The Minelab SD 2200D Metal Detector

Rear Panel Controls (see Figure 5)

5.1.1 Power switch
The Power On/Off switch turns the power from the Battery to the detector On and Off. Always switch the detector Off before connecting or disconnecting the Coil or Battery pack, and when not in use.

5.1.2 Channel switch (Ch1, Ch2 or Both)
The Channel switch selects the channel used for searching: Ch1, Ch2 or Both. Searching is usually done in the Both position, which gives the maximum sensitivity to the greatest range of targets. When detecting in highly noisy ground, the selection of Ch1 rather than Both might stabilise the threshold. However, sensitivity to certain types of targets is reduced when using Ch1 and is not recommended.

5.1.3 Threshold
The Threshold is used to control the loudness of background sound. Minelab recommends a soft audible headphone signal which is comfortable to listen to for extended periods.

5.1.4 Boost switch (Shallow, N [normal] or Deep)
The Boost switch can be used to enhance the signals produced by different types of targets.

In the Shallow position, signals from small targets close to the surface of the ground will be amplified, allowing easier detection of such targets. This option is best suited for quiet ground. For normal detecting conditions use the N position which responds to all signals without boosting. The Deep position is recommended when looking for big targets at greater depth in noisy ground. Random soil signals are smoothed, making small changes in the audio signal from large deep targets easier to hear. However, it may mask some signals from very small targets near the surface.

5.1.5 Tone
The pitch of the background threshold can be adjusted to suit your preference using the Tone control.

5.1.6 Tune
The Tune control is used to lower the effects of electromagnetic interference from sources such as power lines, radio transmitters and other metal detectors. The Tune control is engaged by pressing the push button switch. If electromagnetic interference is experienced when using the detector, simply press the Tune button once to automatically select the best detection frequency.

Front Panel Controls (see Figure 6)

5.2.1 Ground Balance mode (Fixed or Tracking)
To get the best from your SD 2200D, it is important to know how different ground conditions affect the detecting process. Ground contains not only sand, but also many different chemicals, minerals and salts. These extra components are referred to as ground mineralisation and will often produce a sound from the detector, known as 'ground noise'.

The SD 2200D has the ability to cancel out the effects of ground mineralisation so that it minimises ground noise, while retaining maximum sensitivity to metal targets. Cancelling out the effects of ground mineralisation is referred to as 'ground balancing'. This ensures that welcome signals from objects such as gold are not confused with unwelcome ground noise. The SD 2200D has automatic ground balance which adjusts itself to minimise the effects of ground mineralisation when set in Tracking mode.

5.2.2 Iron Discriminate switch
This switch allows you to select between simple discrimination (Disc mode) and discrimination with tone identification (Disc+ID mode), or to turn off the discrimination altogether (All Metal mode).

In the case of All Metal mode, the detector will give varying volume and pitch signals but this information does not indicate the type of metal in the object.

In Disc mode, a strong signal from a ferrous (iron) object will cause the threshold to be 'blanked' or silenced.

Disc + ID mode, a strong signal from a ferrous object will cause the threshold to be 'blanked', just as it does in Disc mode. In addition, a signal of medium strength will trigger the ID mode. In this mode, non-ferrous objects usually produce a tone with a steady pitch while a ferrous object will usually produce a tone with a varying pitch. Repeated sweeps across the target might be required to confirm whether the tone is steady or varying. Note, however, in this mode some non-ferrous objects can also produce a tone with varying pitch, making the operator more likely to mistake a non-ferrous object for a ferrous object. This mode of discrimination should not be trusted until the operator has a lot of experience with listening to the tones produced and comparing them with the objects detected.

If the signals are too weak for accurate discrimination in either of the discriminating modes, the detector will return to the All Metal mode signal. While in the Disc+ID mode, a signal which is too strong to be discriminated will produce a rapidly pulsing signal with constant pitch. This is called an overload signal. A target producing this sound should not be interpreted as being a ferrous target. It should be investigated.

5.2.3 Discrimination Level Adjust
The Discrimination Level Adjust control gives the operator the ability to select the sensitivity and likelihood of a target being ferrous or non-ferrous. The same control also affects how the detector recognises mineral effects in the ground as opposed to metal targets, when ground tracking.

Quick Start Instructions

1. Switch the Power On/Off switch to On.
2. Set the Threshold control so that sound can be heard in the Headphones.
3. Hold the detector at waist height with the shaft horizontal, so that the Coil is vertical. Keeping the Coil vertical, slowly move it around your body through a half-circle until the noise from interference is loudest. Hold this position, keeping the Coil motionless, and push the Tune button once to start the tuning function. Tuning takes approximately one minute. A series of three 'beeps' indicates that the best frequency has been selected.
4. Rotate the Tone control to produce a threshold pitch that suits your hearing.
5. Set the Channel switch to Both and the Audio/Boost switch to either Shallow for small shallow targets, Deep for large, deep targets or N (Normal) for general detecting (see Section 6.2.6).
6. Set the Iron Discriminate switch to the Disc position and turn the Level Adjust to the middle of its range.
7. Ground balance the detector by pulsing the Coil up and down and, while Coil is in motion, flick the Balance Mode switch from Fixed to Track.
8. Your detector is now ready to be used.

