> On Jun 18, 2021, at 1:50 PM, Adrian Godwin <[email protected]> wrote: > > What's this device ? It's more like a CRT than a VFD but is it really a magic > eye ? > > 3 grids (or perhaps 2 grids and a shoot-through anode) seems too complicated > for just a lamp. > > https://www.ebay.co.uk/itm/203331148618 > <https://www.ebay.co.uk/itm/203331148618>
It's a deflection-less CRT. They have red, green, or blue phosphors. Three of them formed a color triad that made up each pixel in a stadium sized video display. The seller says "Indicator can adjust size of DOT, depends on modulation and 1st anode voltage". This would be how the brightness was controlled. Note that the anode voltage is 6kV and the tube requires a special socket. If I weren't so nervous about working around 6kV I'd snag a few. I haven't been watching closely but it seems to me that the current prices are actually a bit lower than when I first saw them years ago and the sockets are more readily available. This my be because of the power supply requirements and/or the fact that three of them wouldn't really do anything interesting. I'd be interested to know the resolution and dimensions of the display they were used for and how they cooled it. A small monochrome dot matrix display might be within reach of mere mortals who like a challenge. At 30mm in diameter 16 x 16 would be about half a meter square. The filament supply would only be 25.6A at 6.3V RMS. I'm not sure as to what the shipping from Ukraine would be. A reproduction Jumbotron would be a REALLY interesting project. Anyone? Terry Bowman, KA4HJH "The Mac Doctor" "If only you could see what I've seen with your eyes."—Roy Batty, Blade Runner -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/6927F498-2328-42AF-A5FB-2E9F10D08455%40gmail.com.
