Bobtails and Half Squares|
These antennas offer big gun DX performance on the low bands,
yet they are surprisingly simple to build. Try one- you will like it!
I am using a bobtail on 30M and its the best darn antenna I've used on that band. I did have one problem, and that was finding a good covering to use on the feed point, but after a little thought and finding the right size metal enclosure we licked the trouble we had keeping the SWR down low, and we have had no effects from the metal enclosure on the antenna. So for anyone who wants a great DX antenna that is simple to build, the bobtail is the way to go. Best 73 and good DXing....Larry WB9ICH|
I completed DXCC on 40m so it's time to move on to 30m. I telescoped the vertical portions of my 40m down to 22'3" and cut the horizontal half wave to 46.8 ft. I changed the coaxial cap to 30 pf but left the coil and tap the same since I don't have the MFJ antenna analyzer anymore. WOW!!!! Last night right after I finished it I worked Antarctica, South Africa, and European Russia--all with 100 watts. Prior to this change I tried several antennas--inverted "V", Gap Vertical, and another ground mounted vertical. I couldn't hear any real DX from my location and did not work anything. What a difference a half-square makes! 73, Rick W7AV
I was looking to put up something with gain on 10M and don't have a tower. The NJ0F bobtail worked great even with the vertical wires almost touching the ground. I made both stateside and DX contacts. I worked a mobile station in FL and I was 59+20 to him using 100W. Then I raised the antenna to about 25ft. My first contact was OQ4UN (John Devoldere). He had a big pileup and I got through to him on the second try with 100W. This morning I worked the Isle of Man for the first time. I was the first stateside station he had heard on the band. I was weak but the signals came up quickly. And, not suprisingly, he was very interested in the antenna I was using. My second contact was San Marino, another new one for me. This is going to be a lot of fun... 73, Mark KB1CRC
I used a half square on 17 meters in Colorado in 1995 at the bottom
of the sunspot cycle. I voltage fed it with a parallel LC network and
one 1/4 wave radial. The flat top phasing line was only 13 feet off of the
ground with the antenna broadside Europe and the Pacific. The results: 100
countries in 30 days with 100 watts. A serious DX antenna.
I was talking to a KL7 one night on 40 meters and he told me he had a 5 element Bobtail because during certain times during the year they had no communications in his area and that the Bobtail made it possible to continue communications. Well, if it worked well for him I thought I would give it a try. At the time, I lived on a ranch in northwest Washington. I put up this monster --5 elements and WOW! With a pattern towards Africa, I was making contacts during daylight hours into North Africa--no one believed me on frequency but I had the QSL's to prove it. What an antenna! No good for close in work however, and if a cow hit the wire --not good. Very narrow banded but it worked like nothing I've ever seen. Now I live on a city lot and your article has sparked me into thinking I could put up at least 2 elements and it would certainly beat the vertical I have... 73, Rick W7AV
I've used a 20 meter half-square for three years at my very heavily treed
lakeside cabin lot with much success. The horizontal section is about 20
feet up strung between two hickory trees with the 1/4 vertical ends hanging
down near the tree trunks. The wire is INSULATED and the ends PROTECTED
against accidental contact with high RF voltage.
I have been using three half-square antennas for the last 5 months, one on 20, one on 15, and one on 10. I have excellent results working DX with these antennas and they were so easy to build. I have come in at the top of several pile ups for DX and have worked several stations when the bands were just opening with great signal reports of 10 to 25 db over 9 all over europe. Great antennas. 73, Frosty W0FP
Do these antennas have to be pretty much in the clear? I had a half square up for 17M and it wasn't very good although the SWR was OK. I fed it in the upper corner. Roy Lewellen told me that they have to be away from everything to work well. Thanks, Henry WA0GOZ
I used an 80-meter Halfsquare portable in an open field since I don't have
room on my small city lot. This allowed me to complete 80-meter DXCC and
5BDXCC in spite of my QTH's limitations. In my opinion, portability is one
of the Halfsquare's best features.
(Bobtails) ARE terrific performers! I have a short story to tell: While I was
stationed on Guam and operating as KG6NAA, I decided (along with three other
stations) to put a serious effort into the 1979 ARRL 10-meter test. My
performance in the North American direction had been pretty dismal (on 10
meters) during the CQWW tests, so I knew I needed something better. You aren't
going to believe this, but the bobtail was the answer. I placed a bobtail 1/4
wave behind another bobtail (phased 90 degrees) and got into the US like
gangbusters. I opened the band before the other guys could hear any signals
from the US. They were using large, high yagis. I had a TH6DXX at 80 feet and
I couldn't hear the US on it until much later (about 1 hour later). This made
a major difference in my score, particularly on the last day.
I guess my point is that a bobtail is very useful on the high bands
(particularly if you need a potent signal in a particular direction). Since
they aren't very large at those frequencies, phasing-in another bobtail is
just what the doctor ordered. Try it.... you'll be surprised!
I have used a half-square on 160-meters for many years
and have been highly pleased with the simplicity and
effectiveness of this array.
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