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The Bubba Pole

Lew Paceley, N5ZE
NETXQRP Club
10/17/00
Updated 10/29/00

If there's anything Bubba likes, it's pickup trucks and fishin' poles. This project combines both to create a 30+ foot high platform for your favorite wire antenna. I wanted a relatively tall, inexpensive, quick-to-erect antenna pole that could travel with me in the back of my pickup and thus was born the "Bubba Pole". The BP can be used to support almost any type of wire antenna including dipoles, inverted vees and various verticals. Wire verticals are especially easy since the pickup bed acts as a natural groundplane.

There are two interesting mechanical insights in this project:

• A twist-to-fit shower curtain rod is used to span the width of the truck bed, and through a pressure fit, support the base of the antenna. See it here.
• Most trucks have tie down points and/or pocket holes in each of the four corners of the bed. These make natural guy points for the guying the pole.

Click here to see the bubba pole with guys. Click here for a picture showing tailgate operation...one of the additional benefits of a pickup truck.

Parts List:

• 1 10' piece of Sched. 40 1.25" PVC pipe
• 1 1.25" PVC Pipe Tee
• 1 1.25" PVC 4-way coupler
• 2 1.25" to 1" PVC Pipe Reducers
• 40' rope (less than 1/4" diameter)
• 1 Black Widow 20' fishin' pole
• 1 Twist-to-fit shower curtain rod, must be long enough to easily span the width of the pickup truck bed at the bed rim
• Duct Tape
• PVC Glue

Tools:

• Hack saw or PVC cutter (to cut the pipe)
• Sand paper (to fit the pipe into the couplings)
• Drill with 1/4" bit (to drill the 4-way coupler to make holes to attach the guy ropes)

• Hacksaw the 10' 1.25" PVC pipe into two 5' sections. Try to keep the cut as "square" as possible. Using sandpaper smooth the two ends of one pipe and one end of the other pipe so that the pipes "bottom" in the PVC fittings. One pipe must fit one end into the 4-way coupler at the top and one end into the PVC tee at the bottom. The other pipe will only fit into the 4-way coupler. Don't oversand and reduce the diameter of the pipe too much...we want a good pressure fit between the pipe and coupler but not a fit so tight that we can't pull it apart readily. The best thing to do is sand a little, then try it. If too tight, sand a little more and try it. Etc.
• Drill 1/4" holes in the two opposing sides of the 4-way coupler, on both the "left" and the "right" outlet of the coupler. These holes will be used to attach the guy ropes. The coupler is actually symmetric, left to right, top to bottom. Pick an outlet of the coupler and move it to your left. That becomes the "left" outlet for drilling purposes. Drill the front side and rear side of the left outlet measuring in about 1/2" in from the coupler opening. Without rotating the coupler drill the "right" outlet on both sides, again measuring in about 1/2 inch from the coupler opening. See the assembly diagram for clarification.
• Trial fit your twist-to-fit curtain rod in the PVC tee. First, insert the 1.25" to 1" reducers on each side - DON'T GLUE YET! Remove the rubber foot from one end of the twist-to-fit curtain rod. Attempt to slide the rod through the couplers in the PVC tee so that approximately half the rod is poking out of each side of the tee. If the curtain rod won't slide completely through the PVC tee then you will need to either take sandpaper (or preferably a Dremel type tool with a sanding attachment) and enlarge the inside diameter of the couplers. Again, work slowly. Sand a little, then try it. We want the rod to easily slide through the couplers. Once you have sized the reducers, use the PVC glue to glue them in place on opposite sides of the PVC tee. Note:I did not glue my couplers flush against the PVC tee but rather left them extended by an inch or so on each side to give a slightly wider "base" to the antenna.
• Glue the PVC tee to the 5' section of pipe which has been sanded on both ends.
• Glue the PVC coupler to the 5' section of pipe which has been sanded on one end. Do not glue the 5' PVC pipe section into either side of the coupler that you have previously drilled! If the holes are drilled in outlets of the coupler that are "left" and "right", we want to glue the pipe into one of the outlets at the "top" or "bottom" of the coupler.
• Cut the rope into four 10' sections and set aside.
• Take the BW 20 fishing pole and using an electric hairdryer, "sweat" the plastic base off of the pole. CAUTION: Keep the pole horizontal while you do this or all of the sections will fall through the bottom of the pole when the endcap is removed! Once the base is removed you must either duct tape the end to keep the pieces from falling out, or for a fancier solution, insert a rubber plug or dowel whose diameter is no greater than the outside diameter of the bottom of the pole, about 1.23" by my calipers on my particular pole. We must be able to insert the pole 9"-12" inside the 1.25" pipe channel with the end plugged. And we need to ensure a good friction fit inside the 1.25" PVC pipe. I used duct tape to wrap the very end of the pole until it fit snugly but completely inside the PVC pipe. The simplest process is to add a few wraps then try it. If it's not snug, add a few more and try it. Etc. You know the fit is right if it doesn't have any side-to-side play yet can be pushed to any arbitrary depth inside the pipe. Since we don't want the BW 20 antenna pole falling down inside the pipe, we must add a second wrap 9"-12" above the end of the pole base. This wrap must ensure that the pole plus duct tape wrap diameter is greater than the inside diameter of pipe, thus keeping it from falling down inside! Same process as before: wrap a few turns and try it. In this case, once we can prove to ourselves that the pole won't slide down inside the PVC pipe it's probably good practice to add another few turns!

