Very interesting, thanks Jeff.
From: [email protected] <[email protected]> On Behalf Of Jeff Walton Sent: Thursday, 29 July 2021 6:37 AM To: [email protected] Subject: RE: [neonixie-l] Red Coated Tubes The color filter is all about contrast. This was often in addition to a customer applied color filter. Nixies were versatile with filters. I can tell you from experience working for semiconductor companies manufacturing LEDs that a lot of testing to come up with a good color for the face of the display was to promote contrast and hide the unlit segments. In the case of red LEDs, most early displays used a black painted face and other LED colors eventually used a grey display face that mimicked the color of the unlit segments. Filters by the end user were almost always used. The segments in a seven or 15 segment LED display are an epoxy-like material that is infused with microscopic glass beads that provide the excellent light dispersion in the segment with no hot-spots. 3M was involved with the original materials that were used when they discovered the glass bead trick in the late 1960s. Prior to using the glass beads, LED displays were not so good with lots of hot spots and dark areas. The early military stuff went with direct viewing LED displays, which were up to 10 LED’s per segment. Those displays were almost always red and many were encapsulated by a soft plastic that would not shear the bond wires over temp extremes. These replace numitron displays that were the early choice for mil spec applications. The glass beads, improvement in brightness and discovery of methods to produce different colors with high brightness were the death of nixie tubes and numitrons for most displays and the advancements were rapid in the 70’s and they’ve only improved since. Jeff From: [email protected] <mailto:[email protected]> On Behalf Of Mac Doktor Sent: Wednesday, July 28, 2021 1:28 PM To: 'John Rehwinkel' via neonixie-l <[email protected] <mailto:[email protected]> > Subject: Re: [neonixie-l] Red Coated Tubes On Jul 27, 2021, at 11:20 PM, Audrey <[email protected] <mailto:[email protected]> > wrote: No I dont think so, from what I've been told it helps with visibility Useful when a colored filter isn't possible or practical. I read something recently about hiding the blue glow as well. I've wondered about that. Terry Bowman, KA4HJH "The Mac Doctor" https://www.astarcloseup.com “...the book said something astonishing, a very big thought. The stars, it said, were suns but very far away. The Sun was a star but close up.”—Carl Sagan, "The Backbone Of Night", Cosmos, 1980 -- 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] <mailto:[email protected]> . To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/A6A5D8D4-0F50-430B-AB4D-E3D25774577A%40gmail.com <https://groups.google.com/d/msgid/neonixie-l/A6A5D8D4-0F50-430B-AB4D-E3D25774577A%40gmail.com?utm_medium=email&utm_source=footer> . -- 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] <mailto:[email protected]> . To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/008201d783f4%2492b2cfd0%24b8186f70%24%40gmail.com <https://groups.google.com/d/msgid/neonixie-l/008201d783f4%2492b2cfd0%24b8186f70%24%40gmail.com?utm_medium=email&utm_source=footer> . -- 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/080c01d7842e%24f0f97000%24d2ec5000%24%40gmail.com.
