The Endfed antenna is up but with mixed results.

The W1SFR Endfed antenna is up and things went very straight forward with the install. My options for a location a limited so I ended up having to place the antenna in a tree that beside our mini home and then down to the shed about 40 feet or so away. The antenna runs parallel with the mini home along the north side of the mini home. The feed end of the of the antenna is about 25 feet up and mounted to the tree. The far end at the shed the antenna is about 15 feet from the ground.  The coax from the antenna to the shack is about 65 feet in total as the Endfed antenna uses the coax as the counterpoise and Steve W1SRF recommends you have at least 25 feet of coax. The time came to flip the switch on my antenna analyzer and see some SWR results:

Band.         Freq.         SWR 
40.              7.0001.     1.9
40.              7.070        2.5
30.              10.100.     4.4 
30.              10.150.     4.5
20.              14.001.     4.5
20.              14.070.     4.3
17.              18.068.     1.5
17.              18.168      1.5
21.              21.001.     1.8
21.              21.070.     1.8

I was a bit alarmed by the results so I emailed Steve W1SFR regarding the results from his Endfed antenna. He came back with positive comments saying my results looked very normal. This is the very reason it's said that with the Endfed antennas you need to use a tuner. The next step was to connect the Icom 7610 to the whole mix and see how things worked. This is where Murphy popped his head up to give me grief! I began to transmit on 40 meters and with the power at 40 watts things started to happen around the shack and house! In the shack my PC was not running but the monitor was in sleep mode. All of a sudden the monitor would wakeup from it's sleep, on my PC desktop I have a program that allows me to post notes on the desktop when I transmitted CW I would see random letters being typed on a posted notes on the desktop, my electronic keyer would send dah's and no dits and finally our new electronic washing machine would just shut down. The other band I tried was 20m and when transmitting CW at about 60 watts the PC monitor would wake up from it's sleep but no other issues. I was wondering it it was the RF coming back on the coax or because the Endfed run parallel with the mini home is about 15 feet away from the home?
I contacted Steve again who informed me that it could be RF on the coax as it's a counterpoise. His suggestion was for me to purchase a 1:1 balun and from there see if it solves the issues. Steve suggested it may or may not solve all the issues and I may have to look at other options for unsolved issues. Well I have a decision to I want to start spending more money and go down a road that may lead me to gaining more "stuff" but still not being able to use the antenna. Now I did get some comments from my blog readers who do have and are using with success an Endfed antenna. 

Mike Weir, VE9KK, is a regular contributor to and writes from New Brunswick, Canada. Contact him at [email protected].

16 Responses to “The Endfed antenna is up but with mixed results.”

  • KI5GQK:

    I have almost the same antenna (Chamaleon CHAII) and the same problem, using a ugly balun at both antenna feed and before entering my shack doesn’t help, so I will try the 1:1 balun to see if it helps.

  • kf6efg - John:

    1. Where does the coax lie? I had a end fed that used the coax as a counterpoise. it ran next (parallel) to some hidden electrical and caused all sorts of havoc on the circuit involved.
    2. Ground your radio and tuner. This alone can clear up most RFI issues, especially on high SWR bands.
    3. Get a good Choke. I recommend this one: . Its a bit pricey, but TOTALLY worth it. Install it on the antenna side of the coax from your tuner, or even 25-30 feet down from the feed point of your antenna.

    GOod Luck and 73’s


  • Logan, KE7AZ:

    I’d suggest some clamp on ferrites on the feedline at 25 feet from the antenna.
    Logan KE7AZ

  • Mike VE9KK:

    Good evening Enrique very nice to hear from you, the ugly balun is only loops of coax and from the reading that I have been doing for RF on the coax you need to use a balun the that incorporates a quality ferrite core for decent attenuation of RF that is on the coax and to stop it from entering the radio. I ordered a 1:1 balun from Balun designs model number 1115. Once it comes in I will be posting the results I paid a bit more for this balun but it’s quality and I am hoping it will do the trick.
    Thanks very much for your input and once I post the results maybe it will help you with our Chameleon CHAII antenna. Oh and by the way I have the Chameleon mag loop antenna and it’s great!!

