After fussing around with a defective bird and finally getting a new one, I did a cold calibration by putting it outside for 20 minutes in 35 degree weather without the battery like many people here advised. I cannot tell you how much faster my P3A warms up. It is ready to go like johnny on the spot. Bang and it is clear to go. Amazing. Listen to the elders, they know their stuff. Thanks to you guys.