[Elecraft] KX3 power reverts from 10W back to 5W - test results
After improving the connection to the battery and using two of the same batteries in parallel, I tested across all bands. Setup: ZS6BKW antenna at 45' in inverted V, with 30' coax from twin line to KX3 Most test runs were without balun, some with a 1:1 Two identical 12V/17Ah batteries, starting with 12.8V at no load All bands from 160m to 10m (minus 60m) at mid-CW frequency Power mostly 5W, 7W, 8W, 10W CW Results: 1. The previous problems appear to have been caused by a weak battery connection. 2. Power levels above 5W were maintained as long as the voltage stayed at/above 11V and the current did not exceed 2.0A 3. Only on 80m, 40m, 30m, 20m, and 17m a 10W level could be maintained. The other bands dropped down to 5W at levels over 7 or 8W. However, with healthier batteries, this situation might have been better because. 4. The batteries (routinely retired UPS) appear to be getting old and didn't hold their full voltage during this relatively short test. 5. SWRs were generally at 1.0:1 with the exception of 160m (2.6:1 with balun) and 17m (1.2:1 without balun, 1.0:1 with balun) Conclusion: A 12V battery in good condition with solid connections should allow me to maintain 10W power with my setup. I put all measured voltages and currents together in a spreadsheet which I would be happy to share. Please ask and provide an email address, and I will mail it to you. 73, Arno K7RNO __ 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 power reverts from 10W back to 5W
I would like to come back to this topic with an update after still experiencing the same issue. I now use my ZS6BKW with a 1:1 current balun between the twin line and the coax. I have tried a 70' and a 30' length of coax to the rig. If you think it will solve the problem, I might even try a 5' length and smolder in the sun! My battery shows 11.4 V during transmit on the KX3's PS meter. SWRs are never higher than 1.3:1 after tuning. PA temperatures are never very high (sitting in the shade). I have tried lower W settings, like 8W, which, on some bands, hold for a while. On other bands, they too revert back to 5W. So, if this is all normal, I don't understand why the KX3 is rated at 10W. Or asking in a different way: what needs to be present to keep the transmitter from reverting down from 10W, and how can I achieve that state with my setup? Please keep in mind that I don't have any antenna analyzing instruments other than what the KX3 provides. Thank you and 73, Arno K7RNO __ 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 power reverts from 10W back to 5W
Arno, Even though the battery voltage measures (as an average) at 11.7 volts during transmit, my suspicion is that it may be glitching for brief periods below 11 volts and the detection circuit trips forcing the KX3 to low power. Check all the connections to your power source and make certain they are wrench tight for a starting effort. The other thing to check are the connections in the antenna system. Again, a loose connection can cause a 'glitch' to a higher SWR. PL-259 connections that are simply 'finger tightened' are possible suspects, snug them up a bit with pliers. Unlike BNC, N, TNC, etc, PL-259s depend on being tight to make the shield connection. 73, Don W3FPR On 8/30/2013 1:50 PM, Arno Dienhart wrote: I would like to come back to this topic with an update after still experiencing the same issue. I now use my ZS6BKW with a 1:1 current balun between the twin line and the coax. I have tried a 70' and a 30' length of coax to the rig. If you think it will solve the problem, I might even try a 5' length and smolder in the sun! My battery shows 11.4 V during transmit on the KX3's PS meter. SWRs are never higher than 1.3:1 after tuning. PA temperatures are never very high (sitting in the shade). I have tried lower W settings, like 8W, which, on some bands, hold for a while. On other bands, they too revert back to 5W. So, if this is all normal, I don't understand why the KX3 is rated at 10W. Or asking in a different way: what needs to be present to keep the transmitter from reverting down from 10W, and how can I achieve that state with my setup? Please keep in mind that I don't have any antenna analyzing instruments other than what the KX3 provides. Thank you and 73, Arno K7RNO __ 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 power reverts from 10W back to 5W
