welcome to just answer
I am Rob And I will see if I can dig up a manual for you>
no luck finding a manual
I am not sure what choppy means?
could the tech have knocked a balancing weight off the blower?
No, I do not think this is a balance issue, the fan blade is not wobbling. What I mean by choppy is instead of the airflow sounding smooth, steady and of the same volume, it sounds as if there are varing volumes (pockets of air) or the airflow is oscillating (chugging).
Could this also be caused by interrupted electrical current to the blower, because it sounds as if the blower is cutting in and out.