KX3 power out
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After a fair time of non-use, today I got out my KX3 and started working
through configuration checklists. Among other things I thought I'd check the power out. For this test I used a Bird 43 and MFJ-260C dummy load. For HF I used a Bird 2-30 MHz 25w element, and for 2m a 100-250 MHz 10w element. I put the KX3 in CW mode and keyed with the KXPD3 paddle. When changing to each HF band I hit the ATU Tune button. On 40m and 20m I found that with the Pwr knob set to 15w, the Bird showed about 8w out. With the Pwr knob set to 5w, the power out is about 3w. After changing the antenna port and Bird element, on 2m with the radio set to 3w the Bird shows about 2.5w out. Any thoughts on these results, or suggestions on other things to check? Thanks and 73, Frank K6FOD ______________________________________________________________ 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 Message delivered to [hidden email] |
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Always something else I remember just after hitting send.
The KX3 is running off the Pro Audio Engineering PAE-Kx33 power supply, plugged into the 9-15 vdc connector. On 7/11/20 12:40 PM, Frank O'Donnell wrote: > After a fair time of non-use, today I got out my KX3 and started > working through configuration checklists. Among other things I thought > I'd check the power out. > > For this test I used a Bird 43 and MFJ-260C dummy load. For HF I used > a Bird 2-30 MHz 25w element, and for 2m a 100-250 MHz 10w element. I > put the KX3 in CW mode and keyed with the KXPD3 paddle. When changing > to each HF band I hit the ATU Tune button. > > On 40m and 20m I found that with the Pwr knob set to 15w, the Bird > showed about 8w out. With the Pwr knob set to 5w, the power out is > about 3w. > > After changing the antenna port and Bird element, on 2m with the radio > set to 3w the Bird shows about 2.5w out. > > Any thoughts on these results, or suggestions on other things to check? > > Thanks and 73, > > Frank K6FOD > > > > ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Frank O'Donnell
Hi.
I would not trust a Bird 43 or similar meter for any "Measurements" whatsoever. Especially if you cannot prove that the slugs and meter body were calibrated together. They are notoriously inaccurate, but are good for quick "power presence" indications, and "ball bark" VSWR checks. I honestly do not know why Bird 43's etc, are so coveted by the ham community, they are awful things for making measurements.. Note that the difference between 8W and 15W, is a bit less than 3dB. (2.73dB, or less than half an 'S' point!) And for 3 and 2.5W it's 0.79dB (Less than 1dB is not bad.) Also, how good is the MFJ load at VHF, VSWR wise. The spec says 1.5:1 above 30MHz. What did the radio say about that? 73. Dave G0WBX (Who's spent the last 30+ years working with QRO RF for a living. kHz to 10's of GHz, and many 10's of kW's.) On 11/07/2020 20:40, [hidden email] wrote: > From: Frank O'Donnell <[hidden email]> > To: "[hidden email]" <[hidden email]> > Subject: [Elecraft] KX3 power out > Message-ID: <[hidden email]> > > Content-Type: text/plain; charset=utf-8; format=flowed > > After a fair time of non-use, today I got out my KX3 and started working > through configuration checklists. Among other things I thought I'd check > the power out. > > For this test I used a Bird 43 and MFJ-260C dummy load. For HF I used a > Bird 2-30 MHz 25w element, and for 2m a 100-250 MHz 10w element. I put > the KX3 in CW mode and keyed with the KXPD3 paddle. When changing to > each HF band I hit the ATU Tune button. > > On 40m and 20m I found that with the Pwr knob set to 15w, the Bird > showed about 8w out. With the Pwr knob set to 5w, the power out is about 3w. > > After changing the antenna port and Bird element, on 2m with the radio > set to 3w the Bird shows about 2.5w out. > > Any thoughts on these results, or suggestions on other things to check? > > Thanks and 73, > > Frank K6FOD -- Created on and sent from a Unix like PC running and using free and open source software: ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Frank O'Donnell
On Sat, Jul 11, 2020 at 12:41 PM Frank O'Donnell <[hidden email]> wrote:
> > After a fair time of non-use, today I got out my KX3 and started working > through configuration checklists. Among other things I thought I'd check > the power out. > > For this test I used a Bird 43 and MFJ-260C dummy load. For HF I used a > Bird 2-30 MHz 25w element, and for 2m a 100-250 MHz 10w element. I put > the KX3 in CW mode and keyed with the KXPD3 paddle. When changing to > each HF band I hit the ATU Tune button. > > On 40m and 20m I found that with the Pwr knob set to 15w, the Bird > showed about 8w out. With the Pwr knob set to 5w, the power out is about 3w. > > After changing the antenna port and Bird element, on 2m with the radio > set to 3w the Bird shows about 2.5w out. > > Any thoughts on these results, or suggestions on other things to check? > >The KX3 is running off the Pro Audio Engineering PAE-Kx33 power supply, >plugged into the 9-15 vdc connector. Do you know that the Bird and slugs are good? Do you know that the dummy load is good? Bird meters, when they are calibrated, are specified at 