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Satellite reception in the Netherlands!
The satellites which are important for us (satellites that TV - pictures transmit) stand all above the earth's equator on a distance of this way approximately 36,000 kilometres. These satellites stand with respect to the ground at a fixed place, for this reason say we that them geostationair are (satellites for example the GPS - position provision system turns in job for the ground.
These job run concerning the North - and south pole, these job for this reason polar job are called.) To indicate the position of one place to the ground has in former days divided in degrees on the ground, this appeared work arithmetic well, think of navigation for ships and planes. The ground one between the pole’s has divided in 180 degrees 90 degrees latitude North to know and 90 degrees latitude South. (N-latitutde lie between earth's equator and the North pole, S-latitude lie between earth's equator and south pole). Concerning the earth's equator one has divided the ground in 360 degrees, namely know 180 degrees longitude east and 180 degrees longitude west. The 0 degrees meridiaan run from the North pole to the south pole and run through Greenwich at London (meridiaan = conceivable line which links both pole’s with each other). This information also will be found in a good atlas.
The position of geostationaire satellite is indicated by the spot where he stands above the earth’s equator, above which meridiaan he stands for example the Astra 1 satellite stand on 19.2 degrees East if now in the atlas then can you look at you see that those satellites stand above the place Mbandaka in Kongo (Africa). The Sirius (5 degrees East) stand above the Atlantic ocean nearby of Sao Tome (small island for the west coast of Africa.)
Earth twists around the pole - ash therefore also the geostationaire satellites. This pole - ash is important for the rotating elaboration. We let the dish twist around the pole - ash so that we will follow the same job. The pole - ash runs right by the ground from North pole to south pole.
The Azimuth are the angle between truth north and the direction in which we see the state of our satellite. Azimuth is indicated in an angle between 0 degrees and 360 degrees. Azimuth for the Sirius satellite is in the Netherlands approximately 180 degrees.
The Elevation is the angle between the surface of the earth and the direction in which the satellite stands differently said, the angle between surface of the earth and the direction, in the vertical area, in which the dish must look at the satellite being able receive.
The Declination is the correction angle which we must apply because the satellites stand not infinitely far gone on a relative short distance of the ground. In drawing mentioned below the red line and the dotted red line reflects the pool-as on the rotor or polarmount the direction in which looks at the dish then. As you can see is the elevation to the satellite a smaller angle. To correct this we let the dish roll over on the polarmount and that angle is called the declination. This declination is for all types of dish right only at off-set dishes this value at the offset angle will be settled.
How does satellite reception work?
A dish system is not so complex as it seems There for there are many questions concerning this manner to watch television . For this reason is a short explanation at his place.
A dish installation exists from three important components: The dish himself, the Low Noise Block or LNB and the receiver. Of course a television is a not unimportant component of the final result.
Your T.V.
Each television is suitable for dish reception. You can both by means of scart cable and with (existing) rf cable pass on the indicator to your TV. If you have a video, you can tape ordinary satellite programmes. Everything work exactly the same such as it would work with a normal cable connection or antenna. Also you continues receive your existing cable indicator .
The dish
The dish himself serves as "lens", which a satellite indicator picks up and reflects the LNB confirmed to to the dish. The size of the dish influence reception quality. That does not means that you are able ruis vrij look at a dish of two meters on your roof must confirm. For reception of the most popular Astra senders is enough picture a dish of only sixty centimetres for a perfectly. Large dishes become interestingly just if you want coordinate on a less strong indicator, such as the Scandinavian Thorsat. The orientation of a dish is of course dependent on the senders whom you want receive, but the dish direction the south will be always more or less established. Also must be taken into account at the drawing up of a dish a free "view" on satellite. This causes generally no problems, but if you live for example on the committed ground in a lane, possibly a problem has. It is not this way that for indicators of several satellites you completely must hang your house full with dishes to receive them. It is possible to mount an engine to your dish, confirm so that the dish can turn automatically to the desired position. With such an elaboration you can receive literally hundreds of canals. Except the ordinary, parabolic dishes there also still flat dishes exist. Instead of reflecting an indicator, a flat dish has been as it were filled with small antennae. By adding these antennae to gether, exits a combined signal which is strong enough to get a clear TV picture. These dishes are particularly suitable for situations in which a normal will be too much on fall or too large, like on historical or caravans pawn.
