K3 bad TX
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I was using SO2R with pair of K3s' and had similar reports with both
radios, so I guess it's not the amp issue. The bands where I got reports were 20M and 15M (on 10M were no propagation and maybe 40M and 80M were too noisy to notice the 2nd sigs). All antennas are OK and no difference was noted with antennas. 73 de Toni, OH2UA >Tke the amp out of the equation and see if you still have the issue. Try a >different antenna and check the SWR. I would suspect one of those to be the >issue. At least it will eliminate some variables. > >Dan AB3EN > Toni Lindén wrote: > > Hi! > > I was trying K3 for first time in SAC contest a couple of weeks ago. > > During the contest I got multiple reports that besides of my run > frequency, I also had other reasonable strong signals "around the > band". > > It cleared out that I had at least one other signal about 7kHz away > from my actual freq. It was quite strong, maybe 40dBs down from my > running freq. > > Have anyone else had similar problems and do you have any suggestion > how to fix this? > > I was using only about 60 to 70 watts drive for the amp and amp was > not pushed over. The same appears on both, CW and SSB. Radio has the > most resent FWs available via K3 utility SW. > > I'm planning to take K3 with me to CU2 for CQWW, but after getting > such a bad reports about "my 2nd pileup" on the same band, I'm not > sure if I'm willing to make such an interference to others on CQWW... > > So if anyone has any advice, I'm more than pleased to hear! > > > 73 de Toni, OH2UA Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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G'day,
For what it is worth. Just done a quick test with my K3/K2 combo. K3 14020kHz. 50W into my beam. K2 with no antenna connected receives a signal at S9+20 on the S-meter. Keying at 14013.67kHz and 14026.38kHz was heard. Additionally I heard signals at 14007.24kHz and 14000.99kHz, didn't tune further above the test signal. The Pre-amp needed to be on but the signals were sufficient to trigger the CW tuning indicator. Close in TX noise faded out below the 14007.24kHz test signal. Draw your own conclusions. Mine are that there is a very low level signal comb approximately at +/- 6.33kHz intervals either side of the K3 transmission. Someone else suitably equipped can measure how far down. Regards, Mike VP8NO ----- Original Message ----- From: "Toni Lindén" <[hidden email]> To: <[hidden email]> Sent: Sunday, October 04, 2009 10:21 AM Subject: [Elecraft] K3 bad TX I was using SO2R with pair of K3s' and had similar reports with both radios, so I guess it's not the amp issue. The bands where I got reports were 20M and 15M (on 10M were no propagation and maybe 40M and 80M were too noisy to notice the 2nd sigs). All antennas are OK and no difference was noted with antennas. 73 de Toni, OH2UA >Tke the amp out of the equation and see if you still have the >issue. Try a >different antenna and check the SWR. I would suspect one of those >to be the >issue. At least it will eliminate some variables. > >Dan AB3EN > Toni Lindén wrote: > > Hi! > > I was trying K3 for first time in SAC contest a couple of weeks > ago. > > During the contest I got multiple reports that besides of my run > frequency, I also had other reasonable strong signals "around the > band". > > It cleared out that I had at least one other signal about 7kHz > away > from my actual freq. It was quite strong, maybe 40dBs down from my > running freq. > > Have anyone else had similar problems and do you have any > suggestion > how to fix this? > > I was using only about 60 to 70 watts drive for the amp and amp > was > not pushed over. The same appears on both, CW and SSB. Radio has > the > most resent FWs available via K3 utility SW. > > I'm planning to take K3 with me to CU2 for CQWW, but after getting > such a bad reports about "my 2nd pileup" on the same band, I'm not > sure if I'm willing to make such an interference to others on > CQWW... > > So if anyone has any advice, I'm more than pleased to hear! > > > 73 de Toni, OH2UA 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 -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.409 / Virus Database: 270.14.3/2413 - Release Date: 10/04/09 06:20:00 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Toni Lindén
Toni,
Yes you had it on 40m too. Actually on 40m the spur came right on my frequency and due to that I did notice it. I was going to let you know but forgot about it. 73 Jim SM2EKM ----------------------- Toni Lindén wrote: > I was using SO2R with pair of K3s' and had similar reports with both > radios, so I guess it's not the amp issue. The bands where I got > reports were 20M and 15M (on 10M were no propagation and maybe 40M and > 80M were too noisy to notice the 2nd sigs). > > All antennas are OK and no difference was noted with antennas. > > 73 de Toni, OH2UA > > >> Tke the amp out of the equation and see if you still have the issue. Try a >> different antenna and check the SWR. I would suspect one of those to be the >> issue. At least it will eliminate some variables. >> >> Dan AB3EN >> > > Toni Lindén wrote: >> Hi! >> >> I was trying K3 for first time in SAC contest a couple of weeks ago. >> >> During the contest I got multiple reports that besides of my run >> frequency, I also had other reasonable strong signals "around the >> band". >> >> It cleared out that I had at least one other signal about 7kHz away >> from my actual freq. It was quite strong, maybe 40dBs down from my >> running freq. >> >> Have anyone else had similar problems and do you have any suggestion >> how to fix this? >> >> I was using only about 60 to 70 watts drive for the amp and amp was >> not pushed over. The same appears on both, CW and SSB. Radio has the >> most resent FWs available via K3 utility SW. >> >> I'm planning to take K3 with me to CU2 for CQWW, but after getting >> such a bad reports about "my 2nd pileup" on the same band, I'm not >> sure if I'm willing to make such an interference to others on CQWW... >> >> So if anyone has any advice, I'm more than pleased to hear! >> >> >> 73 de Toni, OH2UA > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Toni Lindén
It should be easy enough to test for, surely. Just TX into a dummy load and listen on another receiver with a short wire antenna enough to pick up the signal from the dummy load. That's what I'd do if I received such a report from anybody.
