White’s Electronics GMZ User Manual

GMZ Gold Prospecting Detector Information

WHITE’S GMZ GOLD PROSPECTING DETECTOR

The gold nuggets shown above were found by White’s Engineer, Dan Geyer, who designed the GMZ as a simple to operate, reasonably
priced, gold detector. The gold nuggets were all found on a recent vacation trip to the mountain area west of Winnemucca, in Northern
Nevada. That is a US Dime in the middle of the picture for size comparison. The gold is mostly in 3, 4, 5, & 6 grain pieces with a few larger
ones.

The GMZ is a lightweight instrument that operates at a frequency of 50 kHz and uses all of White’s standard
Goldmaster search coils. The GMZ has only 3 controls and features all metal, silent search operation with a
unique ground rejection system.

The Sensitivity control knob turns the instrument power on or off and adjusts Gain. The Ground Reject
control knob adjusts the ground rejection range. The Ground toggle selects either Normal or Salt operating
modes.

The GMZ features an improved ground rejection system that significantly reduces ground interference and
false target responses. The rejection range increases as the Ground Reject control is turned clockwise. Low
mineralized ground requires a narrow range for good rejection. Other soils loaded with black sand or
“hotrocks” require a wider range.

The GMZ gives the prospector continuous control for the ground rejection range required for maximum
sensitivity to gold nuggets. The Salt position provides the ability to search in desert regions with the heavy
concentrations of conductive salt or alkali in the ground. The GMZ operates with the same 12 Volt 8 AA
battery pack as White’s GMT Goldmaster and gets similar battery life, which usually exceeds 50 hrs. of
operation. Simple operation instructions on next page.

For any additional questions contact White’s Electronics at 1-800-547-6911 or www.whiteselectronics.com

GMZ Operating Instructions

The GMZ is designed for fast and easy setup and operation.

The following procedure illustrates the use of the controls.

1. Check that the battery pack is in position and the door is firmly latched.

2. Set the Ground toggle switch to the Normal position.

3. Turn the Ground Reject knob fully counter clockwise to the lowest setting.

4. Turn the Sensitivity/ Power knob on & set it to the factory suggested preset mark.

5. Sweep the search coil across the surface of the ground and listen for any sound level variations

produced by changing mineralization levels from spot to spot. This will be evidenced by chatter or a
sort of clicking sound.

6. Now adjust the Ground Reject knob clockwise while sweeping or pumping the search coil over the

ground until the chatter diminishes or goes away.

7. You might now place a small target, such as a small gold nugget or lead split shot on the ground and

pass the search coil over it in order to note the sound of a target signal. The coil must be kept in
motion while passing over the target. You may criss-cross your coil over the target to mark the spot
where the target is. The Xing of the signal is the typical way to pinpoint the target.

8. You will note that the GMZ does not produce a threshold hum which is typical of other gold

detectors, but instead operates in silence. The only sounds you might hear are targets, as
demonstrated above, or chatter from extreme ground variations. Continuous ground noises are an
indication that the Ground Reject knob should be corrected further clockwise. Never correct the
Ground Reject further than is necessary to control ground interference.

9. You may use the Ground toggle set at Salt when prospecting in alkaline areas often found on the

desert. Particularly when wet, these areas produce a great deal of interference and make it difficult
or impossible to detect. You can reduce this interference by using the salt position. With the Ground
Reject knob set fully counter clockwise, turn the knob clockwise (to the right) until the noise is
diminished. Never correct the Ground Reject further than necessary.

10. As with any metal detector, the Sensitivity control is used to increase depth of detection. However,

when there is interference from environment or ground it is always advised to reduce the Sensitivity
to allow for interference free detecting.

Happy Hunting……… Dan Geyer and Jimmy Sierra

GMZ Service & Warranty

Service

White’s reputation has been built on quality products backed by quality service. Our Factory Authorized Service Centers are factory trained
and equipped. They offer the same quality service as the factory. Service before and after the sale is the cornerstone of our customer
relations.

White’s Authorized USA Service Centers: Before shipping detectors for Services:

Centerville Electronics A. Contact your Dealer. There may be a quick,
10063 Wellington Road simple fix or explanation that will prevent
Manassas, VA 20110 having to send the detector in for service.
Toll Free 1-888-645-0202
Fax: [phone] B. Double check the obvious, such as batteries
E-Mail:[e-mail] and try the detector in another area to be sure
there is not interference.
Electronics Exploration
700 South Main C. Be sure to send all necessary part with your
Lombard, Illinois 60148 detector, such as search-coil, batteries, and
Toll Free: 1-800-392-3223 holders, as these items can result in symptoms
Fax: [phone]
E-Mail: [e-mail] D. Always include a letter of explanation about
your concerns, even if you have talked to the
White’s Electronics Service Center by telephone.
1011 Pleasant Valley Road
Sweet Home, OR 97386 E. Take care in packaging instruments for
Telephone: [phone] shipping and always insure your package.
Fax: [phone]
E-Mail: [e-mail]

Warranty

If within two years (24 months) from the original date of purchase, your White’s detector fails due to defects in either material or
workmanship, White’s will repair or replace at its option, all necessary parts without charge for parts or labor. Simply return the complete

detector to the Dealer where you purchased it, or to your nearest Authorized Service Center. The unit must be accompanied by a detailed
explanation of symptoms of the failure. You must provide proof of date-of-purchase before the unit is serviced. This is a transferable
manufacturer warranty, which covers the instrument two years from the original purchase date, regardless of the owner. Items excluded from
the warranty are non-rechargeable batteries, accessories that are not standard equipment, shipping/handling cost outside the continental
USA, Special Delivery costs (Air Freight, Next Day, 2nd Day, Packaging Services, etc.) and all shipping/handling costs inside the continental
USA 90 days after purchase.

White’s registers your purchase only if the Sales Registration Card is filled out and returned to the factory address by your dealer, soon after
original purchase for the purpose of recording this information, and keeping you up-to-date regarding White’s ongoing research &
development. The warranty does not cover damage caused by accident, misuse, neglect, alterations, modifications, corrosive compounds,
including salt.

Duration of any implied warranty (e.g. merchantability and fitness for a particular purpose) shall not be longer than the stated warranty. Either
the manufacturer or the retailer shall be liable for any incidental or consequential damages. Some states however, do not allow the limitation
on the length of implied warranties, or the exclusion of incidental or consequential damages. Therefore, the above limitations may not apply
to you. In addition, the stated warranty gives you specific legal rights, and you may have other rights which vary from state-to-state.

The foregoing is the only warranty provided by White’s as the manufacturer of your metal detector. Any “extended warranty” period beyond
two years, which may be provided by a Dealer or other third party on your detector, may be without White’s authority involvement and
consent, and might not be honored by White’s Electronics, Inc. If for any reason you should sell your GMZ prior to the date the warranty
expires, the remaining warranty is transferable. This transfer is authorized by calling 1-800-547-6911, and getting an Authorized

Number, or going to www.whiteselectronics.com.