and the connector must be plugged into the AC. The completed coil will have 4 outputs, the wiring to the connector is shown in the text. For a long time it won’t matter how exactly the ends are soldered - you’ll have already completed the coil, you’ll go to the beach to test it (and do the final mixing operation, as I recommend to the most inquisitive designers) and only then will you need to cross the ends on the connector and test the pinpointer in operation with "colored" targets. In the literature, such a finishing operation is called “phasing” the coils. I don’t need any equipment; opponents cannot do without a separate generator, oscilloscope and other instruments. A correctly phased sensor does not move the pin away from the object, but clearly shows that the target lies at the intersection of the windings.

4. Does the resistor remain on the TX coil after checking on the computer and assembly on the substrate?

Answer: No, I installed this 1.1 Ohm resistor only to estimate the frequency and not accidentally burn out the ACE 250. There are no resistors, capacitors or anything at all on the working coil, just the coils themselves.

5. How to properly check the resistance on a graphite screen? And why cut the graphite screen?

Answer:

The picture shows that I simply pressed the probes to the graphite screen at opposite points of the coil, the device showed a resistance between the probes of slightly more than 1 kOhm - this is quite normal resistance. The screen will work perfectly with a resistance of 10 kOhm. It is designed so that colossal static charges of tens of thousands of volts flow down to the “ground” of the MD, so the resistance of the shielding coating of the Rx coil is not of fundamental importance.

The annular cut is needed to prevent the formation of a closed loop (turn) in the form of a graphite screen. Despite the rather large resistance of the screen, it seems to me that such a cut needs to be made. Different authors think differently. I was getting the most out of this coil at every step, so I made a cut in the screen so that the screen would never be a shorted TURN on this coil.

6. Is it worth it to cover the TX coil with a graphite screen?

Answer: I left the transmitting coil Tx without a screen. I believe that the screen will at least slightly reduce the signal that will be “pumped” into the ground. Further tests showed a neutral reaction to static electricity - i.e. indeed, it is enough to shield only the receiving coil Rx.

7. What are the dimensions of the coil lugs? What are they made of and what are they glued to? What is the cross on the substrate and how was it calculated?

Answer: It seemed to me that the lugs should have been attached directly to the bed/substrate and not mechanically connected to the coils. I prepared the seats at the ends of the bed and first glued these 2 ears with some kind of glue, and then reinforced them with epoxy and fiberglass in the process of forming the entire coil. The ears are cut from a sheet of textolite, 0.5 cm thick. The distance between them is not standard for the ACE 250. The ears are clearly visible if you click on the corresponding frames above. The lower rod elbow assembly is made from a garden hose "T" splitter and cut to fit frictionally between the tabs. The cross on the backing means almost nothing, it was just clearly visible through the paper sheet on which I did the initial mixing of the coils and outlined their relative positions.

8. Regarding the cable: did you shrink the heat shrink with a hair dryer? What and how was the cable attached to the coil? Well main question: HOW did you solder the cable? They just connected the 4 outputs from the coils and soldered them to the connector, and what did they attach the 5th cable to on the finished coil?

Answers: I heated the heat shrink tube over a regular electric kitchen stove.

The cable simply sank into layers of epoxy with fiberglass and was fixed on the reel.

My cable wiring is better than any factory or homemade reel. Now I will gradually explain why, although I will not describe the physics.

First, I will characterize the wire itself, which formed the basis of the connecting cable: I used 4 identical pieces of shielded MGTF wire and one piece of unshielded MGTF wire, all of them have a length of 1.5 m. This is the best existing multi-core wire (in my 24 it is very thin copper wires with a diameter of 0.08 mm, and its insulation can withstand the temperature of a soldering iron, since it is made of fluoroplastic; its shielding braid (sometimes I just write “screen”) is silver-plated copper, in short, it is an excellent “military” wire).

And secondly, let's turn to the wiring of the connecting cable, which is shown in the blue frame. It can be seen that all the shielded wires are prepared in the same way, as shown in the red frame, namely, the left end has no shield lead (only the wire itself), and the right end has a shield lead, and all such shield leads of the four wires are collected at one point, indicated by a circle. For complete clarity of perception, I’ll add that the cylinder in the red frame is the wire screen, and the signal wire itself runs inside the cylinder, as is usually indicated on most circuits in the world and, of course, the wire is isolated from the shielding braid (screen), the insulator is fluoroplastic film .

All that remains is to deal with the fifth wire, which does not have a screen (but has insulation). Its left end is shown as such a “chicken foot” - in this place the wire has contact with the graphite coating of the Rx coil - the wire there is bare and glued (more precisely, fused with a soldering iron tip) at several points to the graphite screen. No matter how tempting it may be to run this contact through any of the shields of the four wires (and many factory coils sin with this to save copper), I do this with a separate wire (and also of the highest quality).

