Last Post: March 26:
I was watching one of my favorite YT producers at:
And remembered how surprised one of my co-workers was when I told him to leave our $55k Anritsu WLAN tester powered-on for half an hour, before starting tests with it. He couldn't believe it would require ANY warm up period - despite the fact that the users manual stated the same thing.
Although the YT video above concerns electron tube gear, and the Anritsu is solid state, every device running "at frequency" requires some amount of a warm up time, before it stabilizes. Some may stabilize faster than others, but if in doubt as to the duration, I recommend a minimum of 45 minutes.
Don't let your work get called into question because you didn't follow the proper procedures.