Okay, but sometimes the changeover point is 5 watts instead of 3 -- what's going on in those cases?
Cheers, Julie On Tue, Jan 26, 2021 at 2:32 PM Wayne Burdick <[email protected]> wrote: > There are two windings on the PA output transformer: 1:1 and 1:4. We > select one of these based on power level, battery voltage, and in some > cases, operating mode. > > In the 1:1 setting, the PA drain impedance is 50 ohms, making it more > efficient for at power levels, reducing current drain. > > In the 1:4 setting, the PA drain impedance is 12.5 ohms; the transformer > steps it back up to 50 ohms for the low-pass filters. In this case it's > more efficient at higher power levels, at the expense of higher current > drain. > > Wayne > N6KR > > > > > On Jan 26, 2021, at 11:07 AM, Julia Tuttle <[email protected]> > wrote: > > > > The manual states in a couple spots that the KX3 can transmit more > > power-efficiently when output power is at or below 3 Watts. > > > > Why is this? Is there an (additional?) amplifier stage that is bypassed > at > > these lower power levels? > > > > Thanks, > > > > Julie > > ______________________________________________________________ > > 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 > > Message delivered to [email protected] > > ______________________________________________________________ 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 Message delivered to [email protected]
