Re: [Elecraft] KX3 and SWR
It's not actually SWR that kills PAs, but rather the resulting over-voltage or over-current. With an open circuit load, the risk would be mainly over-voltage, but whilst that would be a problem with a class C PA, I'm not so sure that there is a big risk from class AB, push-pull, ones. A PA might survive a very high SWR for some loads, but be very fussy for other ones. -- David Woolley On 16/03/2023 15:58, Ingo Meyer DK3RED wrote: The KX3 should tolerate an SWR of 1.6:1. I have already unintentionally transmitted with my KX3 (5W CW) without antenna and the KX3 is still in good health. The manual says at page 6: "The KX3 reduces power if SWR is high." __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] KX3 and SWR
Hello Paul, The tuner in my KX3 used to give me a nice 1:1 SWR at 7.05 MHZ. Now the best match it will give there is about 1.6:1. In the "old days" we were happy with anything under 2:1 but can new rigs like my KX3 tolerate this poorer match? I only run 5-watts CW. The KX3 should tolerate an SWR of 1.6:1. I have already unintentionally transmitted with my KX3 (5W CW) without antenna and the KX3 is still in good health. The manual says at page 6: "The KX3 reduces power if SWR is high." 73/72 de Ingo, DK3RED - Don't forget: the fun is the power! www.qrp4fun.de - dk3...@qrp4fun.de __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] KX3 and SWR
My HyGain AV-640 vertical antenna was damaged in a recent winter storm and will need to come down for repairs once the good weather is here to stay and I can get around to it. In the mean time I would still like to use it. The only band that really shows a significant problem is 40-meters. The tuner in my KX3 used to give me a nice 1:1 SWR at 7.05 MHZ. Now the best match it will give there is about 1.6:1. In the "old days" we were happy with anything under 2:1 but can new rigs like my KX3 tolerate this poorer match? I only run 5-watts CW. Let me say "thank you" in advance for any advice anyone might have. 73, Paul - N8XMS __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] KX3 High SWR Only on 6M
Folks: My KX3 is just over a year old. It has developed an odd problem. It shows a high SWR on 6M, and only 6M. It may not be there on initial power up, but it shows up shortly after a bit of Morse code is sent, and does not seem to reliably go away until being shut down. Here are the specifics: KX3 113xx. Configured with: KX3, KXFL3, KXAT3, KXFL3, KX3-2M, KXBC3. I have been operating exclusively 6M, connected to a KXPA100 Amplifier. the SWR issue presents itself hooked up to the KXPA100 as well as disconnected and running barefoot. (I have to bypass the ATU to fully diagnose and simulate the connection to the KXPA100.) I have verified the issue on a known good 50Ω dummy load. Radio sees ~3.4:1 SWR when ATU is bypassed. The SWR rises to 3.8:1 at the high end of 6M band when testing. SWR Band (Freq.) 3.8:1 6M (53.995) 3.2:1 6M (50.090) 1.4:110M (28.025) 1.3:112M (24.900) 1.2:115M (21.025) 1.1:117M (18.100) 1.0:120M (14.025) 1.0:130M (10.125) 1.0:140M (7.025) 1.0:180M (3.550) 1.0:1 160M (1.810) When the ATU is not bypassed and running barefoot, all the other bands quickly seek and find a 1.0:1 SWR and bypass the ATU. But 6M band has a 1.3:1 SWR and had to ratchet a bit on the relays to get to it. The problem started out as an occasional issue, and I could fiddle with changing bands, push a configuration file into it, or just let it be for a bit, and it would behave for a while. But it has gotten worse. I fired the radio up this afternoon, and all seemed okay for a couple of minutes. But after just a few dits and dahs, and a callsign or two, suddenly... 3.4:1 SWR. The radio reduces power out, and thus the KXPA100 is running less than the set/requested power out. I have gone through several troubleshooting steps to this point. Checked radio without KXPA100. Bypassed ATU in radio, and checked direct to a known good load. I am looking first at the 'KX3 Antenna Connector Assembly with LPF' (E850552) as a suspect. Is that a good first substution? Is there something on him that may visually reveal an issue? Can I do an check with a multimeter to verify if it is a likely issue? Where else should I start looking? And, has anyone else encountered this issue with a KX3 running a lot of 6M into a KXPA100? Thanks for any insight on getting my issue identified and resolved. Tim Raymer 73 de KA0OUV __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] KX3 High SWR Only on 6M
