Whites MXT The detector I use is a Whites MXT (or as I call it my "wee noisy!")

Roger has written some in depth articles on using the MXT - well worth a read!

Newcomers guide to the Whites MXT

by Roger The Whites MXT is in my opinion one of the best value detectors on the market today, and once mastered will give a no nonsense performance that will match most other machine on the market, and will beat most when it comes to finds rate because its built more for sensitivity to the low conductive targets like cut quarter and half hammered coins etc., rather than for extreme depth on larger items. If you’ve just purchased one of these machines and need a bit of help, I’ve put a few tips below.

Mode Switch 

Prospecting In my opinion the prospecting mode is not the best to use when searching for small coins in the UK, in tests I did, this mode would reject small coins if any iron was close by, as the discrimination in this mode is working on the percentage of iron in the target, and always seemed to favour the iron over a nonferrous target that was close to it, can be used if you pay careful

attention to the meter readings, but this takes great patience and slows you down to a crawl, therefore reducing your finds rate dramatically Coins/Jewellry This mode to me is more for general coin shooting in parks, picnic area’s etc., where pushing the trigger forward in this mode will reject some types of pull tab, with trigger in centre you get the conventional discrimination, where the audio will be suppressed on any target that’s set to be rejected on the dual control, I found this mode needed the gain to be set carefully to get the best out of it, I have used this mode with success on farmland, but found I had to use reduced gain for best performance on my sites. Relic This is the one I find a real killer on UK farmland, very sharp and sensitive, with the trigger in the centre position you get a low tone for ferrous and high tone for nonferrous, this gives a lot of feedback on what’s under the coil without having to check the meter, I found if I set the threshold at about the 9oclock position I could use this mode with gain set at +3 most of the time without the machine getting erratic, this mode is what gave this machine the reputation of being “noisy”, its not that the machine chatters but the fact it gives a signal for every target, after a while you get used to the constant low tone farts and the high tones really do bang through when over most good targets, but like some other machines you sometimes get an iffy high tone signal, I found the best way to treat these signals was to see if I could get any kind of “two way” signal from them while moving around the target, if I could I’d dig the target, if I could only get a “one way” signal I’d leave it, obviously at first I checked a lot of the one wayers to be sure, 99% turned out to be iron, not a bad percentage, scraping some soil off the surface with your boot to get the coil closer to the target can also help suss out iffy signals. If the constant low tones are annoying to anyone its just a case of pushing the trigger forward, which switches the machine to the standard discrimination mode where the audio is suppressed on all rejected targets, again I found I had to reduce gain in this mode, I didn’t notice any real loss in performance by doing this though, so its really a matter of personal choice as to whether you want to hear the iron or not. Dual Control/Discrimination This setting is the most important when hunting those small thin hammered, Saxon sceats etc., until you get to know the machine a setting of around 2.5 should be about right, at that setting the machine won’t discrim out even a cut quarter hammered, but will take care of all but the largest iron, after getting to grips with the machine I found it best to set the discrim up using a three inch nail, I balance the machine and then lock the tracking, placing the machine on something nonmetallic I pass the nail over the coil about two inches away, turn up the discrim until the nail is just rejected when its passed over the coil in the horizontal and vertical position, on my machine that’s about the 1.9 mark, this can vary quite a bit from machine to machine, using to much discrimination can cause target masking on iron laden sites, although the lightning fast recovery speed on this machine helps separate the targets, also the more you increase the discrim the more depth you will lose, as the old saying say’s “the more you use the more you lose”, and anybody who digs no iron at all, is definitely leaving finds in the ground. Gain Control

