I experienced a related issue with the KX2 ATU during the CQ WW contest this weekend.
After a frequency change during search-and-pounce, I would send my call, KW4M. What was actually transmitted was KM4M. The first dit in the second letter was chopped off. I could hear what sounded like a relay click when this happened. This happened on multiple occasions. Subsequent transmissions were fine until another significant QSY. The CW keying was computer-generated at 25 WPM. -Dave KW4M wayne burdick wrote > Ralf, > > Like the K3's ATU, the KX3's ATU stores up to 32 segments of LC data on > each band. On 160 m the segments are 10 kHz wide (1800-1810, 1810-1820, > etc.). Anytime you move the VFO into a new segment, then transmit, the ATU > will reload the last-used LC data for that segment (or the closest segment > for which data has been stored). If the data is the same as for the > previous segment, nothing will change. If it's different, the LC data will > be sent to the ATU's relays, and the "ATU" icon will flash. > > Note that this will not happen until after you pause 1/2 second in your > transmission. This way we don't mess up the timing on your first > transmission if you were in CW mode. > > My guess is that you moved the VFO into a new segment where you had > previously tuned up into a different load, so that the LC data was a > little different. > > There are a couple of things you might want to do. If you changed > antennas, you can optionally go into the ATU MD menu entry and hold CLR to > erase all of the ATU LC data for the current band. Then retune the ATU in > the part of the band you use, as needed (when SWR is high). > > A more exhaustive approach might be useful if the antenna's SWR varies > widely across the band (often the case on 160 m): Tune up the ATU ahead of > time on every segment. That is, set the VFO to about 1805, tune the ATU, > then move to 1815 and tune the ATU, etc. This is usually overkill, but it > would optimize the LC settings ahead of time for a narrowband antenna. > > You might try the above and let me know what happens. > > Another possibility is that you simply have very high SWR resulting in > RFI. If that were the case, reducing power to a couple of watts would > reduce RFI and the symptoms would go away (or at least be different). My > guess is that this is not what's happening; you're just seeing the ATU > retune in new segments. > > I'll also send you our latest field-test firmware which is likely to be > released as beta later today (rev 1.47). It has significant stability > improvements that could have some bearing on ATU-related problems. > > 73, > Wayne > N6KR > > > On May 2, 2013, at 1:16 AM, DL6OAP < > Ralf@ > > wrote: > >> Hi, >> >> I received my KX3 one week ago and had some fun yesterday with it and an >> end-fed wire antenna roughly 20 mtrs long. The ATU worked great on >> getting >> the SWR down to 1:1 (not on 160) but there was an issue that concerns me: >> while transmitting, the ATU icon in the display went flashing and the SWR >> changed…. > > > ______________________________________________________________ > 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 ----- Dave My Web Site -- View this message in context: http://elecraft.365791.n2.nabble.com/KX3-antenna-tuner-intermittend-operation-tp7573335p7624286.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ 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 Message delivered to [email protected]