Folks: My KX3 is just over a year old. It has developed an odd problem. It shows a high SWR on 6M, and only 6M. It may not be there on initial power up, but it shows up shortly after a bit of Morse code is sent, and does not seem to reliably go away until being shut down. Here are the specifics: KX3 113xx. Configured with: KX3, KXFL3, KXAT3, KXFL3, KX3-2M, KXBC3. I have been operating exclusively 6M, connected to a KXPA100 Amplifier. the SWR issue presents itself hooked up to the KXPA100 as well as disconnected and running barefoot. (I have to bypass the ATU to fully diagnose and simulate the connection to the KXPA100.) I have verified the issue on a known good 50Ω dummy load. Radio sees ~3.4:1 SWR when ATU is bypassed. The SWR rises to 3.8:1 at the high end of 6M band when testing. SWR Band (Freq.) 3.8:1 6M (53.995) 3.2:1 6M (50.090) 1.4:110M (28.025) 1.3:112M (24.900) 1.2:115M (21.025) 1.1:117M (18.100) 1.0:120M (14.025) 1.0:130M (10.125) 1.0:140M (7.025) 1.0:180M (3.550) 1.0:1 160M (1.810) When the ATU is not bypassed and running barefoot, all the other bands quickly seek and find a 1.0:1 SWR and bypass the ATU. But 6M band has a 1.3:1 SWR and had to ratchet a bit on the relays to get to it. The problem started out as an occasional issue, and I could fiddle with changing bands, push a configuration file into it, or just let it be for a bit, and it would behave for a while. But it has gotten worse. I fired the radio up this afternoon, and all seemed okay for a couple of minutes. But after just a few dits and dahs, and a callsign or two, suddenly... 3.4:1 SWR. The radio reduces power out, and thus the KXPA100 is running less than the set/requested power out. I have gone through several troubleshooting steps to this point. Checked radio without KXPA100. Bypassed ATU in radio, and checked direct to a known good load. I am looking first at the 'KX3 Antenna Connector Assembly with LPF' (E850552) as a suspect. Is that a good first substution? Is there something on him that may visually reveal an issue? Can I do an check with a multimeter to verify if it is a likely issue? Where else should I start looking? And, has anyone else encountered this issue with a KX3 running a lot of 6M into a KXPA100? Thanks for any insight on getting my issue identified and resolved. Tim Raymer 73 de KA0OUV __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] KX3 Faulty SWR indication
A few weeks ago I posted this problem, worked on it a bit, then got distracted into other projects. I am now back trying to resolve the faulty SWR issue with My KX3. The problem only occurs on 160, 80 and 60 meters. Using a known good dummy load and cable the indicated SWR on the KX3 is high --- 1.8 to one using 10 watts. An external wattmeter/SWR meter shows the Dummy Load as a perfect load. The reflected power needle does not move. I have done repeated Power Out Calibrations with the KXPA100 (not relevant, I know). The KX3 shows the same faulty SWR Readings with or without the KXPA100. Of course the ATU mode is in bypass. But, when the ATU is active, it matches, shows a proper SWR briefly, then shows the faulty reading as the rig transmits. It was a factory built unit S/N 4932. I'm stumped. I guess it is time to send it home for healing. Dave, K4TO __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] KX3 Faulty SWR indication
The funny SWR also appears with the ATU in circuit but not at the tuning PWR level. It appears when the rig is in "normal" transmit mode after tuning. Bob is likely right though - try turning the power down and see if results in "normal" operation. You may find it power dependent - if so it could be very hard to fix unless you're experienced and willing to solder and unsolder parts. 73's Peter VK4JD -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Bob McGraw K4TAX Sent: Wednesday, 31 January 2018 11:38 AM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] KX3 Faulty SWR indication Based on your description, I'd say there is some instability in one of the stages. The dummy load will present a uniform impedance at all frequencies, thus the SWR will be 1:1. output network will show evidence of reflected power. Using the ATU, it adds filtering thus eliminating the spurious output. I suggest looking at the output on a spectrum analyzer. 