hello, i got a pro-57 that has no reception at all. just making noise when turn lower the squelch switch. but all other function does appear to be ok. i was able to enter all the freq using the keypad but there is no reception whatsoever. the antenna is orginial telescope antenna which i tried on another scanner of mine work fine. i notice the manual on radioshack support page mention that this is a line of sight scanner. is it really require a good antenna for this to work or it has other problems?