KX3 antenna tuner intermittend operation
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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. I'm not sure if the relays clicked or not (have been using earphones) but I think so. At another instance, I saw the "HI CURR" warning in the display and heard a relay clicking (I was only running 4W and the power supply was a 25 A, 13.7 V linear). I think the tuner suddenly went into a kind of bypass mode at both instances. There is a video on youtube showing exactly what happened to me. Is anyone else here experiencing this? Is it related to antenna impedance or poor ground? Have been using the same wire with a K2 and its tuner and never noticed something like this. Vy 73, Ralf, DL6OAP |
Re: KX3 antenna tuner intermittent operation
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Administrator
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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 <[hidden email]> 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Wayne, Thanks for the fast reply. I think I had this issue only two times (am not sure if both were the same band) perhaps during 3 hours or so, but what you are saying would explain why I couldn't reproduce it. If it were RFI, I would expect it to happen all the time which doesn't seem to be the case. Just one more question: are you saying the LC data is not loaded before I transmit in a "new" segment, just like e. g. the Smartuner? The ATU doesn't follow the VFO when I am only in rx mode? Thanks in advance Vy 73, Ralf, DL6OAP
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Re: KX3 antenna tuner intermittent operation
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Administrator
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DL6OAP <[hidden email]> wrote:
> Wayne, > > Thanks for the fast reply. I think I had this issue only two times (am not sure if both were the same band) perhaps during 3 hours or so, but what you are saying would explain why I couldn't reproduce it. If it were RFI, I would expect it to happen all the time which doesn't seem to be the case. > > Just one more question: are you saying the LC data is not loaded before I transmit in a "new" segment, just like e. g. the Smartuner? The ATU doesn't follow the VFO when I am only in rx mode? That's correct. Updating ATU relays while tuning the VFO in RX mode is really annoying. So we only do it when you transmit, and even then we wait for that first gap in the transmission to avoid mucking with CW timing. The ATU is in-line even in receive mode. If you think that loading new ATU LC data would help with receive, just tap XMIT or hit a 'dit' to reload. Wayne N6KR > > Thanks in advance > > Vy 73, Ralf, DL6OAP > > > > Am 02.05.2013 um 17:33 schrieb "wayne burdick [via Elecraft]" <[hidden email]>: > >> 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 <[hidden email]> 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:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> >> >> If you reply to this email, your message will be added to the discussion below: >> http://elecraft.365791.n2.nabble.com/KX3-antenna-tuner-intermittend-operation-tp7573335p7573346.html >> To unsubscribe from KX3 antenna tuner intermittend operation, click here. >> NAML > > > > > -- > View this message in context: http://elecraft.365791.n2.nabble.com/KX3-antenna-tuner-intermittend-operation-tp7573335p7573348.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:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by DL6OAP
Hallo Ralf,
I've had a similar problem with my K2. It was simply a poor (intermittent) connection in the feedline ;-) ω²LC=1 |
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In reply to this post by wayne burdick
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
Dave
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