Reception trouble shooting is best started at the antenna... This test,
http://forum.tvfool.com/showthread.php?t=13646 is a great place to start, even if you aren't concerned about the question of needing a preamp, the test answers the question of whether the antenna is producing a usable signal.
Regarding the ABC test, what does "If reception is degraded, am amplifier is [B]indicated[B] mean? Not to hijack this thread but it seems pertinent to my own situation. Thought possibly the OP could possibly be confused as to its meaning as well.