Nice description, Aball.
All I can add is that that fluctuation can sometimes be related to a tube aging, in which case it needs to be adjusted accordingly. Also, new tubes often go through a lot of change in the first 25 or so hours, so it's wise to do it at installation, then again soon afterwards.
All I can add is that that fluctuation can sometimes be related to a tube aging, in which case it needs to be adjusted accordingly. Also, new tubes often go through a lot of change in the first 25 or so hours, so it's wise to do it at installation, then again soon afterwards.