This controls the sensitivity of the received signal only, as the transmit power uses a fixed setting, i don't think many people realise this and think that raising the gain actually pumps more power out on the transmit side, it just adjust's the gain on the receive side and overdoing this setting on bad ground can distort the audio signal without actually gaining any depth at all, in fact you can lose some of the fainter signals because they wouldn't be heard over the extra noise generated, the gain setting obviously has an effect over the depth at which a target can be heard, it has a big affect on the stability of the machine, especially when detecting on very mineralised ground and/or ground that has a high amount of iron present. The MXT has what I call the standard 0 to 10 gain/sensitivity setting, it also incorporates three + numbers, moving into the + numbers also starts to boost the machines audio, which helps to pick out those faint deep targets. There may be times when working in severe ground conditions that a setting of 6-7 is needed to keep the machine stable, but in general I would always advise to try and set the gain to at least +1 if at all possible without distorting the audio, in the 0-10 range the audio to me sounds a bit weak (may be my bad hearing lol), then again when increasing to the +3 mark, the audio can be very loud, so its pretty vital to have a decent pair of headphones with a volume control, the volume control on full when working in the 0-10 range, and reduced a couple of notches when in the plus numbers, this works well for me with my nugget-buster phones, which are pretty loud on most machines. Although experienced user's of the MXT will want to take advantage of the added depth gained by using high gain settings on good ground, I would advise newcomers to the machine to use reduced gain to start with, as this will give a "cleaner" signal and more positive discrimination. Trac The MXT has a very fast auto-trac system, under normal conditions this is best left in the ground position, although the manual states to “pump” the coil up and down to set the tracking, its so fast that two or three swings over a clean piece of ground will soon have it setup, you’ll hear the machine settle down as you swing, even if you forget the ground balance procedure before you start, the machine will find the optimum setting before you’ve gone a couple of yards. In highly mineralised ground or ground that contains a lot of iron debris, I found it best to “lock” the tracking, this prevents small deep targets being tracked out under these conditions, it will also quieten the machine down as the tracking is not continually “hunting” for the optimum setting with iron under the coil, afraid I can’t comment on the salt setting as I’ve never tried the MXT on the beach. Threshold For the newcomer this is best set so the hum is just audible, and adjust the gain while detecting so the threshold is reasonably stable, after getting used to the machine you can try the trick mentioned above, turning the threshold to about the 9oclock position so its set just below sound, then turn up the gain to get top performance out of the machine, high gain settings will generate some background noise but I found the increase in performance outweighed having to put up with some slight noise, setting the threshold just below sound is just like using silent search on the DFX, doing this hides a lot of the noise generated by using high gain levels below the threshold, without losing any performance, there’ll always be a trade off for running a machine on very low discrim settings coupled with high gain, but when testing this machine on my sites it was one of the few that actually performed better when set to run “hot”.

Meter I found it best to treat all meters as mainly just a gimmick, ok their handy for giving battery voltage, and i use mine to suss out coke when its a big problem on a site, it will accurately give a 0 reading on most coke, this is mainly because the vast majority of coke is near the surface and the meter can id it correctly, if you get an iffy signal in your headphones its no good looking at the meter for help, as the meter uses the same signal as the audio, an iffy signal in the phones will give an erratic reading on the meter, i mentioned earlier my way of dealing with iffy signals. You may hear people who use multi-tone id say that you should pass different metals over the coil to get used to the tone they give off, this is all well and fine, but when those same objects are buried in mineralised soil, probably with iron close by the tone they give may well be completely different, or even several tones together (duelling banjo's lol), also the depth of a target can change the tone it gives, thankfully the MXT has only two tones, ferrous and nonferrous surely that’s all we need to know, i certainly don't want to know what type of nonferrous metal it is when getting a high tone, digging it out not knowing is half the fun. The labels on the MXT i.e.: button, buckle, bullet etc. are more for the American market, and a bit of a joke in my opinion, so if you must use the meter use the vdi numbers, and only when you get a good clean high tone, as that’s when they are most accurate.