73 Bob, K4TAX On 1/30/2018 7:09 PM, Dave Sublette wrote: > A few weeks ago I posted this problem, worked on it a bit, then got > distracted into other projects. I am now back trying to resolve the > faulty SWR issue with My KX3. The problem only occurs on 160, 80 and 60 > meters. > > Using a known good dummy load and cable the indicated SWR on the KX3 > is high --- 1.8 to one using 10 watts. An external wattmeter/SWR > meter shows the Dummy Load as a perfect load. The reflected power needle > does not move. > > I have done repeated Power Out Calibrations with the KXPA100 (not > relevant, I know). The KX3 shows the same faulty SWR Readings with or > without the KXPA100. Of course the ATU mode is in bypass. But, when > the ATU is active, it matches, shows a proper SWR briefly, then shows > the faulty reading as the rig transmits. > > It was a factory built unit S/N 4932. > > I'm stumped. I guess it is time to send it home for healing. > > Dave, K4TO > __ > 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 Message delivered to > rmcg...@blomand.net > __ 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 Message delivered to plamb...@qa.com.au __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] KX3 Faulty SWR indication
Based on your description, I'd say there is some instability in one of the stages. The dummy load will present a uniform impedance at all frequencies, thus the SWR will be 1:1. output network will show evidence of reflected power. Using the ATU, it adds filtering thus eliminating the spurious output. I suggest looking at the output on a spectrum analyzer. 73 Bob, K4TAX On 1/30/2018 7:09 PM, Dave Sublette wrote: A few weeks ago I posted this problem, worked on it a bit, then got distracted into other projects. I am now back trying to resolve the faulty SWR issue with My KX3. The problem only occurs on 160, 80 and 60 meters. Using a known good dummy load and cable the indicated SWR on the KX3 is high --- 1.8 to one using 10 watts. An external wattmeter/SWR meter shows the Dummy Load as a perfect load. The reflected power needle does not move. I have done repeated Power Out Calibrations with the KXPA100 (not relevant, I know). The KX3 shows the same faulty SWR Readings with or without the KXPA100. Of course the ATU mode is in bypass. But, when the ATU is active, it matches, shows a proper SWR briefly, then shows the faulty reading as the rig transmits. It was a factory built unit S/N 4932. I'm stumped. I guess it is time to send it home for healing. Dave, K4TO __ 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 Message delivered to rmcg...@blomand.net __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] KX3 - calibration SWR 99.9-1 is too high for calibration
Hello Just finished updating firmware; using latest utility pgm; radio works fine - 'tune' into dummy load gives 1.1-1. Calibration from utility instantly fails at 1.900 99.9-1 SWR. Can't think of anything to try - commercial dummy load directly connected. Thanks 72 John VE3NFK -- View this message in context: http://elecraft.365791.n2.nabble.com/KX3-calibration-SWR-99-9-1-is-too-high-for-calibration-tp7612498.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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KX3 - calibration SWR 99.9-1 is too high for calibration
John, Try to run the TX Gain Calibration manually. See the KX3 manual page 33. That will tell you whether it fails on only some bands, but not others. The Utility program quits after the 1st error. If the manual calibration succeeds, then you might want to try the Utility process again, but it is not necessary. 73, Don W3FPR On 1/10/2016 11:08 AM, VE3NFK wrote: Hello Just finished updating firmware; using latest utility pgm; radio works fine - 'tune' into dummy load gives 1.1-1. Calibration from utility instantly fails at 1.900 99.9-1 SWR. Can't think of anything to try - commercial dummy load directly connected. __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] KX3 - calibration SWR 99.9-1 is too high for calibration
John, Another thing - you could have a bad coax between the KX3 and the dummy load - overlook nothing, especially simple things like that which are often forgotten. Make no assumptions about the 'goodness' of cables and any adapters. Substitute a known good cable, or disconnect it from the KX3 and measure that end with an antenna analyzer. 73, Don W3FPR On 1/10/2016 11:08 AM, VE3NFK wrote: Hello Just finished updating firmware; using latest utility pgm; radio works fine - 'tune' into dummy load gives 1.1-1. Calibration from utility instantly fails at 1.900 99.9-1 SWR. __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] KX3: Hi SWR on 20m 30m after KX3-2M install
