Dopplesonde fixed bias

[sinusoids]

Unless I have wired a mistake that I can't find, Dopplesonde bias and everything else is from from TUT5 CH 10 schematic and layout. The only difference is the driver, V1, has both triodes parallel and the filament center tap is biased to the same node as the concertina bias.

I'll edit it. I thought the bio was just for your ref when granting access. Mine has a lot of excess info.