Mast Launcher




(A Poor Man’s version of the AB-577 Mast/Launcher?)





I’m not out to re-invent the wheel-maybe just putting a little more air in a soft tire. I was looking for a universal mast support for Field Day portable or fixed use that met a few requirements:

  • Easy to handle and set-up by one or two people (two much easier)
  • Is inexpensive
  • Can support a hex antenna with rotator on top
  • Can reach at least a 40′ height using a strap winch
  • Can be easily moved to the site in a pickup truck
  • Can be used over and over

The product I came up with is 10-12′ high when assembled (Figure 1) and has its’ main section made from a 4x4x12′ pressure treated (pt) beam. The longest section is 6-1/2′ (lower part). It has to accommodate the adding/removing of 5′ mast pieces and space for a strap winch. The top section can vary from 4 feet to 5-1/2 feet long. The shorter length could be better for portable use if reaching the top standoff bracket is a long reach with a step ladder. Figures 1, 2, both show the top section with 4 feet due to easier ladder accessibility.

The keys to this mast launching support are its’ strap winch, its’ versatility and its’ portability.

The portable version has raised a mast with a K4KIO hex antenna and a Yaesu G-450A rotator to 40′ using 3 levels of 3-guys and a strap winch (Figure 2), and it was done by myself with a small assist from my spouse. Of course, with a beam on top, guy control becomes very important and an extra man is handy and will cut the install time exponentially.


Figure B


Figure A

Not only does this design work for portable use, but can be easily adapted for more permanent use, such as attaching to the side of a building or setting in a bucket of cement. For these uses the full 12′ length is recommended. (Figure A) shows my mast support attached to the end of my 15′ high garage. For my permanent install I used the four guy (90°) setup with three levels of guys and with a fourth level guy ring installed in case I go past the 50′ high mark and need it. (Figure B) shows the finish product at the 50′ level with the K4KIO hex and a Yaesu G-450A rotator.

The mast was made using 5′ sections of 1-1/2” EMT (1-3/4 inch OD) and Bend-Gard™ Couplers. This is the same type of mast that had my personal K4KIO hex antenna and G-450A rotator up at 54′ for the last 4 Maine winters standing tall and no bent tubing. For info on the Bend-Gard™ mast set-up, visit

PORTABLE USE If you are interested in portable use, then follow all the steps to complete it.

FIXED USE If using at home and attaching to a building or placing in cement, then there’s no need to construct the base, so skip ahead to the ‘INSTALLING BRACES’ paragraph after cutting the 4×4 sections in the next paragraph.

CUTTING THE 4X4X12′ INTO SECTIONS Note: A list of materials I used is included at the end of the article.

Before we start the base, cut the 4x4x12′ pt (pressure treated) into a 6-1/2′ piece to be the lower base section and a 5-1/2′ top section. As noted earlier, you can cut an additional 12 to 18” off the top section (for portable use) if it makes your ladder reach to the top standoff bracket much easier. You can cut this off now or wait until later when you’re more sure if it’s necessary.

A few pictures and some instructions and you can be on your way. Here we go….

Figure 4

Figure 4

Figure 3

Figure 3

MAKING THE BASE (Figures 3, 4): I used two pieces of 1/2” plywood about 18”x18” (close is fine) and secured them together for a 1” thickness. Now cut a 36” piece of 2×4 and lay it diagonal on the plywood. Drill 1/4” holes through both 2×4 and plywood about 3” in from the diagonal corners and attach with ¼ x 2-1/2” bolts. Now cut two pieces of 2×4 for the other two diagonals. Drill two holes in each piece and attach with bolts. Note: on these two pieces leave at least 5” from the center of the plywood to the closest hole. Lastly, drill 5/8” holes about 2” from the ends of the 2x4s to later accommodate the 1/2”x2′ rebar stakes. Flip the base over so the plywood is on top.

DRILLING THE ‘L’ BRACKETS: This operation is much easier if you have a small drill press, but can be done with a hand drill and some care. Make sure you lubricate/cool the drilling area as you proceed. All four holes in each bracket will be drilled in about 5/8” from the sides.

