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Before yesterdayWB3GCK QRP Amateur Radio

No Counterpoise Speaker Wire Antenna

By: WB3GCK
10 August 2024 at 10:04

Itโ€™s been a while since Iโ€™ve done a cheap speaker wire antenna, so hereโ€™s another one for you. Back in the early to mid-2000s, an antenna commonly referred to as the โ€œNo Counterpoise Antennaโ€ 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, itโ€™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 donโ€™t recall ever putting it on the air.)

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

No Counterpoise Antenna diagram

Iโ€™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 itโ€™s actually โ€œZepp-ish.โ€ Because itโ€™s non-resonant, a tuner is required for this antenna.ย 

I did some extensive research into the origins of this antenna. (OKโ€ฆ 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 thatโ€™s how I first came across it. Pete once made a phased array from two 25-foot versions.ย 

In the August 2020 edition of Ozark QRP Banner, the Four State QRP Groupโ€™s newsletter, Terry Fletcher, WAร˜ITP, had a nice write-up about it. He discusses his experience with both the 25- and 50-foot versions.ย 

This antenna design has been around the block a time or two. So, thereโ€™s no innovation here on my part whatsoever.ย 

Construction

I happened to have a 25-foot roll of #18 awg speaker wire on hand, so this time around, I opted to buildโ€ฆyou guessed itโ€ฆ the 25-foot version.ย 

Construction was about as easy as it gets:

  • I spilt 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 Goopยฎ adhesive. As an alternative, you could just tie a loop at the top or crimp a ring lug over the wireโ€™s insulation.ย 
  • 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 Goopยฎ in the middle of the antenna where one side of the wire was removed. All of this is completely optional.ย 

Construction probably took me all of 15 minutes or so. That doesnโ€™t include allowing the adhesive to cure overnight. However, the antenna was certainly usable without the adhesive and heat-shrink tubing I used. Iโ€™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.

I used my roll-on mount to support a 28-ft Jackite pole
I used my roll-on mount to support a 28-ft Jackite pole

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. (Thatโ€™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 80Mโ€”but stranger things have happened. I wasnโ€™t able to try it, but Iโ€™m sure the KX3 would be able to match it directly connected to the radio without the 4:1 and coax.ย 

I used a 4:1 unun at the feedpoint
I used a 4:1 unun at the feedpoint

Band conditions werenโ€™t very good, so this wasnโ€™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.ย 

72, Craig WB3GCK

My AliExpress Whip on the Air

By: WB3GCK
21 July 2024 at 00:30

I had a chance to use the inexpensive whip I bought through AliExpress recently. While it performed well enough, I encountered a couple of minor quality issues. Thatโ€™s certainly not surprising, given its $18 USD price tag.ย 

I made an early morning trip to Ridley Creek State Park (US-1414, KFF-1414). I coupled the AliExpress whip with my homebrew loading coil. My rig today was my Penntek TR-35 (5 watts, CW).ย 

Extending the whip, I noticed that two of the sections were pretty tight and took some effort to pull them out. Better tight than loose, I guess. Another issue is that the crimp that holds the mounting stud in the bottom section of the antenna was a little loose. When the antenna was fully seated in the mount, I could still rotate the antenna.ย 

My $18 (USD) whip from AliExpress mounted on my homebrew loading coil
My $18 (USD) whip from AliExpress mounted on my homebrew loading coil

Because this whip is longer than a quarter wave on 20M, I didnโ€™t extend the first section from the bottom. Using an antenna analyzer, I was seeing SWR readings similar to my MFJ-1979 whip. The SWR readings seemed stable. So, I guess the suspect crimp is making a good enough connection.ย 

Band conditions seemed so-so this morning. Despite that, I logged 25 contacts on 40M and 20M in an hour, including three park-to-park contacts. I didnโ€™t work any DX stations today, but I worked a station on the west coast in Washington on 20M.ย 

Even with its issues, the whip did a pretty decent job this morning. It wonโ€™t replace my MFJ whip, but it will have a place in my antenna arsenal.

72, Craig WB3GCK

My Wounded Whip

By: WB3GCK
18 July 2024 at 14:19

A while back, I ordered a 5.6M/18.4 foot. telescopic whip from a seller on AliExpress. I didnโ€™t really need it, but having seen them on the Interwebs, I was curious to see what you get for $18 USD. Heck, at that price, why not take a chance?ย 

You can find these whips all over AliExpress. (I have also seen them on Amazon for about $10 more.) One nice thing about them is they are 7.5 inches shorter than an MFJ-1979 when fully collapsed. So, it might fit in backpacks easier. The shorter collapsed length is due to having 14 telescoping sections compared to the MFJ-1979โ€™s 10 sections. Because of its thinner metal and lack of a reinforced base, the AliExpress whip weighs 4.4 ounces/125g less than the MFJ whip. Of course, the other obvious advantage is the incredibly low cost.ย 

There are some downsides though. The threads are metric (10mm), so you need an adapter to use it with a โ…œ-24 mount. Fortunately, adapters are readily available as well. The other downside that Iโ€™ve noticed is that the metal they are made of is pretty thin. (More on that in a bit) The MFJ whip has a heavy stainless steel reinforcement at the bottom, while the AliExpress whip does not.

My antenna arrived from China about a week and a half later. It came wrapped in several layers of bubble wrap with a tough plastic outer wrap. I eagerly opened the package, but I was disappointed to see that the bottom section was damaged. It looked like either someone dropped something heavy on it or Big Foot stepped on it. As I mentioned previously, the metal is pretty thin.

While traveling half-way around the globe, this telescopic whip antenna encountered some rough handling.
While traveling half-way around the globe, this telescopic whip antenna encountered some rough handling.

When I finished uttering every expletive in my vocabulary, I contacted the seller through the AliExpress app and sent pictures of the damage. They promptly shipped out another antenna, and they didnโ€™t want the old one back. So, I set the wounded whip aside, while I awaited its replacement.

The replacement whip arrived 6 days later, which is pretty impressive for a shipment from China. Happily, this shipment arrived intact. I would be remiss if I didnโ€™t give props to the HUI BANG TE Store on AliExpress. Their customer support was top-notch.

When I get a chance, Iโ€™ll take the inexpensive whip out to a park to give it a go. I laid the AliExpress whip next to the MFJ-1979, and it looks like collapsing one section from the bottom on the AliExpress whip makes it about the same length as the MFJ.

I also have some ideas on how to straighten and reinforce the damaged whip to make it usable. That might be a winter project.ย 

72, Craig WB3GCK

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