Hi Arno, I run a similar setup, ZS6BKW, 1:1 current balun, 100ft RG213 coax, I normally run 10W, and haven't observed problems with the rig switching back to 5W. I do run my rig off a 13.8V 20A supply. If you run at a lower voltage, the rig needs to draw more current to maintain a particular power output. Have you observed the display on the rig at the moment it switches back to 5W? Does it display any warning such as Hi Curr(ent)? I am a bit concerned about the fact that you report an SWR of 1.3 *after* tuning. I find the SWR is already low on the bands of interest, and after tuning it shows 1.0:1 VSWR. Even on 80m with a native SWR of 7:1 it tunes up to 1.0:1 and happily runs 10W. So, apart from the power supply, I would be a bit concerned that something may be amiss with your antenna system. 73, Matt VK2RQ On 31/08/2013, at 3:50 AM, Arno Dienhart a...@broadweave.net wrote: I would like to come back to this topic with an update after still experiencing the same issue. I now use my ZS6BKW with a 1:1 current balun between the twin line and the coax. I have tried a 70' and a 30' length of coax to the rig. If you think it will solve the problem, I might even try a 5' length and smolder in the sun! My battery shows 11.4 V during transmit on the KX3's PS meter. SWRs are never higher than 1.3:1 after tuning. PA temperatures are never very high (sitting in the shade). I have tried lower W settings, like 8W, which, on some bands, hold for a while. On other bands, they too revert back to 5W. So, if this is all normal, I don't understand why the KX3 is rated at 10W. Or asking in a different way: what needs to be present to keep the transmitter from reverting down from 10W, and how can I achieve that state with my setup? Please keep in mind that I don't have any antenna analyzing instruments other than what the KX3 provides. Thank you and 73, Arno K7RNO __ 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 power reverts from 10W back to 5W
Hi Matt, Maybe I gave a wrong impression with my statement of SWR never higher than 1.3. Usually, SWR is at 1.0 and only at rare instances do I see 1.3. What I wanted to express is that SWR should not be the cause of the issue. I have not observed the display at the very moment of power switching back and will look for it next time. 73, Arno K7RNO -Original Message- From: Matt VK2RQ [mailto:matt.vk...@gmail.com] Sent: Friday, August 30, 2013 12:32 To: Arno Dienhart Cc: Elecraft@mailman.qth.net Subject: Re: [Elecraft] KX3 power reverts from 10W back to 5W Hi Arno, I run a similar setup, ZS6BKW, 1:1 current balun, 100ft RG213 coax, I normally run 10W, and haven't observed problems with the rig switching back to 5W. I do run my rig off a 13.8V 20A supply. If you run at a lower voltage, the rig needs to draw more current to maintain a particular power output. Have you observed the display on the rig at the moment it switches back to 5W? Does it display any warning such as Hi Curr(ent)? I am a bit concerned about the fact that you report an SWR of 1.3 *after* tuning. I find the SWR is already low on the bands of interest, and after tuning it shows 1.0:1 VSWR. Even on 80m with a native SWR of 7:1 it tunes up to 1.0:1 and happily runs 10W. So, apart from the power supply, I would be a bit concerned that something may be amiss with your antenna system. 73, Matt VK2RQ On 31/08/2013, at 3:50 AM, Arno Dienhart a...@broadweave.net wrote: I would like to come back to this topic with an update after still experiencing the same issue. I now use my ZS6BKW with a 1:1 current balun between the twin line and the coax. I have tried a 70' and a 30' length of coax to the rig. If you think it will solve the problem, I might even try a 5' length and smolder in the sun! My battery shows 11.4 V during transmit on the KX3's PS meter. SWRs are never higher than 1.3:1 after tuning. PA temperatures are never very high (sitting in the shade). I have tried lower W settings, like 8W, which, on some bands, hold for a while. On other bands, they too revert back to 5W. So, if this is all normal, I don't understand why the KX3 is rated at 10W. Or asking in a different way: what needs to be present to keep the transmitter from reverting down from 10W, and how can I achieve that state with my setup? Please keep in mind that I don't have any antenna analyzing instruments other than what the KX3 provides. Thank you and 73, Arno K7RNO __ 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 power reverts from 10W back to 5W
