very interesting info
I had heard the advice to power up the tubes periodically but ignored the reasons
btw and slightly off topic, I'm also a proud owner and user of a Sony DXC-M3AP, a wonderful camera. it recently started to fail after some time in operation, picture from one tube suddenly twisted.
After much probing and ultimately swapping the coil circuits from one tube to another, and revising all the deflection electronics etc, I came to the conclusion that the focusing coil of the green tube assembly failed (short in the middle of the coil?)
I'm not sure if it's a frequent failure and what's the cause, but if you have some spare tube assembly to sell me please contact me
I've been able to capture the moment in which it allegedly fails, in the video below
see how the part of the sensor normally not scanned gets scanned after the coil fails, how bigger gets the FOV after that
https://drive.google.com/file/d/1SJG...ew?usp=sharing
(video download button at the top right part of the google drive preview page)