Thanks, Wayne. I'm glad to hear this isn't typical. I sent a report to tech support with all the details. I'll call later next week, as I'll be out of town with the KX2 until Thursday.
73, Scott K9MA ---------- Scott Ellington --- via iPad > On Jun 9, 2018, at 8:28 PM, Wayne Burdick <n...@elecraft.com> wrote: > > Scott, > > I’m not sure how you’re doing the test, but this is definitely not > characteristic. > > We test every amp for IMD, and we see an average of about -35 dBc (3rd order, > ARRL method) across all bands. This is state of the art for an LDMOS deign > running class AB. Other SS amps using similar designs have have similar > performance. > > Any amp’s gain levels off as it approaches peak power (ie, is slightly in > compression). But it should not be flat-topping unless it’s over driven or is > starved for supply current/voltage. > > Finally, both the transceiver and amp will vary from band to band somewhat in > IMD. You might for example see -40 dBc on one, but in the low 30’s on the > other, on a given band. Again, this is typical of all such SS rigs/amps > except those running class A or using closed-loop feedback (predistortion). > > Please call Monday to discuss your test method with one of our technical > staff. > > 73, > Wayne > N6KR > > > ---- > http://www.elecraft.com > >> On Jun 9, 2018, at 2:21 PM, K9MA <k...@sdellington.us> wrote: >> >> I recently ran a two-tone test and measured CW power gain. (SN1078) It >> doesn't look good. The two-tone waveform shows distinct "flat-topping", and >> the power gain drops 25 percent from 1000 to 1500 Watts. My old 3-500Z >> amplifier is much better. Has anyone measured IMD or linearity, or seen any >> test results? >> >> While I'm primarily a CW operator, I'd be very reluctant to use the >> amplifier on SSB. >> >> 73, >> >> Scott K9MA >> >> -- >> Scott K9MA >> >> k...@sdellington.us >> >> ______________________________________________________________ >> 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 >> Message delivered to n...@elecraft.com ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