Arno, Also check the connections to the fuse in your power cord. You *DO* have it fused do you not? A fuse near the battery is essential to prevent a shower of molten metal if there is any fault in the wire or the connected equipment. Any battery stores a LOT of energy. The automotive blade type fuses are the best for lower resistance connections. 73, Don W3FPR On 8/30/2013 2:45 PM, Arno Dienhart wrote: Hi Don, You (and Matt) might have a point with the power connection. I connect to the battery poles (which have the shape of blades) with copper clips, which are of rather thin copper sheet, so the contact surface is perhaps too small and too loose. I will build a better connection next. My 259 connectors are well tight, so I don't expect any improvement there using pliers. However, should the battery connection improvement not yield the desired result, I will look at the 259s (of which I have four in the feedlines/balun string, plus two female-to-male adapters). Contingency tests have not shown any issues, though. But that was just an Ohm meter with 3V running through. 73, Arno K7RNO __ 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 power reverts from 10W back to 5W
But why is the SWR varying like that? Is it wind moving the antenna or ladder line around, maybe close to something metal? Is it bad connection? Is the balun saturating or heating up (unlikely at 10W, but then I don't know the details of your balun)? With the power, it is important to have solid connections and decent gauge wire, and as Don says, a fuse (preferably an automotive style blade fuse) in order to minimise transient voltage drops. Are you running anything else off the battery? 73, Matt VK2RQ On 31/08/2013, at 4:37 AM, Arno Dienhart a...@broadweave.net wrote: Hi Matt, Maybe I gave a wrong impression with my statement of SWR never higher than 1.3. Usually, SWR is at 1.0 and only at rare instances do I see 1.3. What I wanted to express is that SWR should not be the cause of the issue. I have not observed the display at the very moment of power switching back and will look for it next time. 73, Arno K7RNO -Original Message- From: Matt VK2RQ [mailto:matt.vk...@gmail.com] Sent: Friday, August 30, 2013 12:32 To: Arno Dienhart Cc: Elecraft@mailman.qth.net Subject: Re: [Elecraft] KX3 power reverts from 10W back to 5W Hi Arno, I run a similar setup, ZS6BKW, 1:1 current balun, 100ft RG213 coax, I normally run 10W, and haven't observed problems with the rig switching back to 5W. I do run my rig off a 13.8V 20A supply. If you run at a lower voltage, the rig needs to draw more current to maintain a particular power output. Have you observed the display on the rig at the moment it switches back to 5W? Does it display any warning such as Hi Curr(ent)? I am a bit concerned about the fact that you report an SWR of 1.3 *after* tuning. I find the SWR is already low on the bands of interest, and after tuning it shows 1.0:1 VSWR. Even on 80m with a native SWR of 7:1 it tunes up to 1.0:1 and happily runs 10W. So, apart from the power supply, I would be a bit concerned that something may be amiss with your antenna system. 73, Matt VK2RQ On 31/08/2013, at 3:50 AM, Arno Dienhart a...@broadweave.net wrote: I would like to come back to this topic with an update after still experiencing the same issue. I now use my ZS6BKW with a 1:1 current balun between the twin line and the coax. I have tried a 70' and a 30' length of coax to the rig. If you think it will solve the problem, I might even try a 5' length and smolder in the sun! My battery shows 11.4 V during transmit on the KX3's PS meter. SWRs are never higher than 1.3:1 after tuning. PA temperatures are never very high (sitting in the shade). I have tried lower W settings, like 8W, which, on some bands, hold for a while. On other bands, they too revert back to 5W. So, if this is all normal, I don't understand why the KX3 is rated at 10W. Or asking in a different way: what needs to be present to keep the transmitter from reverting down from 10W, and how can I achieve that state with my setup? Please keep in mind that I don't have any antenna analyzing instruments other than what the KX3 provides. Thank you and 73, Arno K7RNO __ 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 __ 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 power reverts from 10W back to 5W
