Hey RICHS. I understand EXACTLY how the device works and I can derive the equations from scratch that demonstrate the impedance transformation and did so in an earlier post. In addition, the impedance transformation is derived independently in numerous references that I sited as well as an article that KG7SWP cited in an earlier post. It's really not difficult at all though. The transistors see twice the current that the final transformer primary winding sees and half the voltage swing that the final transformer primary sees during their active cycle. Half the voltage, twice the current, that is a 1:4 impedance transformation. This is also very clearly stated in several of the references that I provided wherein the author clearly states that the bifilar feed coil in the push pull output being designed provides a 1:4 impedance transformation. In addition, there is tons of literature out there that already fully explains how "simple transmission line transformers provide a 4:1 impedance change". Where have you been? I would like to see YOU produce a true technical analysis and derivation that shows the device to produce choking action or keeping RF out of the DC supply. THAT would be interesting. You're already involved dude! You're floating out indefensible gibberish, I'm calling you on it, too late to run and hide. Let's see you put that 8 years of college to work and defend some of this with actual technical analysis instead of throwing out platitudes and important sounding words like "phased". Come on, bring it!