Revamping the Endfed antenna

The new location for Endfed....Shingles are my next project
When we moved into our place last August I set up my Endfed as a temp setup and as with most things temp soon becomes long term. My excuse was I just had major house "things" on the go that required my attention. Over the winter the temporary support at one end of the Endfed was starting to show some major wear. I decided to stick with an Endfed antenna as with my lot size it was the best option for me.
The new spot for the antenna
 I was doing some reading on the internet regarding Endfed antennas and the ideal wire lengths. For the size of my lot, the length that was ideal for me was 41 feet. My plan was to remove the balun from the tree it was located in and mount it on my newly renovated shed....now in the pictures the shingles have not been done yet but that is my next project and the shed will be complete. The 41-foot Endfed antenna wire would extend back out to the tree. I guess you could say I just reversed the setup. This setup allowed me to lower the balun to about 6 feet off the ground and have the antenna slope in an upward direction. This setup would allow me to add a counterpoise to the Endfed. When the Balun was located in the tree it was about 25 feet off the ground and I was advised by Ultimax antenna the balun was too high off the ground for a counterpoise to work, I did try it without success. 
Splice making 34 to 41 feet
I first tried the antenna with the counterpoise and was not pleased with the results I removed the counterpoise and gained some better results on some bands. Below are the results with and without the counterpoise. 
Results without a counterpoise:
       Band Freq SWR
    80. 4.000. 7.5
    80. 3.500. 6.7
    40. 7.001. 3.2
    40. 7.070. 3.3
    30. 10.100. 5.0
    30. 10.150. 5.0
    20. 14.001. 1.8
    20. 14.070. 1.7
    17. 18.068. 1.6
    17. 18.168. 1.6
    21. 21.001. 2.6
    21. 21.070. 2.6

Results with a counterpoise:
         Band Freq SWR
    80. 4.000. 9.1
    80. 3.500. 9.6
    40. 7.001. 4.4
    40. 7.070. 4.4
    30. 10.100. 5.0
    30. 10.150. 5.0
    20. 14.001. 2.4
    20. 14.070. 2.3
    17. 18.068. 2.0
    17. 18.168. 2.0
    21. 21.001. 2.6
    21. 21.070. 2.7
Below is the SWR reading when the Endfed was 34 feet long and located with the Balun in the tree. 

Results without a counterpoise:
Band Freq SWR
    80. 4.000. 7.0
    80. 3.500. 8.1
    40. 7.001. 1.8
    40. 7.070. 1.8
    30. 10.100. 3.3
    30. 10.150. 3.3
    20. 14.001. 4.6
    20. 14.070. 4.6
    17. 18.068. 2.5
    17. 18.168. 2.5
    21. 21.001. 1.5
    21. 21.070. 1.5

Results with a counterpoise and the balun 25 feet in the tree:
Band Freq SWR
    80. 4.000. 6.5
    80. 3.500. 9.1
    40. 7.001. 5.2
    40. 7.070. 5.2
    30. 10.100. 2.2
    30. 10.150. 2.2
    20. 14.001. 4.9
    20. 14.070. 4.9
    17. 18.068. 2.7
    17. 18.168. 2.6
    21. 21.001. 1.6
    21. 21.070. 1.5

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

10 Responses to “Revamping the Endfed antenna”

  • Kyle N4NSS:

    One chart I read listed 53 feet and 124.5 feet for optimum lengths.
    I used 53 feet with a 9:1 Unun a line isolator. My tuner in the K3 made it possible for me to operate 80-10 meters.

  • Mike VE9KK:

    Very nice to hear from you Kyle, yes that is true, but I need to keep below 45 feet as I have a very small lot and really can’t go beyond 45 feet. I, too, use a line isolator (1:1 balun). I had a K3 at one time and the tuners are great in these rigs, I have never come across a tuner either in a rig or standalone that is as good as the K3’s.
    Thanks for stopping by and taking the time to comment.
    73,
    Mike
    VE9KK

  • Kyle N4NSS:

    You dangle or redirect the rest (8) feet off to the right/left. Give it a try.

  • Rich N2RIC:

    What sort of balun are you using for your antenna?

    If just 1:1, then the SWRs will be too high, as shown in your tables. If a 49:1 from an EFHW, then the SWR will still be high, but your dividing the random wire antenna’s impedance by too large a factor, thus high SWR again.

    I have used both a 35.5 and 41 foot wire woth a 9:1 unun — my own homebrew version of the Packtenna — with success in my backyard, as both a sloping and inverted L using trees and a 7m fiberglass mast. I also used a counterpoise of about 16 feet.

  • Mike VE9KK:

    Good afternoon Kyle and thanks for another comment, I actually tried that yesterday along with extending the length of the antenna from 41 to 44 feet and both did not change a thing on the SWR side of things.
    Thanks again Kyle for your time and input.
    73,
    Mike
    VE9KK

  • Mike VE9KK:

    Good afternoon Rich and very nice to hear from you and thanks for taking the time to read the post and comment on it. The balun is a 9:1 unun. I do have a 1:1 just where the coax enters the shack from outside. I do this to stop the RF from entering the shack as the coax is the counterpoise. I have tried various lengths of counterpoise and it just does seem to work for me. At this point in time I have a 41-foot wire into the 9:1 and using the coax (55 feet) as a counter poise.
    Have a great week Rich and thanks again for stopping by.
    73,
    Mike
    VE9KK

  • UWE DG1RUG:

    Hallo Mike

    Even i read your MSG about the ENDFED Antenna.
    I am surprised about the ENDFED on your side, i have used those Antennas verry often. But the Antennas are verry sensitive against the surround area, means close to anny IRON or other mettal structure is not good, missmatching and distorsion.
    I have used allmost a length of 13,75 Meter = 45,111 Ft whit quite good results on 40,20,17,12 and 10 Meter. If the Antenna is a permanent construction, thann it make sence, to cut the wire in nearly resonant length on 40 Meter so the other band will be also quite resonant! A counterpoise is not real needed, normaly but there is 1/9 Unun construction, they need a counterpoise.
    I have used most coax cable in a length of 13,5 m or 27,5 m after that i use a ugly balun whit a feeder length of 25 Ft on a pvc tube . May you know what i mean.
    To use 1/9 Unun visit those page; http://dl7ahw.bplaced.net/dl7ahw/Antennenlaenge.html
    Sorry i have only the german page found, according to the charts you can build monoband antennas in those technic .

    BEST REGARDS de DG1RUG UWE

    P:S: http://www.qrz.com/db/dg1rug

  • Mike VE9kk:

    Good evening Uwe and thanks for taking the time to read and leave a comment, I am very fortunate that the antenna is so close to my shed and it works as well as it does. Thanks for the link and I can get Google to translate the page to English.
    Thanks for the input and the link.
    73,
    Mike
    VE9KK

  • Roger M0TJK:

    SWR’s are one thing. More importantly, how were you getting out with and without the counterpoise? You could have 100 foot of feeder, a great SWR but few contacts.
    73 Roger, M0TJK

  • Mike VE9KK:

    Good morning Roger and thanks for taking the time to leave a comment, well to be very honest Roger I did not take the time to look at that…..it was just checking the SWR and moving on. Very good point as I have read in the past that SWR is not everything when it comes to antennas.
    73,
    Mike
    VE9KK

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