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Tuner SWR same on Inductor A-F??

Discussion in 'Amateur Radio Antennas' started by K3ACZ, Jun 19, 2017.

  1. K3ACZ

    K3ACZ
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    W9WDX Member

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    My MFJ-941e tuner works great to tune all bands with SWR of 1-1 or 1-0 on most all bands. Using the normal (to me) K,L,E,J inductor and various cap settings.



    But on 24.990 I get a 1.2:1 no matter if the inductor is set on A-F it doesn't matter.. This is with Transmitter and Antenna caps set at 1/2 and 1/2..

    So 1/2-A-1/2 would be setting.

    I get good reports on all the other bands from various states. I haven't heard anyone on 12m yet up this way (PA).

    Is this possibly normal??? Should I still leave it set on A or set it to F??
     

  2. BJ radionut

    BJ radionut
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    ALWAYS use the MINIMUM inductor setting possible regardless of band...even if VSWR is like 1.5 or even slightly higher...
    This is the most efficient tuning(most power to antenna) and least loss thru tuner...
    Remember even at 2:1 Vswr your radiating 95% plus power to antenna
    All the Best
    Gary/W9FNB
     
  3. K3ACZ

    K3ACZ
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    So use F and not A inductance. Since A is Max and L is Min. ?
     
  4. Road Squawker

    Road Squawker
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    the first alphabetical letter is the MAX inductance, A is max, F is min.

    what happens on 24.990 when you by pass the tuner?
     
  5. K3ACZ

    K3ACZ
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    OK. Here's the inductors on different bands.

    W/1:1 MFJ inline choke on coax approx 8' from xmitter just outside shack wall:

    3.8 E
    7.2 H
    14.28 J
    18.1 J
    21.3 K
    24.94 A
    28.40 K

    Without 1:1 on coax

    3.8 F
    7.2 I
    14.28 H
    18.1 J
    21.3 K
    24.94 H
    28.4 K

    The only noticeable worse is on 14 MHz where it went to J with choke. And at 24.94 from H without choke to A (of F).

    Opinions??
     
  6. K3ACZ

    K3ACZ
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    In bypass I get these SWR:

    24.940. 1-1.2
    (Best I could get with tuner was 1.3:1)
    27.385. 1.4
    28.380 1.5

    Wow.. Didn't know.. :)
     

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