Ted - I had a similar experience. Be sure you are using a stereo plug in the key jack. The QCX requires one. If you put in a mono plug it just keys the transmitter, and the tone you hear may be the side tone.
After my build I heard a tone, so I took my time to carefully do the alignment steps. That ruined my finals because they were on transmit for so long, To make sure, when you're doing alignment just unplug the key from the jack and use the little onboard key.
I had to replace several transistors.
That may not be your problem, but it is one to avoid.
72 and good luck