Simple Ham Radio Antennas. A 80-10 meter Inverted vee antenna. Post #287.


One of the easiest and most cost effective antennas you can build is the 80-10 meter inverted v, a variant of the HF Doublet (horizontal dipole).  The antenna requires a single support mast, two smaller poles to tie off the “drooping” elements, and 450 ohm ladder line/300 ohm television twin lead connected to a balanced “tuner” to work all amateur radio bands between 80 and 10 meters (3.500 MHz to 29.999 MHz).  If you don’t have a balanced “tuner”, run the ladder line or twinlead to a 4:1 current balun and use a short length of 50 ohm coaxial cable to connect the balun to your “tuner.”

During the course of moving into our new home in the Puna District of Hawaii Island (we’re moving slowly, since we’re still working part time), I found a nice spot for a mast in the middle of our planned garden in back of the garage.  Since our home is on 1 acre of agricultural land, I have plenty of room for antennas, including loops, slopers, verticals, horizontal dipoles, and the inverted v.

Materials:

One 33-ft/10.06 meters MFJ telescoping fiberglass mast.

One “Ladder Lock” connector to attach the ladder line to each antenna element.

75-ft/22.86 meters of 450 ohm ladder line.

Six feet of RG-8X coaxial cable with UHF connectors.

Two pvc support poles to tie off the drooping antenna elements. I had two, 10-ft/3.04 meters pieces of schedule 40, 2-inch/5.08 cm diameter pvc pipe sections in the garage.

Two ceramic end insulators to tie off the ends of the antenna elements.

One 5-ft/1.52 meters wooden stake to support the fiberglass mast.

Two 5-ft/1.52 meters wooden stakes to support the tie off posts for the inverted v.

One W9INN 4:1 balun.

One transceiver.  For this project, I used my trusty Ten-Tec Argosy II.

One Heathkit Dummy load.

One low-pass filter.

One Drake MN-4 antenna transmatch.

One “counterpoise bundle” for the Drake MN-4 transmatch.

Nylon ties and vinyl electrical tape.

Basic tools, including soldering iron, wire cutters, screwdrivers, etc.

One hundred 135-ft/41.15 meters of #12 AWG house wire.  I had a spool left over from a wiring project at the new house.  No sense wasting valuable copper.

Twenty-five ft/7.62 meters of nylon rope.

Assembly:

The antenna was built in the garage, because all of my tools and electrical outlets are located there.

The telescoping fiberglass mast was extended to its full length (33-ft/10.06 meters) and the “Ladder Lock” device was attached to the eyelet ring at the top of the mast.

The wire was cut to my chosen frequency of 3.500 MHz using the formula 468/f(MHz)=L(ft). According to the formula, the total length of the antenna would be 133.71-ft/40.76 meters. I rounded off the length to 134-ft/40.76 meters.  Each antenna segment would then be 67-ft/20.42 meters. You may want to cut your wire elements a bit longer to allow for swr adjustments.

I threaded the ladder line through the “Ladder Lock” and soldered each antenna segment to its respective leg of the ladder line. I covered the soldered joint with several layers of vinyl electrical tape.

At the free end of each antenna segment, I attached a ceramic insulator and a small piece of nylon rope to tie off the segment to a support post.

The ladder line was run down the fiberglass mast to a point 16-ft/4.87 meters above ground level. The ladder line was secured to the mast with nylon ties.

The mast was then hoisted onto its wooden stake with the two antenna elements being left free for the moment.

The free ends of the antenna elements were attached to their tie off posts (the 10-ft/3.04 meters pvc pipes). Each tie off post was hoisted into position.  The antenna was adjusted for a uniform “v” shape.

The ladder line was lead to the W9INN balun attached to the garage wall (about 8-ft/2.43 meters above ground level).  Ten feet/3.04 meters of RG-8X went from the balun to the window patch panel.  Inside the shack, a 6-ft/1.82 meters piece of RG-8X ran from the patch panel to the Drake MN-4 transmatch.  The Argosy II, dummy load, and the low pass filter were connected to the Drake MN-4 transmatch with 3-ft/0.91 meters lengths of RG-8X coaxial cable with UHF connectors.  Finally, a “counterpoise bundle” was attached to the ground lug of the Drake MN-4 transmatch.

Initial results:

With the Drake MN-4 in the line, I was able to get a 1:1 match on 80, 40, 30, 20, 15, and 10 meters.  I was running a full 50 watts from the Argosy II.  Results on 80, 40, 30, 20 and 15 meters were excellent with several 59 (SSB) and many 599 (CW) contacts made in Hawaii and on the U.S. mainland. The ten meter band was very noisy at my location and no contacts were made.  Eighty and Forty meters were best in the early evening hours, while 30, 20, and 15 were most usable during the early afternoon to early evening hours.

If you want a versatile, simple antenna that covers 80 through 10 meters, please consider the easily made inverted v.  If you have two high supports (trees, masts, or other structures), you might get a slightly better signal with a horizontal dipole erected at a height of 40 to 60 ft/12.19 to 18.29 meters above ground level.  Even though the apex of my mast was only 33-ft/10.06 meters above the ground, the antenna did very well on both local and DX stations.

This was an enjoyable antenna to build.  Give it a try…you might be surprised how well it works.

References:

http://www.arrl.org/hf-wire.
http://www.hamuniverse.com/htdoublet.html.
http://www.radioworks.com/nhpant.html.
http://www.dxzone.com/dx22153/80-40-20-meter-dipoleantenna.html.
http://www.balundesigns.com/OCFAntenna.pdf.

For updated amateur radio news and happenings, please check out the news feeds provided at the top of this post. These feeds are updated throughout the day.

You can follow our blog community with a free email subscription or by tapping into our blog RSS feed.

Until next time,

Russ Roberts (KH6JRM).
Advertisements
%d bloggers like this: