Can someone tell me what's the difference between 25GP22 and 25AP/XP22?
Thank you.

I don't have time now to check the datasheet, but they should interchange.

Part of a large group of CRT ## that all got replaced by
the 25XP22 / 25AP22. Differences can be face glass color, the MFG or
other small things. Look at the CRT label for the EIA number. It tells
who actually built it & if its been changed. Sub books & data are
on the internet.

Zeno

I remember they had a lighter faceplate than the AP/XP tubes. That type was mostly found in Zenith sets.