Used up aired out 16AP4 on eBay
 

A junk CRT on eBay for $99.
Note the white getter and the dark area on the neck.

This tube was probably used up when it was replaced and it went to air sometime in the following fifty years after that.

Edit, I see a 1957 date code on the base cap, it must have been a replacement tube itself.

I sent the seller a note that it was used and bad, we'll see what they say or do.

http://cgi.ebay.com/Vintage-RCA-16AP...item5adffab697

Damn...I need one of those...Been waiting for a reasonable one to show up...

It seems they reacted to your advice.

That CRT looks like a 16GP4. It's too short to be a 16AP4.

Yea thats what I need a 16gp4 or something close that would work...

The box says 16AP4, but then the tube didn't come from that box originally.
It's still bad either way. :yes:

I know you guys know more than me but..
 

the silver getter looks like new silver and not white on my screen. The white stuff all over looks like that odd mold that gets all over electronic stuff. Could the dark areas on the screen be dirt from a smokey house? Could the tube have been saved because it had very low hours judging by the bright red RCA stamp on the black plastic? Maybe pulled from a set with a chassis that was deemed to much to repair? I just hope all will be certain that is a bad tube before it goes to trash because that silver getter looks new to me not white like others say.

I think the filament burned up...you can see the black ring inside the neck.

That isn't the getter, that is brown glass from Ion bombardment, same as you might see on a Regulator tube or a HV rectifier, a sign of high hours.

Here's the getter, quite white from exposure to air.

I appreciate the explanation as I would have thought that tube was good for sure. That bright red RCA stamp on the neck plug had me thinking low hours and the brown spot looked like a silver getter to me in the photo. I have little experience with old B/W and did not realize where the silver getter is supposed to be.