40 Meter Full Wave Loop. Post #1148.
40 Meter Full Wave Loop
Accessed on 01 June 2017, 19:10 hrs, UTC.
Author: Greg Lane (N4KGL) of Panama City, Florida.
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With propagation favoring the lower HF bands this year (160, 80, and 40 meters), you may want a dedicated antenna for those bands, especially 40 meters where daytime and evening time remain fairly good.
In this article, Greg Lane (N4KGL) describes a 40 meter full wave loop he used for his 2013 ARRL Field Day effort in Florida. His antenna is a diamond-shaped loop using three, 31-foot/9.451 meters Jackite fiberglass poles and his truck to support the structure. Each loop element was cut for the lower portion of the 40 meter band and measured 36-feet/10.975 meters, for a total length of 144-feet/43.902 meters.
Here are some of the antenna details:
I considered feeding it with balanced line but decided to use a 4 to 1 balun at the top of the mast. With this choice I did not get a 1 to 1 SWR but it has a good dip at 40 and the harmonics 20, 15 and 10 meters. For most of it, I could go without a tuner. The rest is easy range of the KX3 internal tuner. I cut it long of course and it was low in frequency. After three trims and much sweat it is just where I want it. The whole thing did fit in my front yard. I had one support at 20 instead of 31 feet because it was getting close to the power line drop for the house. I found the trimming for SWR very sane and was better than my experience with a 40 meter off center fed dipole I used last year.
Greg supplies helpful photos to get you started on this remarkably simple and effective 40 meter antenna. Greg adds that the antenna does fairly well on both the 20 and 15 meter bands.
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