5% of full scale, so +/- 1.25 W for the 25 W element and +/- 0.5W for the 10W element. Bird meters are rugged, but not really all that accurate. The dummy load should be 50 ohms resistive over the frequency range of interest. If they have been cooked, they often change. So, for two meters being off by 0.5W is within the calibration accuracy, even if the slug was calibrated. Slugs don't usually drift much though, unless cooked. Hams hardly ever calibrate their test equipment because it does cost a lot to do so, and it has to be done every year or two. In the case of the slugs, I think that calibration means measure and if bad, chuck it. The meter itself has a calibration, I believe. For 40M and 20m the readings are so different that it is likely something is wrong. Can you measure a different rig or with a different meter? 73, Mark W7MLG ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Frank O'Donnell
As a start, I’d recommend running through TX GAIN calibration using the KX3 Utility …
Grant NQ5T > On Jul 11, 2020, at 3:42 PM, Frank O'Donnell <[hidden email]> wrote: > > Always something else I remember just after hitting send. > > The KX3 is running off the Pro Audio Engineering PAE-Kx33 power supply, plugged into the 9-15 vdc connector. > > On 7/11/20 12:40 PM, Frank O'Donnell wrote: >> After a fair time of non-use, today I got out my KX3 and started working through configuration checklists. Among other things I thought I'd check the power out. >> >> For this test I used a Bird 43 and MFJ-260C dummy load. For HF I used a Bird 2-30 MHz 25w element, and for 2m a 100-250 MHz 10w element. I put the KX3 in CW mode and keyed with the KXPD3 paddle. When changing to each HF band I hit the ATU Tune button. >> >> On 40m and 20m I found that with the Pwr knob set to 15w, the Bird showed about 8w out. With the Pwr knob set to 5w, the power out is about 3w. >> >> After changing the antenna port and Bird element, on 2m with the radio set to 3w the Bird shows about 2.5w out. >> >> Any thoughts on these results, or suggestions on other things to check? >> >> Thanks and 73, >> >> Frank K6FOD >> >> >> >> > > ______________________________________________________________ > 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 > Message delivered to [hidden email] ______________________________________________________________ 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 Message delivered to [hidden email] |
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On 7/11/20 1:19 PM, Grant Youngman wrote:
> As a start, I’d recommend running through TX GAIN calibration using the KX3 Utility … Good suggestion. If a 2-meter module is installed, as is the case with mine, I wonder if the automated calibration using the KX3 Utility flies through all the bands including that one? I wouldn't want to start pressing buttons and find out the wrong way. The reason for my concern is that I only have one dummy load, the MFJ-260C. I'd like to get ahold of the Oak Hills Research RFL-100 mentioned here recently, but unfortunately when I tried to order one a few days ago his website said all sales had been suspended indefinitely due to COVID. I guess I can either scrounge another dummy load, or do the calibration band-by-band manually. Re Mark's questions about the Bird 43 and slugs, I do have an older Bird that I don't trust a great deal, but this one was bought new about a year ago, and the slugs are the same vintage or newer. I can try them out with other radios. As for Walter's point about the ATU, the results are mighty odd. I just set the KX3 to 40 meters with 15 watts out, appropriate slug in the Bird 43, set ATU to bypass and started keying. The power out dropped to about 5w. I then set ATU to auto and tapped the ATU Tune button. With the radio still set to 15w out, the Bird now peaked at about 25w! Is it plausible that antenna tuning activity within the KX3 could actually increase the TPO by ~5x? Or does that cast even more suspicion on the Bird? Frank ______________________________________________________________ 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 Message delivered to [hidden email] |
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This procedure (manual, or automated via the KX3 Utility) applies only to 160-6M
Grant NQ5T > On Jul 11, 2020, at 10:05 PM, Frank O'Donnell <[hidden email]> wrote: > > On 7/11/20 1:19 PM, Grant Youngman wrote: >> As a start, I’d recommend running through TX GAIN calibration using the KX3 Utility … > > Good suggestion. If a 2-meter module is installed, as is the case with mine, I wonder if the automated calibration using the KX3 Utility flies through all the bands including that one? I wouldn't want to start pressing buttons and find out the wrong way. The reason for my concern is that I only have one dummy load, the MFJ-260C. I'd like to get ahold of the Oak Hills Research RFL-100 mentioned here recently, but unfortunately when I tried to order one a few days ago his website said all sales had been suspended indefinitely due to COVID. I guess I can either scrounge another dummy load, or do the calibration band-by-band manually. > ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Frank O'Donnell
I believe that the KX3 does not have bypass relays in its ATU.