Tips 

Coke Coke can be a big problem on some of our sites, but using the meter you can eliminate most of it, I would never be tempted to discriminate coke completely out, as this could eliminate some tiny coins, if I’m on a site with a coke problem I check every high tone on the meter, a loud high tone with a meter reading of 0 and showing foil will be coke, a faint or iffy high tone that gives a two

way signal and a reading of 0 should be dug, some will be small pieces of coke but others have turned out to be fairly deep cut hammered, using this method you can eliminate around 90% of the coke and lose very few finds. Iron stone (hot rock) Iron stone or hot rocks as the Americans call them can be a big problem for some machines, not so the MXT, they give a double bouncing signal nothing like a good target signal, also the meter after a slight delay will show hot rock, if in doubt they can be checked in pinpoint mode, the signal will null when the coil is centred over the hot rock. Iron The whites machines in my mind have discrimination second to none, but like most machines will give a good signal on certain shaped iron and any iron object with a hole in it i.e.: steel washers, iron rings, horseshoes etc., although these give a low tone its usually accompanied by a good high tone as well, you can suss out most of the large iron by switching to pinpoint mode, large iron gives a very wide signal even if buried deep, got to be careful though, a hoard in an iron pot would also give a wide signal lol, personally I dig these signals and have found some interesting iron artefacts by doing so, better to be safe than sorry.

Coils The three coils I’ve decided to keep for my MXT are the 5.3 eclipse, the 10 X 5 elliptical, and the 14 X 8 elliptical. The 14 incher has replaced the 9.5 stock coil on my machine, covers a lot of ground with no loss of sensitivity to small finds, only gets defeated when the iron gets heavy, the only drawbacks I’ve found with this coil so far are it doesn’t like to get within thirty yards of anything electrical, and it’s a tad on the heavy side, mind you I personally have got used to the weight now, and have got through a few six hour sessions with no problems, even though I’m not built like a brick outhouse lol, I’ve found this coil very stable even on max gain, and I reckon its added a good three inches at least to the depth of the MXT, you do get more low tones with this coil as it can sense more of the deeper iron, also more high tone “chirps” as the coil approaches the edge of iron, luckily these chirps are only one way and can be safely left, I reckon this coil is a must for the MXT/DFX.The 10 X 5 elliptical is the choice if the iron gets heavy, its narrow footprint limiting the amount of iron under the coil at one time, therefore target masking isn’t a big problem, again being a DD coil its not affected by bad ground like a concentric coil can be, another must have coil in my opinion, its always returned a higher finds rate on my sites than the 9.5 stock coil.Finally the little 5.3 concentric coil, I love using this coil on stiff stubble, being a round solid coil its fairly easy to brush through the stubble, although a bit more weight would help, good depth too for a small coil, also use it to check heavy iron patches that I’ve been over with my other coils, surprising what it can pull out if used slowly. There is also a small DD shooter coil, haven’t found the need to purchase one, but did try one for a couple of hours a few months ago, personally I couldn’t see any advantage over the 5.3 coil.

Detecting Sites & Hotspots Every half decent field where we hope to find those ancient coins/artefacts will have a few “hotspots”, these usually consist of patches of soil large and small containing man made iron debris, a variety of stages of decomposition will be found, from tiny particles to large chunks,

these “hotspots" believe it or not are the detectorists best friend, they show clearly where most activity has taken place on a particular field possibly over many hundreds of years. Now these “hotspots" may well be the detectorists best friend but their certainly not the detectors friend, many detectors are rendered useless by these patches of iron, the MXT takes them in its stride, especially with the correct coil fitted and settings to suite the conditions. Over the years I’ve seen detectorists avoid these hotspots like the plague when their machines have become erratic and unusable, or the user can’t put up with a bit of chatter from their machine, the trouble is by avoiding such places their missing out on the very spots that hold the vast majority of finds on farmland. When I had more time to spend detecting a few years ago, I used to do what I call a union jack search of a new site, this entailed putting a large coil on my machine and searching the field fairly quickly from corner to corner then side to side etc, marking down on a home made map of the field where the hotspots were, for use on subsequent visits. Nowadays I start with the 9.5 stock coil (now replaced with the 14 inch DD), as I find a hotspot I detect it very slowly to get the easier targets, then mark the spot on the map for future reference, I’d normally do the whole field in this way, returning in the future armed with smaller coils to check out the really heavy iron laden patches that the large coil couldn’t cope with, and to winkle out the tiny coins etc that the iron masked from the larger coil, this exercise is repeated each year as the plough stirs up the iron and finds.

