How To Make Any Land Metal Detector's Operation Wireless - Tutorial, page 9

(...CONTINUED from Previous Page)

The second important part of the project was to shield the transmitter-to-detector connecting cable with a rubber harness.

My goal was to put the transmitter-to-detector connecting cable - stereo audio cable with a 3.5 mm jack, which was included in the wireless headphone system package into a protective tube. Because the cable was supposed to be used with a home audio source, its length was too long for my setup. As I did not want to shorten it and possibly mess up the cable's electrical shielding (the shield reduces electrical noise from other radio sources that may affect the signals), there seemed to be a problem in finding a way to make the cable compactly folded and of a certain length without cutting.

The easiest solution was to use the automotive wire rubber harnesses - corrugated rubber tubes, and wire sleeves that are available in any auto parts store and cost little. So I purchased a variety of them to reach my objective.

The corrugated tubes are wide enough for folding and packing the cable inside the tubes as well as changing its extension if necessary. I decided to start constructing the cable harness from the transmitter end. The harnessed cable should run around and above the container so that any contact with rocks, lumps of hard soil and other debris on the ground would be avoided or, at least, minimized.

I started with a rubber tube that had a right-angled opening at one end. This way, the harness would perfectly follow the cable's path from the start. I pulled the "free" end of the connecting cable through the tube and later repeated this procedure with all other rubber tubes I utilized to complete the cable harness construction.

Before pulling and fixing the rubber tube over the connector, I had to make sure that the tube would not slide backwards off the connector's body after being constricted by a zip tie. A small "bulb" at a point where the wire enters the jack could keep the zip-tie in place. To make the bulb, I used electrical tape which I cut in two narrow lengths.

Then I wound the lengths over a proper spot, so the connector's body bulged at the end.

And I pulled the rubber tube over the jack and secured it with a couple of zip ties.

At the second turn of the connecting cable, I used an S-shaped molded rubber pipe into which I inserted a straight corrugated rubber tube and also secured it with a zip tie.

At the straight segment of the cable path, I used two corrugated tubes, one of which was inserted into another and fitted externally over a short length of a rubber harness in order to make a reinforced joint. The joint was also secured with two zip ties. Most of the connecting cable had been harnessed.

(CONTINUED on Next Page...)