Spark

The MWF Spark is a hand-held long-range locator built around what MWF calls its Long Distance Sensing System (LDS). Rather than sweeping a coil over the ground, the operator holds the unit level by its 360°-rotating grip, presses the scan key and reads the bearing the antenna settles into, confirmed by audio and LED indication. Three settings are chosen before each scan: a target type — gold, silver, bronze or caves and voids — a depth level of 1, 3, 5, 7 or 10 m, and a distance level of 25, 50, 100, 150 or 200 m. MWF specifies a search distance of up to 200 m across a 360° arc and a search depth of up to 10 m, and describes the operating principle as Digital Frequency Signal Processing (DFSP) receiving the electrostatic field of a buried target; those are the manufacturer's figures and the manufacturer's description. MWF also states that an Automatic Tuning System (ATS) prepares the unit for rocky, mountainous, sandy and clay ground without manual adjustment. The unit itself is small and plain: 16 × 9.5 × 2.5 cm, 700 g assembled and about 1 kg packed, with a control face of LED banks rather than a screen — depth, distance, target and battery each have their own row of lights, so there is no menu and no display language to set. A PIC18 microcontroller runs the electronics between 1 and 9 kHz, four replaceable AAA cells give a manufacturer-rated 32 working hours at a maximum 25 mAh draw, and there is no charger, no Bluetooth and no wireless module. Audio has five levels plus a silent mode, the vibration alert is toggled from the same key, and a rear socket takes wired headphones. It ships in a plastic anti-shock case with the transceiver antenna, the carrying handle, a printed user's guide, a tutorial DVD and a three-year MWF warranty card. It is aimed at buyers who want a very portable first long-range locator for open ground — MWF presents it as usable without previous detecting experience — rather than at prospectors who need a swept-coil VLF or pulse-induction machine for small gold.