Instead, when you select "Bypass", it sets the ATU to have no C or L added. If the ATU is not functioning correctly, perhaps with a stuck relay, it may still be affecting the measurements. 73 Bill AE6JV On 7/11/20 at 10:05 PM, [hidden email] (Frank O'Donnell) wrote: >As for Walter's point about the ATU, the results are mighty >odd. I just set the KX3 to 40 meters with 15 watts out, >appropriate slug in the Bird 43, set ATU to bypass and started >keying. The power out dropped to about 5w. I then set ATU to >auto and tapped the ATU Tune button. With the radio still set >to 15w out, the Bird now peaked at about 25w! Is it plausible >that antenna tuning activity within the KX3 could actually >increase the TPO by ~5x? Or does that cast even more suspicion >on the Bird? ----------------------------------------------------------------------- Bill Frantz |The nice thing about standards| Periwinkle (408)348-7900 |is there are so many to choose| 150 Rivermead Rd #235 www.pwpconsult.com |from. - Andrew Tanenbaum | Peterborough, NH 03458 ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Frank O'Donnell
What is the key-down voltage seen on the KX3 display? Measure the regulated voltage at the PS under the same conditions. Is it OK? I had power control problems on my K3 until I solved the sagging voltage problem. GL & 73, K0DTJ
> On Jul 11, 2020, at 12:42, Frank O'Donnell <[hidden email]> wrote: > > Always something else I remember just after hitting send. > > The KX3 is running off the Pro Audio Engineering PAE-Kx33 power supply, plugged into the 9-15 vdc connector. > >> On 7/11/20 12:40 PM, Frank O'Donnell wrote: >> After a fair time of non-use, today I got out my KX3 and started working through configuration checklists. Among other things I thought I'd check the power out. >> >> For this test I used a Bird 43 and MFJ-260C dummy load. For HF I used a Bird 2-30 MHz 25w element, and for 2m a 100-250 MHz 10w element. I put the KX3 in CW mode and keyed with the KXPD3 paddle. When changing to each HF band I hit the ATU Tune button. >> >> On 40m and 20m I found that with the Pwr knob set to 15w, the Bird showed about 8w out. With the Pwr knob set to 5w, the power out is about 3w. >> >> After changing the antenna port and Bird element, on 2m with the radio set to 3w the Bird shows about 2.5w out. >> >> Any thoughts on these results, or suggestions on other things to check? >> >> Thanks and 73, >> >> Frank K6FOD > > ______________________________________________________________ > 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 > Message delivered to [hidden email] ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Frank O'Donnell
On Sat, Jul 11, 2020 at 7:06 PM Frank O'Donnell <[hidden email]> wrote:
> As for Walter's point about the ATU, the results are mighty odd. I just > set the KX3 to 40 meters with 15 watts out, appropriate slug in the Bird > 43, set ATU to bypass and started keying. The power out dropped to about > 5w. I then set ATU to auto and tapped the ATU Tune button. With the > radio still set to 15w out, the Bird now peaked at about 25w! Is it > plausible that antenna tuning activity within the KX3 could actually > increase the TPO by ~5x? Or does that cast even more suspicion on the Bird? The KX3 will definitely cut way back on power out if it sees a mismatched load or a line voltage drop. I use my KX3 to tune a screwdriver antenna. I normally set the power out to about 3W, but sometimes forget and leave it at 15W. When matched, it puts out a full 15W. When it sees a high SWR, it will cut back to a few watts. I have the tuner bypassed. The KX3 will show you what it sees as the SWR as well as the power, and you can also look at reflected power on the Bird. Hopefully those will tell you something. 73, Mark W7MLG ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Brian Hunt
On the KX3 display, the voltage is 14.3v at idle, 13.8v key-down. At the
power supply, 14.5v idle, 14.15v key-down. On 7/11/20 7:51 PM, Brian Hunt wrote: > What is the key-down voltage seen on the KX3 display? Measure the regulated voltage at the PS under the same conditions. Is it OK? I had power control problems on my K3 until I solved the sagging voltage problem. ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Mark Goldberg
On 7/11/20 8:40 PM, Mark Goldberg wrote:
> The KX3 will definitely cut way back on power out if it sees a > mismatched load or a line voltage drop. I use my KX3 to tune a > screwdriver antenna. I normally set the power out to about 3W, but > sometimes forget and leave it at 15W. When matched, it puts out a full > 15W. When it sees a high SWR, it will cut back to a few watts. I have > the tuner bypassed. The KX3 will show you what it sees as the SWR as > well as the power, and you can also look at reflected power on the > Bird. Hopefully those will tell you something. Interesting info, thanks. I'm still baffled at why putting the ATU on auto and tapping to tune would cause the wattmeter to show TPO at 25 watts. Frank ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Frank O'Donnell
I also have the KX3 with 2m module and ATU.
