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High Intermittent SWR ON 20 Meter Band On Cushcraft A4S

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KK4BEY, Jul 29, 2012.

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  1. KK4BEY

    KK4BEY Ham Member QRZ Page

    Hi, I just put up my Cushcraft A4S with the 40 Meter Add On about 4 months ago and everything has been Great up until about 2 weeks ago when we had a Very bad Storm with high winds that blew down power lines around my area. But all turned out ok and my tower and antenna was ok other then now I have a Intermittent up and down high SWR on my 20 meter band only. Im thinking its water that blew into the trap or the sleeve around the trap has got loose and maybe touching but Im not a 100% Sure since it dont do it all the time sometime its ok. So has anyone ever had this problem before or have any ideas whats causing it.
    73, Ron KK4BEY
  2. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    Check the 20m traps on the driven element, which are part of the 40m kit. Sounds like something's making intermittent connection internally.
  3. KD8W

    KD8W XML Subscriber QRZ Page

    Hi Ron,
    I don't know anything about the 40m addon, but I do know something about the A4S. I suspect that you have a connection problem in a trap. I assume the 40m add on, 'adds 20m traps's to the antenna. I would think you would also have trouble on 40m when it occurs since the 20m trap is supposed to be "switching off " the 40m added length when running 20m. I just took mine down a month ago and cleaned everything, fixed some broken traps and put it back up. Its a big bulky antenna, and I don't want to do that too often. I have mine rigged where my wife and I can do the job alone. I think the cushcraft traps are a good design, but the tube-can connection leaves a bit to be desired.

    Good luck
  4. KK4BEY

    KK4BEY Ham Member QRZ Page

    Thanks for the replies. Well I just notice that my 40 meter is doing about the same thing as the 20 meter so I will check the traps out. I just put the beam up back 4 months and hate to take it down but looks like Im going to need too. lol 73, Ron KK4BEY
  5. W9GB

    W9GB Ham Member QRZ Page

    Ron -

    CHECK the drain holes for the 20-meter traps. IF not pointed down, gravity can not drain the trap.
    During your high wind event, you may have developed an intermittent connection (e.g. Loose attachment screw or clamp)
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