Monopole Design

The final GSM-900 monopole antenna design is as follows, a 77.5 mm long 3 mm diameter element coming out of the center of a 200 mm by 200 mm solid metal sheet.

Construction

Materials (Image)

1 @ 3 mm diameter Brass Rod 100 mm in length (thick copper wire would be a suitable alternative) 1 @ 200 mm by 200 mm Copper Sheet (a biscuit tin lid or piece of PCB board would be a suitable alternative) 1 @ N-Type Panel Receptacle Jack (Amphenol Connex Panel Receptacle Jack – Solder Pot Terminal or similar) 4 @ Small Nuts and Bolts (some small washers may also be needed)

Tools (Image)

Hacksaw Sheet metal shears or jigsaw Soldering iron and solder Drill with bits Selection of hand-file’s Rule and pencil Suitable screwdriver and/or pliers for nuts and bolts (I would suggest these as the minimum tools but extra would be helpful such as a vice, etc)

Step 1

Mark and cut the metal sheet to size approximately 200 mm by 200 mm, anything over 160 mm by 160 mm should be fine. Use the file to clean up any sharp edges.

Step 2

Mark the center of the sheet and drill a suitable sized hole so the sheet rests flat on the connector. Place the connector in the hole and use your pencil to mark the center of each of the mounting holes. Drill the holes to a suitable size for your mounting bolts.

Step 3

Using the hand-files shape the end of rod so it fits neatly into the solder cup on the connector. Solder the rod to the solder cup, try and make sure the rod is as straight as possible.

Step 4

Using your ruler and pencil mark a length of 78 mm along the rod, cut just above this mark with your hacksaw. Now using the hand-file carefully file down the the length of the rod until it’s length is 77.5 mm.

Step 5

Mount the element connector on the sheet with the nuts and bolts.

Image ?: The finished monopole antenna.