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Yaesu ATAS-120 Portable Setup

I constructed the following ATAS-120 setup for use on Field Days and other portable situations:

1. I obtained a used "music instrument stand" from a friend, but you can get them at most music stores, I'm told. It's like a small, squat lightweight tripod (25cm/10" legs) with a hole in the center that secures the post (removed) that the music instrument is supposed to sit on.
2. I bought a metal antenna mounting plate at the local CB radio store, and mounted the ATAS-120 to the plate with a double SO-239 and one of its hex nuts.
3. I fit a ¾" length of PVC tubing over the SO-239 and secured it with the second hex nut. The outer diameter of the PVC tubing was chosen to slip inside the music stand's hole.
4. My metal antenna mounting plate had five small holes, so I bought and mounted five sets of small bolts, nuts, and wingnuts to the plate.
5. I constructed radials as follows:
   • bought five ground lugs and 200' of wire (the gauge doesn't matter electrically; you want something that is easy to manage without being flimsy);
   • cut the wire into fifteen 0.1λ (wavelength) radials on 40m (4m/13'), per the ARRL's Antenna Book (Chapter 3, pp. 8-10 in the 20^th edition);
   • stripped ¼" of insulation from one end of each wire;
   • grouped the wires into five sets of three wires each;
   • attached (soldered) the stripped ends of each set of three wires to a ground lug.

1. The coax is threaded up through the bottom of the hole in the music stand and attached to the ATAS-120.
2. The bottom of the ATAS-120 is lowered into the hole in the music stand, and the clamp on the music stand is tightened.
3. The ground lugs on the five sets of wires are attached to the five bolts on the antenna mounting plate with the wingnuts.
4. The wires are spread out at 24° angles as radials on the ground.

Since the ATAS-120 is low to the ground, the whole setup is stable and guy wires are not needed. I set this up in the middle of a dry farm field in Western Washington on Field Day 2004, 2005 & 2006. With a Yaesu FT-897D on 40m, 20m, and 15m SSB, I was easily able to work stations on the East Coast in the middle of the day.