Technique There’s only one way to go here, sloooow and slower still, I always swing the coil straight across the front, covering about a three foot width rather than in an wide semi circle, this way I find I can cover every inch of ground, cos if you miss a small piece of ground, you can bet it will hold a find of a lifetime lol, just covering a three foot search path also ensures the coil doesn’t lift at the end of the swing, and the obvious one, keep the coil as near to the ground as conditions allow, on grass and growing cereal crops etc you can scrub the ground for maximum depth.

My personal settings Mode: Relic Trac: Set to ground position ( balanced on clean ground and locked if working a heavy iron site) Dual Control (Disc): 1.9 (Varies from one machine to another, just high enough to eliminate a 3” nail) Gain +3 Trigger: Centre Position (2 tone id) Threshold: Just below the point of sound (around the 9 o’clock position on my machine)

Good hunting.

Newcomers guide to the Whites MXT by Roger

The Whites MXT is in my opinion one of the best value detectors on the market today, and once mastered will give a no nonsense performance that will match most other machine on the market, and will beat most when it comes to finds rate because its built more for sensitivity to the low conductive targets like cut quarter and half hammered coins etc., rather than for extreme depth on larger items. If you’ve just purchased one of these machines and need a bit of help, I’ve put a few tips below.

Mode Switch 

Prospecting In my opinion the prospecting mode is not the best to use when searching for small coins in the UK, in tests I did, this mode would reject small coins if any iron was close by, as the discrimination in this mode is working on the percentage of iron in the target, and always seemed to favour the iron over a nonferrous target that was close to it, can be used if you pay careful attention to the meter readings, but this takes great patience and slows you down to a crawl, therefore reducing your finds rate dramatically Coins/Jewellry

This mode to me is more for general coin shooting in parks, picnic area’s etc., where pushing the trigger forward in this mode will reject some types of pull tab, with trigger in centre you get the conventional discrimination, where the audio will be suppressed on any target that’s set to be rejected on the dual control, I found this mode needed the gain to be set carefully to get the best out of it, I have used this mode with success on farmland, but found I had to use reduced gain for best performance on my sites. Relic This is the one I find a real killer on UK farmland, very sharp and sensitive, with the trigger in the centre position you get a low tone for ferrous and high tone for nonferrous, this gives a lot of feedback on what’s under the coil without having to check the meter, I found if I set the threshold at about the 9oclock position I could use this mode with gain set at +3 most of the time without the machine getting erratic, this mode is what gave this machine the reputation of being “noisy”, its not that the machine chatters but the fact it gives a signal for every target, after a while you get used to the constant low tone farts and the high tones really do bang through when over most good targets, but like some other machines you sometimes get an iffy high tone signal, I found the best way to treat these signals was to see if I could get any kind of “two way” signal from them while moving around the target, if I could I’d dig the target, if I could only get a “one way” signal I’d leave it, obviously at first I checked a lot of the one wayers to be sure, 99% turned out to be iron, not a bad percentage, scraping some soil off the surface with your boot to get the coil closer to the target can also help suss out iffy signals. If the constant low tones are annoying to anyone its just a case of pushing the trigger forward, which switches the machine to the standard discrimination mode where the audio is suppressed on all rejected targets, again I found I had to reduce gain in this mode, I didn’t notice any real loss in performance by doing this though, so its really a matter of personal choice as to whether you want to hear the iron or not. Dual Control/Discrimination This setting is the most important when hunting those small thin hammered, Saxon sceats etc., until you get to know the machine a setting of around 2.5 should be about right, at that setting the machine won’t discrim out even a cut quarter hammered, but will take care of all but the largest iron, after getting to grips with the machine I found it best to set the discrim up using a three inch nail, I balance the machine and then lock the tracking, placing the machine on something nonmetallic I pass the nail over the coil about two inches away, turn up the discrim until the nail is just rejected when its passed over the coil in the horizontal and vertical position, on my machine that’s about the 1.9 mark, this can vary quite a bit from machine to machine, using to much discrimination can cause target masking on iron laden sites, although the lightning fast recovery speed on this machine helps separate the targets, also the more you increase the discrim the more depth you will lose, as the old saying say’s “the more you use the more you lose”, and anybody who digs no iron at all, is definitely leaving finds in the ground. Gain Control This controls the sensitivity of the received signal only, as the transmit power uses a fixed setting, i don't think many people realise this and think that raising the gain actually pumps more

