SEARCH COILS. The control box and electronics are designed
to operate with both mono and DD coils with a considerable variation
in electrical characteristics. In addition to Pulsepower mono and DD
coils, the detector will also operate with Minelab type mono and DD PI coils.*
These will be a direct plug in, and all that may be necessary is an
adjustment to the Sample Pulse Delay control.
* This is not to be taken as a guarantee  that it will work with all Minelab type coils.  

The picture shows the standard 11in mono coil with low capacitance cable.

CONSTANT CURRENT TRANSMITTER SUPPLY. This feature enables coils with resistances of between 4 ohms and 0.4 ohms to operate at the same pulse current. The transmitter supply voltage is automatically adjusted to compensate for different coil resistances. The peak pulse current is 2.0A and is repeated nearly 3000 times per second.

SAMPLE PULSE DELAY. The main signal channel delay has a minimum setting of 10uS, which can be increased to a maximum of 25uS with the delay control knob. This more limited range of delay adjustment enables the ground balancing circuitry to operate at good signal levels to minimise threshold noise, as well as accommodating different coil types.

GROUND BALANCING CIRCUIT. Considerable time was invested in improving this aspect of the GOLDSCAN 5C. More accurate receiver channel matching and a different way of subtracting the ground signal, result in greatly improved performance over earlier Goldscans, together with much less target signal loss when ground balanced.
Ground balance is by manual adjustment, rather than automatic. This gives the operator the option of fine tweaking, positive or negative, for different situations. Just a single control that is very smooth and non-critical in its setting.

TARGET I.D. A totally new progressive two tone audio circuit was developed to give an useful level of target I.D. All metal targets take the ground decay curve as a reference line. Targets that have a faster decay than the reference, give a sliding high tone, while targets that have a longer decay have a sliding low tone. Combined with this tone change is the normal threshold setting and change of audio amplitude. Most medium, small, or thin, gold or poorer conductivity targets, will give a high tone, while larger or more conductive targets will give a lowering tone. Iron objects, in general, and even small items, such as nails and pins, will give a low tone. These can be distinguished from the more conductive non-ferrous items by the irregular sound and double blip response that is superimposed on the falling tone. Flat iron items give a combination of low and high tones, which are unique. An important feature of this circuit is that the tone always stays high or low ( except for flat iron) right across the scan width i.e. it doesn’t jump to the opposite tone as the object is passed.