Field Testing the (24x11) Elliptical coil and the reasons for using one.
Generally it’s an accepted fact that when detectorists purchase a second coil, it’s normally a larger size than the standard one. This is perfectly in order if the sites being detected are pastureland, or the purchaser only has “quiet” fields and requires more ground coverage and slightly more depth. However, the more prolific finds are found in the areas of past habitation, which means heavier mineralisation and increasing amounts of ferrous material. As conditions become worse even the standard coil can struggle; trying to cope with ever increasing amounts of nails etc. It’s no use having the fastest response speed of any detector if the coil is hitting two signals at one time, (unless of course that they are both good). That’s expecting a bit too much!
When sweeping the coil, if it hits an ordinary size nail on one side of the coil and a coin on the other side at the same time, you won’t even know about the coin. (I’m not talking about going over a nail then a coin). How many times does this happen? Who knows? Because all you hear is the nail. So when this situation arises, the obvious answer it to scale down the coil size, this allows it to get between the ferrous without being overpowered most of the time.
On first impression the elliptical looks tiny compared to the standard coil and first thoughts must be about lack of depth and ground coverage. We have already seen that ground coverage is the one thing we don't require; so if we now look at depth capabilities.
In these “naily” and mineralised conditions, the first adjustment made when using the standard coil is to reduce the Sensitivity; depth is the last thing required, which is just as well, because no matter what you try; in these conditions you won’t get it! Because of the elliptical coil’s size, it isn’t affected so much by the mineralisation, sensitivity can remain higher and the detectors field will be more concentrated, enabling the tiny signals amongst the iron to register. Depth capabilities will at the very least, match if not better, the standard coil. (In these conditions).
In the field.
(Medieval and Roman sites)
When using the elliptical coil, it is important to set the ground balance to 1o’clock instead of 12o'clock.
The most noticeable effect after changing from the standard coil is a reduction in the ear bashing from all the signals. Nails on or just under the surface will still sound out, but with the Iron Volume only needed as high as 8 or 9oclock there is a definite growl, sweeping too fast for the conditions will induce those “is it?” type of signals; by keeping a steady sweep speed in relation to the amount of signals encountered, overcomes these. A definite asset of the smaller coil is that it is easier to follow the ground contours on the plough soil, this in itself brings the coil closer to the ground without the missing gaps on the tops and bottoms and awkward sides of the furrows. Patience is needed, but it becomes very engrossing teasing out the odd good signal amongst all the rubbish, even the tiniest pieces will give out a signal. However, compared to the standard coil, I did find that all signals were slightly quieter, so it definitely pays to keep your mind on what you’re doing! I did find that the front and back inch or so of the coil was a little less sensitive than the central area, but as with all elliptical coils, this is to be expected.
At no time when on this part of my site did I think of changing to the standard coil, obviously if I moved towards the quieter areas, it would then have been more beneficial. It is important to have the right “mindset” when using the elliptical for the first few times, if finds are a little slow in coming, it’s better to increase your concentration, rather than giving up and thinking that you would be better off changing back. Once the first find is in the bag confidence grows, when I’m detecting, that to me is everything. I now look upon the elliptical coil as an integral part of my detecting equipment, when on Roman and Medieval sites or anywhere that ferrous is a real problem, it’s the first out of the bag. The old adage holds true when they say “horses for courses”.
I haven't mentioned about any finds. So the big question is, does it really find?
Come on, you really don’t think I would have written this, if it didn’t?
John Lynn