Category Archives: Antennas

W4KGH end fed matchbox antenna overcomes poor site conditions

IMG_0856There’s no substitute for a real-life experience when it comes to a product testimonial, especially with ham radio antenna reviews. My multiband end fed antenna, a matchbox antenna based on the EARCHI (sometimes called EARC) antenna plans, is a great performer. I regularly hear from customers about how well it is working for them. If you are at all skeptical over what you are about to read, let me tell you up front that I do not offer anything in exchange for my customers’ feedback: The testimonials and reviews I receive are unsolicited. They are also published only with my customers’ permission which allows me to reveal their full names and call signs.

A recent customer asked me to expedite shipment so he could receive the antenna prior to heading out on a camping trip. I did so, and he received it on time (I do pride myself on providing the best customer service in our hobby). Here is his report on using the product during his expedition:

Ken,

Just a quick note regarding the end fed antenna I ordered recently and took on my camping trip.

My location on the St. Lawrence River was in a shallow depression with solid granite rock rising about 12 to 100 feet all around me – NOT a great location to say the least.  Using just a small stone, I was able to get the end of the end fed wire up about 15 ft onto a tree branch, most of the antenna was only about 8 feet off the ground – lol!

The antenna loads up beautifully using my Yaesu FT-897 and associated LDG-100 tuner.  Flat VSWR!

I was able to run the radio at 100 watts and even though I was sandwiched in between solid granite rock and had power line noise that was pretty steady around S7, I did manage to work Spain, Denmark, Czech Republic as well as stateside stations!  I was happy!  I was able to keep my ham urges satisfied which was the goal.  My next camping trip is coming up in a couple weeks, the only thing I have to work on is getting an extension pole of some sort maybe that will reach 15 to 20 feet in order to get the antenna up a bit further.  BUT, the antenna does as I wanted it to, so I’m a “happy camper”!  It’ll be going with me to Florida also for my 2 month jaunt down there in late winter.

73 and thanks too again for the nice pen!

Gary Sroka
KQ2N
Utica, NY

This is the kind of testimonial that keeps this ham interested in making top quality products. And while you can find similar products out there by various other companies, you won’t find anyone with the passion and dedication to stellar customer service that I have.

Buy from me!

73, de Ken W4KGH

Beach house portable installation report from Mike, ND4S

Thanks to Mike, ND4S, who recently purchased the W4KGH end fed antenna and took it along on vacation to operate portable. Here’s what he sent me:

I am home from the beach week and have a report of my portable operation using your antenna. I ran 100 watts from a Ten Tec Eagle w/ internal tuner. I could get a match on all low bands except 40 & 80 meters with just the internal tuner. Using the MFJ Tuner Extender I got a good match on 40 & 80 also. I used the antenna as supplied, I guess that is 55 feet, maybe I should have trimmed it to 53 feet. The far end of the antenna was up about 40 feet on a DX Engineering fiberglass telescoping mast. I am sending photos showing the mast, makeshift insulation (water pipe insulation) where the antenna touched the gutter & downspout, unun location & log page. I put a choke at the unun & ran two 32′ counterpoise wires, one opposite direction from the sloping antenna wire and the other running under the antenna wire, both about 8’above ground. My log speaks for itelf, considering the miserable summer band condx. The installation was somewhat of a compromise but then it was a compromise location, the beach cottage was only 34′ wide so the antenna sloped down and turned down the side of the cottage about 10′. I hope this info is useful, or at least interesting!

beach3 beach4 beach5 beach1 beach2

 

Best way to hang the W4KGH matchbox

Many thanks to Russ, AD0QH for his feedback and photo showing how his matchbox is installed. This is probably the best way I have seen to relieve strain on the studs and I have included this in the updated operating instructions. You can get the cable thimble and clamps pretty much anywhere such things are sold. Russ got his at Home Depot and notes that you can also order them online for around $2.00 per set.