My understanding is Auto is used to tune the antenna but you then switch to MAN to operate after the ATU tunes to your antenna (my KXPA100/KXTA100 works the same way). My original 2m module (kit) did not reach full output so I returned the module to Elecraft and they fixed it. But I still only see 2.5w output on my Bird meter with 25C element into Bird load. My guess the Bird is off calibration though 5% of 25 is 1.25w, so it could be just the limit of the Bird's accuracy. I use it to drive a 60w MOT amp that only needs 2w drive so all good. My KX3 only outputs 12w on HF but I haven't upgraded firmware so maybe that would increase to 15w. No matter as the KXPA100 only requires about 5.5w drive for 100w out on 80-10m and 8w provides 80w on 6m (which is normal). I think the ATU is kind of fussy at times and I have to redo the tuning to have it work right. I usually trust the power & SWR meter on the KXPA100 for day to day use. I have two Bird meters (one is permanently in my 2m-eme antenna line). A couple years ago I discovered the calibration limits of Bird elements when using a 250E element to measure my 150w 1296 amp. It only read 125w. But the element is rated for 400-1000 MHz and falls off above that (which explains the low reading). I now have a 600w amp on 1296 and use directional couplers and my HP432A mw power meter. The 250E and 500E are grossly inaccurate at 1296. BTW Bird dummy loads can be found on e-bay and other ham lists. They are rated to 1000 MHz. 73, Ed - KL7UW http://www.kl7uw.com Dubus-NA Business mail: [hidden email] ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Elecraft mailing list
I believe the calibration is under the label on top of the slug. I would guess if you had knowledge of a source of RF that would deflect the meter accurately mid scale given the slug you were calibrating, then that would be the best you could do.
Not it matters for most ham radio use...fairly accurate repeatability is probably a much more valuable test result. Chuck KE9UW [hidden email] Sent from my iPad > On Jul 13, 2020, at 10:30 AM, Dave B via Elecraft <[hidden email]> wrote: > > Hi. > > I would not trust a Bird 43 or similar meter for any "Measurements" > whatsoever. > > Especially if you cannot prove that the slugs and meter body were > calibrated together. > > They are notoriously inaccurate, but are good for quick "power presence" > indications, and "ball bark" VSWR checks. > > I honestly do not know why Bird 43's etc, are so coveted by the ham > community, they are awful things for making measurements.. > > Note that the difference between 8W and 15W, is a bit less than 3dB. > (2.73dB, or less than half an 'S' point!) > > And for 3 and 2.5W it's 0.79dB (Less than 1dB is not bad.) > > Also, how good is the MFJ load at VHF, VSWR wise. The spec says 1.5:1 > above 30MHz. What did the radio say about that? > > 73. > > Dave G0WBX (Who's spent the last 30+ years working with QRO RF for a > living. kHz to 10's of GHz, and many 10's of kW's.) > > >> On 11/07/2020 20:40, [hidden email] wrote: >> From: Frank O'Donnell <[hidden email]> >> To: "[hidden email]" <[hidden email]> >> Subject: [Elecraft] KX3 power out >> Message-ID: <[hidden email]> >> >> Content-Type: text/plain; charset=utf-8; format=flowed >> >> After a fair time of non-use, today I got out my KX3 and started working >> through configuration checklists. Among other things I thought I'd check >> the power out. >> >> For this test I used a Bird 43 and MFJ-260C dummy load. For HF I used a >> Bird 2-30 MHz 25w element, and for 2m a 100-250 MHz 10w element. I put >> the KX3 in CW mode and keyed with the KXPD3 paddle. When changing to >> each HF band I hit the ATU Tune button. >> >> On 40m and 20m I found that with the Pwr knob set to 15w, the Bird >> showed about 8w out. With the Pwr knob set to 5w, the power out is about 3w. >> >> After changing the antenna port and Bird element, on 2m with the radio >> set to 3w the Bird shows about 2.5w out. >> >> Any thoughts on these results, or suggestions on other things to check? >> >> Thanks and 73, >> >> Frank K6FOD > > -- > Created on and sent from a Unix like PC running and using free and open source software: > > ______________________________________________________________ > 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 > Message delivered to [hidden email] 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 Message delivered to [hidden email]
Chuck, KE9UW
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