Nautilus metal detectors have been manufactured for over 35 years in North Carolina, USA. They have a very dedicated following and are cult machines amongst US civil war artifact hunters because of their superior depth, discrimination and robust construction.
Nautilus have largely been absent from European shores over this time: This has now changed!
Prior to distributing Nautilus we wanted to change the physical design of the detector and we worked with Nautilus on a new stem design. The new stem design mounts the control box under the users elbow and balances the detector perfectly. In addition the new stem allows the detector to be broken down into 3 pieces for easy transportation. All new Nautilus's we sell have the new stem and are CE certificated and RoHS compliant.
We supply the Nautilus DMCIIB and the DMCIIBa. Both offer equal performance. The DMCIIBa is designed for the user who wants all the benefits of Nautilus’s DMC detection system, but with the minimum of controls. The DMCIIBa is for the user who wants complete control over his detector.
What makes Nautilus detectors different?
We live in a world of mass production and homogenisation. Nautilus metal detectors though are different. And different in a positive sense, they have features found on no other detectors, features that provide real benefits to the detectorist.
The Nautilus DMC range is all about putting the operator in control, giving them as much or as little audio information they want in order to make that important decision - whether to dig a target or not.
The analogue design of the Nautilus also means the user knows exactly how his detector is set-up and operating. There is no complicated LCD menu system to navigate, just glance at the controls and you instantly know where you are.
The rugged lightweight aluminium control box offers excellent protection to the electronics inside from physical shocks.
DMC
The DMC system is unique to Nautilus. DMC stands for “Dual Mode Circuit” and in effect it is two detectors operating at the same time; a non-motion ground cancelling All Metal detector and a motion discriminator.
There are some distinct advantages to running a DMC detector because of the operating differences between All Metal and Motion discrimination modes. Most detectors these days are motion discriminators, some have an All Metal mode (which may or may not be a true zero motion All Metal mode).
If a detector has a proper All Metal mode (ie one that operates with a threshold tone and where the volume varies according to the strength of the target signal) it invariably goes deeper in this mode than the motion discrimination mode. However, most users will choose the motion discriminate mode over the All Metal mode and just use the All Metal mode for pinpointing. This is because, they get fed-up with having to check each signal in the motion disc mode, whether that’s changing the actual mode or referring to a target ID meter. Also though the motion mode may not be as deep, it gives a sharp target response to nearly its full detection depth and this in particular makes it easier to hear small targets.
With Nautilus DMC detectors you get the full advantages of both systems, without any of the disadvantages. This is how the system works:
Nautilus DMC detectors come with stereo headphones (the detectors have no external speaker) and the response of the detector is governed by whether the user selects the stereo or mono position on the headphones.
In the mono setting the All Metal and Discriminate modes are coming through the same audio channels. Whilst detecting you will hear the normal All Metal threshold tone, and when a good target is located the threshold tone will rise in volume AND you will also hear a “beep” from the motion Discrimination circuit. If the target is rejected by the discrimination circuit, then there will be no “beep” only a rise in volume from the All Metal circuit. Thus in mono the two metal detector circuits are mixed together.
When the headphones are switched to stereo, each detector circuit comes through on a separate speaker. In one speaker you have All Metal in the other Discriminate. The headphones have separate speaker volume controls so you can regulate the volume for each circuit to your personal preference. Having the headphones in stereo is the most popular way of using a Nautilus DMC detector as it conveys to the user the most information: By comparing the differing audio responses of the two circuits’ you are able to gain a great deal of information about the likely target. Although this audio system is different from any other detector it soon becomes second nature.
Examples of the different DMC audio responses are:
- If the All Metal circuit signal is much weaker compared to the Ground Reject Discrimination circuit, then the target is likely to be good, but very deep/and or small, such as a hammered coin.
The advantages of Nautilus’s DMC system include the following:
As you are searching in All Metal as well as motion disc, the detector will signal on targets that are out of range of the motion disc mode. The user can then investigate the signal further and decide whether to retrieve it or not. Searching only in motion disc the detectorist would walk right over a potentially good target.
Target analysis is totally by audio analysis and is instantaneous, there is no switching of modes or meters to look at.
When you get a good target there is no need to switch to a pinpoint mode because you are already operating in one!
As you become accustomed to the information the DMC system is providing, you will find you can use a lower discrimination setting than you would with a conventional motion detector. Using less discrimination will enable you to find more good hard-to-detect targets at greater depths.
