1. What kind of detector should be used for gold, relic or coin hunting?
2. Is there a machine that only finds gold?
3. How can I overcome interference from other detectors when I am at a rally or detector gathering?
4. How will I know I’m getting interference?
5. Are multi-frequency detectors better than single frequency types?
6. How deep can a good metal detector be expected to find coins?
7. What is the purpose of Notch Discrimination?
8. Why are there so many types of searchcoils?
9. Which coil size is best?
10. What is the best way to pinpoint a target?
11. What is Target ID and how does it work?
12. What is “ground balancing/cancelling”?
Further Q & A
i. How much affect does the moisture of the soil have to do with detection depth?
ii. Are there any good places left to detect?
iii. My VLF metal detector sometimes detects rocks and tree roots. Is this normal?
Frequently Asked Questions answered:
1. What kind of detector should be used for gold, relic or coin hunting?
For gold, the better detectors are single, high frequency machines such as the ones pictured below:
Teknetics T2
XP GoldMaxx Power
White’s TDI
Garrett Scorpion Goldstinger
Teknetics G2
For relics or coin hunting any of the above would be suitable but additionally any machine with a target ID meter, this is useful in park or beach detecting to help identify the target.
2. Is there a machine that only finds gold?
No, this is often claimed but is simply not possible.
3. How can I overcome interference from other detectors when I am at a rally or detector gathering?
The simple answer is to move away from the source of interference. Some machines are more prone to hearing or giving off interference & whilst many top end machines have frequency adjustment available or noise-cancelling you are only getting rid of that immediate source, the next detector may well cause you a problem, this leads to the next question.
4. How will I know I’m getting interference?
Interestingly, whilst most interference you can hear in the form of strange sounds as you near other detectors, some machines you cannot hear anything but this doesn’t mean that you aren’t suffering from interference. The problem you have when you can’t hear it is that effectively the two machines are either reducing detection range or worse still leaving you with zero detection range.
5. Are multi-frequency detectors better than single frequency types?
Multi-frequency machines are no better or worse than single frequency machines, they are simply different, both having advantages and disadvantages. Multi-frequency machines tend to work better than single frequency machines on salt wet beaches whilst single frequency machines have a lot faster recovery speed which is all important on high habitation sites where there is a allot of iron present.
6. How deep can a good metal detector be expected to find coins?
There is no answer to this question as there are too many variables involved, what size coin, what metal, orientation relative to the search coil, how long it’s been in the ground, how much mineralisation in the ground, how much ground effect, is it dry or wet, what detector, what settings for sensitivity, ground, discrimination etc.
7. What is the purpose of Notch Discrimination?
This is the ability to reject or accept an exact object as opposed to rejecting everything up to that object on a discrimination scale.
8. Why are there so many types of searchcoils?
There are two distinctly different types of search coils, Concentric and 2D (sometimes referred to as DD or double D coils), there are different sizes and also different shapes. Each coil type, size & shape will have slightly different characteristics in terms of ability to cover ground, sensitivity to large or small targets and recovery speed.
9. Which coil size is best?
This is difficult to answer but to start with we would advise sticking with whatever the manufacturer has supplied as standard, this is often best to start with, once you have a reference point you can then work out what you are trying to achieve with the detector and then look at which coil will give the best results.
10. What is the best way to pinpoint a target?
If you are using a concentric coil, the target will be in the centre of the coil, imagine an inverted cone, point down, simply lift the coil until you just get the signal, the target is now under the centre.
For 2D coils simply imagine a straight line from front to back down the centre line, when you get a signal is must be down that line, make a mental note of it, now turn you and the coil (most important you don’t ‘hoover’ the coil forwards & backwards, it won’t work) through 90 degrees and do the same again, you now have an imaginary X on the ground, X marks the spot.
11. What is Target ID and how does it work?
Target Identification is the ability to suggest what the target is most likely to be, this can be in the form of little symbols for coins and other metals or it may be a scale of 0-100 or similar.
12. What is “ground balancing/cancelling”?
Metal detectors are all affected by the minerals within the ground, these are detrimental to the performance or depth of detectors and for that reason we need to either cancel them out or balance the ground with the air hence the two terms. When perfect ground balance is achieved you will have maximum detection range in the ground, some detectors have a manual control for this whilst most modern machines are fully automatic ground balancing.
Further Q & A
i. How much affect does the moisture of the soil have to do with detection depth?
In very dry conditions (typically the end of a hot Summer) we tend to get around 10% less detection range, as water is conductive it gives better detection range when the ground is damp.
ii. Are there any good places left to detect?
With an average 9” diameter search coil it would take months non-stop detecting to cover a square mile properly, with England alone having over 50 thousand square miles there are plenty of good places left to detect
iii. My VLF metal detector sometimes detects rocks and tree roots. Is this normal?
No, some older VLF detectors will pick up what we refer to as hot rocks, these are large lumps of iron ore, the more modern ‘motion’ detectors do not pick these up , no detector can detect tree roots, maybe something metallic under the tree root?
