Verify Tx/Rx Path Gain Budgets
Pre-Installation Requirements
3-18
Ocean TRx™ 4500 Installation and Operations Manual
Example of L-Band Rx Levels calculations:
LMR-600 cable length = 50m
LNB Gain = 63dB
Rx Ku-Band = 11.2GHz
CCU "BDMx" attenuation = "0"dB
Satellite EIRP = 39 dBW
Transponder Bandwidth = 36MHz
Used Bandwidth = 1MHz
Result of this example:
LNB Output power = -51.1dBm
Derived Rx L-Band Level received in the modem = -40.9dBm.
Figure
3-16: Calculations for Example of Single OceanTRx4-500 L-Band Rx Path
Parameter
Unit
Value
System Type
N/A
OTRx4
System Band
N/A
Ku
Transponder Saturation EIRP
dBW
39.0
Output Backoff
dB
4.0
Transponder Bandwidth
MHz
36.0
Terminal Used Bandwidth (Rx)
MHz
1.0
Downlink Frequency
GHz
11.20
OTRx4 Antenna Gain (Typical)
dBi
41.0
LNB Gain (Typical)
dB
63.0
Derived Fractional Used Bandwidth
dB
-15.6
Derived Downlink Path Loss
dB
204.5
dBW to dBm conversion factor
dB
30.0
LNB Output Power
dBm
-51.1
POINT
G
Derived LNB Output Power (H15), depends on Satellite EIRP, BW,Ant. Gain, etc,
dBm
-51.1
F to E, D to C
Total Pedestal Attenuations: Cables (L-Band cables) + Rotary Joint + Splitter
dB
-14
C
Derived Output Level Rx from Pedestal
dBm
-65.1
G
Rx C-Band Frequency
MHz
11200
LNB LO Frequency (Inverted)
MHz
10000
Rx L Band Frequency
MHz
1200
Which LMR Cable Type ? (400 or 600)
600
C to B
ADE to BDE LMR Cable length
Meter
50.0
C to B
Derived Cable Attenuation (according to length and LMR Type 400 or 600)
dB
-4.8
BDMx Tx Attenuation Selector (0dB or -8dB)
dB
0
ADMx/BDMx Total Gain (Rx path)
dB
30.0
Standard CCU Losses
dB
-1.0
Derived Total ADE to BDE Gain/Loss (according to length) with Standard CCU
dB
10.2
A
Derived L-Band (Rx) Input to Modem with Standard CCU
dBm
-40.9
OceanTRx4 -Total Rx level Budget (L-Band from LNB to Modem)
