Gold Rat Metal Detectors is located 6/50 Freda Street Upper Mount Gravatt. This is the only store to stock Metal Detectors. Gold Rat Engineering is located 4/16 Redcliffe Gardens Drive Clontarf This is where you will see the largest range of your highbankers, sluices and accessories

General Info

Minelab GPZ 7000 Review

Minelab GPZ 7000 Review

Minelab GPZ 7000 Review

9/10 Very Good Metal Detector
  • Country AU
  • Released -
  • Warranty 2 years
  • Additional coils
  • Headphones included

Minelab GPZ 7000 is seemingly an attempt of Minelab to show everybody who’s the boss in the sub niche of gold prospecting among global metal detector brands. Minelab’s GPZ 7000 metal detector takes prospecting to new heights – or rather, should we say to new depth? Innovative technologies provided in this machine enable the prospector to reach deeper, and spot smaller nuggets among hot rocks, in a more effective way than before. If you are intrigued, please check out the full detailed Minelab GPZ 7000 review.

Rating Explanations
All Purpose 10/10
Key Features 10/10
Easy to Use 8/10
Durability 9/10
Price 8/10
Reviewed by - Michael Moore

Minelab GPZ 7000 Key Features

ZVT Technology

Zero Voltage Transmission technology enables the metal detector to go deeper, to ignore chemical soil components, to prevent inaccurate targeting and false signals.

Super-D Coil

New structure and design of the classic DD coil increases sensitivity and stability of the signal.

High Quality Quick Track Ground Balance

Crucial part of gold prospecting, ground balance makes search more efficient and focused.

Noise Immunity

This feature allows to avoid excess noise from hot rocks, highly mineralized soils, and chemical components usually present near the gold ore deposits.

Wireless Audio

More freedom of movement, more convenience, plus less risk to damage the equipment by pulling the wire.

Full Color LCD Display

High resolution backlit display makes interpretation of signals, and target identification, faster and more comprehensive.

Minelab GPZ 7000 Overview

GPZ 7000 metal detector by Minelab is a new step forward in the sub niche of gold prospecting. Searching for gold dust and nuggets is an incredibly hard and complicated type of metal detecting. As a result, making machines for this type of activity is more complicated, as well, so little surprise brands do not release new models often. Moreover, inventing a new groundbreaking technology for this sphere is also not easy, because it has to really make a difference – otherwise, no one is going to be impressed in the metal detecting world.

However, Minelab has always been a brand that takes gold prospecting seriously. It is safe to say that the brand’s initial focus was gold prospecting. Therefore, when they announced a new metal detector, we could expect something outstanding.

Minelab GPZ 7000 definitely offers an outstanding feature – due to its ZVT technology, this machine allows 40% deeper reach than all the previous models by this brand. Almost twice as deep as before already sounds pretty good, but wait, there’s more. The same technology, combined with high quality ground balance and noise cancellation, makes possible spotting smaller nuggets that could be missed out with previous machines.

These two characteristics alone make the GPZ 7000 worthy of attention. In all other terms, we’ll have to be honest and admit that the machine is not packed with amazing features. Finding more gold deeper in the ground should be enough for many prospectors, and in the rest of tech specs, GPZ 7000 is pretty basic and similar to other metal detecting machines for the same activity by other brands.

Search Coil

GPZ 7000 is equipped with Super-D search coil for increased sensitivity and more stable signal transmission. The coil has enhanced design, plus improved protection from moist and mechanical damage. Since the whole metal detector is not waterproof – that is, the control box can only stand wet weather – it is only the coil that is waterproof up to 3 feet (while this makes little sense).The size of the coil is 14×13”, and it is yet not clear whether other compatible coils will be available – at least we know there aren’t any for now.

Design & Usability

While the solid white coil cover looks a bit weird, the rest of the metal detector boasts sleek design. High quality materials promise long and faithful service, and the color scheme is pleasant to the eye.

