I just bought a lot of miscellaneous stove and lantern parts, and two Radius 433 Special Silent burners were part of it. I had naively assumed it would fit on any silent burner, a quick Google directed me to the disappointing truth (thanks to Bernie Dawg for so clearly answering this question and providing additional details). My first thought was that I needed to braze a smaller tube to an existing silent burner, something I don't yet have the skills to do. Coincidentally, @presscall posted that exact fettle, expertly executed, just a few days later. Seeing it pulled off was encouraging, but I didn't have the patience for that. Then I remembered that my Shinabro Royal 400 C has a silent burner with no tube fixed to it (the tube is part of the inner silent cap). I figured I could add some kind of flange to a tube of the correct size so it would sit atop the burner, accommodating the UFO cap. But an even simpler option than adding a flange would be to have the tube extend all the way down to the jet like the air restictor tube used on a 111T when burning alcohol. So it was decided, I wouldn't be burning kerosene for this experiment. I've made my own restrictor tube for a silent burner before (again, thanks to Bernie Dawg for this video), this should work if I make the tube long enough to extend halfway up into the burner cap. Referring to the burner cross-section in John's post, I cut the tube to length and drilled some air holes. I used 14mm OD brass tubing, it fits loosely in the burner, and only a bit more snugly in the cap. I considered changing the kerosene jet to a 0.5mm Spirit jet, but reading that @presscall had overfuelling issues with the regular kerosene jet, I predicted that the same issue may arise and left original kerosene jet in for the first attempt. Primed with Methyl hydrate, tank generously pressurized. To my delight, it worked perfectly. The heat radiated out very widely, with no hot spot in the middle. I reassembled the stove while it was burning and made some lunch. Scrambled eggs with pickled jalapeños in a flour tortilla. The rest of the stove, including the fuel tank got fairly hot. It seemed like having the flames directed down at the burner dish cause more thermal energy to be absorbed by the burner and transfer to the rest of stove. On a low simmer I removed the tube and tried it with the roarer flame spreader. I was not surprised when it wouldn't even light, given how much air was mixing with the alcohol vapor. The restrictor tube fit snugly inside the tube of the inner cap of the silent burner, so I tried lighting that as well. It burned, but not well. Probably need to change the jet to make that combination work. I am really happy with this set up, and I think one of the two UFO burners has a permanent home inside the case of my Shinabro. I still want to get the other one to work burning kerosene, but this successful experiment was truly uplifting. Anders
