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Parabola Antenna Dish Satellite
When using parabola antenna dish satellite we can get any FTA (Free-to-Air) channel. FTA is broadcast from terrestrial television channels can be watched without having to subscribe to pay TV like broadcast. Free broadcast signals can be captured via an antenna UHF / VHF, or use a satellite dish. Free Press in Indonesia came into force in 1996 from five private television station in Indonesia stands. Because the previous owner charged dues television to watch broadcast television regular TV.How to capture broadcast signals free
1. Through regular antenna or antenna UHF / VHF
In general, TV viewers can catch the broadcast through UHF and VHF antennas. However, this only applies to areas that have a transmitting station of TV station. For television viewers settlement locations within a radius of 10 kilometers from a television transmitter tower, the range has a power good signal.
2. Through dish
This tool can capture live via satellite signals without directed at the base station. With a satellite dish, not only local broadcast that can be captured, but also from overseas TV broadcasts available on the satellite dish antenna whose signal is received. This antenna is suitable for local viewers who can not catch the broadcast through radio stations because of geographical conditions are not adequate, or the unavailability of the transmitting station.
There are four types of popular dishes that are used are:
A. Focal Point Feed (Prime Focus)
In this type of antenna signals received from the satellite is reflected by the paraboloid reflector and immediately accepted by the feed horn is placed exactly at the focal point. Instead the signal emitted from the feed horn directly reflected by the reflector towards the satellite.
B. Cassegrain
Unlike the prime focus antenna, the antenna cassegrain has two paraboloid-shaped reflector and a sub reflector shaped hiperboloid. Signals received from the satellite emitted by the main reflector (main reflector) to the feed horn. (Usually used in earth station PT. TELKOM).
C. Gregorian
In principle, this type of antenna has the same construction type cassegrain, but the Gregorian antenna ellipsoidal-shaped sub reflektornya located next to the focal point.
D. Antenna Offset
In contrast to the above three types of antennas that have an asymmetric reflector system in which both feed and sub-reflector horn lies beyond the scope of the reflector, so that both the incoming signal and sent to the satellite did not encounter any obstacles.
Types of dish Antenna Parabolic base on functions
1. Disc with motor
A dish that is made on a pole and driven by a motor or servo controlled and rotated or rotated to face various satellite positions in the sky. Discs dish that can be driven very much. Parabolic antenna with a motor that can be driven has three different standards, ie DiSEqC, USALS, and 36v positioners. Many receivers can support all three standards above.
2. multi-satellite
Multi-satellite is a dish that can accommodate as many as 16 pieces of the satellite positions (Ku-band). Some designs allow some revenue at the same time from multiple different satellite positions without having to change the position of the disc. Axis / vertical axis Cassegrain reflector works as an off-axis concave parabolic concave hyperbolic. Axis / horizontal axis to work as a concave convex Cassegrain. The main point of the disc moves into the secondary disk, which improves astigmatism through crooked shape / curvature varies. Elliptical crack owned primary disk is designed to adjust to the reduced illumination by a horn antenna dish. Since the spill double / double spill-over, then use a large dish would make more sense.
3. VSAT
VSAT is a type of the most popular dish. VSAT stands for Very Small Aperture Terminal. VSAT dish antenna types provide two-way satellite internet communications and a private network for a variety of organizations. Currently, most of the VSAT operating in Ku-band waves. It happened because of a wave C-band is limited to a few regions in the world. There is a movement which is started in 2005 to encourage the Ka-band satellites that operate at higher frequencies. Type the satellite offers better work with lower cost. Size antennas are varied, starting from the antenna 74 to 120cm in diameter. For most applications, VSAT dish antenna with a C-band by 4 meters.
Keywords: television, television station, or television show is a stub.
