
Originally Posted by
Low Profile
It depends what you want really to measure, how accurate you want to be and why.
For example you could use a quattro LNB (so no switching is required) and couple 18V in order to power the Vertical Low LNB. If you want to be accurate then you would have to quantify the coupler loss, coax loss, lnb gain, dish gain, free space loss and make sure that the Spectrum Analyser is matched (as well as quantifying the SA calibration).
As all of the spot 1 beams are Vertical and Low then it would follow that the IF signal from the LNB would be from 1237Mhz to 1925Mhz (10987 to 11675), so this should be your (full) scan range. You would probably have to reduce the scan range to identify each transponder, and you I would be surprised if the measurements are linear at all frequencies.
To do cross polar measurements, the easiest way would be to store a scan in memory (if possible), then simply rotate the LNB 90 degrees and measure the difference. This would of course give you a system cross polar value (as opposed to a transmitter value)!
The EIRP can be calculated by the measured value minus the system gain, but I would expect the calculated value to be roughly consistent with the manufacturers specifications: help://www.lyngsat-maps.com/maps/intel1002_spot1.html
I've probably missed a few points - or perhaps misunderstood your requirement, so good luck!
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