End-Fed antenna revisited… again!

podcastWell, I really hope all of you had a great summer so far? We had a great one here in Quebec this year. We had plenty of beautiful days with a lot of warm period to go out and play with our ham radio gears…. even also to renew with astronomy that I left behind since 2007! What a great summer!

I was searching for quite some time for references related to end-fed antenna. Not especially for much technical details, but more about experiences from users in the field. I happily found a short, but a great article from W1SFR Stephen wrote back in 2013.

20160216_191324206_iOSAn article I previously wrote about “end-fed antenna using an Un:Un 9:1”. End-Fed link

T68-2 (3 wires)
T68-2 (3 wires)

The main reason I was searching for such document it is because I am using this kind of antenna for portable use, and I really like the simplicity of this antenna for many aspects: fast to deploy, works on many bands, no antenna to tune, honestly effective for casual use, etc… Much of my argument is related to personal consideration of course…. like many other aspects in our lives.

Now back to the document from W1SFR. The document from Stephen was for me a way to bring field experiment results over technical details. And atop of that, he is using an Elecraft KX3, like I use an Elecraft KX2 myself since last May 2016. So I was also very pleased to find in his document a reference chart of wire lengths to use, and which “traps” to avoid when using such antenna.

The end-fed antenna he is using in his article is combined by the use of the same 9:1 Un-Un that I am using. So great! We are now comparing almost an apple with an apple! 🙂

I built my 9:1 Un-Un using the EARCHI documentation that can be found here… EARCHI document. We even use the same length of coax, but not the same type… I’m using the lossy RG-174… I prefer to keep everything smaller and lighter as possible. If I take a look at his comparison tests he presented in his chart using different antenna analyzers, I am also getting similar results on my side with mine.

My results using a RigExpert AA-600 using 25 feet of coax, 35 feet of wire atop of a 31 feet fiberglass mast.

I was reading recently many comments from people that were bored of the actual DX condition when doing outside operation; DX condition are not are their best, hard to operate QRP, etc….  But what the hell…. Hi!! Most of them also discovered that when using digital modes, even when we could find that the DX condition are not at their top, that many, many DX contacts could be easily done when QRP. Let me tell you that I had plenty of fun so far during my last summer! I even found that when using an end-fed antenna, running QRP and using digital modes…. I was able to reduce my power by half… so from a big 10W SSB :-), I used 5W or less when using PSK, RTTY or even JT…. and 1W or 2W was also very often possible. It is fun to try to use less power.. it is part of the hobby… the experimentation!

Well, back to the End-Fed antenna. It is fast to deploy and to have fun. Fairly efficient, especially when using CW or digital modes, compact, lightweight, etc… I prefer this antenna over many others that I actually own, and that I do not use very often for many reasons.

So, the article from W1SFR gave me another confirmation, another point of view, that the End-Fed antenna could be a well performer.

Give this antenna a try! It is a low cost antenna, that could be easily built, and could let you potentially renew with the fun of outdoor operation, in a minimalist way!!

I would like to thank W1SFR Stephen for his great article. Another link from W1SFR…. his antenna kit… www.kx3helper.com.

Meanwhile, do not forget to subscribe to my blog and my YouTube channel as well.

Have fun and stay tuned!


Jeff | VA2SS

End-Fed antenna… a well performer!

As all of us know, there are plenty antenna solutions in books and on the market today. Many manufactures promise with unexpected and excellent results. But don’t be a fool and too much attracted with these results, from time to time, the simplest antenna setup could be well enough, and also cheap to build. A project, this is what amateur radio is all about!

The End-Fed antenna is well known to be a good antenna choice for a fair result you could expect from it. Many of us use it for it’s ease deployment. It is also very easy ton build. The heart of this antenna is the UNbalanced to UNbalanced adapter with a transformation ratio of 9:1, commonly called an UN-UN 9:1. Take a look at my previous post for more details on “How to build an Un-Un”.

Link : https://va2ss.com/2016/04/07/a-tiny-qrp-un-un-91/

So by example, you could expect to bring down an impedance of 450 Ohm to 50 Ohm very easily. I will not talk about the loss and other consideration…. just keep all this simple please. 🙂 My actual End-Fed antenna setup consist of 35 feet of wire, called the radiator, and 25 feet of coax cable. The Un-Un is just in between. This antenna setup will perform well on band higher than 20m, let say between 20m thru 6m.

The antenna can be easily deploy vertical or diagonal. Mine is held by a 31 feet high fiberglass mast. Easy to setup, easy to deploy. For the radiator, I choose a 26 AWG wire made silicon coating. Why silicon coating? It will still flexible even in winter at -25°C. The coax cable need to be simply laid on the ground. Avoid letting the coax cable as a coil. Here the results I obtained when doing some tests earlier this weekend.
As you can understand, I did not use any antenna tuner to get these results. The adding of an antenna tuner will be only to protect to transceiver. The antenna tuner will not work very hard! It is important to understand that this antenna is also very broad. It covers the entire bandwidth of all bands from 20m to 6m below a SWR of 2:1, let’s say with a small exception on 15m band. I use this antenna since 2 years now. And I had many good results with it. Even when running QRP SSB with 10 Watts or less. If you are a CW guy or a digital addict, this antenna will give you many joyful moment! Have fun and let me know about your results if you try this antenna.
Jeff | VA2SS

A tiny QRP Un-Un 9:1

As I would like to take the less space in my mobile arsenal in my next summer outdoor mobile operation, I decided to make a tiny Un-Un 9:1 for my End-Fed antenna based on the schematic published by the :

EARC Emergency Amateur Radio Club

The schematic can be found here

I only took a smaller T68-2 core and a smaller wire gauge…. a smaller of everything. The wire lenght I use for the antenna is 35 feet of 26 AWG flexible silicon coating wire and 25 feet of RG-174 coaxial line. Tiny Un-Un, tiny wire and tiny coaxial cable…. but not tiny results !! 🙂


Until now, this Un-Un 9:1 perform well as expected on 20m band and higher. A longer antenna wire will be tested later.

A very tiny Un-Un 9:1 that can handle QRP power less then 20W PEP.



For building instruction, I invite you to take a look at their schematic from the link I provided at the beginning of this blog.

All the credit goes to the EARC Emergency Amateur Radio Club.

Nice job guys !


More information will be provided later with further test results. I will do a comparaison between the original design and the tiny version. I will use a RigExpert AA-600 to plot a few graphs on how do they react between them.

Stay tuned !


Jeff | VA2SS