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HI-Q Antenna Users, I have Questions..

Discussion in 'Mobile Radio Systems' started by VA7WPN, Jun 22, 2020.

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  1. VA7WPN

    VA7WPN Ham Member QRZ Page

    Antenna Mounting.. I am afraid of this thing coming OFF my Jeep on the high way. I have the QDC, its bolted to a hitch mount. The mount has an isolator on it to keep it from moving. But the antenna still moves quite a bit. Am I safe? are these 3/8-24 bolts and aluminum mounts going to be enough?

    Whip length. I have, what I suspect is a 4/160. I have 2' extension and a 6 lobe Cap Hat (For some reason, I only see 4 and 8 lobe cap hats on the website), but no whip. I have an 8' whip to go on, that that will bring me WAY up past 13'. What lengths have you been using?
     
  2. NG1H

    NG1H Ham Member QRZ Page

    I suspect the problem is in the hitch mounting. Those will move all over the place. I'm not sure what the "isolator" is. There's a hitch stabilizer device made that works fairly well. It's a collar that fits around the receiver with two bolts that press the hitch to one side. The assembly can still wiggle a little but should be much more secure than you have now.

    To see one search for "hitch anti-wobble collar".

    Gene
     
  3. VA7WPN

    VA7WPN Ham Member QRZ Page

    That is what I have, the "Isolator" is that collar.
     
  4. NG1H

    NG1H Ham Member QRZ Page

    Gotya. Then what you probably have is just the nature of mounting an antenna on a vehicle with a stiff suspension. The body is going to rock and so will the antenna. It probably isn't going to break but it is an annoyance to see and it could be possible for the antenna to whack the body.

    Been there, done that. I didn't have a hitch mount but did have a Hi-Q mounted on an arm extending from the frame underneath a truck. I wound up moving it to the roof for other reasons. Mainly to get it to work rf-wise. But before I moved it I did investigate stabilizing methods. Ropes could help in your case with the side to side movement but every time they get wet your antenna will be unusable until they dry. I concluded the best choice would be a bracket mounted higher up. If you look at the antenna's web site and at K0BG's site there used to be pictures of examples. An idea would be to make it out of cutting board material. If you go to a commercial kitchen supply they have them in pretty large and thick sizes. I've used it for other antennas. The product will start to sag after a couple of years in high heat conditions but otherwise holds up pretty well.
     
  5. NG1H

    NG1H Ham Member QRZ Page

    PS - Overlooked the rest of your post. If you have the cap hat then my understanding is you can cut the whip back without making a material reduction in radiation efficiency. Personally I eventually had the antenna mounted on the roof of a truck with the whip on top. Definitely over 13'. Highway driving isn't an issue as the airstream bent the whip back. Fueling wasn't an issue as the stations with diesel fuel tend to have high covers. Driving around suburbs was the main issue. Tree branches where always getting whacked by the whip.

    Gene
     
  6. AJ3O

    AJ3O Premium Subscriber QRZ Page

    I have the 6/160 Piranha that I originally had bolted to a custom mount that was bolted to the accessory rail system on the front part of the bed behind the cab on my Tundra. Well, after close to 6 months I was hearing noises from behind me and noticed movement in the base section that I didn't notice when first installing it. Seems that it started to break the welds at the front topmost section and the corner of the bed on the driver side. So now I have it mounted to an aluminum C-channel bolted to the same accessory rail holes but it is bolted all along the front and sides. I can stand and bounce on it and the truck moves but the antenna really doesn't. Yes, that is an older picture and it is much warmer here than that now. Wind tested at highway speeds (and passing speeds) through all types of weather. I also moved it to where it is visible but just behind the window frame of the sliding window. Mounted like this, I can visually note any movements if it starts to come loose or spin but it is not a hindrance as it is mostly behind the frame and doesn't block more than an additional 3/4". One benefit to moving it slightly towards the center allows me to still go through some drive-thrus for my coffee and clear most overheads.

    I use a 3 foot whip that puts the top of the whip at 11'6" for normal use. I still have to watch out for low branches especially when it is raining or snowing. I also have the 3 foot extension, cap hat and 8 foot whip for portable operations that brings the total height to roughly 20'-6". The normal use setup has allowed me to get DX and POTA on 6 thru 80 meters while mobile. I am very pleased with it!

    A few things that I should mention.
    1. Follow the instructions for the inductance coil for the lower bands. While it does good without it on 6 - 40 meters on my install, it does help with the low bands.
    2. Go to K0BG.com and follow the recommendations for bonding vehicles.
    3. Look into the TuneMatic auto tuners for a safer mobile operation. Otherwise, just pull over and re-tune it manually.

    Don't give up and have fun.

    73,

    Joe / AJ3O
     

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  7. K0UO

    K0UO Platinum Subscriber Platinum Subscriber QRZ Page

    Antenna Mounting.. I am afraid of this thing coming OFF my Jeep
    It will when you take it off road and hit a big tree branch! Experience is talking here!!!
     

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