Alcoma ZENITH 80 - Page 38

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MicrowaveradiorelaylinkZENITH80 
 38/52 1.2
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Figure24 Pointing
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Figure25 Radiationdiagram
The pointing procedure in both horizontal and vertical directions must be repeated several times to
makesurethatthebestmaximumoftheradiationcharacteristicwasfound.Theoppositestationantenna
needstobefinaladjustedthesameway.
CheckingofPointing
ThevalueofreceivedlevelcanbedeterminedbydirectreadingintheASDmonitoringprogramorby
calculation using the calibration graph for RSSI. The RSSI voltage can be measured at the BNC connector
withoutnecessitytoadjusttherotaryswitch.
Tocheckfortheproperpointing,itisgood
tocalculatethesignallevelthatshouldbemeasured.The
maximum allowed deviation between the calculated and measured signal levels is ±3 dB. If the negative
deviation is higher the connection needs to be better pointed. Control calculation is described in chapter
4.2onpage40.
The noise level on
the receiving channel needs to be checked while the opposite station is switched
off.Theminimum requestedseparation of thenoiselevelfromthe received signalis20dB.The opposite 
stationcanbeswitchedoffremotelyusingtheASDmonitoringprogram.
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• Whilewrongpointinginonedirection(e.g.vertical)onlysidelobesmaybefoundinthe
seconddirection.
• Pointing toside lobe isa commonmistake. You may find sharmmacximum, buttheRx
levelis13dBlower.
• Werecommendfindingmainlobeandbothsidelobesduringthefirstpointingstep.