Minelab recommends that you take time to read this manual thoroughly to help get the most out of your new SD 2200D.

Operating Instructions

This section gives a detailed description of how to operate the SD 2200D detector. The 'Detector sounds' section contains definitions of some terms with which the beginner should be acquainted.

Introduction

The SD 2200D can be operated with automatic ground balancing (in Tracking mode) or with the ground balance fixed (in Fixed mode).

When the Balance Mode switch is switched to Fixed mode, the ground balance is held at its current level.

When switched from Fixed to Tracking mode, the detector begins to automatically ground balance through a two-stage process. The first stage is a very rapid adjustment to the ground mineralisation. This stage lasts for five seconds after the switch is thrown. The second stage continues to adjust to the ground mineralisation, but at a greatly reduced speed. Adjustment continues for as long as the detector is kept in Tracking mode.

It may be of use to repeat the ground balance function when ground conditions change rapidly.

If the detector is switched to Fixed mode at any time, it will no longer adjust itself to changes in soil mineralisation, but will stay fixed at the level it last reached while in Tracking mode.

While in Tracking mode, the detector usually stops ground balancing when it detects a target. However, a weak target signal may not be recognised as a target and, if the Coil is repeatedly passed over it, the target could be tracked out. It is therefore recommended to switch from Tracking to Fixed when pinpointing a potential target (see also Discrimination level control on pages 25 and 26).

For best results, use Tracking mode in areas with high ground noise. SD2000 and SD2100 users must note that setting the Channel switch does not affect the operation of the automatic ground balance.

Ground Balance Procedure

Ground balance both channels at once by setting the Channel switch to Both. Move the Coil up and down between 2 cm and 10 cm above the ground (see Figure 7) and, while moving the Coil, set the Balance Mode switch from Fixed to Tracking. The fast ground balance lasts for only five seconds after switching to Tracking. Therefore, it is important to be moving the Coil as the switch is thrown.

Keep moving the Coil until all ground noise has stopped. A persistent signal probably indicates a target in the ground. In this case, move the Coil to a new location and repeat the procedure.

When there is no longer a change in the threshold while the Coil is being raised and lowered, the detector is said to be 'ground balanced'.

Once the detector is ground balanced, you can then decide to detect in either Tracking or Fixed mode. If the ground is mineralised or variable, use Tracking. If the ground is very mild, use Fixed mode and switch back to Tracking temporarily if the threshold becomes noisy. Do not test a target by switching to Tracking when the Coil is above it.

Iron Discrimination switch

The main means of iron discrimination of the SD 2200D is the 'blanking' (silencing) of the threshold which occurs when the detector determines a target is of ferrous metal (magnetic). This form of iron discrimination operates when the Iron Discrimination switch is in the Disc position and the detector is fitted with the supplied 11" Double 'D' (wound) Coil.

Targets must produce sufficiently strong signals for the SD 2200D to successfully discriminate iron objects. Fortunately, most iron junk is located near the surface and much of it can produce the required signal strength.

NOTE: When used in Disc mode, deeper or small targets, whether ferrous or non-ferrous, will produce the normal target audio signal.

When the SD2200D is operated in the Disc+ID mode, the same audio blanking will operate as it did in Disc mode for strong signals. However, there is an additional mode of iron discrimination which can operate with weaker signals. In this case, the detector will jump into the ID audio signal mode.

In Disc+ID mode, the operator needs to monitor the pitch of the signal as the Coil is swept over the buried metal target. Most ferrous targets will produce a changing pitch signal as the Coil is moved back and forth across the target. Non-ferrous targets will produce a signal with a steadier pitch.

Some ferrous targets, particularly thin nail-like targets, can also produce steady pitches just like non-ferrous targets. Some gold will also produce a variable pitch, particularly specimen gold or gold containing a matrix of quartz and/or ironstone. Therefore, only signals with highly variable pitch can be trusted to indicating ferrous targets in the +ID mode.

The +ID target mode of recognition requires considerable operator experience. It is recommended that the operator investigate most targets detected in the +ID mode and learn to distinguish the signals.

Audio blanking on ferrous targets is the most useful form of discrimination, but this will only operate if a Double 'D' Coil is used.