power out on the transmit side, it just adjust's the gain on the receive side and overdoing this setting on bad ground can distort the audio signal without actually gaining any depth at all, in fact you can lose some of the fainter signals because they wouldn't be heard over the extra noise generated, the gain setting obviously has an effect over the depth at which a target can be heard, it has a big affect on the stability of the machine, especially when detecting on very mineralised ground and/or ground that has a high amount of iron present. The MXT has what I call the standard 0 to 10 gain/sensitivity setting, it also incorporates three + numbers, moving into the + numbers also starts to boost the machines audio, which helps to pick out those faint deep targets. There may be times when working in severe ground conditions that a setting of 6-7 is needed to keep the machine stable, but in general I would always advise to try and set the gain to at least +1 if at all possible without distorting the audio, in the 0-10 range the audio to me sounds a bit weak (may be my bad hearing lol), then again when increasing to the +3 mark, the audio can be very loud, so its pretty vital to have a decent pair of headphones with a volume control, the volume control on full when working in the 0-10 range, and reduced a couple of notches when in the plus numbers, this works well for me with my nugget-buster phones, which are pretty loud on most machines. Although experienced user's of the MXT will want to take advantage of the added depth gained by using high gain settings on good ground, I would advise newcomers to the machine to use reduced gain to start with, as this will give a "cleaner" signal and more positive discrimination. Trac The MXT has a very fast auto-trac system, under normal conditions this is best left in the ground position, although the manual states to “pump” the coil up and down to set the tracking, its so fast that two or three swings over a clean piece of ground will soon have it setup, you’ll hear the machine settle down as you swing, even if you forget the ground balance procedure before you start, the machine will find the optimum setting before you’ve gone a couple of yards. In highly mineralised ground or ground that contains a lot of iron debris, I found it best to “lock” the tracking, this prevents small deep targets being tracked out under these conditions, it will also quieten the machine down as the tracking is not continually “hunting” for the optimum setting with iron under the coil, afraid I can’t comment on the salt setting as I’ve never tried the MXT on the beach. Threshold For the newcomer this is best set so the hum is just audible, and adjust the gain while detecting so the threshold is reasonably stable, after getting used to the machine you can try the trick mentioned above, turning the threshold to about the 9oclock position so its set just below sound, then turn up the gain to get top performance out of the machine, high gain settings will generate some background noise but I found the increase in performance outweighed having to put up with some slight noise, setting the threshold just below sound is just like using silent search on the DFX, doing this hides a lot of the noise generated by using high gain levels below the threshold, without losing any performance, there’ll always be a trade off for running a machine on very low discrim settings coupled with high gain, but when testing this machine on my sites it was one of the few that actually performed better when set to run “hot”. Meter

