Price - Stock No 290
This kit will help locate pipes or other metal objects to a depth of 8 cm. Whether fossicking or renovating, this kit is simple to use.
- Inspect the tracks for fine breaks and test the
continuity of each track with an electronic circuit
tester or ohm-meter.
- Identify the resistors using a multimeter or the
Resistor Colour Chart .
- Bend the legs of the resistors to match their
respective holes and push them through from the plain side of the
P.C.Board. Solder in place - refer Soldering
- The 14 pin IC socket can be pushed carefully
into place. Solder in place.
- Identify the capacitors - refer
- The ceramic capacitors are not polarised. Solder the ceramic capicitors in their respective positions.
- The 100uF electrolytic capacitor is polarised, identify the location and orientation and solder.
- Eight PCB pins can be pushed into the holes where the
leads connect. These can be soldered.
- The transistor must be orientated correctly and soldered.
- Figure 8 wire is enclosed for use when mounting the potentiometer, switch and earphone socket away from the PCB - these are only short lengths and the remainder is for connecting the coil (L1).
- Using wire strippers, bare and tin the ends of the lengths of fig 8 wire - see refer Tinning wire.
- Solder the battery snap, potentiometer, switch and earphone socket to their respective PCB pins.
- The enamelled copper wire needs to be wound onto a round former 140mm in diameter, 40 turns.
- Trim the remainder enamelled copper wire. The ends of the coil must have the enamelling removed to allow soldering. Use a sharp knife or fine sandpaper to remove the enamelling from about 5mm of both the ends of the coil.
- Shrink tube is provided to insulate the ends of the coil after soldering to the fig 8 wire. Solder the connections and shrink the tube. Connect the figure 8 wire to the PCB pins for the coil.
- Establish the correct orientation of the 4001 with the
locating dot on the IC and on the diagrams. Insert the IC into the
socket with care.
- The Metal Locator is now complete and ready for
Connect a battery and plug in the earpiece.
Adjust the potentiometer until no noise is heard.
Pass the coil over a metal object, if the kit does not 'buzz' re-adjust the potentiometer.
Fine tune until maximim sensitivity is reached.
Troubleshooting if necessary will involve careful
checking of locations and polarity of components, the diodes and that the
locating DOT on the 4001 is as the drawing shows. Re-solder all joints and
check to make sure you have not bridged
across between any two adjacent component legs.
First we must understand what the IC 4001 is. Datasheet for the 4001.
This kit works by setting up two oscilators. One is adjusted by the 5K potentiometer, the second is influenced by the inductance value of the coil (L1).
As the coil moves over a metal object the second oscillator changes its frequency. The frequencies are added and when the frequency differs the difference is output to the earpiece.
Contact CdS electronics