  • Mike VE9KK:

    Good evening Logan, that is something I have never considered and I do have some clamp on ferrites but I will not be able to wrap the coax around the coax I would just have to have them clamped on the coax. This is not the best for attenuation but I do have about 8-10 and it’s worth a shot.
    Logan have a great weekend and thanks for the info.

  • Paul Wa3tiu:

    [email protected]
    Rather than spend more money; why not try a quarter wave counterpoise wire connected to the common side of the transformer.
    Maybe one cut to a quarter wave for each band.
    Variations in swr were noticed when the length of the counterpoise was changed.
    Forty meters is only used; so the end fed was cut to length.Noise was minimized by repositioning the antenna to another direction.

  • David, KJ4CMY:

    Sorry you are having so many problems with your antenna. I look forward to hearing how it goes after the balun.
    I have a G5RV and have never had any problems like this.

  • Mike VE9KK:

    Good morning David thanks for stopping by the blog, the issue I have been having has me on the internet learning about Balun’s, Endfed antennas and RF in the shack. It has and still is a great learning time for me. In time I will get it all sorted out and have gained more knowledge in the process.
    Have a great weekend David

  • Jaap PA7DA:

    I ‘am using several types of EndFed antennas. All with a Balun
    Please take a look at this website

  • Zal----VU2DK:

    My 2 cents worth—-this antenna will almost be high impeadance termination on most bands—you will require a pi-network tuner or try a simple L network.
    Best bet is to keep the single wire outside the shack & if possible tune there & bring in the coax cable to the rig—-I remember having the same problem with off centre fed Windoms in the 1960s—you could also try a multiple ground system outside to terminate the coax braid—-more you use ferrites & baluns ,etc—you have a lossy system–when there is loss there is less RF & we think all is honky dory !!!

  • Jim Smith:

    A 1:1 balun is cheap and easy to make…don’t go out and buy one. There are lots of articles, books and plans on the web to show you how and just what you need.

  • Mike VE9KK:

    Good evening Zal and I am always open to anyones 2 cents, at this point time I don’t have an outdoor tuner and the only one I have at my dispose is the LDG AT100pro. As for a multiple ground setup the property is very small here and really hard to do. BUT I have managed to try some options that have worked very well for my situation and I just posted about it.
    Zal very nice to hear from you and thanks very much for your input.

  • Mike VE9KK:

    Good evening Jim, well the jury was out and came back the verdict has been read…….late last week I purchased a 1:1 balun from Balun designs.

  • Mike VE9KK:

    Good morning Jaap and very nice to hear from you again, thanks for the link I just had a fast look at it and later this evening over a cup of tea I will take the time and read it over. Thanks for sending this and the more info I can get the better.
    Have a good day

  • Mike VE9KK:

    Good evening Paul and thanks for the great feedback, as for a repositioning of the endfed that is not an option as the lot is not that big and the East/West orientation is the best setup for the lot. I am going to fiddle with the counterpoise idea over this long weekend (Thanksgiving up this way) as see how it works out.
    73 and thanks for taking the time to comment.

  • Mike VE9KK:

    Good evening John and thanks for the questions,
    1. The coax is running along the ground under our mini home and as far as I can tell there is no electrical anything running parallel with it.
    2. Today I did ground the rig, tuner, antenna switch, PC and power supply. I brought all these items down to a comment point and then a single cable to a ground. I noticed the band scope on the 7610 was now very quite.
    3. I have ordered and it’s on the way a 1:1 balun from Balun Designs and I am hoping once this arrives it will be the end to my issues. The chokes that I tried that were on the Chameleon coax worked great and once I get a quality 1:1 balun from Balun designs I feel the issues will be a past memory. I have seen the Myantenna product before but I did have a balun from balun designs in the past and decided to stick with them.
    John thanks for the questions and have a great weekend.

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