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Thread: End fed antennae swr

  1. #1

    Default End fed antennae swr

    Hi All
    I have an endfed antennae mostly used on 40 meter band, its coupled to an ATU, and I have the swr reading zero on transmit just 4 watts output, but if I very slightly increase the swr,I get an extra watt on forward power which is the transmitters full output.
    So my question is! Do I set the atu to give zero reflected with slightly less power out, or can I adjust atu to give a very slight amount of reflected showing and get that extra 1 watt increase?
    Iím thinking thereís some mismatch somewhere giving me theses readings!?
    Look forward to your replies

  2. #2
    gnuuser's Avatar
    Join Date
    Apr 2020
    NW Pa,USA


    depending on what mode you are using the extra watt may not make much difference in the db level.
    slight mismatch is not a critical factor. if your swr is below 2 to 1 there is very little chance it will damage your transmitter.
    things to look for depend on your antenna configuration, type of feed line, proximity to structures, and possible moisture inclusion on the feed-line. ( coaxial cables are notorious for this).
    vertical ground plane antennas often may be tuned better by adjusting the angle of the ground plane elements slightly.
    dipoles by lengthening or shortening them.

    tuners do not actually tune the antenna, but they do tune the impedance that the radio sees.

    physically tuning your antenna to its feed-line provides true impedance to the radio and better performance, The downside of hard tuning an antenna is that it is physically sized for one specific frequency range.
    magnetic loop type antennas are smaller in size and quite powerful (and depending on the wattage output can induce some dangerous voltages on the outer loop) they are however far more tuneable, with a downside is that when you change frequency's you have to re tune the antenna.
    Im so old dirt was my apprentice

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