Just wow.... https://www.ebay.com/itm/274654341777
107 views
Skip to first unread message
Michail Wilson
Jan 25, 2021, 9:58:23 PM1/25/21
to neoni...@googlegroups.com
Nicholas Stock
Jan 25, 2021, 10:16:13 PM1/25/21
to neoni...@googlegroups.com
--
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 neonixie-l+...@googlegroups.com.
To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/MW2PR0102MB343580CEA8EACA0D7B37699B82BC9%40MW2PR0102MB3435.prod.exchangelabs.com.
gregebert
Jan 26, 2021, 12:30:49 AM1/26/21
to neonixie-l
Interesting notes from the seller, mentions slight ghosting. The clock-chip does the multiplexing, though it was probably intended for LEDs which dont have requirements for blanking time.
The PC board is typical of consumer products: single-sided phenolic. Even do-it-yourself PCB kits used epoxy boards.
Downright scary how much the 7971's are selling for...
jf03...@gmail.com
Jan 26, 2021, 11:48:07 AM1/26/21
to neonixie-l
On Monday, January 25, 2021 at 9:30:49 PM UTC-8 gregebert wrote:
Interesting notes from the seller, mentions slight ghosting. The clock-chip does the multiplexing, though it was probably intended for LEDs which dont have requirements for blanking time.
The chip is a National Semiconductors MM5314. I have a Panaplex evaluation kit that used this chip, and I do not remember seeing any ghosting (and the Panaplex and B7971 were both made by Burroughs).
My B7971 clocks used the Cal-Tex CT7001 which multiplexes with 120µs ON followed by 40µs OFF. You can see ghosting, even on some of the segments that were not wired (floating). Must be due to some parasitic capacitance somewhere.
Downright scary how much the 7971's are selling for...
I still have a bunch of spares (none of my 7971's died of natural causes, so I have lots). I am rooting for the price to go up to help fund my retirement.
Nick Andrews
Jan 26, 2021, 12:09:50 PM1/26/21
to neoni...@googlegroups.com
Hmm, maybe you should send some of those spares to me for safe keeping then, in case of natural disaster there...
--
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 neonixie-l+...@googlegroups.com.
To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/04fbff29-dca0-477e-9c8b-4abfdd53bb5bn%40googlegroups.com.
Reply all
Reply to author
Forward
0 new messages