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Old 17-12-2011, 10:30 AM   #34
mrsun18
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Join Date: May 2011
Posts: 2,809
This post is to address the question of whether filter is used in the design for the rooftop antennae, common known as Master TV Antenna (MATV).

In this discussion MATV refers to the whole system while antenna (singular) or antennae (plural) refers to the metal element assembly only.

For simplicity, consider a MATV catering just for Chan 5 and Chan 10 (TV2). The antenna for Chan 5 will be pointing towards Bukit Batok, which is where the transmitter is. For TV2, the antenna will be pointing towards JB.

The Chan 5 antenna is receiving, at the same time, Chan 10 signal. But the quality may be poor, containing a lot of ghosts. Similarly, TV2 antenna is receiving good Chan 10 signal but poor Chan 5 signal. Now if the outputs from these 2 antennae are simply fed into the amplifier without processing, the amplified output will contain poor quality signals in both Chan 5 and TV2. It is necessary to filter out weak and poor signals from antennae so that only clean and good signals are fed into the amplifier.

So, in this particular example, only Chan 5 and TV2 signals will be available through the MATV.

In the case of HDB MATV, the design cater only for local TV stations, TV1 and TV2, no signals from other transmissions will be available. If one can receive other stations, that is because of strong ambient signals resulting in good direct pick up. These don't come from the rooftop antennae.
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