Skip to main content

Simple Ham Radio Antennas: The Aluminum Foil Vertical. Post #278.

I knew it would happen.  The time I ran out of antenna wire.  After several years of using old #14 AWG house wire, #18 AWG speaker wire from Radio Shack, and remnants from studio wiring projects at my former employer (Pacific Radio Group), I had finally exhausted my wire supply for homebrewed antennas.  What to do until the next sale at Lowe's, Home Depot, and Ace Hardware?  Give up? Banish the thought!.

With last week's beautiful weekend before me, I needed some cheap wire to erect my latest antenna "masterpiece."  I found my resource in the kitchen in the form of a new roll of "Diamond Aluminum Foil"--the stuff my xyl uses for cooking tasty treats and dinners.  Since there were several new rolls near the stove, I decided to "borrow" a new roll and apologize later.  Besides, I would buy another roll the next time I visited the supermarket.

According to the label on the container, the roll contained 66.66 yards (199.98 feet) or 60.96 meters of aluminum foil.  The foil measured 12 inches/30.48 cm wide.  By carefully cutting a narrow strip of aluminum foil and taping it to a MFJ telescoping fiberglass mast, I would have the crude beginnings of a 40-10 meter vertical. By attaching carefully cut lengths of aluminum foil to my feed line, I could also make a crude, but satisfactory "counterpoise" system to complement the vertical element.  By using a few aluminum nuts and bolts, I could attach a 450 ohm ladder line to the foil elements and have a multi-band antenna capable of working 40 through 10 meters.  A sturdy antenna transmatch ("tuner") and a 4:1 current balun would permit operation with my Ten-Tec Argosy II transceiver.

If the antenna "fizzled", all I would lose is some aluminum foil and a tarnished ego.  So, with aluminum foil, some basic tools, a spare mast and assorted tape and nylon ties, I ventured forth into the abyss.

MATERIALS:

Here are the materials I had available in the shack and in the garage:

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

A spare 5-ft/1.52 meters wooden support stake for the mast.

Two, 5-ft/1.52 meters wooden stakes to support the 450 ohm feed line until it reaced the garage wall, where I had positioned a W9INN 4:1 current balun approximately 8-ft/2.43 meters above ground.

Fifty feet/15.24 meters of 450 ohm ladder line.  This would be the antenna feed line.

Six feet/1.82 meters of RG-8X coaxial cable with UHF fittings. This cable would run from the balun to the window patch panel.

Six feet/1.82 meters of RG-8X coaxial cable with UHF fittings. This cable would run from the patch panel to the Drake MN-4 transmatch ("tuner").

Short pieces of RG-8X coaxial cable (3-ft/0.91 meters) to interconnect the Argosy II, low-pass filter, and Heathkit Dummy load to the Drake MN-4.

A "counterpoise bundle" consisting of 1/4 wavelength wire pieces for 40, 20, 15, and 10 meters.  For the counterpoise, I used a wire bundle from a previous antenna project.  The counterpoise bundle would be connected to the ground lug of the Drake MN-4.

And finally, a set of nuts and bolts to attach the aluminium foil vertical element and counterpoise wire to the 450 ohm feed line.

ASSEMBLY:

The antenna was built on the ground.  To determine the length of the vertical element, I used the general formula 234/f (MHz)=L (ft.)  Using 7.088 MHz as my selected frequency (the local "watering hole" for the Hawaii Afternoon Net), I carefully cut an aluminum foil strip 33-ft/10.06 meters long and 0.5-in/1.27 cm wide.  I cut two "counterpoise" wires having the same length and width.

I secured the thin aluminum foil vertical element to the fiberglass mast with nylon ties and vinyl electrical tape.  At the bottom of the vertical element and at the ends of the aluminum foil counterpoise wires nearest the mast, I carefully secured each leg of the 450 ohm ladder line with aluminum nuts and bolts.  One leg went to the vertical element.  One leg went to the junction of the two aluminum foil "counterpoise wires.  I wrapped the base of the fiberglass mast with plastic bags to protect the antenna and counterpoise connections from the weather.

I slowly hoisted the mast onto its wooden support stake and attached the 450 ohm feed line to two wooden support stakes to keep the ladder line off the ground.

The aluminum foil counterpoise lines were carefully supported by low level wooden garden stakes.  The counterpoise elements were approximately 6-in/15.24 cm above ground.

