Dish Installation

Best locations for satellite dish installation.

Dish Installation Requirements

1. First, you have to decide on the exact location where best to install your satellite dish. There are a few issues that you need to take into account here. Considerations shall include:

2. Remember that Dream satellites are in a geo-stationary orbit above the equator. Therefore, a satellite dish must point due South when your position is located north of the equator.

3. Choose a location that is easily accessible in case you need to clean snow or debris out of your satellite dish, or to re-adjust the dish in case it has lost its alignment. A suitable location is to attach the dish to a post which has been sunken in the ground.

4. The chosen location should be unobstructed by trees, branches, buildings, etc. In addition, make sure that the growth of new foliage does not impede your system.

5. Ideally, the selected location should be such as to allow you to take a route that is as straight and as close to your television set as possible.

6. Pick a location that is away from power lines and other service utilities.

KoreaSat5 at 113E.

Azimuth & elevation in Shanghai, China: 196.0° & 52.7°
Freq. Tp: 12390 V ; 12430 V ; 12470 V ;
System Encryption: DVB-S Conax Nagravision 3
SR-FEC SID -VPID: 25600-5/6
Beam EIRP (dBW) C/N lock: NE Asia 0-53.1 6.5

Useful Links

DirectTV Antenna Installation Manual.pdf file
Satellite Dish Aiming Angle & Point Direction Caculartor in China (Web Link)

Shanghai Dish Installation Work Gallery

How satellite dish works

When standard-definition television signals are transmitted in digital form, its pixels have rectangular shape, as opposed to square pixels that are used in modern computer monitors and modern implementations of HDTV. The table below summarizes pixel aspect ratios for various kinds of SDTV video signal. Note that the actual image (be it 4:3 or 16:9) is always contained in the center 704 horizontal pixels of the digital frame, regardless of how many horizontal pixels (704 or 720) are used. In case of digital video signal having 720 horizontal pixels, only the center 704 pixels contain actual 4:3 or 16:9 image, and the 8 pixel wide stripes from either side are called nominal analogue blanking and should be discarded before displaying the image. Nominal analogue blanking should not be confused with overscan, as overscan areas are part of the actual 4:3 or 16:9 image. The pixel aspect ratio is always the same for corresponding 720 and 704 pixel resolutions because the center part of a 720 pixels wide image is equal to the corresponding 704 pixels wide image.

If you have more interests on how a dish antenna works to receive Dream signal, please continue the read the following explaination from wiki:

A satellite dish is a dish-shaped type of parabolic antenna designed to receive microwaves from communications satellites, which transmit data transmissions or broadcasts, such as satellite television.

Principle of operation

Schematics of reflection principles used in parabolic antennas. The parabolic shape of a dish reflects the signal to the dish's focal point. Mounted on brackets at the dish's focal point is a device called a feedhorn. This feedhorn is essentially the front-end of a waveguide that gathers the signals at or near the focal point and 'conducts' them to a low-noise block downconverter or LNB. The LNB converts the signals from electromagnetic or radio waves to electrical signals and shifts the signals from the downlinked C-band and/or Ku-band to the L-band range. Direct broadcast satellite dishes use an LNBF, which integrates the feedhorn with the LNB. (A new form of omnidirectional satellite antenna, which does not use a directed parabolic dish and can be used on a mobile platform such as a vehicle was announced by the University of Waterloo in 2004.

The theoretical gain (directive gain) of a dish increases as the frequency increases. The actual gain depends on many factors including surface finish, accuracy of shape, feedhorn matching. A typical value for a consumer type 60 cm satellite dish at 11.75 GHz is 37.50 dB.

With lower frequencies, C-band for example, dish designers have a wider choice of materials. The large size of dish required for lower frequencies led to the dishes being constructed from metal mesh on a metal framework. At higher frequencies, mesh type designs are rarer though some designs have used a solid dish with perforations.

A common misconception is that the LNBF (low-noise block/feedhorn), the device at the front of the dish, receives the signal directly from the atmosphere. For instance, one BBC News downlink shows a "red signal" being received by the LNBF directly instead of being beamed to the dish, which because of its parabolic shape will collect the signal into a smaller area and deliver it to the LNBF.

Modern dishes intended for home television use are generally 43 cm (18 in) to 80 cm (31 in) in diameter, and are fixed in one position, for Ku-band reception from one orbital position. Prior to the existence of direct broadcast satellite services, home users would generally have a motorised C-band dish of up to 3 metres in diameter for reception of channels from different satellites. Overly small dishes can still cause problems, however, including rain fade and interference from adjacent satellites. In a single receiver residential installation there is a single cable from receiver to LNB and the receiver uses different power supply voltages (13/18V) to select polarization and pilot tones (22 kHz) to instruct the LNB to select one of the two frequency bands. In larger installations each band and polarization is given its own cable, so there are 4 cables from the LNB to a switching matrix, which allows the connection of multiple receivers in a star topology using the same signalling method as in a single receiver installation