Defects of Installation Satellite Dish Antennas

al_madhi

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My Location
Riyadh - Saudi Arabia
#1
Introduction :-
When the three powerful satellites , Hot Bird , Aabsat and Nilesat start transission to Arabic Countries and specially Middle East Area , and due to the power outputs of these satellites , it became possible to receive all these three satellites by using one fixed dish only .

Therefore , some Asian workers, Indians , Bengalis and Philippineos who work at the shops selling satellite dishes and equipments created a methode known to the people in Middle East Area The Commercial Method , which means to receive three satellite on one fixed dish only .

Firstly :- How possible to receive three satellite on one fixed dish ?

1 - Only if the desired satellites to be received are closed to each other so that the position of one satellite does not exceed more than 13 degree to the next satellite position, and the power output of these satellites not less than 45 dBw . and the diameter of the dish not less than 180 cm .

2 - If the above condittions are met , It is possible to receive three satellites on one fixed dish, But the quality of the reception are not equal because of the following :-

A - Regarding the European Satellite Hot Bird the quality of the reception will be excellent 100% because the dish is pointed directly to the satellite Hot Bird , so that the incident rays of the transmission will be reflected from all sectons of the dish to the LNBF .

B - But regarding the Arabian Satellite Arabsat , the quality of the reception will be medium 50% because of the dish is not pointed directly to the satellite Arabsat , Only the lower section of the dish will reflect half of the incident rays of the transmission of the satellite Arabsat . Because only the lower section will pointed directly to the satellite Arabsat and not all the sections of the dish .Therefore half of the power of the transmission
from Arabsat will be receivced and the other half of the power from Arabsat will be lost , And this will lower the ability of the dish to receive the whole power transmission from the the satellite arabsat .

C- Also regarding the Egyptian satellite Nilesat , the quality of the reception will be medium 50% because of the dish is not pointed directly to the satellite Nilesat , Only the Upper section of the dish will reflect half of the incident rays of the transmission of the Nilesat , Because only the Upper section will pointed directly to the satellite Nilesat and not all the sections of the dish . Therefore half of the power of transmission from the Nilesat will be received and the other half of the power from Nilesat will be lost . , And this will lower the ability of the dish to receive the whole power transmission from the satellite Nilesat .


Secondly :- How to Install the Commercial Method ?

1 - Installing thin rods on the rim of the disc which holds the LNBF of the European satellite Hot Bird as follows :_

A - The Rod which is fixed on the rim of the disc downwards and tilted 45 degrees towards the left while you facing the the dish fixed on it on the otherside the LNBF of the satellite Arabsat .

B - The Rod which is fixed on the rim of the disc Upwards and tilted 45 degrees towards the Right while you facing the dish fixed on it on the otheside the LNBF of the satellite Nilesat .

Thirdly :- The Defects of the Commercial Method :-

1 - The Dish unable to receive the whole Transmissino power transmitted from both satellites Arabsat and Nilesat which will lower the ability to receive channels transmitted over weak frequencies , Because not all the frequencies transmitted from the same satellite are equal in power , some frequencies are strong , some meduim and some very weak .

2 - The Effects of frozen video signals sudden or frequent or blackout according to the power of the transmitted frequency due to the vibration even if this vibration is very weaK will cause the LNBFs to change position due to the weight of the LNBFs on the rods if these rods are very thin and causes the vibration during srong wind .

3 - During very strong winds or thunderstorms , the dish will move from its previous position and cause the rods to change its postions , which will reqired to reposition the dish and also reposition the rods which
will required a lot of work . Addition to that when heavy rain falls on the dish will cause the satellite signals to divert and do not reflect all the incident rays to the LNBFs .

Fourthly :- According to the Telecommunicatuion Engineering to receive 100% from the satellite, Each satellite must have a fixed dish pointed directly to it .

Fifithly :- In case if there are many satellites to be received or to receive the whole satellites from east to west you must use a motorized dish in order to point the dish directly to the desired satellite .
 
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#2
Nice tip, Al Madhi.

I have seen this in use too, with a slightly smaller (5-foot - 1.5m?) dish.

But if roof mounting space is not a problem the cost of two extra 4-foot (1.2m) dishes is about $40 and another $20 for two universal LNBs, and about $10 for a 4-port DiSeq switch so it may not be such a bad cost for clear signal.

I enjoy seeing so many people helping out with good suggestions and advice and help, it's great.
 
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