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Thread: Going mobile again

  1. #21
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    resistance is too high leading to a "fake" low SWR? how would I get to 50 ohms? is the cable bad? wow, questions!

  2. #22
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    No. Read up on how to properly use your meter. You need to tune antenna as close to feedpoint as possible. 1ft coax jumper or less, or even a barrel connector and go direct to feed point (connector) of antenna. Or you'll need to use a 1/2 wave electrically tuned coax jumper. Here is the formula to do this as IDK what coax you are using and the Velocity Factor (VF), will be needed to make it the right length.
    Formula:
    492xVF/freq (in MHZ).
    So for example. Your coax is .85 VF.
    492x .85/ 27.205= 15.55ft coax jumper needed to tune antenna at 27.205MHz. Now that I have confused the shit out of you LOL, don't worry it did me too, take this formula and use it to tune your antenna the proper way using your antenna analyzer. Then once this is done, you can use whatever length of the same coax you want and the reading should be the same as when you tuned the antenna as now your antenna system if done correctly is at 50ohms. And you will have the correct VSWR readings as well as R and X. Good luck and keep reading, the more you learn about your antenna analyzer and how to use it, you'll enjoy tuning antennas and it will be a breeze!! Hope this info helps!! Have fun!!

  3. The Following User Says Thank You to 222FL For This Useful Post:

    alpha78 (02-27-2016)

  4. #23
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    Read up on how to really use your meter. There is a lot of good stuff on that analyzer if you know how to use it the right way. Took me a while to get it, but once you see the light, things get very clear!!

  5. #24
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    I get the gist but think I need to take a class or something. Going to get this book:
    Antenna Physics: An Introduction



    changed my mind, going to buy the Basic Antennas book by Joel R. Harris W1ZR as more my speed (?)

    This book will provide a foundation in antenna theory and design necessary for anyone undertaking more advanced topics such as those presented in The ARRL Antenna Book.
    • Includes:
    • Dipole Antennas
    • Antenna Impedance
    • Transmission Lines
    • Practical Two Element Arrays
    • Wideband and Multiband Antennas
    • Reflector Antennas
    • Yagis for HF and VHF
    • Loop Antennas
    • Antennas for Microwave Applications
    • Vehicle Antennas
    • Antenna Measurements

    Plus, an Introduction to Antenna Modeling...and much more!


    and because I'm struggling searching this stuff online found this one: Understanding your antenna analyzer
    Last edited by alpha78; 02-27-2016 at 05:34 PM. Reason: update

  6. #25
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    feels like going down the rabbit hole hahaha! but know what I have currently is at best one size fits all. guess I could write the mfr to get the VF on the firering cabling? but say do the math and get the dimension. wouldn't that only apply in theory as it would change when actually installed and running around the vehicle through the firewall plus whatever other external influences?

    good stuff though. I like to understand what's going on best I can at least. mind starting to get blown though on all this smith formula, reactance, funny looking math symbols and all that.

  7. #26
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  8. #27
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    Nope, should not. And here is a good read as well.

    http://www.radiomods.co.nz/coaxlength.html

  9. #28
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    And also Walter Maxwell's book named "Reflections" published by the ARRL. Another good read.

  10. #29
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    Love the Lincoln. Snip the white wire and instant 11 meter
    Last edited by WarHawk; 01-17-2018 at 05:25 AM. Reason: Typo

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