Brian, Can’t help wondering if ESD or similar build-up occurred with low humidity in the winter. Frank KG9H On Jan 28, 2015, at 3:26 PM, Brian Waterworth brian.waterwo...@gmail.com wrote: I had a similar situation with my KX3 just after the RTTY round-up at the beginning of January. I also have the 2M module installed and experienced the same challenges with the inductors. SWR values after 2M module install seemed to be ok on HF. I actually can't recall if they were high as I didn't check. But, the auto-tuner had no trouble achieving less than 1.5:1 matches with a regular ATU cycle (not the aggressive cycle) into my G5RV shorty. After the round-up, I couldn't achieve less than 3 on most bands (ATU assisted) and in some cases an SWR of 75:1!! I tried measurements into two different dummy loads that I had around the shack. I bypassed the ATU and measured on all bands. I had high SWR on all HF bands into both dummy loads. The sad ending to my tail is that I had to send the KX3 back to Elecraft for warranty repair. The report back, from the Elecraft tech looking at my rig, was that 5 of the RF board's ICs were blown. Probable cause: near field lightning strike or greater than 100+ watts of RF energy into the KX3. It is winter where I am (snow, cold :-) and we don't get lightning at this time of year. Also, I don't know how 100+ watts would have slipped into the KX3. It isn't near any other RF source with that kind of power. It is interesting, Ed, that you are reporting something similar to my situation. I hope you resolve your problem without having to send your KX3 back. P.S. I struck up a nice email conversation with the folks at Elecraft support and they guided me through some tests and asked for measurements. They too didn't want me to have to send the rig back. But, the results of the SWR measurements told them that something bad was wrong and the KX3 needed servicing. regards, Brian VE3IBW On Wed, Jan 28, 2015 at 1:59 PM, Ed Hamlin w...@earthlink.net wrote: Hi I just recently installed the 2M transverter in my KX-3. I’m now noticing high (11 to 25) SWR readings on 20m and I wondered if this might be related (I don’t recall such high readings before). I’m using an off-center fed dipole that has worked quite well in the past. The KX3 autotuner worked so well in the past, and I’ve seen it tune on relatively short random wires, so inability to tune on a good antenna seems rather odd. Part of the installation required displacing L40 and L43 on the main RF board to make room for the SMA connector. It’s possible to break one of the leads on the inductor while doing this. L40 (as I recall) felt pretty tight and I may have inadvertently pushed it too hard. What would be the symptoms of an open circuit on either of those inductors? Other than high SWR on 20m and 30m, I haven’t seen any anomalous behavior. 73s Ed __ 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 Message delivered to brian.waterwo...@gmail.com __ 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 Message delivered to kg9hfr...@gmail.com __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] KX3: Hi SWR on 20m 30m after KX3-2M install
I had a similar situation with my KX3 just after the RTTY round-up at the beginning of January. I also have the 2M module installed and experienced the same challenges with the inductors. SWR values after 2M module install seemed to be ok on HF. I actually can't recall if they were high as I didn't check. But, the auto-tuner had no trouble achieving less than 1.5:1 matches with a regular ATU cycle (not the aggressive cycle) into my G5RV shorty. After the round-up, I couldn't achieve less than 3 on most bands (ATU assisted) and in some cases an SWR of 75:1!! I tried measurements into two different dummy loads that I had around the shack. I bypassed the ATU and measured on all bands. I had high SWR on all HF bands into both dummy loads. The sad ending to my tail is that I had to send the KX3 back to Elecraft for warranty repair. The report back, from the Elecraft tech looking at my rig, was that 5 of the RF board's ICs were blown. Probable cause: near field lightning strike or greater than 100+ watts of RF energy into