Hi Arno, If your fully charged batt reads 11.4 V AFTER the KX3 has switched back to 5 W, the voltage reading with 10 W (maybe 50% more current?) will most probably be below 11 V. I would suggest that you try to gradually increase the output power from 5 Watts and read the voltage and currents from the KX3s meters. This way you will have a measure for the voltage drop and the series resistance in your battery connection and power leads. Greetings Ralf DL6OAP Am 30.08.2013 um 19:50 schrieb Arno Dienhart a...@broadweave.net: I would like to come back to this topic with an update after still experiencing the same issue. I now use my ZS6BKW with a 1:1 current balun between the twin line and the coax. I have tried a 70' and a 30' length of coax to the rig. If you think it will solve the problem, I might even try a 5' length and smolder in the sun! My battery shows 11.4 V during transmit on the KX3's PS meter. SWRs are never higher than 1.3:1 after tuning. PA temperatures are never very high (sitting in the shade). I have tried lower W settings, like 8W, which, on some bands, hold for a while. On other bands, they too revert back to 5W. So, if this is all normal, I don't understand why the KX3 is rated at 10W. Or asking in a different way: what needs to be present to keep the transmitter from reverting down from 10W, and how can I achieve that state with my setup? Please keep in mind that I don't have any antenna analyzing instruments other than what the KX3 provides. Thank you and 73, Arno K7RNO __ 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 power reverts from 10W back to 5W
Here is a few questions. 1) are you running from a external battery or the internal aa batts. 2) have you run a check on the cables to make sure there are no crimps/bends/breaks in the line with a volt meter ot cable tester or such 3) what is your external power source ? anything under 13.8v like a 12v laptop power supply will have issues. 4) do you get a high current warning when you transmit before it fails back to 5w from 10w ? 5) have to proply grounded your station even when portable when possible ? -- R.Neese KB3VGW __ 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 power reverts from 10W back to 5W
I should have mentioned it again: I am powering from a 12V 17Ah sealed lead acid battery. From: KENT TRIMBLE [mailto:k9...@socket.net] Sent: Friday, August 30, 2013 12:26 To: Arno Dienhart Subject: Re: [Elecraft] KX3 power reverts from 10W back to 5W Are you powering the rig with internal batteries? K9ZTV On 8/30/2013 12:50 PM, Arno Dienhart wrote: I would like to come back to this topic with an update after still experiencing the same issue. I now use my ZS6BKW with a 1:1 current balun between the twin line and the coax. I have tried a 70' and a 30' length of coax to the rig. If you think it will solve the problem, I might even try a 5' length and smolder in the sun! My battery shows 11.4 V during transmit on the KX3's PS meter. SWRs are never higher than 1.3:1 after tuning. PA temperatures are never very high (sitting in the shade). I have tried lower W settings, like 8W, which, on some bands, hold for a while. On other bands, they too revert back to 5W. So, if this is all normal, I don't understand why the KX3 is rated at 10W. Or asking in a different way: what needs to be present to keep the transmitter from reverting down from 10W, and how can I achieve that state with my setup? Please keep in mind that I don't have any antenna analyzing instruments other than what the KX3 provides. Thank you and 73, Arno K7RNO __ 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 - No virus found in this message. Checked by AVG - www.avg.com Version: 2013.0.3392 / Virus Database: 3211/6622 - Release Date: 08/30/13 __ 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 power reverts from 10W back to 5W
Hi Don, You (and Matt) might have a point with the power connection. I connect to the battery poles (which have the shape of blades) with copper clips, which are of rather thin copper sheet, so the contact surface is perhaps too small and too loose. I will build a better connection next. My 259 connectors are well tight, so I don't expect any improvement there using pliers. However, should the battery connection improvement not yield the desired result, I will look at the 259s (of which I have four in the feedlines/balun string, plus two female-to-male adapters). Contingency tests have not shown any issues, though. But that was just an Ohm meter with 3V running through. 73, Arno K7RNO -Original Message- From: Don Wilhelm [mailto:w3...@embarqmail.com] Sent: Friday, August 30, 2013 12:17 To: Arno Dienhart Cc: Elecraft@mailman.qth.net Subject: Re: [Elecraft] KX3 power reverts from 10W back to 5W Arno, Even though the battery voltage measures (as an average) at 11.7 volts during transmit, my suspicion is that it may be glitching for brief periods below 11 volts and the detection circuit trips forcing the KX3 to low power. Check all the connections to your power source and make certain they are wrench tight for a starting effort. The other thing to check are the connections in the antenna system. Again, a loose connection can cause a 'glitch' to a higher SWR. PL-259 connections that are simply 'finger tightened' are possible suspects, snug them up a bit with pliers. Unlike BNC, N, TNC, etc, PL-259s depend on being tight to make the shield connection. 