I haven't been inactive in February 2022, I've just not updated the blog.
I have been playing extensively [time permitting] with WE 439A/6167 dekatrons, trying to get them spin reliably, which I haven't succeeded yet. In return I found out that they did contain a bit of radioactive material which is not indicated on the box nor on the glass. I am still unsure which isotope they used, since it is still pretty active after 72 years.
After receiving a small batch of IV-22 VFD displays from Ukraine and planning a clock, today I re-checked the Bad IV-27M bought in 2016 and, with the correct datasheet, I found the filament on pins 4+5 and it does light up properly. Hooray! By the way, the filament runs at 3V 160mA and segments light up with 12V.
