The red arrow points to that metal rod going all across the tube. That’s on pin 3, which is the one marked with that “conductive layer”. It’s on the back, maybe it’s what they meant and I may have translated it wrong.
I would think that this pin has to be the positive side of the filament, so that the negative part is the one in front of the segments which might result in a bit more brightness.
What do you think?
I add here the link to the site with a lot of datasheets, a couple of which have been translated by me www.spark-tube.com/datasheets/
Maybe you'll find it useful. Mine are the IV-1, IV-3, IV-6, IV-12
Last edit: 5 months 1 week ago by 64bittz. Reason: Added link
Not sure what to make of that. In my admittedly rather limited experience with vacuum tubes, I don't think that "extension of the cathode" (for lack of a better term) is going to be emitting any electrons. As far as I know, and I could be wrong, heat and a thermionic coating are needed for a cathode to behave as a cathode, i.e. emit electrons.
Also, I tried translating that text from the data sheet "катод, проводящий слой на внутренней поверхности баллона " using Google and then Apple. No groundbreaking results: Google gave me "cathode, conductive layer on the inner surface of the balloon" and Apple said "cathode conducting a layer on the inner surface of the cylinder".
Any native Russian speakers reading here that can clear this up? I suspect there's a disconnect between idiom and literal translation...
Look into it later when the dust is clearing off the crater.
Yeah that rod there is not emitting anything, it's just connecting top to bottom, but there might me some voltage drop on that too, that's what I meant.
I have a friend that is native russian and I made him check the translation some months ago, he didn't spot this one as wrong so I have no idea what else to think. He's not an electrical person so maybe he thought it made sense to us, but in reality it doesn't. Only a native russian speaker that is well familiar with the topic might be helpful.
This part is a complete mistery to me since I began reading these datasheets
I've been watching this thread with interest, hoping just to learn more about VFD tubes. What comes to my mind for the purpose of that "bonding strap", for lack of anything better to call it, is that since a cathode connection is negatively charged it will repel electrons. It could have something to do with keeping the electrons focused on the anodes.