Help-Tube swapping/crt reference (sencore) differences--explain?
 

I'm about to do some more swapping of tubes in some basic 1980's arcade
monitors. I have read up about all the success people have with tube
swapping, and have even done them myself (but with an identical part number
tube) However, I have some questions regarding some differences I see on
reference material (e.g. from Sencore's website) on the tubes I'm planning
to swap, as I have lots from donor TV's ready and waiting to replace old
burned in ones!


First,, yes, I have checked the yoke resistance and deflection angle
(19V90's) and pinouts and socket type and mounting ears/etc.. So I know
everything matches... up to that point. However I have questions on what
these things mean literally (and practically) from Sencore's reference
materials.

Original tube lists "CRT Bias" as 132V, 68V or D for their 3 systems. Why
the differences? Isn't a voltage a voltage and the same? What are these
three "CR7000/CR70/CR31" system differences they refer to?

Also, the original tube lists KVoltage of 125, Anode of 30 and Focus of
5000/6000

Just one of the replacement tubes I want to use lists:
CRT Bias of: 116V, 68V, D
KVolt: 100, Anode:25, Focus 7000
Everything else (pinouts,...) are identical.

My questions a
1) Do I need to worry about these differences or can this ALL be compensated
for by adjusting (increasing or decreasing) the SCREEN, FOCUS and/or
cutoffs/drive/bias/brightness controls, or is there some significant problem
or safety issue about the differences in ratings? What about ratings not
listed (sometimes Focus, Anode or KVolt isn't listed)?

2) If this is an issue, what HAS to be the same and what can vary?

Lots of people have reported using different tubes from salvaged TV's with
success, and I can't believe they are all matching all these parameters
100%. Also there is a web site selling new chassis that only needs to know
the # of pins and the yoke resistance from your donor tube to sell you a new
chassis, so to me, that means, all the rest does NOT matter, even in an old
(1982) chassis?

I guess this is mainly a question in reading and understanding the ratings
in the reference material from an expert who knows.

Thanks in advance!