Tvheadend

hi
can u give me a hint how to measure the signal quality of the sat signal?
the built in doesnt work well with my hardware. which is tevii s471 and asus e45m1-m pro or whatever.
is there maybe an "external" application for that? i dont want to plug in the dreambox only to finetune the signal with the lnb&dish.
thanks
cheers
rigo