78% efficiency seems high. But your calculations assume that all the meters are accurate.
KPA500 is rated at 500W in linear mode and is supposed to have an efficiency around 50% at this level. At a higher drive the amp will be less linear but at a higher efficiency. At low power the efficiency increases linearly with output power. If about 50% with 500W then about 62% with 620W. A data sheet for Microsemi 1 KW module shows efficiency curves in Fig 19 at www.freescale.com/files/rf_if/doc/data_sheet/MRFE6VP61K25H.pdf. About 65% efficiency at 700W with IMD3<-40db. Reaching 80% at 1.4 KW and IMD3>-28db. The dissipation is about 370W at 700W level and 350 at the 1.4 KW level. These numbers do not include losses in transformers and filters. Ignacy, NO9E -- View this message in context: http://elecraft.365791.n2.nabble.com/KPA500-efficiency-tp7577015p7577042.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