the KX3. It is winter where I am (snow, cold :-) and we don't get lightning at this time of year. Also, I don't know how 100+ watts would have slipped into the KX3. It isn't near any other RF source with that kind of power. It is interesting, Ed, that you are reporting something similar to my situation. I hope you resolve your problem without having to send your KX3 back. P.S. I struck up a nice email conversation with the folks at Elecraft support and they guided me through some tests and asked for measurements. They too didn't want me to have to send the rig back. But, the results of the SWR measurements told them that something bad was wrong and the KX3 needed servicing. regards, Brian VE3IBW On Wed, Jan 28, 2015 at 1:59 PM, Ed Hamlin w...@earthlink.net wrote: Hi I just recently installed the 2M transverter in my KX-3. I’m now noticing high (11 to 25) SWR readings on 20m and I wondered if this might be related (I don’t recall such high readings before). I’m using an off-center fed dipole that has worked quite well in the past. The KX3 autotuner worked so well in the past, and I’ve seen it tune on relatively short random wires, so inability to tune on a good antenna seems rather odd. Part of the installation required displacing L40 and L43 on the main RF board to make room for the SMA connector. It’s possible to break one of the leads on the inductor while doing this. L40 (as I recall) felt pretty tight and I may have inadvertently pushed it too hard. What would be the symptoms of an open circuit on either of those inductors? Other than high SWR on 20m and 30m, I haven’t seen any anomalous behavior. 73s Ed __ 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 Message delivered to brian.waterwo...@gmail.com __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] KX3: Hi SWR on 20m 30m after KX3-2M install
Folks, Do not be complacent about static coming in from the antenna in the winter. Even though there may be no lightning - wind, rain or snow can build up a very large static charge. I am not saying that was Brian's situation, but be aware that possibility does exist. Make certain there is a DC path across your feedlines to bleed off a static charge. A non-inductive resistor with a value between 5k and 50k will do the job. If you use an antenna switch, that is a good place to add those resistors. If you have no other choice, mount the resistor in a PL-259 body and put it on one side of a TEE adapter - the rig goes on one other side and the last side goes to the antenna. 73, Don W3FPR On 1/28/2015 4:26 PM, Brian Waterworth wrote: It is winter where I am (snow, cold :-) and we don't get lightning at this time of year. __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] KX3: Hi SWR on 20m 30m after KX3-2M install
Hi I just recently installed the 2M transverter in my KX-3. I’m now noticing high (11 to 25) SWR readings on 20m and I wondered if this might be related (I don’t recall such high readings before). I’m using an off-center fed dipole that has worked quite well in the past. The KX3 autotuner worked so well in the past, and I’ve seen it tune on relatively short random wires, so inability to tune on a good antenna seems rather odd. Part of the installation required displacing L40 and L43 on the main RF board to make room for the SMA connector. It’s possible to break one of the leads on the inductor while doing this. L40 (as I recall) felt pretty tight and I may have inadvertently pushed it too hard. What would be the symptoms of an open circuit on either of those inductors? Other than high SWR on 20m and 30m, I haven’t seen any anomalous behavior. 73s Ed __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] [KX3] Unstable SWR Reading (maxwel...@aol.com)
Hi Tom, Regrading your comments below: I am seeing a similar concern with my KX3/KXPA100 home station. The KXPA100 ATU tunes it right down to 1.1-1.2. Then when I start transmitting it jumps up between 2 and 3. This doesn't happen all of the time nor on all bands. I have worked with Dick and he has put a lot of effort into my concern, much of it off hours by the way. Great service and great concern demonstrated by Dick. Try to get a response from the big three at all-let alone on weekends. We ran traces on the tuning process and it shows a good tune right down to where it needs to be. However, the SWR then jumps up when I go to full power. I am not sure it is a real problem as the power