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How to Make a Telescopic Mast

Amateur radio operators frequently require portable antennas that are easy to set up and take down under emergency conditions. Deed restrictions in some communities do not allow antennas for aesthetic reasons. Despite federal legislation protecting amateur radio, some ham radio operators have circumvented restrictive covenants by disguising all or part of their antenna systems as flagpole masts, which entirely contain or partially support their covert antenna systems. Build a 50-foot tall telescoping PVC pipe mast for your amateur radio antenna that is portable, easy to install and remove, and which doubles covertly and patriotically as an ordinary flagpole.

Things You'll Need

10-foot length of 1-inch diameter Schedule 40 PVC pipe
10-foot length of 1 1/2-inch diameter Schedule 40 PVC pipe
10-foot length of 2-inch diameter Schedule 40 PVC pipe
10-foot length of 2 1/2-inch diameter Schedule 40 PVC pipe
10-foot length of 3-inch diameter Schedule 40 PVC pipe
10-foot length of 4-inch diameter Schedule 40 PVC pipe
1-inch diameter Schedule 40 PVC end cap
1 1/2-inch diameter Schedule 40 PVC pipe coupling
2-inch diameter Schedule 40 PVC pipe coupling
2 1/2-inch diameter Schedule 40 PVC pipe coupling
3 3-inch diameter Schedule 40 PVC pipe couplings
4 2-inch long by 1/4-inch bolts with wing-nuts and washers
4 2 1/2-inch long by 1/4-inch bolts with wing-nuts and washers
4 3-inch long 1/4-inch bolts with wing-nuts and washers
4 3 1/2-inch long 1/4-inch bolts with wing-nuts and washers
4 4-inch long 1/4-inch bolts with wing-nuts and washers
4 4 1/2-inch long 1/4-inch bolts with wing-nuts and washers
Roll of 50-lb. test mono-filament fishing line
Metal or plastic tent stakes
PVC cement
Duct tape
Tape measure
Indelible marker
Drill with 5/16-inch bits
Hacksaw
Sandpaper
Stepladder

Instructions

- 1
  Measure and mark a circumference 2 feet above the bottom of each of the five narrowest 10-foot lengths of PVC pipe.
- 2
  Use duct tape wrappings to form two gaskets on each of the four narrowest 10-foot lengths of PVC pipe but not on the 3 inch or 4-inch diameter pipes. One duct tape gasket should be at the bottom of each pipe and one just below the 2-foot circumference line marked previously. Each pipe should now fit firmly inside the next larger diameter pipe and should slide smoothly and evenly. Add or remove turns of duct tape to accomplish this snug but easily movable fit.
- 3
  Install the 1-inch end cap on the top end of the 1-inch pipe and install the respective couplings at the top ends of each of the four next larger diameters of pipe. Use PVC cement to make all coupling and fitting connections permanent.
- 4
  Use the hacksaw to cut off the bottom 2 feet of the 3-inch pipe. Because the gap between the 3-inch and 4-inch pipes is greater than 1/2 inch, use two 3-inch couplings as spacers. install one at the bottom of the 3-inch pipe and use another to reconnect the cut 2-foot length to the 3-inch pipe. This should now slide easily into the 4-inch pipe. Use duct tape to take up any additional space as in the smaller pipes or sand, as necessary, to ensure firm but movable fit.
- 5
  Assemble the mast on the ground by sliding each section into the next larger diameter section up to the 2-foot line. The 2 foot overlap in each section will give the 60 feet of pipe a 50 foot completed length.
- 6
  Drill pairs of 5/16-inch holes at right angles to each other and one inch apart above and below the lower and upper gaskets respectively. Drill through both inner and outer pipes to ensure that holes will line up later. Add markings to the pipe ends to help with later alignment. Drill additional pairs of holes at right angles to adjust the mast lower, as needed. Increase the overlap between each pair of pipes to increase overall mast stability.
- 7
  Slide all of the pipe sections fully into each other. Total collapsed length should be about 11 feet. Stand the collapsed mast up in your desired location using a stepladder to access the top of the collapsed unit.
- 8
  Begin extending the mast one section at a time and tie three 60-foot pieces of mono-filament fishing line just above the upper bolts on the 1 1/2-inch pipe. Stake these out as guy-lines when the mast is fully extended. Insert bolts into upper and lower pairs of holes in each overlapping portion of mast. Repeat this process for each section. Maximum height will be 50 feet with 2 feet of overlap between each pair of pipes. Increase stability by shortening the mast with greater overlap and by adding additional guy-lines, as needed.

Ham Radio