73, Don W3FPR On 8/30/2013 1:50 PM, Arno Dienhart wrote: I would like to come back to this topic with an update after still experiencing the same issue. I now use my ZS6BKW with a 1:1 current balun between the twin line and the coax. I have tried a 70' and a 30' length of coax to the rig. If you think it will solve the problem, I might even try a 5' length and smolder in the sun! My battery shows 11.4 V during transmit on the KX3's PS meter. SWRs are never higher than 1.3:1 after tuning. PA temperatures are never very high (sitting in the shade). I have tried lower W settings, like 8W, which, on some bands, hold for a while. On other bands, they too revert back to 5W. So, if this is all normal, I don't understand why the KX3 is rated at 10W. Or asking in a different way: what needs to be present to keep the transmitter from reverting down from 10W, and how can I achieve that state with my setup? Please keep in mind that I don't have any antenna analyzing instruments other than what the KX3 provides. Thank you and 73, Arno K7RNO __ 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 power reverts from 10W back to 5W
All are good suggestions, this and the others. I will try them out and report back. At this point, my money is on my flimsy clips. FTR, I do have an inline 7.5A fuse, automotive dual blade type. To Matt: maybe I am still not communicating clearly. The SWR does not vary ceteris paribus, only when I go on certain bands (or even only one band). I didn't make a record of which one and how many but I did tune each band from 160 to 10m (except 60m). The balun is specified for 200W (LDG). No metal contact along the feedline. Antenna is 14 gauge, twin is 18 gauge, coax is RG-8x. Nothing else is running off the battery (a UPS type). -Original Message- From: Ralf Wilhelm [mailto:r...@super-deutschland.net] Sent: Friday, August 30, 2013 13:19 To: Arno Dienhart Cc: Elecraft@mailman.qth.net Subject: Re: [Elecraft] KX3 power reverts from 10W back to 5W Hi Arno, If your fully charged batt reads 11.4 V AFTER the KX3 has switched back to 5 W, the voltage reading with 10 W (maybe 50% more current?) will most probably be below 11 V. I would suggest that you try to gradually increase the output power from 5 Watts and read the voltage and currents from the KX3s meters. This way you will have a measure for the voltage drop and the series resistance in your battery connection and power leads. Greetings Ralf DL6OAP __ 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 power reverts from 10W back to 5W
Hi Richard, Only saw your post now, so here are your questions with answers below: 1) are you running from a external battery or the internal aa batts. 2) have you run a check on the cables to make sure there are no crimps/bends/breaks in the line with a volt meter ot cable tester or such 3) what is your external power source ? anything under 13.8v like a 12v laptop power supply will have issues. 4) do you get a high current warning when you transmit before it fails back to 5w from 10w ? 5) have to proply grounded your station even when portable when possible ? 1. External 12V/17Ah UPS bat 2. No 3. See 1. 4. Not sure. I will check this next time 5. No grounding As I said, I believe my weak battery connection to be a good candidate for the culprit. 73, Arno From: Richard Neese kb3...@gmail.com To: elecraft@mailman.qth.net Subject: Re: [Elecraft] KX3 power reverts from 10W back to 5W Message-ID: 5220e687.3020...@gmail.com Content-Type: text/plain; charset=ISO-8859-1; format=flowed (list of five questions) __ 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 power reverts from 10W back to 5W