meter shows I am getting out OK. But it is concerning to be transmitting 100 watts and seeing the SWR jump up to 3 after it has tuned down to 1.2. I don't believe it is in my antenna because I put an LDG tuner in the line and it tunes solid and stays there. I know gut feel isn't very scientific but I think there could be an issue with the SWR circuitry. At lower tuning powers it senses SWR OK, but with higher power levels it doesn't. It may well be that my SWR is varying and maybe the sensing circuits in the KXPA100 are just more sensitive than the LDG circuits, I don't know. All we really know at this point is that the traces look really good, the ATU takes the reported SWR down to more than acceptable values even when the antenna SWR is above 10. I may try putting a variable dummy load on it to see if I can duplicate the problem into a known stable load. Keep in mind that this is more of a nuisance item to me and I love the KX3/KXPA100 combination. 10m was wide open this weekend and I worked Japan, New Zealand, Hawaii, and China with a very minimal horizontal loop at 15 feet. I know this is anecdotal but I believe the low noise receiver and filtering made it possible. Good stuff! Tom/AE5QB From responses to my original post, several people have mentioned SWR instability they believe associated with the KX3 rather than connections, feeder, antenna, etc. Of course, that being said it is completely possible the problem might indeed be an antenna (in my case often used in windy conditions when mountain-topping), feeder, etc., heating issue in antenna or component or poor connection, most likely in feeder. So far this week I've not had the opportunity to investigate further but I plan to. Please keep me posted on anything you discover in further conversations with Elecraft. Thanks to everyone else for your input on the topic and I'll let you know what I find as soon as I have the chance to try a few equipment combinations. Interestingly enough in my case this problem has only started to occur recently. So something has changed, whether associated with antenna, feeder or radio. I did not see this issue on my first 14 or so SOTA activations. Best regards, Gary K6YOA __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] [KX3] Unstable SWR reading
On my last two portable outings I've noticed that after a few QSOs I start to get unstable SWR readings, with the radio reporting fluctuating SWR ranging into the 2 and 3's. I'm using a tuned antenna, plus pressing the ATU button results in 1:1 matching. Everything is fine for a while and then the SWR reading go unstable midway through the QSO. Pressing the ATU button seems to resolve the problem for a while but it starts up again. I realize it could be a problem with the cabling or antenna but visual inspection seems to indicate everything is fine and so far I've not been able to replicate the problem on the bench. Has anyone seen this type of problem with the KX3? __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] [KX3] Unstable SWR reading
The only time I see that sort of fluctuation is at home, when it is raining. I'm using 450 ohm ladder line to feed an 88-foot long doublet, 45 feet up. Prior to the rain coming down, I can press Tune and get a great match on any band, 80-6 meters. When the rain starts up, my SWR jumps up to 2.5:1 or more. That 450-ohm stuff has to go. Are you operating in rainy conditions, or with that stuff? Jim / W6JHB On Monday, Mar 31, 2014, at Monday, 10:02 AM, Gary Hawkins wrote: On my last two portable outings I've noticed that after a few QSOs I start to get unstable SWR readings, with the radio reporting fluctuating SWR ranging into the 2 and 3's. I'm using a tuned antenna, plus pressing the ATU button results in 1:1 matching. Everything is fine for a while and then the SWR reading go unstable midway through the QSO. Pressing the ATU button seems to resolve the problem for a while but it starts up again. I realize it could be a problem with the cabling or antenna but visual inspection seems to indicate everything is fine and so far I've not been able to replicate the problem on the bench. Has anyone seen this type of problem with the KX3? __ 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 Message delivered to w6...@me.com __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] [KX3] Unstable SWR reading
