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A SIMPLE INVERTED VEE ANTENNA

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DON’T READ THIS ARTICLE by Danny-W4DAN

if you are NOT INTERESTED in a good, simple, easy to construct, and inexpensive antenna.

Recently, I vacationed with my family in a mountain cabin near Blue Ridge, Georgia. I am not one that enjoys "roughing it," so I took a rig and antenna. Planning a portable antenna was somewhat of a challenge because I like to band hop. I wanted something that would work well, be easy to put up and take down, and capable of working several bands.

I decided to build a wire antenna that would work 80 through 10 meters.

I constructed a half wave dipole for the lowest frequency to be operated, which was 80 meters. This resulted in making the length of each leg of the dipole 67 feet. I knew that if I fed it with coax, the automatic tuner in the transceiver would not necessarily match the antenna on all bands. Other problems like stray R.F. and feed line losses could occur. To prevent these difficulties, I decided to use twin lead to feed the 80 meter dipole. I knew that a balanced line tuner would be needed which would involve setting up another "box" at the operating position. Not knowing how much space would be allotted for a station in the mountain cabin, I realized the importance of conserving space. It also seemed a shame not to use the rig’s automatic built in tuner.

Instead of using a balanced line tuner, I utilized a 4:1 balun with a short piece of coax going to the transceiver. On the antenna side of the balun, I connected ladder line. My choice was an old Heathkit air wound balun. Any 4:1 balun with a coax connector at the input and balanced line connectors on the output could have been used. This allowed the automatic tuner to work very well within its impedance matching range. The antenna was configured in an inverted V fashion for ease of support. The test set up in the back yard indicated that there should be no trouble when it was hoisted for operation in the mountains.

I had no idea of what structures or trees would be available for support, so I took one of the MFJ telescoping fiberglass masts with me. I don’t recommend the MFJ mast because it is very flimsy and does not support well unless you use very small antenna wire and the small type of ladder line. I used 3/8 inch ladder line and 20 awg wire. The mast came in handy, though, when tied to the second story balcony rail. I then attached the feed point to the top of the mast, and pushed it up. All that was left to do was tie off the ends of the two legs and run the feed line under the door and into the cabin. The worst part was keeping the small wire from becoming entangled.

 

 

 

 

Actual operation was a breeze and a pleasure. I discovered how well my automatic tuner actually performed during this portable operation. Once tuned up on each band, the tuner’s memory kicked in when switching back to previously tuned bands. Having several antennas for different bands at home, I had never experienced the convenience of such quick band changing. It was great.

I contacted several "local" stations on 40 and 80 meters with good signal reports sent and received. I was amazed at the number of European stations that I worked on 17 meters. The cabin was located brook side in the valley between the mountains....not generally recognized as a great radio location. As soon as I returned from the vacation, I erected an antenna of similar design with heavier gauge wire and larger feed line.

This antenna can be configured differently if constructed for limited space areas. It will work with very little loss of efficiency by diverting part of one or both ends of the legs in almost any imaginable direction. I recommend hanging this antenna from a tower or tree if you are going to use it at your home QTH. If your transceiver does not have a built in automatic tuner, an outboard auto tuner or even a manual tuner not designed for balanced feeders may be used. Be creative and tailor it for your particular situation. This is a good all band antenna.

For permanent installations, insulated wire sizes may be between 14 and 18 awg or any size you are comfortable with. Choose a good quality balun and ladder line that is capable of handling the maximum power you intend to use.

Keep the coax as short as possible, but using up to ten or fifteen feet should work well. A length of coax long enough for placing the balun outside the house is okay, IF you have a problem running the twin lead to the inside. The length of the twin lead may be as short as thirty feet, although, I suggest using at least 68 feet or more for easier tuning. Because of the low loss characteristics of ladder line, one can use several hundred feet if desired. I am using 100 feet of feed line.

I continue to enjoy "residual relaxation" from the vacation by using this all band, non-switching, easy to build, and inexpensive antenna. Questions? Feel free to contact me via email at Danny@w4dan.us or call toll free at 866-479-6160.

 

 

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