Quote:
Originally Posted by kx250rider
I remember reading someplace, that a second letter in the sequence (in CRTs following bottle diameter) meant it was a better design tube. (i.e. 21YP4 vs. 21FEP4, etc)
So the string for a 21AXP22A would be:
21 ____________ AX________________________P22___________A
Bottle size_______Tube model Type_____________Phosphor type__"A" = aluminized
Charles
|
I knew that the "A" often referred to the aluminized bell inside the B&W CRTs, but didn't think that's what it meant for color CRTs, so I just looked it up.
The data sheets indicate the difference in the 21AXP22 and 21AXP22A is the addition of a high resistance coating inside the neck of the tube to eliminate the need for the external resistor between the CRT and the anode power supply. A high-resistance coating certainly wouldn't be made with aluminum.
http://pdf.datasheetarchive.com/inde...s-00173622.pdf
I'm also not sure the first part of what you're trying to say in your post is either clear or correct.
.