If you are seriously considering an SB200 that needs a keying circuit, the standard upgrade for any of the SB200/201/220/221 is the Harbach "Softkey" keying mod, which changes it from your keying +200 volts (compatible with nothing modern) to a tame low negative voltage low current key voltage that works with anything modern. http://www.cis.rit.edu/people/faculty/montag/vandplite/pages/chap_9/ch9p1.html .
There are many SB2xx amps, made modern with a full set of Harbach mods, still in use and likely to be around as long as we have ham bands. There are little circuits that can be put in tiny boxes, which you can find with Google, but the permanent answer is to bring it up to spec with the Harbach mods. 73 and good luck, Guy K2AV On Saturday, March 7, 2015, W4MIL via Elecraft <elecraft@mailman.qth.net> wrote: > > I've not been active in some time with my KX-3. Last firmware update was > MCU 1.61 and DSP 1.23. > > What are the latest (non-Beta) releases available? Also, does anyone have > recommendations on a good desk mic for the KX-3? And any recommendations > for an interface to allow keying of an SB-200 amplifier? > > I've tried to keep up with all of the comments over the past 1.5 years, > but things change as the KX-3 has evolved and individual experiences may > differ today from those in the past. > > Thanks in advance for any info. > > 73 Chuck W4MIL > > > > > チャーリー ミルトン > > > > > ______________________________________________________________ > 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 k2av....@gmail.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
