Thanks Leigh & Don, I'm not as concerned about maxing output, though getting 4 watts on 20 meters (like I'm getting on 80 meters) would be nice. I do like to experiment a little, so trying the 2SC5739 would be interesting.
I am interested getting some idea about part to part variability. I have a lot of experience with LEDs and the variability they exhibit coming off the assembly line, and am wondering if other semiconductor devices - like the 2SC2166 - show similar variability in efficiencies? Thanks, Chip AE5KA On Wed, Feb 9, 2011 at 7:22 PM, Don Wilhelm <[email protected]> wrote: > Leigh, > > Elecraft is currently shipping KX1s with the 2SC2166 again. I have > built 4 in the last month and all 4 have that transistor. > > The thermal pad provides better heat conduction and should not be > eliminated if a plastic tab transistor is used - only the shoulder > washer is eliminated. > > 73, > Don W3FPR > > On 2/9/2011 7:21 PM, Leigh L. Klotz Jr WA5ZNU wrote: > > Here's some info to read: > > http://elecraft.365791.n2.nabble.com/KX1-Q6-question-td662532.html > > and here, in this erratum superseded by the revision E manual which shows > > the changeover: > > http://www.elecraft.com/manual/KX1_Owners_Manual_Errata_Rev_D-1.pdf > > > > It seems that Elecraft went from a 2SC2166 to a 2SC5739 for RoHS > compliance. > > > > A side benefit is that the new part eliminates a thermal pad, shoulder > > washer, and thus a potential for a short from the KX1 build. > > > > Some have reported improved output on 20M with this part, albeit with the > > usual warnings about too much power causing you trouble later if you > don't > > have a great match to your antenna, a strong possibility under the KX1 > > normal operating conditions. > > > > Leigh/WA5ZNU > > > ______________________________________________________________ > 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 > ______________________________________________________________ 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