Antenna Assembly:

• With the lower PVC section and shower curtain rod in approximately the middle of your pickup truck bed, thread the twist-to-fit shower curtain rod through the pipe tee on the lower PVC section. This is the section consisting of the 5' PVC pipe, pipe tee and reducers. I have to remove one of the rubber end caps from the shower curtain rod to do this. Carefully manuever the curtain rod into position and begin lengthening the rod. Make sure the rod ends stay level and securely positioned on the edge of the top rim of the pickup truck bed. The curtain rod bears all the weight of the antenna so you want to make sure that it doesn't/can't slip. It needs to be tightly secured or the whole assembly will fall into the bed - not good.
• Tie each 10' piece of rope to it's corresponding tie down in each of the four corners of the truck bed. Use a simple knot here because you will likely need to make some tension adjustments in a few minutes once the pole is up. Take each loose end and drape it over the curtain rod. The idea here is to make it easy to grab the guy ropes while holding the assembled pole straight up.
• Now take the BW 20 fishing pole and the top 5' PVC section with coupler, and while standing in the bed of the pickup truck securely snug the BW 20 fishing pole end into the PVC pipe. Pull the top section of the fishing pole out and attach your antenna wire/feeder. Continue lengthening the pole to full height by pulling out sections. Now for the tricky part. Observe how the 4-way coupler on the bottom of the PVC section with the fishing pole must fit the bottom section already in place. I always align the 4 way coupler so that the two open ends (with the guy rope holes) are parallel to rear axle of the truck. Now push the 4 way coupler onto the lower section making sure that it seats firmly. Don't use too much force or you could bend your curtain rod. A twisting action is sometimes helpful. This part of the assembly process is a little unwieldy due to the fact that you have to manuever a 25' foot long pole, but fortunately the PVC/BW 20 combo is fairly lightweight.
• Push the assembled pole into a vertical position. While continuing to hold the pole in a vertical position, tie each of the guy ropes to its corresponding hole in the 4-way coupler. Don't try to make tension adjustments here, we'll do that at the bed tie-down points next. Got it all tied off? Great! Almost done. Now, while trying to keep the pole vertical, make any tension adjustments needed at each tie point. Don't overdo it! The guy ropes need to be secure but should not pull down so hard that they could bend the curtain rod. The wind-loading of the BP is relatively small so there's no need to get too exuberant in the guy department.

Update 10/29/00
I found I could make the antenna even faster to set up (and take down) by using 4 snap hooks with swivels (the kind you clip a dog leash to a collar with) on the rope ends which are attached to the 4-way coupler. Since I try to place the shower curtain rod in about the same place every time I set up, it means that I can usually avoid having to retension the ropes too. I got the snap hooks at Wally World (sorry, southern term... Walmart) for $1.97 per pair and you need two pair for the four guy ropes.

I should note that I found two problems relating to the press-fit shower curtain rod while setting up in the rain at our local QRP club meeting. Each rod end has a thin plastic cap over it to protect the surface that the rod is being pressure-fit to. On my rod I found that the repetitive pressure of fitting the rod in the truck bed was forcing the metal rod end to cut through the thin plastic cap. This resulted in some small surface scratches on the truck bed rim. The second problem I found was that the plastic end caps don't provide much friction when wet.

I pulled both plastic end caps and found that while one end had a nylon cap underneath the plastic cap (and hence, was not wearing through), the other end was completely hollow. I pulled off the worn-through end cap and replaced it with an 84 cent rubber stopper (it looks like the kind you use to plug test tubes with in high school chemistry!) I bought at Home Depot. In testing it today in the wet weather, it seems to have both solved both problems alluded to above. I may replace the plastic cover on the one, as-yet-unmodified rod end with a hard rubber cap of the type used on metal chair legs if I find that there still isn't enough friction.

Untested Ideas
I don't see any reason why you couldn't take a St. Louis Vertical and use the 10' PVC section of the Bubba Pole as a base. Note that this would force the radials to be elevated. Also, at least 9" of dowel must be extended from the end of the pole. The dowel would need to be wrapped in two places with duct tape to increase its diameter as per the directions above. The spike assembly should fit easily in the 1.25" PVC pipe.

Another possibility would be to use larger diameter PVC and make a Bubba Pole antenna using the DK9SQ 10 meter mast. Counting the pickup truck elevation, that would put the top up about 47' or so!