Arno, Sure someone from Elecraft will respond with a technical explanation...sounds a bit like default behaviour to me and also shows there is a difference in the battery and the internal PA voltage and you are maybe close to the fold back voltage. If the supply voltage drops below 12V (I use 7AH SLA batteries so see this often) then it can be lower at the PA internally (c11V + a bit) when it is the KX3 folds back to 5W, no real warning it just does it. I found it a bit annoying when I knew mine was running hot but then the KX3 was designed with battery /P operation in mind (I assume). The KX3 does the same thing to protect the KX3 if the PA gets too hot (you could try this, not sure it will damage the KX3 so be warned, I did this when I fitted a heatsink to reduce the issue... set power out to 10W, key down or send dah dah constantly with a keyer for a few minutes into a dummy load (not on air!) to make it fun do this in bright sun and watch the PA temp rise and rise and the rear metal panel gets hot, eventually the temperature will exceed what is 'safe' and the power will reduce, same thing happens for excess current say if a PA transistor is failing or an antenna impedance/VSWR changes there are multiple reasons and a few other situations all are designed to protect the KX3. You could monitor the KX3 reported PA temperature and the KX3 reported voltage and see when it happens so you know when to adjust the power out level yourself or know when it is likely to happen. I have a really nice light weight /P switch mode mains power supply it provides 12.2V (was for a CCTV camera) the KX3 will never exceed 8W out with it on CW, if you set 10W it folds back immediately to 5W. 72 Dom M1KTA On 05/08/13 22:49, Arno Dienhart wrote: So I had set up in the park, with a charged 12V 17Ah battery connected. It was a hot day but I was in the shade. Every time I set power level to 10W and keyed the TX, it reverted back to 5W instantly. Why? The Volt meter showed 12.3 V at RX and dropped to 11.7V at TX. Was that the reason (getting below 12V)? Was the PA getting too hot? It never went below 5W. Thanks for any tips, 73, Arno __ 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 power reverts from 10W back to 5W
I have found that with even a freshly charged 7Ah battery that the power folds back, on some bands especially, even if the internal atu has found a good match. However, in almost all cases setting the power output to 8W rather than initially 10W it doesn't happen as much, at least not until the battery voltage has fallen well below 12V. 73 Stephen G4SJP On Tuesday, 6 August 2013, Dominic Baines wrote: Arno, Sure someone from Elecraft will respond with a technical explanation...sounds a bit like default behaviour to me and also shows there is a difference in the battery and the internal PA voltage and you are maybe close to the fold back voltage. If the supply voltage drops below 12V (I use 7AH SLA batteries so see this often) then it can be lower at the PA internally (c11V + a bit) when it is the KX3 folds back to 5W, no real warning it just does it. I found it a bit annoying when I knew mine was running hot but then the KX3 was designed with battery /P operation in mind (I assume). The KX3 does the same thing to protect the KX3 if the PA gets too hot (you could try this, not sure it will damage the KX3 so be warned, I did this when I fitted a heatsink to reduce the issue... set power out to 10W, key down or send dah dah constantly with a keyer for a few minutes into a dummy load (not on air!) to make it fun do this in bright sun and watch the PA temp rise and rise and the rear metal panel gets hot, eventually the temperature will exceed what is 'safe' and the power will reduce, same thing happens for excess current say if a PA transistor is failing or an antenna impedance/VSWR changes there are multiple reasons and a few other situations all are designed to protect the KX3. You could monitor the KX3 reported PA temperature and the KX3 reported voltage and see when it happens so you know when to adjust the power out level yourself or know when it is likely to happen. I have a really nice light weight /P switch mode mains power supply it provides 12.2V (was for a CCTV camera) the KX3 will never exceed 8W out with it on CW, if you set 10W it folds back immediately to 5W. 72 Dom M1KTA On 05/08/13 22:49, Arno Dienhart wrote: So I had set up in the park, with a charged 12V 17Ah battery connected. It was a hot day but I was in the shade. Every time I set power level to 10W and keyed the TX, it reverted back to 5W instantly. Why? The Volt meter showed 12.3 V at RX and dropped to 11.7V at TX. Was that the reason (getting below 12V)? Was the PA getting too hot? It never went below 5W. Thanks for any tips, 73, Arno __**__**__ Elecraft mailing list Home: http://mailman.qth.net/**mailman/listinfo/elecrafthttp://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.**htmhttp://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 -- Sent from Gmail Mobile __ 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 power reverts from 10W back to 5W