The machine is somewhat heavy – heavier than many metal detectors in general – so one should expect they need to be ready to use it for long hours. However, the shaft is collapsible and can be suited to the person’s height, plus, the whole thing is well-balanced. Wireless audio system offers more freedom in movement, so we believe that, but for the weight, the user experience should be positive.

Considering that GPZ 7000 was created specifically for gold prospecting, and was designed to manage with specific problems that most prospectors face, it does not include numerous and various search modes – simply because this is not a universal tool. Instead, there are only two search modes, each with three sub modes for finer tuning.

Gold Mode (High Yield, General, Extra Deep)

Gold Mode has three variations. High Yield is for increased sensitivity, to spot even the finest gold dust. General is for conditions unexplored, when the prospector is not yet sure what they need. Extra Deep is for increased depth of reach.

Ground Type (Normal, Difficult, Severe)

As any other metal detector, GPZ 7000 can be used in general purposes, and this mode reflects possibilities for general search, depending on the location type.

Minelab GPZ 7000 All Features

To better understand the specifications of GPZ 7000 by Minelab, compare it with other machines for prospecting, and maybe make an informed choice about it, please learn more about the full list of features and functions available.

Technology and Frequency – Zero Voltage Transmission for enhanced depth and sensitivity of the machine in hot rocks, and complicated grounds in general. This also applies to highly mineralized waters and wet sand.

Search coil is 14×13” Super-D – this search coil with skidplate promises more stability and control in signal transmission and reception. A new enhanced structure means more immunity to physical damage, and also more immunity to unstable signal from mineralized soils.

Wireless audio system plus non waterproof socket 6,3mm – there is always a possibility to use standard wired headphones if needed, but wireless audio is indeed a must have for all metal detectors these days. Wireless system provides more freedom of movement, and less risks of damaging the headphones by catching something with the wire. The headphones in the kit are non-waterproof KOSS, by the way.

Backlit Full Color LCD Display 320×240 pixels – some metal detectorists believe that interpretation should be performed relying on sound signals, but a high quality and informative display is actually an irreplaceable thing. The abundance and accuracy of information provided on display is a huge help for interpretation of the sound signal.

Discrimination offered for GPZ 7000 is All Metal type. While one may not be impressed much, the machine was created for gold search, therefore, it is only natural to expect that all other metals should be ignored.

Ground Balance is Audio / Manual Quick Trak for exceptional sensitivity and clean identification of potential targets. It is not news that gold is mostly located in highly mineralized places with many hot rocks, plus, the environment can change in terms of mineralization pretty often within the same location. So, fast and accurate Ground Balance provides clean search and more comprehensive signal.

20 sensitivity levels. Remember we have discussed enhanced sensitivity? Well, GPZ 7000 has 20 sensitivity levels that can be additionally adjusted, separately from the search mode.

Noise Cancellation is backed by 256 channels, and can be tuned automatically or manually. Such number of channels guarantees to the user that no additional noise will interfere with the signals, be it noise from the soils, or from other metal detectors around.

The Threshold has 50 levels and the Pitch from 1 to 100. The Target Volume is adjustable, and has 20 points for Range and Limit.

The whole thing is powered by the Li-Ion rechargeable battery pack, and low battery indicator is available. The battery life is comparatively low, though – from 8 to 10 hours.

The shaft is collapsible and can be adjusted – from 46 to 65 inches in different positions. It is easy to pack and transport the metal detector with a collapsible shaft. This is valuable, considering that the whole thing weighs 3.32 kg / 7.32 lb.