The 450 ohm ladder line was attached to the W9INN balun on the garage wall, a 6-ft/1.82 meters length of RG-8X with UHF connectors was attached to the balun, the coax was led to the window patch panel, and a final 6-ft/1.82 meters length of RG-8X was run from the patch panel to the Drake MN-4.  Smaller pieces of RG-8X connected the transmatch to the Argosy II, the low-pass filter, and the Heathkit Dummy load.  As a final step, I attached a "counterpoise bundle" to the ground lug of the Drake MN-4.

INITIAL RESULTS:

For a rapidly made, spur-of-the-moment antenna, results were surprisingly good.  With the Drake MN-4 in the line, I was able to get a SWR of 1.1 to 1 on 40, 20, 15, and 10 meters.  With the Argosy II running around 10 watts, I was able to get some excellent contacts both in Hawaii (late afternoon) and the U.S. mainland (late morning through early evening hours).  On average, depending on the band in use, CW reports ranged from 559 to 599 and SSB reports fell between 54 to 57.  Not exceptional, to be sure.  But the antenna works.  Best of all, my cost was virtually nil, except for the aluminum foil which my xyl will soon discover is missing.

I'll keep the antenna up for a few weeks, just to see how well it survives our summer showers and tropical heat.

This was a fun and educational project.

REFERENCES:

http://www.arrl.org/hf-vertical.

http://www.dxzone.com/catalog/Antennas/Vertical/.

http://astromag.co.uk/vertical.

http://www.wc7l.com/VerticalTheoryp1.htm.

Thanks for joining us today!  You can follow our blog community with a free email subscription or by tapping into the blog RSS feed.

Aloha es 73 de Russ (KH6JRM).

BK29jx15--along the beautiful Hamakua Coast of Hawaii Island.

Enhanced by Zemanta

Comments

Popular posts from this blog

G5RV Multi Band HF Dipole Antenna. Post #1555.

If you can't see the video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=aeNHIQ_j4Dk This well-produced and richly illustrated tutorial on the classic G5RV HF Dipole Antenna was presented to the Brandon Amateur Radio Society in Brandon, Florida in 2017 by Bernie Huth (W4BGH).  Bernie does an excellent job of  explaining the pros and cons of this popular HF antenna from the late Louis Varney (G5RV).  Although Varney envisioned his design primarily as a 3/2 wavelength antenna for the 20 meter Amateur Radio band, radio amateurs have used the antenna for multiband use.  The G5RV is an excellent choice for the 20 meter band.  Performance on other HF Amateur Radio bands is good enough to qualify as stand alone HF antenna if you can only erect one HF antenna. For the latest Amateur/Ham Radio news and information, please visit these websites: http://www.HawaiiARRL.info. http://www.arrl.org. http://www.arrl.org/arrl-audio-news (a wee

Amateur Radio Bicycle Mobile Setup. Post #1554.

If you can't see the video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=2zWb-KnkGdY. Here's a way to use Amatuer/Ham Radio while you work on shedding a few pounds in useful exercise.  Why not equip your bicycle for 2 meter/70 cm mobile operation? In this short, well-made video, "taverned" shows us how he used a mag mount antenna, a simple C clamp, and a basic ground system to convert his mountain bike into a mobile station.  The project is straight forward, simple, and gives you emergency communications while you peddle down the road. For the latest Amateur/Ham Radio news and information, please visit these websites: http://www.HawaiiARRL.info. http://www.arrl.org. http://www.arrl.org/arrl-audio-news (a weekly podcast which is updated each Friday afternoon). https://hamradiohawaii.wordpress.com. https://bigislandarrlnews.com. https://amateurradionewsinformation.com (Amateur Radio News & Information).

An 80-Meter Vertical Helix

Like many amateur radio operators, I live on a small lot surrounded by neighbors, utility lines, and civic-minded citizens concerned about the "attractiveness" of my community.  Whether by design or outright fear, I've adopted the "stealth" approach to ham radio antennas.  It's the old "out of sight, out of mind" idea applied to amateur radio antennas. The amateur radio press is full of articles describing the struggle of amateur radio operators to pursue their hobby under the burdensome regulations of CC & Rs, HOAs, and other civic minded citizens who object to antenna farms.  So far, my modest verticals, loops, and inverted vees have blended well with the vegetation and trees bordering my small backyard.  Vertical antennas have always been a problem because of the limited space for a radial system.  There are times, however, where a shortened vertical for the lower HF bands (such as 80/75 meters) is necessary where horizontal space is lack