The LNB
The LNB is the actual antenna of a dish installation. The indicator reflected by the dish is caught by the "feedhorn" part of the LNB and by the LNB them selves is converted into a lower frequency, so that the indicator can be conducted by a cable to the receiver. There are several types LNB ’s, such as LNB 's with double a termination, with which you a dish can use LNB ’s for the earlier-mentioned flat dishes for two receivers (digital and analogous), and "high gain". As a rule universal LNB for most of the applications satisfy. A simple manner for two indicators is receive two assembling LNB ‘s beside each other to a dish. Because of this you can coordinate two (adjoining) satellites at the same time, without much money from up having give to an engine. This "thing" works for example sticking out for both Astra and Eutelsat to receive on a 80cm dish. However your receiver must have two entrances. If not, there are diseqc-switches available with which it becomes still possible two receive signals.
The receiver
The receiver puts a satellite signal in an useful television picture. Receivers are provided with remote control and are simple serve. Your existing cable indicator becomes, exactly like at a video tape recorder, ordinary looped, so that you can look at the same time also to these canals. There two types of receivers because two types of signals exist; digitally and analogous. The more modern digital receiver has been developed for digitally compressed canals. Digital techniques produce a sharper picture quality and make it possible more canals on the same satellites to put. You want look at to Dutch the commercial and public senders, then you must look out to a digital recipient. Moreover is even the simple analogue receiver provide with luxuries such as remote control, stereo sound (by means of TV or amplifier) and scart outputs.
What is DiSEqC ?
With the DiSEqC everything is controlled from the receiver at the dish. DiSEqC 1.0 controls the Switch. Version 1.2 controls the rotor. As from version 2.0 is also possible get reports of the headed dish. DiSEqC work by means of modulation on 22Khz the indicator.
Digital Satellite Equipment Control - it was developed by defining a standard among other things EUTELSAT and Philips, with the aim for heading recipients and terminal equipment such as rotors, LNB switches, etc. One can hang therefore for example two dishes (e.g. for the Astra and for the Hotbird/EutelSat) to 1 receiver.
Why DiSEqC?
Older satellite receivers started all kinds of itself-considered use alternatives for heading terminal equipment where for the user the question became always larger: what is appropriate whit?
Satellite stipulated recipients changes gear for with 14/18 volts tension to be able choose between the horizontal and Vertical polarisation.
Another reorientation, frequently done with 22Khz tone-burst, is chooses between several satellites (2 LNB's yes or no on 1 or 2 dishes).
Meanwhile however the upper frequencies range (11.7 up to 12.75 GHz) is always more interesting for e.g. digital programmes. For that the use universal LNB's (10,7-11,7 and 11,7-12,75 GHz) use it 22kHz-Signaal also to change gear between the two frequencies reach.
Because of this the head signal expires which we need to make it possible to change between 2 satellites.
With DiSEqC becomes everything differently, in our digital society we can pass on to our satellite equipment to, as it happens, also digital commandos. DiSEqC are downward compatible, therefore old edge apparatuss are also still useful. We intend that omschakelaar for changing gear between two dishes, which are for DiSEqC 1.0 means, very well cooperate with DiSEqC 2.0 receiver.
The other way around, however, it is possible that a DiSEqC 1.0 receiver can not go along with DiSEqC 2.0 switch... these are only empirically stipulate because some DiSEqC 2.0 equipments listen for example yes or no to DiSEqC 1.0 commandos.
TIP: Agree therefore with the dealer that you stipulated equipment can return if it does not work!
The diSEqC concept works further with the concept of 14/18 volts and 22Khz tone-burst. At DiSEqC one sends vervolgens about this the digital commandos (both the reciever and the omschakelaar must be therefore, however, able understand DiSEqC).
