Moxons on Pacific Beaches
By Bill Vanderheide, N7OU
For the last several years Iíve been using vertical Moxons on portable operations around the Pacific. My inspiration was M3KXZís article on his beach mounted Moxon. I used Peteís EZNEC dimensions, a pair of DK9SQ poles, 18 gauge insulated wire, a Bud center connector, and RG8X cable. Here are some pictures of the antennas at each QTH and notes on how they performed.
South Cooks Ď07. In October, 2007, I operated as E51NOU on Rarotonga while serving in schools with the Global Volunteers organization. Our accommodations, the Kii Kii Motel, overlooked a north-facing beach of coral rubble. Itís hard to imagine a more perfect QTH. Even so, having operated there twice before in 2006, I wanted an antenna with gain so I packed along a Moxon for 20m. Using 100w, I made about 2000 CW QSOs with the antenna, about 900 of them in Europe, my target audience. Alongside the Moxon I had a vertical wire, 8m long, also on a DK9SQ pole, with 25 radials and an LDG Z11 autotuner in a waterproof box at the base. Against this reference antenna the Moxon had 1-2 S-Units of gain. Both antennas were about 2m above the high tide line.
South Cooks Ď08. The set-up on Rarotonga worked so well that I decided to repeat it while volunteering there again in Sept/Oct, 2008, except that this time I put up a Moxon for 17m. Again, the Moxon had 1-2 S-Units of gain over the random wire vertical. Each morning, about an hour after my sunrise, before I had to set off for work, I liked to troll for Europeans on 17m. Iíd get an opening every 2-3 days. One morning I had a pipeline into the UK and worked 15 stations in as many minutes.
Christmas Island. Also in 2008 Bob, W7YAQ, and I operated from Eastern Kiribati, signing T32YA and T32OU. As part of our antenna farm, we had vertical Moxons for 17m and 15m, both set up on the north-facing beach, just above the high tide line. Using a Butternut HF9V down the beach for reference, the Moxons delivered the usual 1-2 S-Units of gain. During the ARRL DX CW Contest the 15m Moxon was a killer, giving us 862 QSOs with our 100w. But there was a surprise, too. Our 20m Moxon showed no gain over the HF9V, despite a lot of tinkering and repositioning. We didnít have a good way of measuring its F:B.
Tuvalu. In February, 2009, Bob and I teamed up for a DXpedition to Tuvalu and operated as T27A and T27OU. This time our QTH on the atoll of Funafuti was not ideal for our vertical antennas. With no usable beach we had to set them up in thick, salty vegetation on an east-facing shoreline, just above high tide. Again, for whatever reason, our 20m Moxon showed no gain over the HF9V. Our Moxons for 17m and 15m showed gain, but nothing as dramatic as on T32, more like 1 S-Unit than 2. The photo shows the 17m Moxon aimed at North America.
Oregon. On the Oregon coast, closer to my home in Portland, Iíve had success with a 20m vertical Moxon while operating QRP as N7OU/BB in the annual Flight of the Bumblebees. In 2007 and 2008 I set up on the Bayocean Peninsula, a sand spit that allowed me to shoot eastward over the saltwater in Tillamook Bay. When compared to a sloping 8m wire, the Moxon again came through with 1-2 S-Units of gain. Both years I placed in the top 3, even though I was way out on the Left Coast.
Looking ahead, if we ever get sunspots again, Iím eager to try vertical Moxons on 10m. My 20 ft. crappie poles would be perfect. Iíd also like to experiment with a multiband vertical Moxon and one that uses a single pole.
73, Bill N7OU
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Steve Hammer, K6SGH