Antenna placement

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=62617
Printed Date: July 07, 2025 at 5:21 PM

Topic: Antenna placement

Posted By: jumargibbs
Subject: Antenna placement
Date Posted: September 13, 2005 at 4:34 AM

I've spent a lot of time doing a stealth install, so I really don't want to advertise my security system by sticking an antenna on the windshield of my truck. Any ideas on hidden antenna placement?

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Ken

Replies:

Posted By: sharc
Date Posted: September 13, 2005 at 11:13 AM

Hi Ken,

As high as possible and away from metal objects as they will affect transmit and receive performance. RF will go through glass and plastic, but metal can greatly affect RF transmit & receive patterns. The higher the antenna, the greater the "line-of sight" range (distance) will be. Perhaps some others have some good suggestions. Is this a FM or AM antenna? What does it look like? This might help others to be able to tell you the best mounting location.

- Jim

Posted By: jumargibbs
Date Posted: September 13, 2005 at 4:47 PM

The body of the antenna is a triangle, with 2 horizontal 'rabbit ears'. It's a CrimeStopper alarm.

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Ken

Posted By: Steve23
Date Posted: September 13, 2005 at 6:13 PM

Ken I was wondering the same exact thing. I tried to find a more low profile type antenna but had no luck. I ended up sticking mine as far up as possible above the rear view mirror. You cant really see it too well because of the tint strip. Something I didnt know, you cant put them near metal trim? My truck has a piece of trim along the headliner above the windshield, less than an inch from the antenna. Is this really bad for reception?

Posted By: sharc
Date Posted: September 13, 2005 at 8:43 PM

Steve,

There's probably not much of a better place to mount it. Ideally, an antenna for any device should be mounted at least 1/4 wavelength from an object. Ideally, this would be above your car! LOL. Realistically, this is impractical and very obvious! Metal will affect the pattern, but to what extent, depends upon the operating frequency of the system. If you're not having any problems arming and disarming, then I would not worry about it. Once thing you might try sometime is parking in an large open field or large empty parking lot and try arming and disarming the car from various distances in various directions. See if there's one direction that drops out sooner then the rest. My antenna looks like one of those antennas on a cordless phone. Mine too is mounted on the glass behind the rear-view mirror and points downward. You're right, the tint does help hide the antenna, and mine had a flat ribbon cable designed to be tucked away behind the headliner.

I wonder if they make decoy antennas...... something more obvious that a thief would pay more attention to. Let him cut that cable and "think" he's beat you.

- Jim

Posted By: jumargibbs
Date Posted: September 13, 2005 at 9:56 PM

I'm going to try different locations, including under the dashboard. All I really need is a guaranteed signal transmission from the truck to my bedroom. Nightime is when a break-in will probably occur and I'd like to be able to come out and greet the would be thief. I'm protecting my tools....to heck with an '88 truck.

Ken

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Ken