If all this sounds complicated in theory, in practice its very easy, in fact the great beauty of the Nautilus DMC system is its intuitive nature. After a short while the operator will not even think about analysing signals, he will just know whether its good or bad. And the more you use the detector the more intuitive it becomes.
In addition to the DMC audio responses Nautilus detectors can be set to be like a regular silent search motion detector. Nautilus DMC detectors also have an non-motion TR discrimination mode to allow effective searching of salt water beaches.
Search Loop Balance (SLB)
This is a feature you will find on no other range of metal detectors:
For optimum detector performance the coils of a VLF (very low frequency) IB (induction balance - nearly all hobby detectors are of the VLF IB type) should be “balanced” with the detectors circuits. In extreme hot and cold environments, and over time, etc, the architecture of the coil can change and the detectors search coils will be unbalanced, ie away from their optimum point. Nautilus detectors allow the user to restore this optimum balance via the SLB function. On the DMC IIBa its is automatically carried out by depressing a button, on the DMC IIB the user manually sets the SLB.
 Transmit Power
The Transmit Power knob increases or decreases the primary electromagnetic search field sent out by the search coil: It is best thought of as controlling the overall gain of the detector.
 Vernier dials8:1 Vernier dials are used for the Ground Balance and Discrimination knobs. This means that the main black knob turns 8 times compared to the inner silver marker dial. They may look like something out of an episode of Dr Who, but they allow very precise adjustment and are hard wearing.
Batteries
The Nautilus DMC range is powered by four 9 volt PP3 batteries, providing approximately 20 hours use. The batteries are mounted in heavy-duty holders on the outside of the detector. This allows for easy access and quick changes in the field, protects the electronics from any battery leakage and there are no flimsy battery covers to loose or break.
If rechargeable batteries are used they can be recharged in situ via the detectors recharge socket.
Nautilus coils
Nautilus has bucked the trend for epoxy filled spider coils. It prefers the solid coil design for better searching in difficult terrain such as stubble fields and overgrown woods. Not being epoxy filled also allows for easier repairs in the event of any problem.
Nautilus coils are made in-house using the latest construction techniques and materials. The coils are light yet rugged. They have thick mounting lugs and a heavy duty cable strain relief. All connectors are heavy duty, nickel plated with a threaded locking ring. The latest generation of coils are thinner in profile and lightweight.
The coils are of a concentric design, giving the detectors excellent depth and pinpointing properties. The standard coil supplied with the detector is 10”. Other coil sizes available are; 6”, 8” and 15” enabling virtually any treasure hunting application to be accomplished.
Other features and controls:
Non-Motion Discrimination
The Nautilus user has a choice of either Ground Reject Discrimination (Motion Disc) or Non-Motion Discrimination (TR Disc). On nearly all inland sites the user will choose Ground Reject Discrimination, because this usually provides the best target response and discrimination. But on salt-water beaches motion disc modes usually have a very hard time and this is the principal reason Nautilus gives the user the option of selecting Non-Motion Discrimination. In this mode the user using the discrimination control can cancel out the effects of salt-water and happily detect on the wet part of the beach, not just the dry sand.
Auto Tune
Many detectors that have a true All Metal threshold mode incorporate some degree of automatic retuning denying the operator the benefits of true manual tuning. And some detectors with a true non-auto re-tune All Metal mode do not have a auto-re-tune option and can be very unstable requiring constant retuning. The Nautilus gives you the benefit of both full manual and automatic tuning.
The Auto Tune function works with the detectors All Metal and TR Disc modes and can be switched on or off. In the Off position the All Metal mode has absolutely no automatic retuning, it can be held stationary over a target and it will not tune the target out. The benefit of using the Auto Tune in Off is that this gives the maximum amount of target information to the user, giving an experienced operator an accurate assessment about the size and depth of a target. It is particular helpful to operate the detector with Auto Tune Off if you are looking for large deep targets. The detector can still be re-tuned in this mode via the re-tune button on the hand grip.
With Auto Tune On the All Metal mode re-tunes itself constantly to threshold. The re-tune speed is reasonably quick and with Auto Tune On the All Metal mode will tune out a target in a couple of seconds if held over it. The advantage of using Auto Tune is that is provides a more uniform threshold tone and target response, particularly useful in “busy” areas.
The Auto Tune also works with the Nautilus’s TR Non-Motion Discrimination mode, to provide an even threshold to compensate changing levels of mineralisation etc. Salt-water beach users will find this feature particularly useful.
In the Nautilus DMC range you have an amazingly versatile detector
- An auto-retuning TR discriminator
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