How To Make Any Land Metal Detector Operation Wireless - Tutorial, page 4
Select and Modify Container for Digital Transmitter
A container for a digital wireless transmitter must have an air-tight lid not to allow moisture and dust get inside and be durable enough to withstand any accidental bumps into rocks, roots and lumps of hard soil when placing a detector on the ground. A regular plastic food container (or storage container) can best serve the purpose if it is made of thick plastic and have a self-locking, non-flexible lid.
A Digital Wireless Transmitter Is Enclosed In A Plastic Food Container
Theoretically the container's size should be large enough to fit the transmitter plus a length of a male plug - two inches, of the transmitter-to-detector connecting cable to be plugged into the transmitter. To avoid using the container that is much larger than the transmitter, I decided to insert the male plug into the container obliquely so that the plug would form a 45 degree angle with the container's bottom and, thus, be right above the transmitter. As the transmitter's height is only 2.7 cm (approx. 1") and the container's height is 5 cm (aprrox. 2"), so there was enough room left for additional connectors and wires. To complete the connection with the transmitter, I used a female-to-male adapter set with a right-angled plug (as shown on page 7).
Dimensions of the Sennheiser TS-160 transmitter, oval in shape, are 8.7 cm x 9.7 cm x 2.7 cm (3.4" x 3.8" x 1"), so the transmitter is much smaller in length than my home-made armrest (see details on next page). A container with dimensions 12 cm x 12 cm x 5 cm (4.7" x 4.7" x 2") could provide enough internal space for the transmitter with all connectors. When being attached to the armrest, this medium-sized container would not occupy unreasonably large space or make too much of a bulge outwards.
Of course, you may find and use a better container of any type, but keep in mind that if the container is of some unusual shape and foreign make, you will have hard time replacing it if needed. Nothing to say about making new holes in the armrest. This is why a regular plastic food container is the best choice for its availability, low weight and low cost.
Next step was to make narrow rectangular holes on the container's edge (NOT on the container's sidewall or bottom!) for zip ties that would keep the container firmly attached to the armrest. If you make the holes in the container itself, the transmitter's protection against moisture and dust will be compromised. Mark the spots for the holes to be made on the container's edge after you determine the container's optimal position on the outside (right or left) of the armrest. The marked spots on the container must correspond to the holes made on the armrest (see details on next page).
Three Marked Spots for Holes on Container's Edge
Use a soldering iron with a large tip of a Chisel type to make three holes. The plastic is easily melted by the soldering iron, so apply it with slight pressure not to mess up the edge.
The hole's width should correspond to the width of a zip tie you are going to use; however, the narrower the hole, the better.
An Optimal Hole for a Zip Tie
Further modifications of the container are described on page 6.