Nautilus, GPX & Nexus

[filternozzle]

Reading a recent thread reminded me of the Nautilus and how it was perceived and received by detectorists here in the UK. 

My detectors of choice are GPX-5000 and Nexus MP/Ultima, with a selection of coils.   Prior the Nexus my favoured VLF being the Nautilus DMC-IIB. 

At the time, relatively few UK detectorist had heard of the Nautilus and of the few who had and went on to purchase, most gave up on it.  They couldn't get their heads round the necessary coil balancing or get to grips with the unique way it could ID iron and the way the batteries were exposed on the underside was a total turnoff. 

Nevertheless, as a lot of readers will know, the Nautilus was a very good detector, deep with good iron discrimination.  The fact that some expressed negative opinions, didn't and couldn't change the fact that the Nautilus DMC-IIB was a very good detector. 

I have recently ordered the Nexus 21" Concentric coil for use on my GPX.  This coil is like two coils in one.  With just the outer coil in operation it's a 21" mono (no discrimination and max depth), when both the inner and outer are in use, discrimination comes into play. 

Two cables come from the coil into a small box, this in turn connects to the GPX coil connection.  The little box has a two position switch for maximum depth (mono) and discrimination (Hot Ground) by using both the inner and outer coils. 

I will let readers know my opinion in due course. 

[filternozzle]

My Nexus 21" Concentric coil has arrived, yippee!  A whole lot faster than expected.     We are in lock down here so I think it will be some weeks before I can get onto a decent site to put it through its paces.   However, as soon as the rain stops I will paddle out in the garden to get a feel of it, not ideal I know but I just can't wait to give it a try. 

Will take a couple of photos and post up as soon as possible. 

[filternozzle]

[Chase Goldman]

So what's special about this coil and the scientific principles involved?

[filternozzle]

28 minutes ago, Chase Goldman said:

So what's special about this coil and the scientific principles involved?

I have no idea of the scientific principles involved.   I am just a very enthusiastic detectorist.    This coil is different to any others for my GPX, in that it is concentric and whilst used as a concentric discrimination can be used.  Alternatively it can be used as a mono coil for maximum depth without discrimination.  As a mono it makes use of the 21" outer coil.  As a concentric it is using both the inner oud outer coils. 

Once I am free from the covid lock down, I will be able to see how it performs in the field.  I hunt coins and artifacts in the UK. 

[Chase Goldman]

So it has its own dedicated toggle switch to switch between the modes?  What setting do you use on the GPX itself - DD?  And what happens if you reposition the the coil switch on the GPX control box to Cancel/Mono?  Can it be used in noise cancel mode, too?  It also talks about a mineralization mode - what's that?  Very littlle information on the website itself.

[filternozzle]

51 minutes ago, Chase Goldman said:

So it has its own dedicated toggle switch to switch between the modes?  What setting do you use on the GPX itself - DD?  And what happens if you reposition the the coil switch on the GPX control box to Cancel/Mono?  Can it be used in noise cancel mode, too?  It also talks about a mineralization mode - what's that?  Very littlle information on the website itself.

With the coil control switch on CC, I would have the GPX on DD, with the Coil control switch on M, the GPX will be set to Mono.  With the GPX on Cancel, the coil control switch with be on CC. 

Yes, the original coil switch settings were referred to as "hot ground, or mineralised ground" and "maximum depth".   I believe some people found that confusing, so it is now named CC & M.  M is mono, and will give max depth, CC is concentric which may be better in highly mineralised soil and also offers the opportunity of discrimination. 

As mention, I haven't had a chance to use the coil yet because of Covid lock down here in the UK.  However, I will post my thoughts once I have had a chance to swing it on one of my detecting sites. 

[filternozzle]

Still not been able to get out in the field because of Covid restrictions.   However,  I have been out into the back garden and am delighted with it. 

The most striking point is the ability, at the flick of a switch, to change from a 21" mono to a 21" concentric coil.  

It will probably be sometime in March before travel restrictions are lifted but as soon as they are, I will be heading to a site or two to see what this coil can turn up for me.  The sites have in the past produced medieval hammered coins, but the last few years have been extremely lean. 

[kac]

So it is either a large mono or as concentric would it be similar to the dual field more than an actual concentric coil?

You lifting weights during the lock down to get into shape to swing that beast? :)

[filternozzle]

4 hours ago, kac said:

So it is either a large mono or as concentric would it be similar to the dual field more than an actual concentric coil?

You lifting weights during the lock down to get into shape to swing that beast? 🙂

 The manufacturer describes it as a concentric. One coil transmits and the other receives. 

The weight is not bad for such a large coil, probably due to it being encased in carbon fibre.  At 1100g it compares well with the smaller Coiltek 14" Elite Mono (1100g) and Nugget finders closed 15" Round Evolution Spiral Mono (1000g). 

I also use a bungy, so no need for the weight lifting. LOL