I’ve built half a dozen simple fire type units, Jim. From 5 gallon buckets and 20 lb and larger propane tanks. I’ll post a link to the one I use most often built in 2020. It started out as a modified copy of a very successful Don Mannes gasifier he built for his Geo Tracker. Kind of copied from some pictures Eddie Ramos drew about that video from post 276.
I built this.
Still use it now but never got good results with the hearth design so I blocked off everything below the red tank and just installed a regular pipe nozzle in the upper tank section. Also removed the cyclone because it was unnecessary and down graded the filter to just a ammo box filled with course sawdust. Just a simple fire. Works fine for a 600 cc generator engine. I don’t remember if Troy Martz used a water drip on his gasifier but if not you will definitely want one.