The central position of the Iron Discrimination switch activates All Metal mode. There is no discrimination in this mode. Targets will cause pitch and volume of signals to vary, but these variations convey no consistent information about the type of metal.

If a target signal is too weak for the detector to discriminate when it is set in one of the discriminating modes, it will revert to All Metal mode. As soon as the signals become strong enough, the detector will resume discrimination.

It is not advisable to pin-point in Disc+ID mode because the duration of the signal is too long (i.e. too 'broad' a signal). Pin-pointing is best performed in All Metal mode.

It is recommended that once a target has been located and the operator is using the discriminator, the Coil should be rapidly passed back and forth over the target centre several times. Remember to switch back to Fixed balance for this.

At all times (particularly when discriminating or ID-ing a target), the Coil must be passed smoothly over the ground surface while maintaining the coil height above the ground.

The form of ferrous discrimination which blanks the signal will not work if a Monoloop Coil is used instead of the recommended Double 'D'. In that case, the Disc mode will be identical in response to the All Metal mode. The Disc+ID mode will operate in the ID mode giving pitch discrimination, but will still not blank ferrous signals.

Operation of the Disc+ID mode is affected by signals which are too strong. If the signal is too strong in +ID mode, the detector will emit a rapidly pulsing signal of constant pitch. This is to guard against erroneous interpretation indicating an overload of signal. Lift the Coil slightly higher above the ground and the discrimination functions will return.

CONTROL ROTATION

Battery

The 6-volt rechargeable Battery supplied with your SD 2200D will give power to operate the detector for 10-12 hours after being fully charged. These Batteries may be recharged at any time during their discharge cycle. It is very important to fully charge the Batteries before storage. DO NOT leave a Battery fully discharged for longer than 1 day.

Battery Chargers

Two types of battery chargers (Mains and 12V vehicle charger) are supplied with the SD 2200D.

Searching

The SD 2200D is a 'motion' detector, which means that it must be moving over a target in order to detect it.

The Battery should be worn in the back-pack supplied. This places the Battery at the furthest distance from the Coil.

Ensure that you do not set your shaft length too short. If the Coil is too close to your body it might detect your pick, the Battery or any other metal that you are carrying.

NOTE: DO NOT wear steel cap boots or shoes with metal eyelets!

If you are getting false signals as you sweep the Coil, check that they are not produced by any metal you are carrying. Move the Coil closer, then further away from your body to see if the signals are coming from items such as your pick or the Battery. If they are, you must increase the distance between the Coil and these items.

The Coil should be swept over the ground in a side-to-side sweeping motion. As the operator moves forward slowly, the search pattern looks like a snaking path. To ensure that the ground is thoroughly searched, approach the area from three directions (see Figure 10 [bottom]).

While sweeping the Coil it is important to keep it parallel to, and at the same height above the ground at all times. The easiest way to achieve this is to have the Coil lightly touching the ground. DO NOT raise the Coil at the ends of each sweep as this will reduce your detection depth (see Figure 10 [top]).

Each sweep of the Coil should overlap the area of the previous sweep to ensure a full coverage of the search area. Be aware of the search pattern of your Coil and overlap sweeps to take this into account.

Prospecting Tips

The SD 2200D has superior ground balancing and it is possible to find quite large objects near the surface in well-worked areas because other detectors have been unable to cope with the high degree of mineralisation present. You should therefore dig all signals, even in previously detected areas.

Very large changes in the mineralisation of an area can produce a signal in the detector. Typically, you might get a response from a concentration of orange/reddish dyke material or clay. Similarly, in loamy conditions, a pocket of dark orange/reddish colouration may produce a sudden signal change.

It is NOT recommended that you try to ground balance the detector in an attempt to 'test' a questionable response. This may cancel weak signals from very deep targets. If in doubt, scrape away some soil above the suspect signal and if the signal gets stronger, it is a target. Dig it!

If the ground is extremely variable and causes the detector to be very noisy, you may try operating with the Channel switch set to Ch1. This will reduce noise caused by varying mineralisation but some nuggets may not be detected, because the full range of nuggets is not detected in Ch1 or Ch2, only when the Channel switch is set to Both.

Charcoal can sound loud at times and rather like a metallic object when close to the surface. Charcoal is usually created by farmers burning off tree stumps or by bushfires. Once the charcoal under the surface is removed, the signal will vanish.

Hints for Maximum Gold Recovery

• Keep the Coil as close to the ground as possible.
• Listen very carefully. This is more important than concentrating on looking.
• SLOW DOWN! Do not rush – take your time.

Identifying Target Signals

Metallic targets will usually give a 'solid' sounding response when the Coil is swept across the object from any direction. Ground noises usually give a broad uneven response when the Coil is swept from different directions. A metallic target generally sends out a short, sharp and mostly symmetrical response.

