The Nox 18’’ Coil Verses Its Little Cousins..

[Erik Oostra]

During the last month I’ve been taking my new 18’’ Nox coil along to compare it to both the 15’’ and 15x12’’ coils on wild targets.. To keep the swapping around to a minimum, the 18’’ coil is always kept on a Nox 600 and the others are swapped around on a Nox 800 on alternate days.. I realise this doesn’t make it a fair comparison as from one day to the next I’m comparing the 18’’ coil to either the 15’’ or 15x12’’ coil, never all three at once on the same wild target..

In my defence I can only say that I’ve found that both the smaller coils are pretty similar in performance..  Some days one might sniff out a target that the other one’s missed, on other days it’s the reverse.. In terms of depth and sensitivity to targets there’s no real noticeable difference between the two.. What I’m after here is a comparison between a very big coil (for a VLF detector) and its more modestly sized cousins.. Is bigger really better?

As far as added hassles go, it’s been worth the effort of walking back to where I left the other detector as for me wild target comparisons are the best way to get very intimate with the latest addition to my coil harem..

So far there’ve been no ‘Wow that’s deep!’ moments but I wouldn’t be surprised if the knockout blow is yet to come.. I’ve still got a gut feeling that given time the 18’’ coil will sniff out deeper targets than the other coils, just not sure if that’s gonna be by as much as 30% as Coiltek claims..

Having said that, the 18’’ is surprisingly sensitive for such a big coil.. It didn’t pick up a small gold ring that the 15x12’’ coil sniffed out, but to my big surprise it did hit on two silver 6-pences, a copper 1 cent piece and bits of junk that the other coils couldn’t find - despite cranking up the sensitivity.. Not even a faint iffy signal or a quick flash on the target ID, whilst with the 18’’ coil all these small deep targets screamed ‘Dig Me!’.. While I can see the large coil missing a low-conductive target, I didn’t expect to see the smaller coils missing high-conductive targets.. What voodoo is at work here?         

On wet/dry salty sand I’ve been running the 18’’ coil on the same settings and sensitivities as the smaller coils (between 21-23).. In bays with layers of black sand beneath coral sand or in moving salty water I’m using lower sensitivities (between 18-21).. In trying to make the coil run ‘better’, I haven’t noticed any real depth loss or gain by mucking around with the sensitivity settings only between the Beach 1 and 2 programs.. Which is the same as the other coils..

I’m finding the same amount of targets at the same depths running within the same sensitivity range I’d normally use in that situation.. The only real variables for me are black sand and moving salty water but these just make the coil a bit noisier compared to the others and don’t seem to effect its overall performance.. In bays with high EMI it sometimes squawks its head off..

Coverage wise this thing is a monster but it’s not much heavier to swing than the other coils.. It’s been great for making sure I’ve covered long stretches of beach as best I could without missing anything too glaringly obvious.. I haven’t used the under-the-armpit-around-the-neck-along-the-arm harness yet but that’s mainly because I’ve been swapping around with lighter coils.. After a long day swinging this coil you’d definitely be a bit sore by sunset..       

While I’m waiting for it to stun me with its touted knockout depth, I’ve got no regrets so far about buying the 18’’ Nox coil.. Whatever voodoo it used to sniff out those small coins when the others couldn’t makes it worthy of its place in the toolbox..   

[Valens Legacy]

2 hours ago, Erik Oostra said:

While I can see the large coil missing a low-conductive target, I didn’t expect to see the smaller coils missing high-conductive targets.. What voodoo is at work here?  

The reason that it will do that on a regular basis is the way you cross your eyes while drink a beer while swinging the coil from the left to the right.

You may try to swing from the right to the left to compensate for the problem.

Good luck with your new coil and may the detector god's be kind to you.

[JCR]

13" is the biggest coil I regularly use on any of my detectors & I use them often. Not only for the added depth(which they can give)but also because they will hit coins on edge & some masked targets smaller coils miss. I suppose it has something to do with the angles of the Tx/Rx field lines.

[Erik Oostra]

10 hours ago, JCR said:

13" is the biggest coil I regularly use on any of my detectors & I use them often. Not only for the added depth(which they can give)but also because they will hit coins on edge & some masked targets smaller coils miss. I suppose it has something to do with the angles of the Tx/Rx field lines.

When I start hitting targets that I can't reach with another coil I always start to wonder what else I've missed.. The smaller coils missing several high-conductive targets still has me freaked out.. 

[JCR]

I suppose that is why it’s called hunting not collecting.

[LawrencetheMDer]

Thanks for the very helpful info, esp on the 18" coil.

I have a 17" coil on my CTX 3030 I've had for 8-9 yrs and the whole thing weighs more than 6 lbs (slightly less than 3 kgs) limiting use, now.

I have run the 15" coil on my 4 (2 drowned) Equinox 800s for 4-5 yrs and I'm very happy with stats showing I find 11% more coins compared to the 11" standard coil.

Just received the 15" coil for my Manticore.  I found the Manticore difficult to use with the standard 11" coil (large coils have spoiled me in the ocean).

This is the first I have read of an 18" coil for the 800/900, so very interested in a Dealer in the USA.  Any suggestions?

Happy Hunting