Originally Posted By: Shotts
Typically anything less than 4 wave lengths is considered near field and can interfere with normal operation. Seems like TV wavelengths are in the 1-5m length in which case you will need to be 12-20 ft from large metal objects to reduce near field interference. YMMV


The middle of the UHF band would be close to 650MHZ. So .5 meter would be the wave length. 4 or 5ft. Above the tallest part of the roof you should be good. Think of a yagi as a flash light looking for the tower. You cant see it if you are looking through the roof. If you are on the same side of the roof as the tower is it could help reception. Short answer 3 or 4 feet above the ridge and pointed at the tower (or in the middle of the cluster) you should be good.


1-5 meters would be well below the UHF tv band.

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