The Kit

The kit includes the following items (may vary depending on the seller, though):

  • metal detector
  • 14×13″ Waterproof Super-D Smart Search Coil
  • Koss UR-30 Headphones
  • WM 12 Wireless Module (non-waterproof)
  • Pro-Swing 45 and additional J-Strut
  • 2 Field Guides
  • X Change 2 Software and Instruction Manual CD
  • Car Charger Plug
  • USB Charging Mini Cable for Wireless Module
  • USB PC cable to connect GPZ 7000 for GPS Data to X Change and Google Maps
  • Li-Ion Rechargeable Pack
  • BC 10 Battery Charger with Multi-Country / Universal Charging Plugs
  • Battery Terminal Connection Cable for Charging Directly from a Car Battery
  • GA 10 Guide Arm


Minelab is not the only metal detecting brand that makes machines for gold nugget prospecting. However, Minelab may be considered the most prospecting-focused brand, and they strive to invent new things to meet the detectorists needs in the best way possible. GPZ 7000 is not the fanciest machine in the world, and it may definitely lack some features many detectorists would prefer to have. However, this model seems to be another step forward an enhanced, more efficient, and more productive prospecting.

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More info from the Manufacturer Minelab GPZ 7000

Pump Flow Capacity and ratings

Pump Flow Capacity and ratings

This is a subject that can really confuse some people when it comes to purchasing a pump to run their highbanker. Often flow rating is referred to by the HP of an engine "beware of any seller of supplier who refers to Horse power" when talking about water flow it has zero rating of flow and any engine can run any pump to some degree.

HP or horse power is the driver not the mechanism that pumps water so you want to focus more on the fitted pumps output rating not HP.

You have two primary factors to consider, you would opt for low HP if you want something small and easy to carry but with small often comes lower efficiency so there is a trade-off and some exceptions to this rule.

Hi HP generally means big and bulky so from a 2.5hp engine to a 8hp engine we're looking at a difference in weight of 5 to 55kgs dry. Quite the variation when considering carrying this into the bush.

I personally have no issue carrying anything up to 6.5hp at a dry weight of 26kgs because i like the economy of a large engine running low rpm all day on a tank of fuel.

Pumps and flow ratings

Manufacturers will make claim to ratings to sell a product, its not uncommon to see a listing on ebay for a 1" pump that put out 18,000 litres per hour. In order to put out that level of water through a 1 inch pipe that pump would have to produce over 100 PSI so you have to ask yourself  "How can they make and sell a pump for under $150 that puts out that much psi?"

The answer is usually they can't, not at 2.5HP or even 3HP for a 1" pump. 4HP and we are in the realm of possibility. Shop around and compare some more respected brands like Honda, Thornado, Rato to name a few. You will find most 1" pumps put out about 9000 litres at 2.5hp and up to 12,000 litres for 3hp engines. Again there are some exceptions to the rule but they are never cheap.

Here's a table to gauge capacity of flows

How much Flow do i need for my Sluice or Highbanker?

For your average 25cm wide sluice you will want to have available in flow around 14,000 litres per hour, for a larger sluice 300-400 wide i would recommend not less than 15,000 and as high as 34,000 litres per hour.

This accommodates common lift, pressure requirements for cleaning in your spray bars and assuming you will block some of your take with debris at some point.

There are a few different types of pumps and really they can be broken down three  categories, High Flow, low flow high pressure and hybrid hi flow high pressure.

In the picture below we have at the top a Honda hi flow pump rated at 16,800 litres per hour, then to the left a small 12,000 litres per hour, then to the right of it 16,000 litres per hour and right at the bottom the hybrid turbo pump 24,000 litres per hour, commonly used in applications that require great pressure and volume like small dredges and highbankers that need lots of water.

These are common small engine pumps using engines under 3hp.

highbanker pump range

Here we have the more common 6.5 HP engines running either Hi Flow pumps or Hi pressure pumps. The Hi Flow pump runs a single large impeller and simply moves allot of water really fast without much head height and is susceptible to friction loss.

While the hi pressure pump runs twin impellers which create a mass of pressure inside the smaller housing which limits flows but can pump straight up a hill very well, this type of pump is more suited to fire fighting or small commercial dredges.

With a hi pressure twin impeller pump it is crucial to make sure you do ot suck any stones into the impeller or you will ahve to disassemble the whole assembly to get the pump flowing again, high flow pumps do not suffer form this as the impeller veins are wide open.

For a highbanker you will want the hi flow pump it is the most economical option and you can create your own pressure where you need it at the spray bars.

twim impeller pump