One thing that hasn't been mentioned is that the K3 has a built-in 6A fuse for the basic rig and a separate 20A circuit breaker for the KPA3. So it's not like there's no protection at all between the APP connector and the internal circuits.
73 -- Joe KB8AP On Aug 13, 2010, at 9:02 AM, Willis wrote: > The transistor is the most probable reason for the fuse blowing but > the fuse may save the other components and semi conductors as well > as the circuit board. The original query stated he would be using > an Astron 35 which has a current limiter but limiting the current to > 35 amps will still allow a lot of damage. > > Sent from my iPhone > > On Aug 13, 2010, at 9:55, gdaug...@stanford.edu wrote: > >> Ian wrote... >> >>> The other important point is that fuses provide ZERO protection >>> until >>> AFTER they have blown. In the life and death of a semiconductor, >>> even a >>> few milliseconds is a very long time indeed. >> >> I like to tell the story about a series of tests we did when I >> worked at Fairchild, in >> Silicon Valley. Our little VHF silicon transistors were very >> expensive, and quite >> fragile. We tested many fuses to identify which one(s) would be >> suitable protection >> for the transistors. To summarize: transistors are a very >> effective way of protecting >> fuses! >> >> 73, >> >> George T Daughters, K6GT >> CU in the California QSO Party (CQP) >> October 2-3, 2010 >> >> >> ______________________________________________________________ >> 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 > ______________________________________________________________ > 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 ______________________________________________________________ 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