Tightening the spring on my Pella retractable screen.

by Claudia
(Ft. Colllins, CO)

I would like to tighten the spring on my Pella retractable screen.
I had the company tighten it a year after installation but it did not hold the
tension. It gets too expensive to have the company come out every year to
tighten the spring. Can you tell me how I can do this?