18 Jan
2010
18 Jan
'10
12:16 p.m.
On 17 Jan 2010 at 17:46, William Donzelli wrote:
Are those similar to the DM160s used in Europe? Those are sub-minature
triodes (about 1" long and 1/4" in diameter with 4 connections -- the 2
ends of the (1V or so) filament, control grid, and fluorescent anode.
You need about 24V on the anod to get it to glow, and a -3V grid bias
will curt the valve off and stop it glowing. They were used as indicators
on computer/paper tape equipment in the 1960s (and then LEDs came and
sp[oilt the fun!). I have mever tried cross-coupling a pair to make a
flip-flop, now that would be an interesting project....
-tony
Clearly 6977 indicator tubes are used for the
blinkenlights.
Rectangular slots in the panel? Otherwise, your eyes are better than
mine.
Hmmm, one could build a whole computer using 6977s as the active
device. Wouild make a heckuva glow-in-the-dark display...
Cheers,
Chuck