I found it best to treat all meters as mainly just a gimmick, ok their handy for giving battery voltage, and i use mine to suss out coke when its a big problem on a site, it will accurately give a 0 reading on most coke, this is mainly because the vast majority of coke is near the surface and the meter can id it correctly, if you get an iffy signal in your headphones its no good looking at the meter for help, as the meter uses the same signal as the audio, an iffy signal in the phones will give an erratic reading on the meter, i mentioned earlier my way of dealing with iffy signals. You may hear people who use multi-tone id say that you should pass different metals over the coil to get used to the tone they give off, this is all well and fine, but when those same objects are buried in mineralised soil, probably with iron close by the tone they give may well be completely different, or even several tones together (duelling banjo's lol), also the depth of a target can change the tone it gives, thankfully the MXT has only two tones, ferrous and nonferrous surely that’s all we need to know, i certainly don't want to know what type of nonferrous metal it is when getting a high tone, digging it out not knowing is half the fun. The labels on the MXT i.e.: button, buckle, bullet etc. are more for the American market, and a bit of a joke in my opinion, so if you must use the meter use the vdi numbers, and only when you get a good clean high tone, as that’s when they are most accurate.

Tips 

Coke Coke can be a big problem on some of our sites, but using the meter you can eliminate most of it, I would never be tempted to discriminate coke completely out, as this could eliminate some tiny coins, if I’m on a site with a coke problem I check every high tone on the meter, a loud high tone with a meter reading of 0 and showing foil will be coke, a faint or iffy high tone that gives a two

way signal and a reading of 0 should be dug, some will be small pieces of coke but others have turned out to be fairly deep cut hammered, using this method you can eliminate around 90% of the coke and lose very few finds. Iron stone (hot rock) Iron stone or hot rocks as the Americans call them can be a big problem for some machines, not so the MXT, they give a double bouncing signal nothing like a good target signal, also the meter after a slight delay will show hot rock, if in doubt they can be checked in pinpoint mode, the signal will null when the coil is centred over the hot rock. Iron The whites machines in my mind have discrimination second to none, but like most machines will give a good signal on certain shaped iron and any iron object with a hole in it i.e.: steel washers, iron rings, horseshoes etc., although these give a low tone its usually accompanied by a good high tone as well, you can suss out most of the large iron by switching to pinpoint mode, large iron gives a very wide signal even if buried deep, got to be careful though, a hoard in an iron pot would also give a wide signal lol, personally I dig these signals and have found some interesting iron artefacts by doing so, better to be safe than sorry.

Coils The three coils I’ve decided to keep for my MXT are the 5.3 eclipse, the 10 X 5 elliptical, and the 14 X 8 elliptical. The 14 incher has replaced the 9.5 stock coil on my machine, covers a lot of ground with no loss of sensitivity to small finds, only gets defeated when the iron gets heavy, the only drawbacks I’ve found with this coil so far are it doesn’t like to get within thirty yards of anything electrical, and it’s a tad on the heavy side, mind you I personally have got used to the weight now, and have got through a few six hour sessions with no problems, even though I’m not built like a brick outhouse lol, I’ve found this coil very stable even on max gain, and I reckon its added a good three inches at least to the depth of the MXT, you do get more low tones with this coil as it can sense more of the deeper iron, also more high tone “chirps” as the coil approaches the edge of iron, luckily these chirps are only one way and can be safely left, I reckon this coil is a must for the MXT/DFX.The 10 X 5 elliptical is the choice if the iron gets heavy, its narrow footprint limiting the amount of iron under the coil at one time, therefore target masking isn’t a big problem, again being a DD coil its not affected by bad ground like a concentric coil can be, another must have coil in my opinion, its always returned a higher finds rate on my sites than the 9.5 stock coil.Finally the little 5.3 concentric coil, I love using this coil on stiff stubble, being a round solid coil its fairly easy to brush through the stubble, although a bit more weight would help, good depth too for a small coil, also use it to check heavy iron patches that I’ve been over with my other coils, surprising what it can pull out if used slowly. There is also a small DD shooter coil, haven’t found the need to purchase one, but did try one for a couple of hours a few months ago, personally I couldn’t see any advantage over the 5.3 coil.