DiSEqC are useful for both analogous, digital and analogous and digital installations.
DiSEqC alternatives:
Mini-DiSEqC
Mini diSEqC using earlier-mentioned Tone-Burst the (= Mini-DiSEqC), can be worked with two universal LNB's (for both analogous and digital satellite reception), where choose the omschakelaar always 1 of the two LNB's. This switch is special DiSEqC switch which is sent with the 14/18 volts and 22 the kHz Tone-Burst.
DiSEqC 1.0
DiSEqC version 1.0 permit it that we can hang 4 dishes to the reciever, by hanging the switch (slave) to the receiver (master) to which with digital commandos chooses which LNB use must become.
Used the indicator exists from the next information:
- low or high frequency link
- vertical or horizontal polarisation
- which LNB must the desired programme catch.
Applications of DiSEqC 1.0:
- reception with 1 satellite (1 LNB therefore) - 14/18 volt
- reception of 1 satellite that both digital and analogous retransmission have - 14/18 volt
- reception of 2 satellite (2 LNB's therefore) - 14/18 V + Tone-Burst
- reception of 4 satellite (4 LNB's therefore) - 14/18 V + Tone-Burst and Loop-Through.
There be meanwhile special LNB's that use of a so-called Loop-Through signals where the signal of a 2nd LNB can be looped by the 1st LNB. This type application is already useful at DiSEqc 1.0.
DiSEqC 1.2
DiSEqC 1.2 is an extension on 1.0, where the receiver can rotors head also once more for automated to twist of a dish.
DiSEqC 2.0
At DiSEqC one has once more built in thereby a return canal, which gives information concerning the number of LNB's connected and the way they are connected. With tone-burst on a certain frequency, the LNB's and the switch to the reciever make recognizable that they are there.
Applications at version 2.0 (beside the applications which we saw already at 1.0):
- Reception of maximum 4 satellites
- Return signals with information concerning the number and the types LNB's connected.
DiSEqC 2.1
A most important difference that we possibly can receive to a maximum of 64 satellites... seem to me a lot of dishes at my wall of my house but it’s possiblel... it (send
me please please a photograph if you have 64 dishes at your wall!).
Which DiSEqC version do I need?
If you want 1 dish, with 1 LNB and want to receive 1 satellite, it doesn’t matter which DiSEqC equipment your receiver supported.If you wish to receive 2 satellites, e.g. the Astra and the Hotbird (EutelSat) then he receiver must have a minimum possibility to 1 switch with DiSEqC. A possible reorientation with Tone-Burst can be also enough.
For the use of 3 or 4 satellites you have however nevertheless minimum DiSEqC 1.0 or higher necessary.
If the dish is rotating by means of e.g. a rotor, then you must have minimum DiSEqC 1.2 .
Almost ALL switches are provide with DiSEqC 2.0, but are possible by the downward compatibility also along with receivers which lower DiSEqC versions use. At least: that is the theory. Practical appears that one that empirically must test, agrees therefore real connecting.... for this reason always with the concessionnaire that e.g. switch can be brought as these do not work.
Most of the DiSEqC switches in Europe have been considered for use with the Astra and the Hotbird (Eutelsat), as well as the associated receivers. For most of the switches one of them can go that DiSEqC 1.0 for the reciever nevertheless minimum are...
Honestly said all more recent receivers, if it is now analogous or digital, support for minimum DiSEqC 1.0.
Headsignals.
Several head signals are used with this way little possible wire nevertheless of everything to be able control at the dish. First of all there is feeding tension for the LNB. Those are 13 or 18 volts to change the polarisation (vertically/horizontally). Then there is 22Khz signal to change the LNB to the high or low link. This 22Khz signal is also used for the DiSEqC signals. For readjusting the Future IMT dish LNB 12 volts indicator with separate wire are used. For the Future IMT within manageable time also DiSEqC control will be available which is incorporated in the cable, which generated from 22khz the indicator 12 volts indicator.
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