The Wooden Antenna Mast – How to Make a Classic
Making a Classic Wooden Mast for Wire Antennas
Glowing Tubes and Wire Antennas
Ever since becoming interested in Ham Radio as a teenager, I’ve been fascinated with wooden antenna masts. In the 1970’s, I discovered them while perusing the local library on Saturday afternoons. This library had a well-stocked shelf with hobby electronics and radio titles, including the ARRL Radio Amateur’s Handbook. These were not the most current editions, and many went back to the 1940’s and 1950’s. But oh, the wonders they held.
I dreamed of rack cabinets full of tube-based transmitters and receivers — this being before transistors had progressed beyond the realm of the exotic. In those same books with all the tube gear were wire antenna plans; dipoles, inverted “V,” Zepp and the like. And, they were often supported by a stout wooden mast or two. They lent a nautical air to the antennas and fired my teenage imagination. Perhaps it was also because we were living in an apartment at the time, and therefore such things were out of reach. All the more alluring.
The (Teen) Age of FM
I got a technician-class license just before graduating from High School, and my interests had shifted to VHF FM; then the hot thing in Ham Radio. Antennas were smaller with a decided preference for aluminum masts and rotors. All my friends were on 2-Meter FM, and I had a Drake TR-22C. Tiny, portable and capable (with the addition of a Touch-Tone pad) of making telephone calls. I upgraded my license and dabbled with some HF gear, But VHF FM ruled the day.
Dreams of DX Re-awakened
Fast forward 20 years, and I had completed college and settled into a career. Married, and with just a little money left over each month, we invested in some raw land in the Texas Hill Country. By 1996, we were able to build a house on that land, and my dreams of world-wide HF communications were re-awakened. Building the house took almost everything we had, so there wasn’t much left over for Ham Radio.
I remembered those wooden mast plans from so long ago. Using several 20-foot 2 by 4’s left behind by the construction crew, and adding four 8-foot 4 by 4’s for mounting posts, there was enough lumber to build two 36-foot tilt-up masts. Spaced 150-feet apart, they supported a multi-band Zepp antenna, center-fed with open-wire line. Adding an antenna tuner made from bits and pieces of an old ARC-5 transmitter, I was in business. With an Icom IC-720A, I started working the world. Our rural location was very quiet. I could hear signals as never before. Amateur Radio Paradise.
Ham Radio and the Internet
The only problem with wooden masts is, they rot. Short of time and energy with a career and family, I never treated the wood and it was already damaged from use as a cement form. On top of that, a family of wood peckers nested in one of the masts, and before long, it collapsed. The other collapsed soon after, and my interest in ham radio was waining anyway. I was working at a university and why mess with Ham radio when you have access to the then-new and exciting Internet?
Another 15 or 20 years passed and ironically, a podcast, called Ham Nation lured me back. The four posts were still anchored in the ground, so why not rebuild them with better lumber and some good varnish? They would still be good for wire antenna experiments. With a refurbished Butternut vertical, I had the basis of a decent HF antenna farm.
Back to a 1940’s Classic
The first mast was rebuilt according to the A-frame design published in QST over 80 years ago. This time, I used pressure-treated yellow pine — much denser and stronger than the original SPF lumber used in the first version. Construction was simple with lots of long deck screws holding the main parts together.
I also laminated lengths of 1-by-2 onto the A-Frame sides and especially the single 2-by-4 top section — for added strength. Construction adhesive and 1 1/4-inch deck screws were used for this.
The A-frame is “sandwiched” around the top mast with about two feet of overlap. Two 3/8-inch eyebolts and nuts hold the assembly together and also provide convenient guy points.
Wood treatment and winching system
Once completed and treated with Sikkens log varnish (we live in a log home). The entire assembly pivots on a piece of 3/4-inch steel water pipe mounted through both of the 4-by-4 posts.
Using treated yellow pine instead of SPF lumber produces a very heavy assembly — more than I could imagine pivoting into place by hand. So a boat winch and some counterweights provided the mechanical advantage. With these aids, one person can easily raise and lower the mast. Completed, it measures about 36 feet from top to bottom.
The Second Mast
Static Dacron rope — two lengths at the top mounted 120 degrees apart— act as guy lines. Pulleys and Dacron rope mounted near the top and opposing the guy lines, allow the raising and lowering of wire antennas. Once tensioned, the guys and wire antenna provide robust support for the mast at the top.
After completing the A-frame mast and using a while, I decided to try the “simple 40-foot mast” design published by the ARRL at the same time. It did look simpler to build, and I was curious how it would compare in strength. By sandwiching several pieces of lumber for the bottom section, I would also be able to pull the warped lumber into square on the bottom section. I also decided to taper the top section to reduce the overall weight of the mast.
I used the same type of boat winch as well. As mentioned before, these masts are very top heavy, so a collection of old fitness weights at the bottom helps when raising the mast.
Once secured in a vertical position, the weights can be removed. I was a little short of 2 by 8 lumber to mount the winch system, so I milled a piece of Afghan Pine from a tree cut down on my place a couple of years before. It’s almost a hardwood, so I expect it to last quite some time.
Raising the Mast
Because the masts are heavy, raising them is a little hairy. Once they reach about a 45-degree angle though, the winch load is greatly reduced. I used 1-inch wide ratchet straps to secure the base of the mast to the cross brace. That seemed better than keeping constant tension on t
Wire antennas are hoisted into the air using Dacron rope and the pulleys mounted at the top of each mast. Once the antenna is tensioned, the rope is tied off using marine-style cleats, This way, it’s easy to lower an antenna for service or replacement.
Performance
So far, I’m pretty happy with the antenna system. Visually, the masts fit right in with the heavily-wooded acreage where we live. The 36-foot height gets the antenna well above the treetops. Cut for 80 meters, the End Fed Half Wave antenna is impressive for something so simple. About 34 feet of the overall 130.4-foot length rise vertically on the A-Frame mast with the remaining wire attached horizontally to the other mast with Dacron rope. It seems to work well on all bands — although 30 and 17 meters require an antenna tuner. Since the 49:1 UnUn effectively grounds the antenna through its windings, lightning concerns are reduced. A 225-foot run of LMR 400 into the shack means this antenna even performs pretty well at 10 meters and above. With our quiet location, I’ve been continually surprised what I can hear and work. So maybe those hams of yesteryear had something going on?
