Transponder EIRP dBW Number of Transponders (Worst case about 60 on one polarisation) Satellite total EIRP dBW Satellite Position Double click on satellite to open "single satellite view" with lots of details Satellite Position East West equals West Site Position Latitude North South Degminsec Longitude East West Degminsec Azimuth Degrees Elevation Degrees Slant Range Km Atmospheric Loss dB (use 0.2dB) Downlink Frequency Mhz Free Space Path Loss dB Power reaching Antenna dBW Power flux density at earthstation dBW/M^2 Antenna Diameter m Antenna Efficiency % Antenna Gain dBi Feed Loss dB LNB Input VSWR 1: (Probably not needed 1:1 =0 dB loss) LNB input power dBm LNB Gain dB LNB output power dBm LNB 1dB Compression point dBm

 

This calculator calculates total LNB power for all carrieres on one polarisation. 
On a single polarisation it can be "worst case" 60 transponders.30 in lowband and 30 i highband. 
For standard Universal LNB's both highband and lowband must be taken in to consideration. For LNB's with only one local oscillator 
frequency only highband or lowband needs to be taken into consideration.

To avoid intermodulation noise in the LNB as result of saturation it is recommended that the LNB Output power is 7dB lower than the LNB's 1dB 
compression point. A good LNB has a compression point higher than +5dB. 
To find the compression point see the datasheet for your LNB.

LNB's should be designed to work with a total satelite EIRP of 70dBW without being saturated. This is extremly important to avoid LNB saturation 
when new satellites( more power) is added on a orbital position.

20©01-20©15 Jens T. Satre