On the 2” side drill the two holes in about 3/4” from the end. Note for all holes: Center punch all the holes for an easier drill bit start. On two brackets on the 4” side, drill the holes in about 3/4” from the end. On the other two brackets’ 4” side, drill the holes in about 1-1/4” from the end. This way the 2” lag screws won’t hit each other when installing.

ATTACHING ‘L’ BRACKETS TO PLYWOOD BASE: Find the approximate center of the plywood and place a small piece of 4×4, if you have a small piece laying around, approximately centered and scribe the four sides on the plywood with a pencil. If no small piece, then use the base section you just cut. Stand a section upright on the plywood center and mark it’s outline on the plywood. Important note: when marking the outline, align the 4×4 so it’s in alignment with the diagonal 2x4s of the base. This way when you place the ‘L’ brackets, both bolt holes in the ‘L’ brackets’ 2” side will be drilled through both the plywood and into the 2x4s.

Place one bracket against one side of the 4×4 and mark the holes on the 2” base side. Drill the two holes using a 3/16” drill bit, prox size, and fasten with two 5/16 x 2-1/2” lag screws. Center the 4×4 upright again and place another ‘L’ bracket next to the 1st one (90°), and mark and drill the holes. Again attach the bracket with two 5/16 x 2-1/2” lag screws. Again, stand up the 4×4 and mark and drill and attach another bracket. Hold off placing the 4th bracket for now.

Now with three brackets attached to the base, stand the 6-1/2′ section of 4×4 upright and mark the locations for the vertical holes. Drill the two holes for each of the three brackets into the 6-1/2′ section. Attach with 5/16 x 2” lag screws. The 6-1/2′ piece should easily stand on the base by itself. Now, place, mark, drill all four holes and attach the 4th ‘L’ bracket.

Figure 6

Figure 6

Figure 5

Figure 5

‘INSTALLING BRACES’ between the two 4×4 sections (Figures 5, 6): First, cut two pieces, each 18” long, off of the 1 x 4 x 8′ pt board. The next step is installing the 1 x 4 x 18” pt braces above and below the two 4×4 sections. Both 4×4 sections need to be approximately level and in-line. It’s easier if you remove the base so you can work closer to the floor-less chance of it tipping off the supports. Separate the two 4×4 sections by a good inch (winch opening). Place pieces of 1x4x18” on the top and bottom of the 4x4s equally overlapping the 1” space. I clamped around the three pieces on one side with two wood clamps. We will drill and attach one side at a time. That will allow us to line up the sections better if we don’t drill the holes perfectly. Mark the four holes on one of the clamped sides as follows: All holes are in from the sides about 1”. From the 1” opening end of the top 1x4x18” mark two of the holes in about 1-1/2”. Move in another 5-1/2” and mark the other two holes. Drill one 5/16” hole through all three layers. Make sure your bit is long enough to go through all three layers. Place a 5/16 x 5-1/2” hex bolt w/washer through the hole, washer, nut and snug it just tight. If the 4×4 has moved out of alignment some, you can tap it back into position at this time. Drill another hole and repeat the process. Now the 1x4x18” is rigid on one end so you can remove the clamps and finish off the other two holes on this side of the 4×4.

Now you can do the other side of the 4×4 in the same manner. Check your 1” spacing, your level and your alignment and then clamp as before. Drill and attach as done on the other side.

Figure 7

Figure 7

INSTALLING THE FLASHING: attach the flashing over the top of the bottom section (by the 1” separation) of the 4x4x6-1/2′. Cut a piece of flashing at least 12” long and overlap it on the end of the 4×4. The flashing will cut down on the friction when moving the strap. Fold it flat on the edges and nail it as tight as possible. I used four roofing nails on each side.


Next we install the lower 3 or 4” standoff bracket. It can be placed about 1 to 6” above the 1” opening. If using a shortened top section, 1” above is better. This give more separation between the two standoff brackets. This will be the side holding the mast so attach it on a side with a 1” opening. Cut two pieces of 1×4 into 12” pieces (other piece goes for top support). Offset two 3/16” holes in the center area and attach with 5/16 x 2-1/2” lag screws. Center the 3” or 4” standoff bracket on the support and mark the holes. Drill 5/16” holes and secure with 5/16 x 1-1/2” hex bolts with washers and nuts. Next mount the top standoff support just below the top of the structure in the same manner as the lower one and attach the standoff bracket. If you haven’t shortened the top section yet and plan to do so, now is the time.