Any wind? Feedline motion can cause that, depending on surroundings and if open line On 3/31/14, 10:02 AM, Gary Hawkins wrote: On my last two portable outings I've noticed that after a few QSOs I start to get unstable SWR readings, with the radio reporting fluctuating SWR ranging into the 2 and 3's. I'm using a tuned antenna, plus pressing the ATU button results in 1:1 matching. Everything is fine for a while and then the SWR reading go unstable midway through the QSO. Pressing the ATU button seems to resolve the problem for a while but it starts up again. I realize it could be a problem with the cabling or antenna but visual inspection seems to indicate everything is fine and so far I've not been able to replicate the problem on the bench. Has anyone seen this type of problem with the KX3? __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] [KX3] Unstable SWR reading
I mentioned this kind of problem a few years ago with my K3, but did not get a satisfying answer. My SWR fluctuates all the time between 1.5 to 2.5 while my external SWR is solid as a rock. Also using the internal tuner. Oh yea, both my K3's have got the same issue. Must be my personal influence :-) After being worried for a couple of month, I dont care anymore. As long as they can hear me and my K3 doesn't go wild or so . just go. 73's, Evert PA2KW -Oorspronkelijk bericht- Van: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] Namens Gary Hawkins Verzonden: maandag 31 maart 2014 19:02 Aan: elecraft@mailman.qth.net Onderwerp: [Elecraft] [KX3] Unstable SWR reading On my last two portable outings I've noticed that after a few QSOs I start to get unstable SWR readings, with the radio reporting fluctuating SWR ranging into the 2 and 3's. I'm using a tuned antenna, plus pressing the ATU button results in 1:1 matching. Everything is fine for a while and then the SWR reading go unstable midway through the QSO. Pressing the ATU button seems to resolve the problem for a while but it starts up again. I realize it could be a problem with the cabling or antenna but visual inspection seems to indicate everything is fine and so far I've not been able to replicate the problem on the bench. Has anyone seen this type of problem with the KX3? __ 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 Message delivered to ev...@pa2kw.com __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] [KX3] Unstable SWR reading
I had an experimental antenna which exhibited this kind of behavior. I could not send out my QTH data on PSK31 without having the SWR go through the roof. My conclusion was that the common mode choke, wound with parallel wires on a small type 41 core, was heating up enough to pass the curie point and lose inductance and choking ability. I changed the feed arrangement and the problem went away. Getting the old feed technique to work is on the future projects list. Cheers - Bill, AE6JV On 3/31/14 at 10:02 AM, g...@hawkins-zhu.com (Gary Hawkins) wrote: On my last two portable outings I've noticed that after a few QSOs I start to get unstable SWR readings, with the radio reporting fluctuating SWR ranging into the 2 and 3's. I'm using a tuned antenna, plus pressing the ATU button results in 1:1 matching. Everything is fine for a while and then the SWR reading go unstable midway through the QSO. Pressing the ATU button seems to resolve the problem for a while but it starts up again. I realize it could be a problem with the cabling or antenna but visual inspection seems to indicate everything is fine and so far I've not been able to replicate the problem on the bench. Has anyone seen this type of problem with the KX3? --- Bill Frantz| I wish there was a knob on the TV to turn up the 408-356-8506 | intelligence. There's a knob called brightness, but www.pwpconsult.com | it doesn't work. -- Gallagher __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] KX3 W1 SWR Measurement
An example evaluation of a rig's SWR meter, using two 200 ohm resistors in parallel, SWR should be close to 2:1. Power set to 4.0 W. The KX3 and W1 indicate SWR = 1.8:1. http://www.kn5l.net/Elecraft/KX3-W1-SWR-p1010859.jpg YMMV John KN5L __ 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] KX3 KXAT3 SWR re-tune request threshold