how to hang end fed

73 de Ken W4KGH

Tom’s Radio Room Show Tests My End Fed SWL Antenna

A couple of weeks ago, Tom Stiles, who produces a YouTube show, Tom’s Radio Room, contacted me and asked if he could review my W4KGH Economy SWL Antenna. I sent him one and am happy to report that he has done some thorough testing on my product. The latest and most conclusive test of the series, TRRS #0839 – Antenna Testing Using SNR, is shown here, but there are several others you might want to watch:

TRRS #0817 – Shortwave Antennas to be Tested: https://youtu.be/uNmmfOXWjNA
TRRS #0823 – Setting up Antennas for Testing: https://youtu.be/aqBwhDe3lWE
TRRS #0827 – Real End Fed Antenna: https://youtu.be/WaL99xR_lyg
TRRS #0828 – End Fed Antenna Testing???: https://youtu.be/7EQ2H9h9AI4
TRRS #0829 – End Feeding Antenna Testing: https://youtu.be/uJzxTliWHss

All of these videos are informative and give you a better idea of how the SWL antenna box works. I like Tom’s laid back style and he is quite thorough in his examination. You might want to subscribe to his channel if you find the information interesting. I thank Tom for taking the time and showing his interest in my product.

W4KGH SWL Receiving Antenna Technical Details

I’ve had a few people ask me for specifics on how the SWL Receiving Antenna works. It’s quite simple, actually: A specially wound transformer is used to match the antenna to the radio for maximum signal transfer. Now, you can just take, say, 50 feet of wire and hook it directly up to your receiver and it will work, but much of the received energy will be lost in the wire before it gets to your radio. The reason for this is a mismatch of the impedance (the RF equivalent of resistance, measured in ohms) of the antenna itself to the impedance of the receiver. Simply put, this mismatch can cause up to 90% of the received energy to be lost in the antenna wire. Not a good thing. The solution is to match the antenna impedance as close to the radio impedance as possible. This is done by dividing the antenna impedance by 9 using the transformer shown below.

Diagram of impedance matching transformer

Impedance matching transformer

Photo of W4KGH SWL Receiving Antenna

The W4KGH SWL Receiving Antenna

Typically, the impedance of an end-fed wire is quite high. It can be several hundred to several thousand ohms. The impedance of the antenna connection at the radio is typically 50 ohms (sometimes 75). You can see that if the antenna impedance is 450 ohms, this would be a 9:1 mismatch. This would result in the loss of much of the received signal. The transformer would reduce 450 ohms to 50 ohms for a perfect match (450/9 = 50) at the receiver. This would result in most of the energy received at the antenna being transferred to the radio.

In the W4KGH SWL Antenna matchbox, terminal A goes to the antenna wire. Terminal B is either connected to a ground rod or jumpered to terminal C which is connected to the coax shield. Which method is used depends on how much background noise is present at the listening site. One or the other configurations will be found to reduce noise. Directly grounding terminal B will also eliminate static buildup on the antenna wire that can damage the radio. This is much safer than connecting a long wire directly to the radio.

Bottom line: The matching transformer allows for more efficient signal transfer to the radio, resulting in the ability to pick up much weaker signals than an unmatched long wire. Additionally, by grounding one end of the transformer secondary winding, static charge on the wire is eliminated protecting the radio from damage.

Laser-engraved box cover–you like?

Enraved CoverI found a great deal on a small laser engraving machine and decided to try engraving the cover of the matchbox instead of affixing a paper label. The paper label can make the box more visible in some cases and this isn’t good when stealth is the goal. Besides, the label really isn’t essential; I doubt you will forget the box’s purpose, especially once it’s deployed.

Still, some may prefer the paper label, so I will continue to enclose one if you want to attach it over the engraving. My question is: Do you like it, or should I stick with the paper label?

Hit replay, or use the contact form to let me know what you think.

73,

de W4KGH

Using the W4KGH SWL receiving antenna

The W4KGH SWL antenna does not require any assembly; it is ready to deploy.

