Quote:
Originally Posted by ed857
Hi all
I have a Philco with a weak 21YP4 CRT. I also have a NOS 21EP4B rebuild.
Will the 21EP4B sub for the 21YP4? The bulbs sure look the same.
Thanks,
Ed  |
The 21EP4 CRT is a magnetically focused, cylindrically faced CRT. The 21YP4 is an electrostaticly focused, spherically faced CRT. To use the 21E as a sub, a magnetic focalizer, would have to be fitted, but the CRT face would not match the mask opening.
