>Then it came to my mind that joining the two articles seems almost >ideal: A class AB/F amp with ARF1500 MOSFETs would be free of >hotspotting, because in the AB class it would run at very low >voltage (20 or 30V at most) and above that it would be running class >F. At the same time, the reduced dissipation goes a long way in >helping with the cooling problem. > The added complexity of the modulated switching power >supply would be rewarded by the high efficiency. And the whole thing >would still be small, lightweight and reasonably cheap. Any takers, >out there? >I would be really interested in knowing what you think of this. Am I >a crazy dreamer (from reading too much 73) and just loosing my time, >or do you see merits to this approach? Or do I come late, and >someone has already done it? >Manfred, XQ2FOD. Hi Manfred, There is a small problem, often overlooked, in the envelope restored Class D/E/F "linear" scheme. The group delay through the modulating path must be equal to the RF path delay for the system to exhibit low distortion. This can be realized over a narrowband but, when a wideband system is considered it may prove to be easier to build an entire envelope restored transmitter than to construct a standalone linear. 73 & Welcome to the group! Marv WC6W http://wc6w.50webs.com/ * ________________________________________________________________________ FREE for 30 Days! - Holiday eCards from AmericanGreetings.com http://track.juno.com/s/lc?s=197335&u=http://www.americangreetings.com/index.pd?c=uol5637