Wayne, I can't confirm a low Z as I don't have an analyzer. If this helps to guess: I was using the ZS6BKW version of the G5RV, with 70' of coax connected to the window line from the doublet and no matching network between that connection. The ATU was able to achieve a 1.0:1 SWR. RX was exceptionally low-noise but TX did not get a lot of contacts (may have been other factors). 73, Arno -Original Message- From: Wayne Burdick [mailto:n...@elecraft.com] Sent: Monday, August 05, 2013 19:46 To: Arno Dienhart Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] KX3 power reverts from 10W back to 5W Most likely your antenna load Z was on the low side, increasing TX current drain. Either excess TX current or supply voltage below 11 V can cause power to revert to 5 watts. 73, Wayne N6KR http://www.elecraft.com On Aug 5, 2013, at 5:46 PM, Arno Dienhart a...@broadweave.net wrote: Hi Wayne, I measured with the built-in meter. Sorry, I don't have a dummy load, so I cannot test that. Next time I will connect two of the same sealed lead acid batteries in parallel and see if something changes. No problem to use two. Thank you for the explanation. At least I can be sure that nothing is wrong with my KX3. 73, Arno -Original Message- From: Wayne Burdick [mailto:n...@elecraft.com] Sent: Monday, August 05, 2013 17:02 To: Arno Dienhart Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] KX3 power reverts from 10W back to 5W Hi Arno, The KX3 requires 11.0 volts minimum on key-down for power output levels of greater than 5 W. We do this to ensure low IMD in SSB transmit mode, but it's good practice in general because most 12-V batteries can be damaged quickly if you let the voltage go much below 11.0 with a heavy load applied. When you measured the voltage on key-down, were you using a voltmeter at the battery, or the one in the radio? You could have been dropping some voltage across the power supply wires (+ and - leads probably about the same), or in the KX3's DC input circuitry (reverse-polarity diode, current sense resistor, etc.). So even if you read 11.7 V, it's possible that you briefly dipped below that 11.0 threshold. Try running it into a dummy load, using the same battery. What is the voltage on key-down? (Make sure to bypass the ATU or tune it into the dummy load for this test.) 73, Wayne N6KR On Aug 5, 2013, at 2:49 PM, Arno Dienhart a...@broadweave.net wrote: So I had set up in the park, with a charged 12V 17Ah battery connected. It was a hot day but I was in the shade. Every time I set power level to 10W and keyed the TX, it reverted back to 5W instantly. Why? The Volt meter showed 12.3 V at RX and dropped to 11.7V at TX. Was that the reason (getting below 12V)? Was the PA getting too hot? It never went below 5W. Thanks for any tips, 73, Arno __ 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 __ 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 power reverts from 10W back to 5W
So I had set up in the park, with a charged 12V 17Ah battery connected. It was a hot day but I was in the shade. Every time I set power level to 10W and keyed the TX, it reverted back to 5W instantly. Why? The Volt meter showed 12.3 V at RX and dropped to 11.7V at TX. Was that the reason (getting below 12V)? Was the PA getting too hot? It never went below 5W. Thanks for any tips, 73, Arno __ 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 power reverts from 10W back to 5W
Hi Arno, The KX3 requires 11.0 volts minimum on key-down for power output levels of greater than 5 W. We do this to ensure low IMD in SSB transmit mode, but it's good practice in general because most 12-V batteries can be damaged quickly if you let the voltage go much below 11.0 with a heavy load applied. When you measured the voltage on key-down, were you using a voltmeter at the battery, or the one in the radio? You could have been dropping some voltage across the power supply wires (+ and - leads probably about the same), or in the KX3's DC input circuitry (reverse-polarity diode, current sense resistor, etc.). So even if you read 11.7 V, it's possible that you briefly dipped below that 11.0 threshold. Try running it into a dummy load, using the same battery. What is the voltage on key-down? (Make sure to bypass the ATU or tune it into the dummy load for this test.) 73, Wayne N6KR On Aug 5, 2013, at 2:49 PM, Arno Dienhart a...@broadweave.net wrote: So I had set up in the park, with a charged 12V 17Ah battery connected. It was a hot day but I was in the shade. Every time I set power level to 10W and keyed the TX, it reverted back to 5W instantly. Why? The Volt meter showed 12.3 V at RX and dropped to 11.7V at TX. Was that the reason (getting below 12V)? Was the PA getting too hot? It never went below 5W. Thanks for any tips, 73, Arno __ 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 power reverts from 10W back to 5W
