About Magnet Mounts

Magnet mounts offer a convenient method of installing an antenna on a vehicle. The magnetic mount antennas also give you an alternative choice instead of drilling a hole in the roof of your vehicle, especially if the use is only for vacation, temporary use or portability is required of a communications system. However, there are some considerations that should be noted.

  1. Magnet mount antennas actually get their ground through capacitive coupling with the metal of the vehicle. The capacitance that the magnet forms with the surface of the vehicle is what couples the RF circuit to the body of the car. It determines the efficiency of your antenna installation.
  2. When removing the magnetic mount from the vehicle, do not slide it across the roof or surface. This may make it easier to get to and remove, but the dirt and metal particles on the roof will leave scratches on the paint from the sliding action. It is best to grab the coil and tilt it towards you to easier break the bond that the magnet has with the metal surface of the vehicle. As this bond is broken, you can then lift it from the installation position.
  3. Do not leave the mount in one location for extended periods of time. The vehicle paint will discolor and moisture under the mount can cause rust to form on or under the painted surface. Periodically remove the mount and clean both the mount and the area it is on to prevent this. If you live on the coast or in an area where there you receive a lot of rain or snow, this should be performed about every 3-4 months. Dryer climates can do the cleaning every 6 months (in the fall and spring).
  4. The damage to the surface of the vehicle can be lessened with the use of a thin material between the magnet mount and the surface. A recommended item to use is nylon. This can be from a pair of ladies nylon panty hose cut into a circle about 1/4 to 1/2" larger than the diameter of the magnet mount.
  5. Beware that if you are using a high power amplifier, the probability that heat will discolor the vehicles paint is greatly increased. The higher the power, the sooner (and more severe) this will occur. Using high power will require more attention to the finish of the roof and movement of the mount.
  6. Pay particular attention to the routing of the coax cable, watching doors and windows for coax pinching. Continuous slamming the door or raising the window to hard on the coax cable will weaken it and cause the center conductor to break.
  7. If corrosion or rust sets up inside the magnet mount, the magnet may come loose from plate. If this occurs, the antenna may be separated from the magnet (which may stay on the surface of the vehicle) when the antenna is removed. The best way to remove the bare magnet from the surface is with the use of a large pair of channel lock (aka water pump) type pliers. Expand the pliers to the largest opening, grasp the magnet from the center hole to the outer edge between the teeth. Carefully, yet forcefully, lift as you tilt back the pliers. This will cause the bond to loosen and break allowing you to remove the magnet from the surface. The mount can now be repaired or replaced.
  8. How do I repair this separation?
    NOTE: Refer to magnet mount assembly for location of all parts.
    The following steps should be done outside, in the garage or other well ventilated area.
    • A. Clean all surfaces with a small steel toothbrush type brush.
    • B. Use a cleaning solution that will dissolve rust and corrosion. A good example is the pink type of Navel Jelly. Follow the directions on the label for best results.
    • SeparationC. Allow all parts time to completely dry.
    • D. Place magnet on newspaper or cloth.
    • E. Mix a 2-part solution of epoxy.
    • F. Run a 1/4" to 3/8" bead around the center of the "donut" of the magnet.(see illustration to the right).
    • Place the bead of epoxy as shown above
    • G. Holding the metal plate by the outer edges, carefully align the plate above the magnet, without touching.
    • H. Slowly lower the plate towards the magnet. CAUTION: Watch fingers - as you lower the plate, the pull of the magnet will become increasingly stronger to a point that the magnet will quickly pull the plate onto it with a loud snap.
    • I. After the plate is attached to the magnet, carefully slide and align the two pieces so they match.
    • J. Watch for excess epoxy oozing from the center and outer edges of the two joined pieces. Clean any excess with a damp cloth.
    • K. Allow magnet/plate assembly to dry overnight.
    • L. Reassemble the magnet mount system
      Note: It may be neccessary to replace the 2 piece mylar protective covering (part number 880-500127) on the bottom of the magnet.