[SECC] Antennas for Those Who Can't Put Up a Tower

[Bill Coleman]

Jeff,

I understand your thoughts here. While I do have a small tower and beam at my Gwinnett QTH, I spend much of my time in the Parsonage (my wife is a United Methodist Minister) in Fulton county. Getting modest but effective antennas into the air occupies much of my thinking.

I think your low-band antennas are solid:
160 - Excellent antenna for this band
80 - Dipole at 65 feet is good. You might consider a vertical. Maybe adding an 80m trap to the 160m inverted L?
40 - Your 40m dipole could be higher.

I don’t see a mention of any receiving antenna. I’d recommend a set of K9AY loops, unless you can find about 400-500 feet of linear distance away from your antennas for a beverage.

On the higher bands, it has been my experience that you are at a disadvantage if you don’t have some kind of directional antenna. This means a Yagi, Quad or Log-Periodic. Let me go over some of the options I’ve considered.

1) Tri-bander hung from trees. If you have a plentiful number of supports, this might be an option. This is what would have done when I was in Floyd county, but I didn’t have a suitable antenna. If you hunt at hamfests, you can find a used small tri-bander for around $100. Cushcraft A3S is my favorite, but there are others. Sometimes, you can get these antennas free. I have a 30-year-old Butternut HF4B that given to me by an ex-Ham friend. I rebuilt it, and now I’m trying to figure out a way to rig a temporary support at the Parsonage to get it 20-25 feet up.

2) Wire Log-periodic. Four or five elements would cover 20-10m adequately and offer a little bit of gain. The mechanical aspects of hanging such an antenna are complex.  You need a lot of ropes or a clever way of joining and spacing them.

3) Quad or Delta Loop - You could hang a second full-wave loop and make your loops directional. You might even consider making the second loop a little short and adding a short-able loading coil to make it reversible (a Reflector / Director).

4) Moxon. You can easily compute a optimal 2-element Moxon antenna. For 20m, the sides are about 9 feet long. A couple of pieces of PVC pipe might maintain this spacing or careful use of halyards at the corners. 

I also have the crazy idea of trapping the DE of a 20m Moxon for 15m and 10m, and adding parasitic reflectors, creating a tri-band Moxon. I’ve yet to model this antenna but I’m convinced it would work. One day, I’m going to build it. 

Of course, any of this options would likely be fixed in one direction using ropes. For contesting in this area, you are likely to want antennas pointed in three major directions: NE - for Europe, North Africa and the Middle East, SE - for South America and the Caribbean, NW - for Asia. Any of the smaller directive arrays are going to be pretty broad.

When I was in Floyd county, I scoped out three locations where I could hang such antennas and considered a switching arrangement using remote relays on a single feed line. 


Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at arrl.net
Web: http://boringhamradiopart.blogspot.com
Quote: "Not within a thousand years will man ever fly!"
            -- Wilbur Wright, 1901