I used the following information to help me set up my antenna. It is available at the channelmaster Web site. Here is the pertinent information, I hope it helps...
Large trees can present reception problems and nearby high-voltage power lines can cause interference that cannot be completely eliminated. Also, aluminum foil on insulation, aluminum or steel siding, metal gutters at the attic level, and metal lath under older plaster walls all can interfere to some degree with reception.
Several roof-type mounting brackets and swivel mounts are adaptable for use in attic installations. The mounting bracket is used to attach the short mast to a rafter or rafter support. The antenna is then mounted on the other end of the mast. The antenna however, must not touch the attic floor. Also, remember that the antenna should be attached to the mast right side up, even though the installation appears to be the reverse of an outside installation.
Instead of using a mast, you may suspend the antenna from the inside of the roof with guy wires or nylon rope. But don?t let the guy wires touch the antenna elements. They will short out the antenna. Once you have the antenna mounted or suspended, you are ready to run the transmission line. If at all possible, keep it indoors. Coaxial cable is the best transmission line for any antenna installation. It should be used instead of twin lead even in attic installations.
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