The reason I suggested boosting the cathode voltage was based on my own experience with the A101; apparently I misread the datasheet and thought it needed about 15V, and it didn't work smoothly. After boosting it, it ran much better. At 45 volts, your design has plenty of margin for the A101 and the OG4 based on the datasheets I found online. If the current is correct (400uA), the only other factor you can control is the timing.
Once you have it working smoothly, try reducing your anode voltage to make sure there is some margin in the design, so that as the tube ages it will still work. On Sunday, November 8, 2020 at 2:02:46 PM UTC-8 [email protected] wrote: > Thanks for the tips > > I have an A101 and an OG4 running great on the same circuit - just having > issues getting the 3-guide OG3 running (i'm aware the OG3 needs more > amperage and a different drive circuit and it's got that). Anode to main > cathode voltage is about 225 and Anode to Guides is about 180 so yeah about > 45 volts drop for the guides compared to the main cathode. > > What makes you suggest a slightly higher voltage drop at the cathode > resistors - something about the appearance? > > As for drive, i've taken a fairly simple 4-step approach (I can reverse > the direction and it doesn't stick so i'm happy the drive is working unless > i'm missing anything?) > > It's been running for about 2 hours now and it's improving constantly - > much less sticking each time, so I suspect it's mostly the Dekatron itself > being sticky. I'll leave it overnight and see if this helps. it's probably > also worth noting it only sticks clockwise - if I run it anticlockwise it > spins fine. > > On Sunday, 8 November 2020 at 21:30:44 UTC gregebert wrote: > >> First thing to check is your timing. I use a symmetric 6-phase approach >> where you have overlap on the 3 groups of cathodes. >> Secondly, you might need a bit more voltage-drop at the cathode resistors >> (ie, make them slightly higher value). >> >> I had this problem with my homebrew A101 spinner, and once I had about 30 >> volts across the cathode resistors it continues to run flawlessly after >> nearly 8 years of continuous operation. >> On Sunday, November 8, 2020 at 12:16:54 PM UTC-8 [email protected] >> wrote: >> >>> Hi >>> >>> I'm playing around and familiarising myself with Dekatrons. Have an >>> arduino-interface PCB so running them off Arduino. OG-4 and A101 running >>> nicely but i'm struggling with the Argon 3-guide tubes. >>> >>> Here's a video of what it's doing - it looks like it's driving correctly >>> but it's failing usually at the same pin everytime. But sometimes it's >>> circling nicely. >>> >>> https://photos.app.goo.gl/tznRK8o7DN14wGbX7 >>> >>> Is this a hardware fault ('sticky' pin on the dekatron) or is this a >>> fault in my software to drive it? >>> >>> I know some Dekatrons can be a bit tricky and sticky, if this is just a >>> sticky pin, what's the best way to try and resolve it? If the answer is >>> 'run it for hours' - is it best to run it super fast or slow? >>> >>> Many Thanks >>> >> -- 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/852e2b86-ea4b-4101-935e-cb5e040f28afn%40googlegroups.com.
