![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEglHCEReQnnPPgwfhdfE5-DpuE1_NZAH5oQBSr_a17uUSkfiiGnWbUZnV6X9bjUyYRvL7yYuaW4wRv3A5cAmGtHWOZeZ746wYXzTfl3y8YnxDLsfad4gWx3tJEMUSz_Nqh9Xtv5dGV_Naa1/s200/20170517_233450.jpg)
At the Marzagla rally I spotted a small box with a 7-segment symbol and "Nixie", all hand drawn/written. Inside there were three small 9-digit VFD's looking NOS. Five € for the three.
The display looked like the Russian IV-18 and IV-21, with all pins on one side, but they have no external markings and one extra digit. So they are not an IV-21. To simplify things these tubes had an insulator slipped over filament wires: that left [9 + (7+1) =] 17 more wires to idenfity (9 digits, 7 segments, 1 decimal point).
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj1ACW8oKQkcCXVe6ZQHKfHr6Ll3568a1n95k9qkeIg8qKzHcxcYbjqK3s956vkIn2z6Bkb3hj4mfj5KLl5Yka0mV7H6wVizDfyAq9smOyAw_TVaF2O76XCBeahZoS5VdzLcGj7FeuXf54G/s320/20170517_233528.jpg) |
Back side. No markings! |
The visual area is about 3.5 cm, and the whole tube is about 6.5 cm long. I can make a desktop clock/display since you won't be able to read at a distance.0
Since the filament was already identified, I began from it. I started at about 1Vdc and raised it in partial darkness in order to observe if the filament would start to glow (not good, sign of too much current). I settled at 1.5V and started looking for segments and digits. A good news is that it glows even at 12 V, so I will have not to worry of having and dealing with a higher voltage as most VFDs require (30 V, some even more).
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh_iyqxmYxR6W-7sB0EfVq5bhCSgytZNbzwjhMkfG-QWvjvVkkEyXIVyTLZoNgz5OaSWwUblXYE4l4s4CwZI9vOrAtKsPMCIwQCPxEqFCkxqJ9nGiFEHIefWYTmBTM_1wVrPIVjpzrkQXgL/s320/20170517_235401.jpg) |
Octopus! |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjD6Pp4leGn7Se1D-aAetdNBk_JWgM5YTswUDPvKHzQgKsDJjJx7luWMx9nSgT10nCHkERAK__jbSNCcxgpRlZQtXn3xdF33X6ZLE76YIvTG6JYWcJUxheUZYQZOMiGpiZjETHdIhD0nXJs/s200/20170517_235941.jpg) |
Spreading the wires. |
Luckily grid pins are on one side and segments on the other. Not willing to design a PCB for this display I took advantage of the long leads and build a simple adapter on veroboard. I will chop off the extra board under the display and let it hang out of some sort of vertical structure .... when I will be done with all the electronics involved.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjzHuoTaXD-U-WE4uVeANZs4erava6OLQO3O7GkWcH6dGmSymiDgtr4HRQjY0oIZ02VxKkwP0Lt_UuuKVwYYiQCCHLF1W3k0nsx_SCCa15YKUMESt6FBn6aKiJ9lwOLoNkhJPRwIni1On8k/s320/20170522_224150.jpg) |
A not-so-quick and dirty adapter. |