Michael, doubling power results in a 3 dB signal increase. Most of the formulas
you need for the kinds of things you're wanting to know about are in the General
Class manual but more complex formulas for more complex issues can be found in
the Extra manual.
Tom
Tom Brennan KD5VIJ, CCC-A/SLP R/D - AU
web page http://titan.sfasu.edu/~g_brennantg/sonicpage.html