Unfortunately the 3rd order IMD of a typical 12 Volt PA is barely acceptable when operating at 100 Watts let alone pushing 120 Watts from a K3. The K3 would output 120 Watts, or 110 Watts in later firmware, and yet is recommended by Elecraft to run 100 Watts max on SSB. Running a K3 at 25 Watts improves the IMD on SSB by around 10 dB. My Acom 1000 amplifier runs the UK limit of 400 Watts with less than 30 Watts drive.
For amplifiers needing 120 Watts of drive you need a higher power transceiver than a K3, at least that way you stand a chance of having a clean signal on SSB. 73 Dave, G4AON K3/100 #80 ---------------------------------- Most 3-500 based amplifiers with 2800 V (no load) on the plates require 120 Watts or so for "legal limit" output. That's about 11 dB gain. Part 97.317(a)(2) limits the maximum gain to 15 dB (approximately 50 W drive for 1500 W out). The extra 10 to 20 watts of drive makes a difference for those who have SB-220, TL-922, AL-82, AL-1300, AL-572, etc. amplifiers. It can mean another 200+ W output. 73, ... Joe, W4TV ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
