Intelsat 1002 + measuring equipment!

E

eng. m. neif

Member
My Satellite Setup
Lawrence
My Location
Bristol
Dear all,

Can anybody explain to me step by step how to do a couple of measurments on Intelsat 1002 spot 1?

1) Using Hewlett Packard E4403B Spectrum Analyzer, how can i perform a beacon search of Intelsat 1002 spot 1 and perform a peak search?

2) How to measure the cross-pol in Intelsat 1002 spot 2 using the same Spectrum analyzer? I need a bit of information on this one because I am not familiar with cross-pol.

3) Last one, How to measure the downlink EIRP using the same Spectrum Analyzer.

Any help on any question is much much appreciated.

Thank you in advance.

M. Neif.
 
eng. m. neif said:
Dear all,

Can anybody explain to me step by step how to do a couple of measurments on Intelsat 1002 spot 1?

1) Using Hewlett Packard E4403B Spectrum Analyzer, how can i perform a beacon search of Intelsat 1002 spot 1 and perform a peak search?

2) How to measure the cross-pol in Intelsat 1002 spot 2 using the same Spectrum analyzer? I need a bit of information on this one because I am not familiar with cross-pol.

3) Last one, How to measure the downlink EIRP using the same Spectrum Analyzer.

Any help on any question is much much appreciated.

Thank you in advance.

M. Neif.
Click to expand...

It's highly unlikely that any members of this forum have a professional instrument such as that.

Is there nothing in the handbook that can help you?

A spectrum analyser specifically made for satellite testing would be better suited for those measurements.

Llew
 
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!
 
Llew said:
It's highly unlikely that any members of this forum have a professional instrument such as that.

Is there nothing in the handbook that can help you?

A spectrum analyser specifically made for satellite testing would be better suited for those measurements.

Llew
Click to expand...


~The handbook wont tell how to do measurments, it will only tell how to operate the analyzer.

I wanted to know how to measure using the analyzer. in fact it could be any spectrum analyzer, not that one in particular.

thanks
 
Low Profile said:
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!
Click to expand...




Thanks a lot for your help, it definitely helps.

So questions 2 and 3 are sorted! What about the beacon. I know that every satellite has a beacon so that it can be identified. Is there any way that you could tell me how to perform this search? I knew from an old friend of mine but I kind of forgoten how its done.

Thanks again for your help
 
Further reading, might be of some interest _http://www.satsig.net/spectrum-analyser.htm
 
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