MFJ 929 Auto tuner

Discussion in 'Amateur Radio Equipment Reviews' started by KU3X, Oct 21, 2009.

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  1. GM8UPI

    GM8UPI Ham Member QRZ Page

    Just removing the power does not fully clear the memories. Suggest you try method as given in handbook.
    I think you may be surprised at the result in regard to getting back original "out of box" operation from your SGC239 !

    73 de GM8UPI
  2. AC0FP

    AC0FP Ham Member QRZ Page

    Thanks for the suggestion, I will try that after I change my grounding system. The SGC239 says it works without a ground or balun to match balanced antenna/line to unbalanced coax output.

  3. GM8UPI

    GM8UPI Ham Member QRZ Page

    Yes, I have used it to match 300 ohm ribbon feeder to a doublet, without any problems.
    73, Dave
  4. AC0FP

    AC0FP Ham Member QRZ Page

    Thanks again Dave. My intent was not to "hijack" the original posters thread.

    I reset the memories to erased and the SGC239 acknowledged that was done. I have added a bigger choke (more beads) balun to the coax feed coming from the the SGC239 and that seems to help, in fact my match to my 20 meter vertical dipole is now my best match where it used to be the worst. It appears that RF is or was definitely involved! :eek: I really need to get an antenna impedance bridge to find out whether my antenna system is presenting a reasonable (matchable) impedance to the SGC239!

    I may need to start a SGC239 thread.


    Frank :)
  5. GM8UPI

    GM8UPI Ham Member QRZ Page

    OK on the thread start-up. I'm sure no one will complain about hi-jacking !!
    I have found that as long as you keep antenna lengths to manual suggestion minimums for bands, the SGC239 does a good job. 160 mtrs can be a bit of hit or miss, probably due to the limited inductance available for switching in, but apart from that, seems to do ok.
    Never had any problems with RF in shack when feeding 50 ohms coax to antenna, but straight wire or even balanced feeder (300 & 450 ohms) can be troublesome, if distance between rig and ATU is less than 6 - 7 ft.
    My set up usually has ATU fed from rig with approx 10 ft of 50 ohm coax, with the ATU as close as posible to the antenna wire entrance to shack. ie as far away as possible from operating position.
    Works for me using my caravan (RV) for operating /P.
    Best of luck !!

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