the next step would be to get rid of linear amplification. It’s an over 90 year old technique that was originally all but necessary to amplify SSB. New methods employing saturated switching amplification would be much more efficient (90% or more) while having much lower IMD (-80 db or more) and produce a lot less heat all while maintaining 12 volt operation and eliminating the TX D/A converter. Probably some form of RFPWM but there are other options.
The wireless data people are all over these technologies as power efficiency in that area is an extreme requirement but because of the frequencies involved this can be a tradeoff against suppressing switching byproducts and require complicated bandpass filters. For HF Ham radio applications only a fairly simple low pass filter would be necessary. A thought for a K4S or K5? Sent from my iPad > On Nov 4, 2019, at 6:21 PM, Wayne Burdick <n...@elecraft.com> wrote: > > Hi all, > > We've chosen to have the K4 continue to be a field-capable radio, inheriting > the characteristics that have always made the K3/K3S (and the K2 before it) > the preferred rig for FD, DXpeditions, and multi-transmitter stations. Thanks > to a lightweight but rigid internal aluminum frame, the K4 weighs only > slightly more than the K3/K3S, while integrating in a large LCD in a way that > increases width by less than 3 inches. (Unlike on many rigs, our front panel > includes separate optical encoders for VFO A, VFO B, and RIT/XIT.) > > Current drain of the K4 is half that of most competing high-performance > desktop radios, so it can be used with emergency power. At home, use 13.8 to > 14.2 V for lowest IMD. In the field, the K3 (and now, the K4) automatically > scales maximum power output based on supply voltage, and can run down to as > low as 11 V. > > 73, > Wayne > N6KR > > >> On Nov 4, 2019, at 3:07 PM, Buck <radiok...@gmail.com> wrote: >> >> Perhaps the K4 should have been a 40V radio and the K3S remain as the 12V >> "portable" or "field" version. >> >> k4ia, Buck >> K3# 101 >> Honor Roll 8B DXCC >> EasyWayHamBooks.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 w...@w2xj.net > ______________________________________________________________ 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