MOUNTING THE GUY ROPE SCREW EYES (eye lags): Place the three ¼ x 3” eye lags a couple of inches below the top standoff support. Place them on the three other sides from the standoff support side. Drill three 3/16” holes with the odd side hole offset an inch to keep from contacting the other two eyelets, then install. Your lowest level of guy rope support attaches here.

Figure 8

Figure 8

MOUNTING THE WINCH (Figure 8). It’s easier to install in the flat position before standing the support upright. Position it on the back side from the standoff brackets and down from the 1” opening in a comfortable position, say 18”. You’ll need extra lag screws if not included with the winch.

The mast support structure is now complete.

A few thoughts:

You may notice a few extra holes in the framework. Disregard them as they were from other designs I tried along the way.

You’ll need a ladder for portable operations. I used a Werner 16 footer that collapses into about 4′ and is rugged and very portable and sets up as an 8′ step ladder. If installing a beam on top, either an extra man or extra ladder is helpful to hold the beam off the ground while you attach it to the mast/rotator and attach the necessary cables.

When splitting the support for transporting, the easiest way is to remove the 5/16 x 5-1/2” bolts from the bottom section driving them out with a plastic/hard rubber head hammer (doesn’t damage the threads) and a small rod or a screwdriver with a shaft smaller than the bolts. You may have to loosen a little, but not remove, the top four support bolts to install/remove the bottom piece.

Figure 10

Figure 10

Figure 9

Figure 9

Caution on winch hookup to mast (Figure 9): When attaching the winch strap to the mast pipe, I used a 2” muffler clamp. Clamp it in the web area just above the winch’s hook a to a spot about 2” above the point on the pipe where the top of the coupler and pipe meet. Don’t over tighten it and don’t clamp it in the zone where the Coupler will be placed as the muffler clamp may ding the pipe and then the Coupler won’t slide on to the pipe.

On the 1-1/2” EMT (1-3/4” OD) mast with Bend-Gard™ Couplers (Figure 10): There seem to be a reluctance to use EMT for permanent use though I have had exemplary performance from it at my home. For portable use it could be ideal. You have very transportable 5′ sections, they are inexpensive, they are quite rugged, and they go up and come down very easily with a very minimal number of people. With Bend-Gard™ Couplers they fit great and add rigidity about every 4′ 3”. What’s not to like! For more info on the BEND-GARD™ mast setup visit:


  • 1 ea 4 x 4 x 12′ pt (pressure treated) beam
  • 1 ea 2 x 4 x 8′ stud
  • 1 ea 1 x 4 x 8′ pt board
  • 1 ea 18” x 18” x 1” (or equivalent) piece plywood
  • 4 ea ‘L’ brackets 2” x 4”x 1/8” thick ($3.15 ea)
  • 4 ea 1/2” x 2′ rebar rods
  • 6 ea ¼ x 2-1/2” hex bolts, nuts, flats
  • 8 ea 5/16 x 2” lag screws(hex heads)
  • 12 ea 5/16 x 2-1/2” lag screws(hex heads)
  • 8 ea 5/16 x 5-1/2” hex bolts
  • 4 ea 5/16 x 1-1/2” hex bolts
  • 50 ea prox. 5/16” flat washers
  • 12 ea 5/16” nuts (threads to match bolts)
  • 3 ea ¼ x 3” screw eyes (eye lags)
  • 1 ea 12” piece of 3” to 3-1/2” flashing w/8 roofing nails
  • All of the above came from The Home Depot hardware and lumber sections except for the plywood and flashing which I had laying around.
  • 1 pr 3” or 4” standoff brackets rated for 2-1/2” pipe.
  • has a large selection.
  • 1 ea strap winch 1500# came from Wal-Mart. The brand I have is American Power-Pull.

Much of this article is probably common sense with a few new thoughts here and there. Sometimes common sense reminders are a good thing.