[Shark Bait (Stu)]

This thread has inspired me to fit a fan to the underside of my primary mirror. I have set it up to blow onto the pyrex surface. The SW sales pitch claims that a cooling fan isn't required for pyrex but a number of threads on this topic has convinced me to see for myself.

The wires are a little untidy at the moment. I will tidy them up when I have had a chance to confirm that it is worth keeping.

This unit was purchased from a local computer store and is running off my 12V portable power supply. All components were picked up for just under $20.