I believe the new Anan-8000DLE does exactly this, and steps up the voltage to 50V. No idea if there's any noise related to these boost converters. Seems like a neat idea, just not sure how it will work in practice.
On Mon, Feb 20, 2017 at 4:08 PM, Bill Frantz <[email protected]> wrote: > The short answer is they can. It is only a matter of engineering time, > cost, resulting price, number of customers and competing projects. In other > words, the usual business considerations. > > Lets work the idea through for several of the Elecraft RF amplifiers: > > The 10-15W K3(s) amp: This amp can have significant IMD at low voltages as > we have discovered with our QRP, all Elecraft, field day operation. The KX3 > seems to do better, so reengineering the amp may be a better solution. For > field day, we try to have fresh batteries available. > > The 100W K3(s) internal amp: This amp also has low voltage IMD as we found > during our 100W California QSO party expeditions. But, consider the K3(s)'s > construction. The front of the radio is the digital portion, including the > DSPs and the front panel computer. All of this digital noise is isolated > from the analog circuits in the back of the radio. If Elecraft were to > include a boost power supply with the internal amp, that high-current > switcher would be in the analog section, and probably impossible to quiet. > Solution: Get an external boost power supply. > > The KXPA100 external amp: This form factor would be an ideal place to > include a boost power supply. The use profile includes portable battery > operation and designing isolation for the power supply into the package > seems straight forward. > > The KPA500 external amp: The amp setup procedure sets the voltage to to > 65v to 85v and the specifications call for about 1000 VA of power or about > 13A at 75v. That would be nearly 75A at 13.5 volts assuming 100% > efficiency, so it would be a good idea to put the boost power supply next > to the battery and run 75v to the amp. It would make a nice high power > mobil rig. > > 73 Bill AE6JV > > In thread "Re: [Elecraft] Chinese ebay amps for KX3", on 2/20/17 at 5:47 > AM, [email protected] (Charlie T, K3ICH) wrote: > > So now, tell me why a mid-sized radio can't have a built in 12 V to say, 50 >> V converter to drive some HV FETs for cleaner output specs like the Yuge >> radios. >> > ----------------------------------------------------------------------- > Bill Frantz |The nice thing about standards| Periwinkle > (408)356-8506 |is there are so many to choose| 16345 Englewood Ave > www.pwpconsult.com |from. - Andrew Tanenbaum | Los Gatos, CA 95032 > > ______________________________________________________________ > 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]
