Satellite Internet Forum

[inquisative]

When you go looking for a specific satellite using the analyser, why do you need to input a frequency into the analyser in the 950 - 2150 MHz range?

I install satellite broadband for a number of operators who use different satellites. They give me a specific frequency in the 950-2150MHz range to input before searching for the satellite.

The thing that confuses me is this - I know all the spectrum plots for the various carriers. Without putting any frequency into the spectrum analyzer I can tell that I am on the right carrier, so, what is the purpose of inputing the 950-2150MHz frequency?

Any help appreciated.

[superhet72]

In essence a spectrum analyzer is a form of radio receiver with a display at the output indicating the output level. The receiver is tuned or scanned over the required range and the filters are chosen to accept the required signal bandwidth.

The spectrum analyser uses the superhet principle used in many radio receivers as the underlying principle on which its operation depends. The superhet principle uses a mixer and in addition to a locally generated or local oscillator to translate the frequency.

The mixing principle used in the spectrum analyzer operates in exactly the same manner as it does for a superhet radio. The signal entering the front end is translated to another frequency, typically lower in frequency. Using a fixed frequency filter in the intermediate frequency section of the equipment enables high performance filters to be used, and the analyzer or receiver input frequency can be changed by altering the frequency of the local oscillator signal entering the mixer. Although the basic concept of the spectrum analyzer is exactly the same as the superhet radio, the particular implementation differs slightly to enable it to perform is function as a spectrum analyzer.