Baby tarheel

Discussion in 'Mobile Radio Systems' started by KK4YDR, Feb 25, 2016.

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  1. KB1CKT

    KB1CKT Ham Member QRZ Page

    Ground would be an issue, but I wonder about mirror mount onto a Thule (or Yakima, your choice) crossbar on the roofrack. Presumably you could drill that to your hearts content. The Lil looks like it is fine on a 3/8 mount (assuming the mount uses a quality 3/8 bolt), so I don't think the fancy Tarheel C clamp is required (but it may be useful in terms of mounting options--your call). That would just leave figuring out how to connect antenna base to roof plane (coax and motor leads would just drape down and in the door).
     
  2. K0BG

    K0BG Platinum Subscriber Platinum Subscriber QRZ Page

    Remember Shawn, anything will work. It is only to what "degree" you apply to the term "work" that determines the least common denominator. Remember too, except for hamsticks, ATAS, and Lil Tarheel antennas, ground loss is your biggest loss. It behooves you to do what you can to minimize it even if you use any of these.
     
  3. KB4OIF

    KB4OIF Premium Subscriber QRZ Page

    OK. Went with the Diamond K550 mount and the coax assembly that it matches up to. Going to mount it right next to the post of the roof rail so I can get a good ground. Should be a screw that is into the body of the SUV there. My new Yeasu 891 will be here in the next hour or two. Tuner will be here tomorrow.
     
  4. KB1CKT

    KB1CKT Ham Member QRZ Page

    Sounds like fun. I've been tempted by the '891, seems like a nice mobile rig.
     
  5. KB4OIF

    KB4OIF Premium Subscriber QRZ Page

    Seems to be a study built radio. Can't beat the price right now. 574 dollars from HRO. Soon as the tuner get here tonight, I am going to try it out. Am hopeful that he come earlier than he has been. I have an apt at 430. Thinl I have a second option for the antenna mounting. Uhaul will install a hitch for about 140 dollars with the wiring. May go to one on the back end and mount the tarheel there if the K550 will not work. Read your thought on hitch mounts Alan. How do you have your mounted Alan.

     
  6. KB1CKT

    KB1CKT Ham Member QRZ Page

  7. KB1CKT

    KB1CKT Ham Member QRZ Page

    Problem with hitch mounting is that it puts the feedpoint very low, in many installs. Think of it this way: you have the car hatch, or the rear of your car. Think of it as a large conductive surface (because it is). Now lay an antenna next to it. This starts to shunt the antenna: it's a parasitic capacitance. I think it looks a bit like a microstrip transmission line, actually, and with equal current induced in the sheet metal, at a constant distance, not actually radiating a signal. Worse: it places shunt capacitance across the coil, increasing its losses.

    Even if you start an antenna support structure low on the car, the antenna base should still be as high as possible.

    In a different thread, I experimented with a screwdriver. I got 21 ohms at resonance, at antenna base. On the end of coax, I could get below 2:1 SWR. Problem is, that was no ground under the antenna. That won't work (well). Just because it matches up / loads up doesn't mean it actually radiates very well!
     
  8. M0GVZ

    M0GVZ Ham Member QRZ Page

    It will. I regularly do 70+ MPH into strong headwinds and it is just fine. The K400 has absolutely no problem with the Little Tarheel II.
     

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