# Distance to the station: travel, the higher the signal has the lowest (off), it is the result of image and sound quality is reduced. Because UHF signals weaken earlier and can travel less distance, they are hard to get, compared to FM signals. Video and Audio – TV signals are composed of two carriers. The video (image part) fades faster than sound, which is why sometimes in a position to sound but no picture explains are received.
# The terrain between your location and the issuer: For example, the sender is at high altitude (high tower on a hill) and your house is located in a low valley – the TV signals over-pass “on your location, by the antenna away. In contrast to AM radio signals that follow the curvature of the earth, the TV signals travel in a straight line – “a tangent” on Earth, is the TV reception on the “Line of Sight” is based on the sender to the satellite TV receiver.
# Other obstructions (tall buildings, hills, etc.) can also interfere with broadcast signals. Interference from buildings, water towers, etc. “ghost” (multiple pictures displayed on the screen) can cause – the signal from the transmitter is reflected by an obstacle, reflected this signal happens to your TV, a fraction of a second later than the original signal, allowing multiple images.
* The use of “directional antenna” which is a good side and rear rejection has, can eliminate or reduce the “phantom effect”. it sometimes “spirit” can not be solved by moving the antenna away the reflecting obstacle.
# Type and size of the antenna: The antenna size needed depends on the distance from the transmitter to your position. The size of the antenna, including the duration and the number of elements increases as the distance between the point of entry and the rise of the issuer. At the end zones, stacking antennas (with multiple antennas on the same mast) is a solution.
