I agree with Don.. I wouldn't waste the time checking that transistor. It would be an exercise in futility. My bet is on the KUSB.
David, W4SMT --- On Fri, 1/8/10, Don Wilhelm <w3...@embarqmail.com> wrote: > Roger, > > I do not believe the transistors on the IO board should be > very high on > the suspect list. It is rare to find a component > failure unless it has > been subjected to some unusual stress - component > degradation in 3 years > or less is highly unlikely, 20 to 40 years, maybe, but not > 3. > May I suggest that the KUSB itself would have the highest > probability of > failure, and your tests so far have not done anything to > check it (other > than the checks from the computer device manager). > The adapter could > have something as subtle as a broken wire in the cable. > Can you try another adapter, or better yet, try using a > computer with a > real serial port. > > 73, > Don W3FPR > > Roger Dallimore wrote: > > Many thanks for all suggestions privately and to this > list. > > > > I can confirm that; > > > > Ports have been checked with K3 utility > > Checked correct port in device manager on PC > > Did not stop after upgrading software > > I am using KUSB with latest drivers since arrival of > K3 #191 > > K3 is set at 38400 baud > > > > I'm going to examine the transistor on the IO board. > Apparently the > > plastic transistors can degrade over time on older > K3's and the voltage > > drops under load to the RS232. Thanks to K1WHS > for this suggestion. > > > > 73 & HNY! > > > > Roger MW0IDX > > > > > ______________________________________________________________ > 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
