View Full Version : 2nd Anode

01-10-2012, 08:08 AM
Why is the HV connector of a CRT called the "Second Anode" Whats the first?
Isn't everything before that a grid untill you get back to the cathode?
Sounds like a misnomer, perhaps came about after the anode was put on the bell of the glass instead of at the scocket. Any thoughts?

Electronic M
01-10-2012, 12:11 PM
I guess that when, in HV focus CRTs, the second anode voltage is lost that the focus "grid" becomes the default anode.....Which might explain the term.

01-15-2012, 09:54 PM
I can find references in which all the elements between the cathode and final anode are called grids. Also, notes to the effect that there were some electron gun designs using a low voltage on the focus electrode and other designs using a high voltage.

So, I could speculate that when the high voltage focus electrode was introduced, someone called it an anode becuse of its positive voltage, and then it necessarily became the first anode; but the references I have do not make it clear.

Edit: note also the term "ultor" applied to the final anode.

01-20-2012, 06:55 AM
I always thought "ultor" was a neat name, sounds so much more outer space and scary and to stay away from or you'll get burned, so I guess the name is a good one.