It’s been a while since I’ve done a cheap speaker wire antenna, so here’s another one for you. Back in the early to mid-2000s, an antenna commonly referred to as the “No Counterpoise Antenna” was making the rounds on the Internet. I thought I might give it another look.

The No Counterpoise Antenna is either a 25-foot or 50-foot length of two conductor wire with half of one conductor removed. Essentially, it’s a radiator fed through a balanced line feeder. The 25-foot version is said to cover 20M through 10M, while the 50-foot version is supposed to cover 40M through 10M. It was usually connected to a balanced tuner of some sort or sometimes fed through a 4:1 balun. It was typically constructed from zip cord or speaker wire. So, this is perfect for another speaker wire project. (Actually, I built the 50-foot version years ago, but I don’t recall ever putting it on the air.)

A picture is worth a thousand words, so here goes:

I’ve seen this antenna sometimes referred to as a Zepp. A true Zepp is basically a half wave radiator with a quarter wave balanced line matching section. Unlike a true Zepp, the No Counterpoise Antenna is non-resonant, so I guess it’s actually “Zepp-ish.” Because it’s non-resonant, a tuner is required for this antenna. 

I did some extensive research into the origins of this antenna. (OK… I just did a few Google searches.) Jeff Imel K9ESE came up with this design. I remember Jeff used to sell a high-quality version of the antenna on eBay. The reviews were generally positive.

Pete Millis, M3KXZ, is another name often associated with this antenna. I think that’s how I first came across it. Pete once made a phased array from two 25-foot versions. 

In the August 2020 edition of Ozark QRP Banner, the Four State QRP Group’s newsletter, Terry Fletcher, WAØITP, had a nice write-up about it. He discusses his experience with both the 25- and 50-foot versions. 

This antenna design has been around the block a time or two. So, there’s no innovation here on my part whatsoever. 

Construction

I happened to have a 25-foot roll of #18 awg speaker wire on hand, so this time around, I opted to build…you guessed it… the 25-foot version. 

Construction was about as easy as it gets:

• I split the speaker wire halfway and cut off one side
• Next, I twisted a loop at the end of the single wire and secured it with some Goop® adhesive. As an alternative, you could just tie a loop at the top or crimp a ring lug over the wire’s insulation. 
• I stripped and tinned the wires at the feedpoint and installed spade lugs. You can just strip and tin the wires, if you like.
• To keep the speaker wire from splitting further, I put some heat shrink tubing a couple of inches up from the lugs. I also added a dab of Goop® in the middle of the antenna where one side of the wire was removed. All of this is completely optional. 

Construction probably took me all of 15 minutes or so. That doesn’t include allowing the adhesive to cure overnight. However, the antenna was certainly usable without the adhesive and heat-shrink tubing I used. I’m just prone to overkill.

On the Air

To test the No Counterpoise Antenna, I drove down to Ridley Creek State Park (US-1414, KFF-1414). Using my drive-on mount, I supported the antenna from a 28-ft Jackite pole. I used a homebrew 4:1 unun at the feedpoint and ran 15 feet of coax into the cab of my truck to my KX3 (5 watts, CW). I used the long side of the antenna as the radiator.

Before I got started, I checked to see how the tuner in the KX3 would handle the antenna. The KX3 easily found a 1:1 match on all bands from 40M through 10M. Just for the heck of it, I tried 60M and 80M. The KX3 was able to find a good match on those bands, too. (That’s not too surprising, given that I once forgot to attach my coax to an antenna, and the KX3 still found a match.) I doubt this antenna would work well on 60M and 80M—but stranger things have happened. I wasn’t able to try it, but I’m sure the KX3 would be able to match it directly connected to the radio without the 4:1 and coax. 

Band conditions weren’t very good, so this wasn’t an ideal test. Despite the mediocre band conditions, I logged 13 contacts during my short activation. Most of my contacts were on 40M. There was considerable fading on 30M and 20M, but I made a contact on each of those bands.

