49:1 Transformer.

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by K2ICC, Nov 21, 2020.

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  1. K2ICC

    K2ICC Ham Member QRZ Page

    Just replaced the 9:1 with a 49:1 and 135' of wire. Length could be that or 136'. So far, 80 is low at 3.520 to 3.620 and all other bands workable as internal tuner can take care of it. Now, checking them very close, all seems to be better at the lower end of each band, too low on the band. Mounted on a 2"x8" piece of wood 36" high.

    The coax is 30' of LMR-400 super flex. I am aware of adding a capacitor in the middle of the wire, to bring up the 80 meters closer to SSB. Now, as all seems to be better at the lower end of the band, I was planning to cut 1' of the wire first. Just looking for some guidance. Thanks.
     

    Attached Files:

  2. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I'd just use it.

    The resonance on the higher bands is never quite harmonically related, it's more like x2.05, x3.1, x4.15, x5.2, etc. so having it resonant at the low end of 80m is "usually" desirable if you're going to use it on other bands.
     
  3. K2ICC

    K2ICC Ham Member QRZ Page

    I know by adding a capacitor of 300pf to 500pf in the middle of the wire will increase freq on 80 meters, while leaving other bands intact. Now, as all seems to be on the lower end, then taught of cutting some wire.
    The plan was to lower the SWR so the internal tuner can handle the 80 meters band. Also, low enough on other bands so the amp can also work.

    Thanks.
     
  4. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    What kind of amp?

    My toob amps can easily deliver full power into a 5:1 or worse VSWR without any kind of external tuner.

    What kind of amp?
     
  5. K2ICC

    K2ICC Ham Member QRZ Page

    My amp is an Ameritron AL-811H. My brand new IC-7300 went bad using this amp. Came back from repair. Using now an interface to protect the radio, but the amp has no output even on a dummy load.
    I believe the tolerance for SWR is not that high, but trying to be careful with it.
     

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