If you are not sure whether the sound is ground noise or a target, you need to find out if the signal is valid. Scrape a shallow hole about 7 to 10 cm deep over the suspected target. Sweep the Coil over the hole at the original ground level but DO NOT dip the Coil into the hole. If the signal has decreased in volume or is less defined, it is a ground noise. If the signal remains the same or becomes louder, it is a metallic target. If you are still not sure, make the hole deeper and repeat the process. You will also notice that mineral noises are often experienced from one direction only, on the return swing it is no longer there.

The 'Halo Effect', which is built up around a buried metal object, makes the object appear to be larger to the SD 2200D than it actually is. This will be reduced once the target is disturbed from its position in the soil. An example of this is when a small target, detected at a substantial depth with the SD 2200D, is barely or not even detectable once recovered from the ground. Even if reburied, the 'Halo Effect' will disappear.

It is not recommended that you try to eliminate what might appear to be faint, isolated ground noise by balancing the SD 2200D, as you might balance out the response from a deeply buried metallic target.

Pin-pointing

To find an object and reduce the size of the hole required to remove it from the ground, it is necessary to pin-point the exact location of the object. The technique described here will be particularly useful with the Double 'D' Coil, but it will also work with Monoloop Coils.

If a target signal (or a soft signal) is heard, first confirm it by circling the Coil around the target while operating the detector in Track mode. While the Coil is moving around the target, switch the mode to Fixed. This will give a very accurate ground balance on this area. One of the pin-pointing techniques may then be used.

When a likely object is detected, sweep the general area with the Coil, taking note of where the strongest signal is received. By shortening the length of the sweep it should be possible to draw an imaginary line in the ground where the strongest signal is located (see Figure 11).

Turn and face the target at 90 degrees from the initial direction and repeat the process. The object is located where the two imaginary lines cross.

If using a Monoloop Coil, small shallow nuggets will give a signal near the rim of the Coil. Another pin-pointing technique for Monoloop Coils is to turn the detector coil onto its side and move the Coil while it is vertical, across where you suspect the target to be. This may assist with pin-pointing (see Figure 12).

Digging the Target

Once you are sure of the location of the target it is necessary to dig a small hole to recover it. In order to preserve the environment, the hole should be as small as possible. Always replace the soil and grass which is removed.

It is essential to carry at least one of the following digging tools with you when searching:

• a small, strong digging spade
• a pick
• a shovel
• a crowbar (for very deep objects in hard ground).

Before digging, clear the area of loose surface material and check that the sound is still there. If it is not, the target must be amongst the surface material.

If the signal is still there, dig down a few inches. If the target cannot be seen, sweep the Coil over the hole. If the signal has gone then it must be in the pile just dug. Make sure that there are no objects buried in the soil under the pile. Take care when you dig as damaging a nugget can reduce its value. Start digging approximately 10 cm in front of the target to reduce the chance of damage. Pile the diggings carefully as it may be necessary to search them. It will also be necessary to replace them, once your search ends.

If the target is located in the soil that was removed, sweep the Coil over the pile and pin-point where it lies in the dirt. Keep halving the pile which includes the target. If it is still difficult to find the target, lay the detector down with the search coil flat on the ground. Take a handful of the diggings and pass it over the Coil. If there is no signal, place the handful carefully in a new pile and repeat with another handful. Your hands and wrists must be free of any metallic jewelry and watches.

Once the object has been dug up, it is a good idea to sweep the hole again to ensure that there are no other targets. If you find an object in a particular hole, search the surrounding area very carefully as it is likely that there are more objects nearby. If you hear a target, keep searching until you find it – it is there and might be valuable.

NOTE: Always refill the hole before leaving and scatter leaves, etc., as you found it.

Search Coils

The SD 2200D is supplied with an 11" Double 'D' as its preferred Coil. Coils supplied on the SD2000 are not suitable for use with the SD 2200D. Coils supplied with the SD2100, will operate on the SD 2200D.

NOTE: Monoloop Coils are not recommended for use with 'Iron Discrimination' technology, but they will operate perfectly in the All Metal mode and can be used in Disc+ID mode by experienced operators.

Batteries

As well as the 10A/hr battery, Minelab has a smaller lightweight battery available. This is 4.5A/hr which gives approximately 4 to 5 hours running time per charge. The total weight of this small battery is only 968 grams.

Corporate Clothing

Minelab also has a range of good quality clothing such as caps, T-shirts and jackets available. Ask your local dealer for details.

FCC Compliance

NOTE: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

• Re-orient or relocate the receiving antenna.
• Increase the separation between the equipment and receiver.
• Consult the dealer or an experienced radio/TV technician for help.

EC Conformity

NOTE: This product complies with the essential requirements of EMC Directive 89/336/EEC.