Antenna Analyzer

Discussion in 'Ham Radio Discussions' started by KC3SWL, Oct 13, 2019.

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  1. KX4Z

    KX4Z Ham Member QRZ Page

    Oh, did I ever learn a big lesson the HARD way last weekend.....tuned up a little flatpack uhf duplexer all perfect-like, with a siglent spectrum analyzer and a homemade directional coupler.....and the added Loctite to secure the nut/screws...ad the next day it was WAY out of tune.

    Oops.
     
  2. K1VSK

    K1VSK Ham Member QRZ Page

    Loctite - the tool of optimists.
     
    WC5P likes this.
  3. WD0BCT

    WD0BCT Premium Subscriber QRZ Page

    That's why I never use Lock-Tite....I Use Lock-sort of Tite. They make some that require less effort to loosen. I forget the color codes...but Lock-Tire is available in multiple strengths. I believe I used the blue lock tire and not the maroon.
     
  4. KX4Z

    KX4Z Ham Member QRZ Page

    Grin -- I don't think the issue had anything to do with SETTINGS --- I think it had to do with CONDUCTION or capacitance between the threads of the screw (which support a tuning apparatus) and the casing of the cavity. So I don't think it matters WHICH locktite you use , I think the error was in allowing it to go into the threads that connect the shaft to the body. That should be fixable by rocking it back and forth a bit and a modest amount of retuning if needed.

    but I won't put any more in there!!!!
     
  5. WD0BCT

    WD0BCT Premium Subscriber QRZ Page

    I was responding to the tool of optimists comment. I am never so optimistic to think that anything I lock tite won't require future modification!
     
  6. KX4Z

    KX4Z Ham Member QRZ Page

    yeah, dumb me used the red.....but I already went through this once, too dumb to recognize what has happening, NOW it makes more sense......

    thanks!
     
  7. AG4RT

    AG4RT Platinum Subscriber Platinum Subscriber QRZ Page

    Never use the red loctite unless you’re really sure you never want take it apart. You can get it apart, but you need a lot of heat.
     
    KU3X likes this.
  8. KX4Z

    KX4Z Ham Member QRZ Page

    yeah, that's what i've always used, but in this case, it wasn't that difficult to get apart.
     
  9. KM1H

    KM1H Ham Member QRZ Page

    The current $40 nanoVNA's are making all that overpriced stuff obsolete. Leave it to the Chinese to score again with a winner. A ~$125 version with a larger screen is also available.
    I finally upgraded from a late 80's MFJ-259B I bought new.
     
  10. W2JKT

    W2JKT Ham Member QRZ Page

    Purple: You can use this on adjustment screws
    Blue: You can, but shouldn't use this on adjustment screws
    Red: Never use this on adjustment screws
     
    KU3X likes this.

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