This was hardly a rigorous evaluation, but the 25-foot No Counterpoise Antenna got the job done. I need to give it another try, when conditions are better.

Anyway, if you have some speaker wire and a few minutes to spare, give this one a try and see what you think. 

72, Craig WB3GCK

Single-band wire dipoles are one of the easiest antennas to make.

But just because they are easy to make doesn’t mean they do not work well. In fact, single-band wire dipoles outperform many antennas in many circumstances.

You will need these supplies to build your dipole:

• Roll of wire
• Measuring tape(s)
• Wire cutters
• Balun
• Insulators
• Solder (optional)
• Antenna analyzer
• Cable ties

You can use many different kinds of wire. Some people have used string soaked in saltwater! However, copper or copper-clad steel wire is generally considered the best. Stranded wire is generally better since solid wire can stretch under tension.

So how long do you need the wire to be?

From the OnAllBands article, “How High Should My Dipole Be”:

“The half-wave dipole is two equal lengths of wire with the feedpoint in the center. Each wire, or element, is a quarter wavelength of the frequency you want to transmit on. The basic formula for dipole construction is dividing 468 by the desired resonant frequency, in MHz. As an example, a dipole cut for 14.225 MHz SSB is 468/14.225 = 32.9 feet total length. Divide 32.9 in half, and we see each element of this dipole needs to be 16.45 feet long.”

There are other factors to consider when determining dipole length, such as proximity of the ground and other nearby objects. Because it’s difficult to find the ideal length before actually hanging the wire, it is always best to start any wire antenna slightly longer than the calculations might indicate and then shorten the antenna, measuring its performance each time.

Now you have calculated this number. This is the length of wire you need on BOTH sides of the balun. Some of these wires are really long! How on earth do you measure and cut a wire that long?

Find a long, straight area. Roll out a heavy-duty measuring tape that will mark how long you need the wire to be. When my Elmer and I did this, we stuck a broomstick in the roll of wire and set both ends of the stick on different chairs. Next, as one held it steady, the other walked the wire out to the length of the rolled-out measuring tape.

Tie, solder, crimp, or any combination of these to each side of the balun. Short for “balanced to unbalanced,” a balun is a device used to convert a balanced signal to an unbalanced one.

For a good explanation of what that means, visit this OnAllBands article,“Baluns vs. Impedance Transformers.” Also check out this article from Moonraker, “What Is a Balun? Why You Need One and When to Use It.”

Attach your feedline to the balun. Attach insulators at the non-balun ends of the wire. This will help you hang your wire dipole without worrying if something is touching the ends of the antenna, causing your readings to be off.

Measure the SWR of the antenna. It is easiest to do this with an antenna analyzer with a graph display of SWR and frequency like those from RigExpert. If the SWR dip in the graph is at a lower frequency than the one you wanted, then your antenna is too long and you need to remove some of the wire. Clip very small amounts of wire from each side and take a lot of SWR readings. If the lowest SWR reading is at a higher frequency than your intended frequency, your wire is now too short.

Editor’s note: For more information on dipoles, read these OnAllBands articles:

• Dipoles—A Domestic Secret Weapon
• Tuning Your Dipole Antenna Installation
• Dipole vs. Vertical—Which Antenna is Better?

Also, if you’re not inclined to collecting all the pieces and parts to build your own dipole, DX Engineering has taken care of it for you with their Single-Band Dipole Kits, which include:

• Two premium 14 AWG stranded copper, relaxed PVC antenna wires with crimped and soldered 1/4-inch ring terminal on one end of each wire
• DX Engineering DXE-MC20-1-1 MaxiCore 20 1:1 Balun
• High-Strength DXE-WA-BMB Wire Antenna Balun Mounting Bracket and End Insulators
• Stainless steel hardware

Questions? Share them in the comments below or email me at KE8FMJ@gmail.com.

The post Ham Radio 101: A Few Basic Tips on Building Wire Dipoles appeared first on OnAllBands.