Hi David and the group, I am on my way to ruling things out as to the source of the bug I am seeing:
1) I can make it happen with a commercial power supply and dummy load. The power supply has nothing homebrew about it, and I checked that the plug fit correctly into the KX1. 2) I took the internal batteries out while testing to rule out that the plug was bad and the power was intermittently reverting back to the 9V internal. I did not see anything reset or power cycle, just the TUN->CAL bug described earlier. 3) When the rig does automatically go from TUN to CAL when I transmit, if I turn the rig off, and then turn it back on, it goes back to TUN, with the correct L and C values from before the glitch. If I purposely turn the ATU to from TUN to CAL and then turn the rig off and on, it stays in CAL mode, as expected. This leads me to believe it is not a problem with the MCU going to a bogus state, but a glitch in a relay control line that is causing a relay to flip. 4) Similar to 3, when I see it switch from TUN to CAL on a transmit, and I switch bands, and then switch back to the original band, the ATU state returns back to the correct TUN state with the correct L and C values. 5) I re-soldered all the caps on the ATU board and any other connections that looked suspect. No change. My next step is to try the add'l bypass caps on the relay control lines, as Wayne suggested. I'm leaving that till last to see if I can pinpoint the cause of the problem before adding extra hardware to mask it. David, G4DMP, thanks for your feedback on the good result from adding the bypass caps. That encourages me that this will solve (mask) the problem. Thanks to all who sent me suggestions so far. 73, Mike N9OHW --- David Pratt <[EMAIL PROTECTED]> wrote: > Hello Mike - > I had a similar problem a while ago and Wayne > suggested fitting some > bypass capacitors in various places around the > processor on the ATU > board. Unfortunately I am unable to get to either > the information or the > rig at the moment as the contents of the shack are > in storage due to > building repairs. > > In my case, during an over while I was transmitting, > the KX1 started > retuning the antenna and ended up with a very low > power and a high SWR. > Fitting the capacitors as Wayne suggested totally > cured the problem. > > 73 > > David G4DMP > > In a recent message, Michael Madden > <[EMAIL PROTECTED]> wrote ... > >I took the KX1 out yesterday for more field > testing. > >This time, I wrapped with a torroid the 6" > unshielded > >lead from the external battery holder. The idea > here > >was that RF was getting into the 6" battery lead > and > >somehow the dirty DC was tripping the ATU > controller. > > > >Well, at first, it seemed like the problem was > solved. > > But after about 1 hr of having the KX1 on, I > started > >getting the problem again. (The problem with the > ATU > >switching from TUN to CAL by itself when I start > >transmitting.) This time, I only saw it on 30M. > But > >it was intermittent: when it started happening, I > >shut the rig off, turned it back on, switched > bands, > >and then I wouldn't get it for a while. > > > _______________________________________________ > Elecraft mailing list > Post to: Elecraft@mailman.qth.net > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
