SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I would like to adjust the spray range of a Hunter PGP Sprinkler Head. It is now set for a 180 degree fan spray range, and I would like to change it to a 90 degree range. Do I have to change the head, or can it change the settings on the head I have now. I see an adjustment screw over the hole where the water sprays out of the head, and I assume it is for adjusting the length of the spray away from the spray head. I also see another hole in the top of the spray head, it may be a hole for a hex key. Maybe this is a way to control the degree of the "fan" the water will spray from left to right and back again.