Detecting Sites & Hotspots Every half decent field where we hope to find those ancient coins/artefacts will have a few “hotspots”, these usually consist of patches of soil large and small containing man made iron debris, a variety of stages of decomposition will be found, from tiny particles to large chunks,

these “hotspots" believe it or not are the detectorists best friend, they show clearly where most activity has taken place on a particular field possibly over many hundreds of years. Now these “hotspots" may well be the detectorists best friend but their certainly not the detectors friend, many detectors are rendered useless by these patches of iron, the MXT takes them in its stride, especially with the correct coil fitted and settings to suite the conditions. Over the years I’ve seen detectorists avoid these hotspots like the plague when their machines have become erratic and unusable, or the user can’t put up with a bit of chatter from their machine, the trouble is by avoiding such places their missing out on the very spots that hold the vast majority of finds on farmland. When I had more time to spend detecting a few years ago, I used to do what I call a union jack search of a new site, this entailed putting a large coil on my machine and searching the field fairly quickly from corner to corner then side to side etc, marking down on a home made map of the field where the hotspots were, for use on subsequent visits. Nowadays I start with the 9.5 stock coil (now replaced with the 14 inch DD), as I find a hotspot I detect it very slowly to get the easier targets, then mark the spot on the map for future reference, I’d normally do the whole field in this way, returning in the future armed with smaller coils to check out the really heavy iron laden patches that the large coil couldn’t cope with, and to winkle out the tiny coins etc that the iron masked from the larger coil, this exercise is repeated each year as the plough stirs up the iron and finds.

Technique There’s only one way to go here, sloooow and slower still, I always swing the coil straight across the front, covering about a three foot width rather than in an wide semi circle, this way I find I can cover every inch of ground, cos if you miss a small piece of ground, you can bet it will hold a find of a lifetime lol, just covering a three foot search path also ensures the coil doesn’t lift at the end of the swing, and the obvious one, keep the coil as near to the ground as conditions allow, on grass and growing cereal crops etc you can scrub the ground for maximum depth.

My personal settings Mode: Relic Trac: Set to ground position ( balanced on clean ground and locked if working a heavy iron site) Dual Control (Disc): 1.9 (Varies from one machine to another, just high enough to eliminate a 3” nail) Gain +3 Trigger: Centre Position (2 tone id) Threshold: Just below the point of sound (around the 9 o’clock position on my machine)

Good hunting.

Depth and the MXT by Roger

Although I wouldn't recommend comparing different machines using "in air" depth tests, comparing different coils on the same machine would in my opinion give a very good comparison of the depth capabilities of each coil.Looking at the above figures its pretty obvious to me the MXT performs better "in ground" than "in air", this is based on depths of finds out in the field, for instance the MXT fitted with the 14 incher found a hammered penny on rough plough at 11" with a good strong signal, but would only get it at 10" in air.

The figures also show what a cracking little coil the 5.3 is, matching the 10" X 5" DD on three of the targets even though its only about half the size of that coil. In my write up about the 14 incher I reckoned it had a 2" to 3" gain in depth over the 9.5 stock coil, seems the bigger the target the bigger the gain. These tests were done after the machine was ground balanced and then the tracking "locked", the gain was set to max (+3), discrim at 1.9, in fact it was set up exactly as I use it in the field, all measurements were taken while still getting a good two way signal using headphones.

Obviously this test is only a rough guide to compare the coils capabilities, and certainly not set in concrete,it obviously doesn't take into account mineralised soil, or the presence of iron, if someone else tried this test they would probably come up with a different set of figures, there are so many variables when doing these tests, like the amount of interference, type of headphones used, where the cut off point for a good signal is etc etc, but it does give a reasonable idea of performance for each coil.