spectrum analiser has built in sats and transponders just like a receiver, but has a screen combination, for the graph or picture view.
if you have set a receiver for correct sat to correct transponder, then dish and lnb to correct position, then u can use the analiser, the fact is you have to know what you are looking for and what you want to see on screen in graph form. where high peak will mean youve got the sat you are looking for on the set transponder or freq.
theones i know are PROMAX PRX- MC377 and PRX Prolink 3 -PRX-PROLINK3+
google and read about it.