The first of three planned monobanders for W1AN/W1DX is in the air. The project was started over a year and a half ago by Mike K1DM and I after collecting parts for two monoband antennas from a pile of aluminum at the QTH of Bill N1HRA. One antenna was a 15M-5 element and the other turned out to be 20M-4 element. The second 15M beam was from Mikes QTH. Missing parts, aluminum and new hardware were purchased for all three antennas. The old aluminum was given a thorough steel wool cleanup and two 15M beams were assembled per changes found in the ARRL Antenna Book. Testing on the MFJ analyzer was done by Mike and I at 40 feet by raising with a line and pulley on the south 90 foot tower. Minor adjustments were completed.
Tower preparation continues. Along with Mike, Pat NG1G and Ken K3IU have also contributed to getting the rotor and mast at the top swapped and old antennas down and new mounts up. The 36 foot side mounted mast and rotor were installed a couple weeks ago. There still remains some relocation for the repeater antennas and old mounting hardware needs to be removed.
Since we were going to stack the 15M beams, identical 3/4 wavelengths of coax were cut and checked with the MFJ analyzer to confirm they had the same electrical lengths. I slipped and secured several ferrite cores on the coax near the feedpoints of both to keep most of the RF off the outside of the coax to minimize the affect on the RF lobes of the antennas. I fabricated attachment points from aluminum strap and angle and used phillystran to minimize boom sag for both beams.
To raise the antennas I welded up a fixture that would slip over the galvanized steel tram cable and hold the antenna in a position to keep the boom level with the elements at an adjustable upright angle to avoid interference with the guy wires on the ride up. A pulley was secured about two feet above the end point of the tram cable and 1/2″ line provided by Mike K1DM was attached from the pulley to the tram fixture to haul up the antenna. Initially I was going to haul up the antenna with the use of a garden tractor with a climber ready to receive it on the tower. But first, I wanted to see how much effort would be required if I used my own horsepower to raise it. It turned out to be surprisingly easy. In fact, I hauled it up first with only a slight upward angle on the elements. This angle turned out to be too small, so I lowered the antenna and changed the angle to almost 45 degrees and it went up the 75 feet with little pain.
Once the antenna was up I took a break and has some lunch. I hadn’t secured it yet to the mast and was trying to decide if I had the energy to make the climb. I could wait for another day. Having a ground crew would certainly make things easier and much more would be accomplished including getting ready for the second antenna. I have a personal limit of one cliimb a day. I had planned this to be a three man project. I made the climb and with some effort I was able to secure the antenna on the mast. It looks pretty nice up there. On this one, I can say, I put it up all by myself. That done, for the second antenna I will need a ground crew. It’s a much longer way down if you forget a tool or drop a wrench from 110 feet. And it’s much more enjoyable to share the accomplishment with friends.
73,
John, W1AN
