How to Find Carrier

i want to know how we can fine the carrier on spectrum analyzer , whats thing are required for finding carrier mean LO , IF ...?

Please explain if any one knows..

set the peak search in the desired frequency range
Then reduce the BW and set the marker to center frequency.
check the peak is not changed if changed then repeat the same.

Set the centre frequency of the spectrum analyzer into your desired frequency, press trace button on the front panel menu. you will get a required frequency with some other frequencies, Use peak search marker. Then you get the required carrier freuquency.