Your site layout–or your personal preferences–will dictate how to hang the antenna. Hanging the antenna horizontally will take up the most real estate and is usually not feasible in an urban setting or a small subdivision lot. A vertical installation can work if you have tall trees on your lot or live in a high rise apartment or condominium (drop it from a sixth story window, for example).  An inverted vee or sloper configuration is usually practical just about anywhere. The idea is to get the end of the antenna or the apex of the vee as high as you can.

My personal preference is the sloper. This configuration has an omni-directional receive pattern closest to that of a vertical antenna, especially at lower to mid HF frequencies. It also allows you to keep your ground run short and close to the end of the antenna.

How you configure your ground will depend on conditions at your location. The antenna matchbox contains a 9:1 impedance matching transformer with both the primary and secondary grounds connected to separate studs on the matchbox (B & C in the photo). Normally, you would want to short these two connections and connect them to ground. You could also leave this connection ungrounded at the antenna end and ground the receiver end. The problem with that setup is that the coax shield can pick up noise, since it can act as part of the antenna. If you have a “radio quiet” location, this won’t matter, but few locations are free of man-made noise these days.

SWL Box

Matchbox Connections: A-Antenna, B-Secondary Ground, C-Primary Ground

Another configuration is to remove the short and ground the antenna side of the transformer (B). (This is the best connection to keep static charge from building up on your antenna.) Then, you can try grounding the receiver end or letting it float (no ground) to see which gives you the least amount of noise. A good way to test this is to tune in a relatively weak signal and see which configuration results in the best reception. Whatever you choose, there must be some sort of ground connection to stud B–even if just a counterpoise wire–on the matchbox or you’ll suffer severe performance degradation.

Wherever you make your actual ground connection, be sure to use at least a 6 foot ground rod. You can get these at your local hardware store or any big box home improvement store.

As always, I’m available for support if you need it. Just use the secure contact form.

73,
Ken W4KGH

A special testimonial

Many thanks to Art, W6GRT, who had this to say about the matchbox:

Hi Ken,
Great device!  I enjoyed it this afternoon for the first time.  I used my Youkits
HB-1B, Elecraft QRP ATU, followed by 25 feet of RG-8X, your matchbox, and
64 ft of wire sloping up my back hill tied to a plum tree.
First QSO, Simpsonville, South Carolina, followed by Redmond, WA.  I hope you do
very well with this product.  You and Begali keys have the best customer service
in our hobby.  I wish I could say the same for every ham radio product.
God Bless you and 73,
Art, W6GRT, Santa Clarita, CA
W6GRT1 W6GRT2

Antenna analyzer results for end-fed matchbox

EFMBA-newSo, I get the question all the time, “Can I use the matchbox without a tuner?” My answer is always this: For best results, you are going to need a tuner. Why? Simple. With an end fed antenna, the impedance is always going to be high and as you change bands, it’s going to vary all over the place. It may or may not fall into a range where the matchbox can deliver an impedance that your rig’s internal tuner can tolerate. Then again, it may under certain conditions and with different rigs. I realize that’s rather a vague explanation, so I took out my trusty MFJ-259B SWR analyzer, hooked up the matchbox with 50 feet of #18 wire, 16 feet of #20 counterpoise and 50 feet of RG-58 coax. The antenna was deployed as a sloper with the far end at about 12 feet over a tree limb and the fed end at about 3 feet off the ground. Here’s what I found:

160m (1.9 MHz): SWR=10.5
80m (3.75 MHz): SWR=5.2
40m (7.150 MHz): SWR=4.4
30m (10.125 MHz): SWR=2.8
20m (14.175 MHz): SWR=4.4
17m (18.118 MHz): SWR=2.6
15m (21.225 MHz): SWR=2.3
12m (24.940 MHz): SWR=1.8
10m (28.85 MHz): SWR=2.2
6m (52.0 MHz): SWR=2.5

It’s pretty obvious from these numbers that in my case, I could probably get by on 30m and 17m thru 6m without an external tuner. Your mileage will vary. And even though these SWR numbers seem to look OK, there is much more to SWR than just a number. This article will give you a better understanding of the subject.

73,
de W4KGH