Hi folks, For years, I have worked portable with an inverted-vee as a multiband antenna and a ladder line feeder. With the KX1 internal tuner, the T1 or a LDG Z-817, once tuned in a band, I did not have to re-tune as long as I stayed in that band. However, with the KXAT3 and with the same antenna, the ATU symbol often begins to 'flash' if I change frequency within a band requiring a new tuning even if I tuned on that band. So... I wonder if a new menu item could be added in the KX3 offering the possibility to set the SWR threshold over which there would be no re-tune request by the KXAT3? That threshold could be adjustable offering 3 choices like 1.5:1 and 2:2 or also even to 3:1 for example. I can cope easily with a 3:1 SWR, the loss is not so great... Meanwhile, thanks again for that wonderful rig. Pierre VE2PID KX3 S/N 190 __ 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
Re: [Elecraft] KX3 KXAT3 SWR re-tune request threshold
Hello Pierre. Once you have initally tuned in the band of your choice, why don't you just bypass the internal ATU? 73, Stan WB2LQF On Wed, Aug 1, 2012 at 6:58 PM, Pierre wrote: I can cope easily with a 3:1 SWR, the loss is not so great... __ 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
Re: [Elecraft] KX3 KXAT3 SWR re-tune request threshold
Hi Stan, What I often do is to make very frequent band change so I would have to repeat each time the bypass/debypass process... I would prefer to have a higher threshold for all bands. Or another possibility: At the start of a session, I could do a tuning somewhere in each band I plan to use. Then I would by-pass the ATU. Don't know if the L/C setting would be retained and recalled on band changes even if the ATU is by-passed..?? -- View this message in context: http://elecraft.365791.n2.nabble.com/KX3-KXAT3-SWR-re-tune-request-threshold-tp7560139p7560143.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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KX3 KXAT3 SWR re-tune request threshold
Pierre, When you bypass the tuner, it is taken out of the circuit (well almost) - sort of like no tuner at all. You would only want to set the tuner to bypass if you have resonant antennas or you are working into a dummy load. 73, Don W3FPR On 8/1/2012 8:00 PM, Pierre wrote: Hi Stan, What I often do is to make very frequent band change so I would have to repeat each time the bypass/debypass process... I would prefer to have a higher threshold for all bands. __ 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
Re: [Elecraft] KX3 KXAT3 SWR re-tune request threshold
Pierre, Wayne has responded on the KX3 Yahoo group that the band segments are 20 kHz wide, so if you start at the bottom of the band (well - 10 kHz inside) and do an ATU TUNE, then move up 20 kHz and do another ATU TUNE - continue until you get to the top of the band of interest - the KXAT3 will remember the settings for all those band segments and you will not have to touch the ATU TUNE again until you change the antenna being used for that particular band. When working in the field, I do this as part of my initial setup and there is no further concerns about tuning. At home I set the tuner to bypass because I have resonant antennas for each band - no tuner required. 73, Don W3FPR On 8/1/2012 8:00 PM, Pierre wrote: Hi Stan, What I often do is to make very frequent band change so I would have to repeat each time the bypass/debypass process... I would prefer to have a higher threshold for all bands. Or another possibility: At the start of a session, I could do a tuning somewhere in each band I plan to use. Then I would by-pass the ATU. Don't know if the L/C setting would be retained and recalled on band changes even if the ATU is by-passed..?? -- View this message in context: http://elecraft.365791.n2.nabble.com/KX3-KXAT3-SWR-re-tune-request-threshold-tp7560139p7560143.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: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
Re: [Elecraft] KX3 KXAT3 SWR re-tune request threshold
Thanks for clearing that one up, Don. I thought bypass would keep it from attempting to retune but hold the last solution. I guess I should read the manual, eh? On Wed, Aug 1, 2012 at 8:47 PM, Don Wilhelm wrote: Pierre, When you bypass the tuner, it is taken out of the circuit (well almost) - sort of like no tuner at all. __ 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
Re: [Elecraft] KX3 KXAT3 SWR re-tune request threshold
On 8/2/2012 12:47 AM, Don Wilhelm wrote: You would only want to set the tuner to bypass if ... you are working into a dummy load. That would be me. Fred K6DGW Auburn CA __ 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
