I'm brand new here. I just happened to stumble onto the site. Years ago I taught Radar Electronics for three years in the AF and I was an ATC Radar Technician for 22 years. The reason I say all this is : I have a General class Ham Radio license and want to update to Extra class.The question pool is FULL of electronics formula and theory questions (phase angle,polar and rectangular coordinates,logrithms, etc)-- the reactance & time constant math and the "easy" stuff I pretty much remember, but a lot of the "hard" stuff I've forgotten . (SORRY TO GET SO WORDY). Does anyone know a good electronics theory book (above basics) that would be good to study to help me get some of this knowlege back. I'd appreciate any info anyone can offer. Thank you . Uncle Levi