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Thread: Glass mounted antennas and metallic content glass

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    Default Glass mounted antennas and metallic content glass

    Back when glass mounted antennas came out I had a Larsen antenna with a 110W Syntor X, and it was the hottest radio we had. I could hit our UHF fire repeater well over 100 miles away, and with taller hills between the two locations. I'm looking at how to install an antenna on a 2018 Silverado, and not looking forward to having to drop the ceiling liner to roof mount an antenna. But glass mount antennas now carry warnings about glass with metallic content. How common is it, and how can you be sure? It seems most windows are tinted these days, but I don't think tinted equates to metallic content.

    Thanks,

    Jim


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    The warnings refer to windows with embedded circuit traces for defrosters or disguised AM/FM antennas. If the tint is film you can cut a hole out of it and place the antenna over it.

    Also...
    not looking forward to having to drop the ceiling liner to roof mount an antenna.
    I just put 14 holes in a PPV Tahoe, and the standard installs I do at work require 6 minimum, 8 if there's room. I budget 2 full days just for dismantling the interior and dropping/removing the headliner for antennas and cabling. But hey, once you've done a dozen or so it's not so bad.

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    If the vehicle has darkly tinted windows, there's a good chance it uses vaporized copper in the glass. Look for the manufacturer imprint in one of the lower corners to see if it has the letters CU. If you can't find an imprint, then drive out to an area where your cell phone has low bars. Roll the windows up and down while watching the bars. If there is significant change, the windows have vaporized copper.
    Bow wow wow yippie yo yippie yay

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    Quote Originally Posted by KY1H View Post
    .. not looking forward to having to drop the ceiling liner to roof mount an antenna.
    I guess you'll have to plan your next sunday to do so, I assure you won't regret going the hard way. A quarter wave (or even a stealth "dildo load" antenna) will outperform that window antenna for sure.

    I wouldn't like to have a 110w load in that kind of antenna anyway. have you measured the VSWR?

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    Buy, borrow, or rent a low-e glass detector. They are about $250 on Amazon. MOST glass these days will fail the test. NEVER consider putting 110w through a glass-mount antenna. Two problems: You run a strong chance of melting something (or breaking the glass) and RF exposure hazards.

    The SAFE approach is the hard way. On the roof with a permanent antenna.
    Apparently NOT a radio professional.

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    My current needs would be like 30-50 watts. The 110 watt Syntor was way back in the day, in the mid 80s. I don't recall just what the VSWR was, but it wasn't anything I considered a problem. Glass mount was still fairly new, and as I recall a salesperson talked me into trying it. I was amazed at how well it did. We had police cruisers with the same type setup with Syntors but with trunk mount antennas that couldn't touch my range. I don't think I can find a glass mount for this particular installation that will let me work around the defroster lines, so I think that will eliminate glass mount anyway.

    Thanks,

    Jim

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    Take the dome light or third brake light out of the Silverado and drop a permanent antenna around there. Fish the coax down a rear pillar and you're set. It's not really that hard. I have 6 in my roof.
    Schrodinger's Radio: It is simultaneously too loud and too quiet, but you will never know which until someone transmits.

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    Dropping the headliner and installing 3 antennas in my 4runner (which requires about an hour and a half of work just to get the headliner down) took me a solid half day. That included running power and data for three remote mount radios as well. It was extremely satisfying and still is to see properly-mounted antennas on the roof. It's worth the effort.

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    Myself and a friend recently put 4 NMO mounts in the roof of my 2019 Traverse in a matter of about 7 hours including lunch and other distractions. The actual work of dropping and reinstalling the headliner was a small fraction of that time. My friend has been doing this way longer than I and said it was the easiest he has done.

    Do it right the first time and you won't have to worry about it later.

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    Quote Originally Posted by box View Post
    Do it right the first time and you won't have to worry about it later.
    I couldn't agree more. So many issues go away or never occur if you use that attitude.