What do we have as a result of soldering the connecting cable? - all ends of all coils are run along shielded wires, each with its own wire, all shielding braids of wires and the wire coming from the shielding shell of the Rx receiving coil are soldered at one point (and then connected through the 5th pin of the connector to the main “ground” on the MD board) .

The resulting homemade cable is wrapped with electrical tape along its entire length and then pulled through a heat-shrinkable tube.

Theoretically, the parameters of the connecting cable can still be improved if you use not just shielded wires, but each of them is additionally insulated along its entire length (my wires had a bare braided shield).

9. Could you tell us in more detail about mixing the coils? Interested in how to connect the tester if the plug and coils are soldered to the cable?

Answer: You need to measure (and reduce to zero) the AC voltage at the output of the Rx receiving coil and it is advisable to do this in the field. But first you need to test everything on the table in order to make a drawing of the relative position of the coils, and make a bed/substrate based on the drawing.
The pins of connector 1, 4 now go to the ASI block and the Tx coil starts generating from it. The induction voltage is induced in the receiving coil Rx and when tuning/mixing the coils should be reduced to a minimum (to all zeros on the tester). In practice, do this: do not touch pins 1, 4, and completely unsolder the Rx coil pins from the pins 2, 3 of the connector and connect the tester to these wires (solder the probes) in the AC voltage measurement mode. After obtaining “zero” voltage at the output of the Rx coil, sketch the relative position of the coils and cut out the bed/substrate based on the drawing. Then glue the Rx coil to it (it should already be in the graphite screen, and the screen is connected by wire to pin 5 of the connector), now you can go to the beach to set the “zero” as accurately as possible, taking into account the influence of the ground. (In the ACE 250 there is no ground detuning, it is set only once “to the average” at the factory, so by making a coil with pre-compensated ground influence, you will significantly improve the MD parameters set by the factory. “Ground roar”, by the way, is tens of times higher than the useful signal ).
In the field, you need to first find the abs. a place that is clear of metal debris (your original coil will help you here), then place a new coil on the sand and carry out the “mixing” as at home, on the table, i.e. connect the coil according to the method described above, “reduce” to four zeros on the device, and after “reconciling the coils,” fix their position on the substrate with glue. The tester should be kept away from the coil. To fix the final position of the coils, you should use non-plastic glue (it can “float” when using the coil in the heat), but preferably the “droplet” type, which is sold in small tubes. Upon arrival home, you can already apply the first layer of epoxy with fiberglass.

The lower leg of the rod was made from suitable polyethylene tubing. This friction elbow fits onto an aluminum rod and does not have any other fastening elements. The ends of the knee are reinforced with epoxy and fiberglass.

And the last. If I started making this coil now, I would give a much larger allowance for the “bed”. What’s wrong with the fact that it would be the one that would encounter all sorts of obstacles in the way of the coil’s movement? - then with the coil (the protruding edge of the bed/substrate) you could literally dig the sand.

All pictures are clickable.

It has the largest selection of additional coils - from branded Garrett search coils to third-party coils. The sizes of coils for the ACE 250 also vary - small snipers, medium universals, large deep ones. Round, Elliptical, DD and Mono. Such a number of coils for the ACE 250 sometimes leaves the user in a quandary - Which coil should you choose for your ACE 250? Each reel has its own advantages and features, which Kopatel store specialists share in the review – Reels for ACE 250.

The size of a metal detector coil is directly related to the detection depth; the larger the coil, the deeper it searches. But to be precise, the size of the coil determines the volume of soil processed - the larger the coil, the more volume of soil it captures. This is where the depth increases.

With an increase in the volume of processed soil under the metal detector coil, the speed of covering the search area increases. Large-sized coils are very convenient to use not only for searching for deep targets, but also for quick reconnaissance of the area.

For example, having traveled on the map to the site of a proposed farm, and not immediately finding traces of the exact location of the object (the grass hides broken bricks and fragments of ceramics), a metal detector is usually turned on and reconnaissance begins, searching for the borders of the farm. Reconnaissance with a metal detector is carried out in 2 ways - a concentric trajectory from a point and long straight trajectories. In both cases, the goal is to find confirmation that you have reached the intended search location. Coins, horse meat, household utensils of that time - these are the finds that will confirm that you are in the right place.

When going to an unfamiliar place for the first time, even with an old map attached, it is not easy to find the intended spot. Plus/minus 100-200 meters on the old map in modern reading cannot be considered an error. In reconnaissance mode with a metal detector, it is important to find your site as quickly as possible - the faster you find it, the more time will be left for a real search with a metal detector that will bring valuable finds. This is where the large coil on the ACE 250 will provide the best help - the fastest possible coverage, signaling for deep targets.