Hi Wayne, I measured with the built-in meter. Sorry, I don't have a dummy load, so I cannot test that. Next time I will connect two of the same sealed lead acid batteries in parallel and see if something changes. No problem to use two. Thank you for the explanation. At least I can be sure that nothing is wrong with my KX3. 73, Arno -Original Message- From: Wayne Burdick [mailto:n...@elecraft.com] Sent: Monday, August 05, 2013 17:02 To: Arno Dienhart Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] KX3 power reverts from 10W back to 5W Hi Arno, The KX3 requires 11.0 volts minimum on key-down for power output levels of greater than 5 W. We do this to ensure low IMD in SSB transmit mode, but it's good practice in general because most 12-V batteries can be damaged quickly if you let the voltage go much below 11.0 with a heavy load applied. When you measured the voltage on key-down, were you using a voltmeter at the battery, or the one in the radio? You could have been dropping some voltage across the power supply wires (+ and - leads probably about the same), or in the KX3's DC input circuitry (reverse-polarity diode, current sense resistor, etc.). So even if you read 11.7 V, it's possible that you briefly dipped below that 11.0 threshold. Try running it into a dummy load, using the same battery. What is the voltage on key-down? (Make sure to bypass the ATU or tune it into the dummy load for this test.) 73, Wayne N6KR On Aug 5, 2013, at 2:49 PM, Arno Dienhart a...@broadweave.net wrote: So I had set up in the park, with a charged 12V 17Ah battery connected. It was a hot day but I was in the shade. Every time I set power level to 10W and keyed the TX, it reverted back to 5W instantly. Why? The Volt meter showed 12.3 V at RX and dropped to 11.7V at TX. Was that the reason (getting below 12V)? Was the PA getting too hot? It never went below 5W. Thanks for any tips, 73, Arno __ 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 power reverts from 10W back to 5W
Most likely your antenna load Z was on the low side, increasing TX current drain. Either excess TX current or supply voltage below 11 V can cause power to revert to 5 watts. 73, Wayne N6KR http://www.elecraft.com On Aug 5, 2013, at 5:46 PM, Arno Dienhart a...@broadweave.net wrote: Hi Wayne, I measured with the built-in meter. Sorry, I don't have a dummy load, so I cannot test that. Next time I will connect two of the same sealed lead acid batteries in parallel and see if something changes. No problem to use two. Thank you for the explanation. At least I can be sure that nothing is wrong with my KX3. 73, Arno -Original Message- From: Wayne Burdick [mailto:n...@elecraft.com] Sent: Monday, August 05, 2013 17:02 To: Arno Dienhart Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] KX3 power reverts from 10W back to 5W Hi Arno, The KX3 requires 11.0 volts minimum on key-down for power output levels of greater than 5 W. We do this to ensure low IMD in SSB transmit mode, but it's good practice in general because most 12-V batteries can be damaged quickly if you let the voltage go much below 11.0 with a heavy load applied. When you measured the voltage on key-down, were you using a voltmeter at the battery, or the one in the radio? You could have been dropping some voltage across the power supply wires (+ and - leads probably about the same), or in the KX3's DC input circuitry (reverse-polarity diode, current sense resistor, etc.). So even if you read 11.7 V, it's possible that you briefly dipped below that 11.0 threshold. Try running it into a dummy load, using the same battery. What is the voltage on key-down? (Make sure to bypass the ATU or tune it into the dummy load for this test.) 73, Wayne N6KR On Aug 5, 2013, at 2:49 PM, Arno Dienhart a...@broadweave.net wrote: So I had set up in the park, with a charged 12V 17Ah battery connected. It was a hot day but I was in the shade. Every time I set power level to 10W and keyed the TX, it reverted back to 5W instantly. Why? The Volt meter showed 12.3 V at RX and dropped to 11.7V at TX. Was that the reason (getting below 12V)? Was the PA getting too hot? It never went below 5W. Thanks for any tips, 73, Arno __ 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 __ 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
