[Dekatron]

I made a similar Excel sheet but used yours and added my info, however I moved the diagram to a separate sheet to keep the data on another sheet.

When the 6AU5GT arrived to me it was unfortunately damaged, there was a short between G1 and the Cathode. While examining the valve I could see that the cathode had fallen down through the top mica sheet and was tilting to one side. Some hard banging of the valve in my hand moved the cathode to the side enough so that it is almost centered but I couldn't get it to come through the mica sheet at the top.

The measurements in my VCM163 and Roetest V9 shows that the results are in line with Davids and I added them to the Excel-sheet. I made measurements with both Anode voltage set at 200V like in the AVO VDMs and also with 250V like David used. I only made measurements at 250V with the Roetest. With my VCM163 and a grid voltage of -20V I got a Gm of 4.4mA/V @ 46mA Ia with 200V and 4.6mA/V @ 49mA Ia at 250V. The Roetest used a grid voltage of -22.5V and there I got a Gm of 3.9 @ 39mA. I'll add my measurements to Davids sheet when I have some more time and post a scan here.

I will test a bunch of 6CH6/EL821 that are NOS unopened in their Pinnacle boxes and ship to David so that he can send them out to people for further testing. Hopefully I'll be able to include two used 6AU5GTs that show similar results to Davids.