But large coils have their own characteristics that prevent them from being used in searches as a universal solution. Large coils consume more electricity from the metal detector (10-20%). Large coils have more weight, and for the lightweight ACE 250 this results in a slight imbalance in the overall design of the metal detector. Larger coils, due to their size, are subject to a greater likelihood of acquiring multiple targets at the same time - in heavily littered areas, a large coil will either jam nearby targets, or will not be able to accurately determine the exact location of the target you want.
Pinpointing large reels to small targets is a weak point. Due to its size, it is very difficult for a large coil to determine the exact center of a target.

For example, the coil for ACE 250 Nel Tornado detects scales at almost twice the depth (compared to the standard one). But when digging out the flake found with the ACE 250 and the Tornado coil in the field, we had to expand the primary hole. Of course, it doesn’t take that much time and the silver flake is worth it, but when searching with large coils you should always take this feature into account.
Small coils for the ACE 250 will give the most accurate pinpoint even on a target the size of a pellet. But the detection depth of Sniper coils (the so-called small coils for metal detectors) rarely exceeds 25 centimeters. Sniper coils work great in heavily littered areas with a high concentration of nearby targets. In such areas it happens that even with a medium-sized coil it is impossible to search - the discriminator signals are erroneous, the pinpoint does not work accurately.

The medium coils for the ACE 250 are versatile, with a good balance of target selectivity and pinpoint accuracy. The standard ACE 250 reel, Garrett ACE PROformance, with dimensions of 6.5 by 9 inches, is exactly such a reel. A lightweight and waterproof search coil, which becomes the first experience for novice searchers. This reel is perfect for the ACE 250, and it’s not worth increasing it without searching experience and understanding what targets you encounter. Moreover, the owner’s own ACE 250 reel will not leave him without finds.

ACE 250 test on Garrett ACE PROformance 6.5*9” reel. Air test. Coin purposes and military finds. Garrett ACE 250 sensitivity is maximum.

5 kopecks, Ancient copper coin of Queen Catherine, maximum depth - 28-29 centimeters.
5 kopecks USSR, maximum detection depth - 25 centimeters.
German bayonet, maximum detection depth - 44 centimeters.
Army helmet from the Second World War, maximum detection depth - 55 centimeters.

Having gained experience in searching with a metal detector, the original Garrett ACE 250 coil will no longer be enough - you will want to pick up deep targets that the original coil missed and increase the speed of searching with a metal detector. This is where the choice of reels for the ACE 250 is provided - the Kopatel store has the largest selection of reels. Reels Garrett, Nel, MarsMD, Detech. There are very large reels for ACE 250, for example, Nel Big 15*17. But effective work with such coils on the ACE 250, depends on your experience with large coils. Therefore, when choosing the first large reel for the ACE 250, you should pay attention to the reel models:

Nel Tornado 12*13
Detech Ultimate 13
Mars MD Goliath 15

Each of these three coils has its own advantages. Nel Tornado has excellent sensitivity to small targets, is perfectly balanced for the work of the ACE 250 discriminator. Detech Ultimate 13 is lightweight, comes with plastic protection, excellent performance on the ACE 250. The Mars MD Goliath 15 coil is the largest of these three coils, but with such size, Mars MD Goliath in most cases allows you to work with the ACE 250 at maximum sensitivity.

5 kopecks, Ancient copper coin of Queen Catherine, maximum depth - 45 centimeters.
5 kopecks USSR, maximum detection depth - 41 centimeters.
German bayonet, maximum detection depth - 62 centimeters.
Army helmet from the Second World War, maximum detection depth - 78 centimeters.

5 kopecks, Ancient copper coin of Queen Catherine, maximum depth - 41 centimeters.
5 kopecks USSR, maximum detection depth - 35 centimeters.
German bayonet, maximum detection depth - 57 centimeters.
Army helmet from the Second World War, maximum detection depth - 68 centimeters.

5 kopecks, Ancient copper coin of Queen Catherine, maximum depth - 47 centimeters.
5 kopecks USSR, maximum detection depth - 43 centimeters.
German bayonet, maximum detection depth - 70 centimeters.
Army helmet from the Second World War, maximum detection depth - 81 centimeters.

When choosing a large coil for the ACE 250, you need to take into account not only its detection depth, but its other properties - work on nearby targets, what sensitivity it allows you to work at, susceptibility to interference. The Kopatel store specialists know all the reels in practice, and will readily tell you and answer all your questions. Coils for metal detectors ACE 250 in the store