Julian, G4ILO. K2 #392 K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html |
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In reply to this post by Toni Lindén
I've just run my K3 at 70 Watts into a 50 Ohm load, 14.020 MHz. Results
were spurs at +/- 11.9 KHz which are between 103 and 106 dB down. The noise at 7 KHz out from the carrier is 106 dB down, even at 50 WPM keying (internal keyer). There was a spur 263 KHz up which was 98 dB down. On 21 MHz there is a fixed spur on transmit at 21.028 MHz, it's still 94 dB down, no sign of the +/- 11.9 KHz spurs. Tuning the K3 across the band while transmitting and watching the signal (both 20m and 15m) didn't produce any odd spurious signals, except those noted above. Measurements done with a Microtelecom Perseus receiver and 50 dB attenuator. The Perseus has a similar specification to a spectrum analyser and used direct A/D conversion without mixing. 73 Dave, G4AON K3/100 #80 =============== Mike VP8NO wrote: For what it is worth. Just done a quick test with my K3/K2 combo. K3 14020kHz. 50W into my beam. K2 with no antenna connected receives a signal at S9+20 on the S-meter. Keying at 14013.67kHz and 14026.38kHz was heard. Additionally I heard signals at 14007.24kHz and 14000.99kHz, didn't tune further above the test signal. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Toni Lindén
I had a similar problem on receive for a while - also transmit. It turned out to be a fault in the VCO. I found it using my spectrum analyser. If you don't have one consider getting one. A panadapter will also show it. Hunting around with another rig is not as good a method but should also work if that other rig is clean itself - it will be hard to find a rig as clean as a properly operating K3 though.
I am suspicious as I would not expect both rigs to have VCO faults. It might well be something else like a stray maganetic field or PSU issue. If it is a VCO fault, your K3s should show it on both TX and RX. You can use your signal generator to produce a strong carrier and tune for the spurs. If you do not have a signal generator a crystal oscillator would do as well. If it is only on TX, it is not the VFO. There is a mod for the older VCOs you ought to do but it is not directly for this problem. My faulty VCOs spurs were - I think 30-40 dB down and the phase noise was pretty bad - I have an analyser plot of it somewhere. [Found it - my spurs were +-500Hz - I think something in the VCO was oscillating at audio] To fix it I swapped over the VCOs between sub and main, it not being very practical to send stuff back when you are outside the US and with this sort of thing the instability might not show up in a different K3. The second VFO which was a later version is very very clean, there are a couple of spurs either side of the carrier but a long way down. Good luck fixing it.I just wish all the other people out there cared as much as you do about their transmitted signals as I come across some really bad ones on the bands - usually from overdriven linears.
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In reply to this post by Toni Lindén
I don't understand ... if you used two different K3's and the same amp (I assume for both K3's), how does that remove the amp as a possible cause of the spurs? I don't think you narrow anything down to the K3 until you check the results into a dummy load. If you have two K3's, transmit into a dummy load with one while you check for spurs with the other. 73, Dave AB7E Toni Lindén wrote: > I was using SO2R with pair of K3s' and had similar reports with both > radios, so I guess it's not the amp issue. The bands where I got > reports were 20M and 15M (on 10M were no propagation and maybe 40M and > 80M were too noisy to notice the 2nd sigs). > > All antennas are OK and no difference was noted with antennas. > > 73 de Toni, OH2UA > > > >> Tke the amp out of the equation and see if you still have the issue. Try a >> different antenna and check the SWR. I would suspect one of those to be the >> issue. At least it will eliminate some variables. >> >> Dan AB3EN >> >> > > Toni Lindén wrote: > >> Hi! >> >> I was trying K3 for first time in SAC contest a couple of weeks ago. >> >> During the contest I got multiple reports that besides of my run >> frequency, I also had other reasonable strong signals "around the >> band". >> >> It cleared out that I had at least one other signal about 7kHz away >> from my actual freq. It was quite strong, maybe 40dBs down from my >> running freq. >> >> Have anyone else had similar problems and do you have any suggestion >> how to fix this? >> >> I was using only about 60 to 70 watts drive for the amp and amp was >> not pushed over. The same appears on both, CW and SSB. Radio has the >> most resent FWs available via K3 utility SW. >> >> I'm planning to take K3 with me to CU2 for CQWW, but after getting >> such a bad reports about "my 2nd pileup" on the same band, I'm not >> sure if I'm willing to make such an interference to others on CQWW... >> >> So if anyone has any advice, I'm more than pleased to hear! >> >> >> 73 de Toni, OH2UA >> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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I believe by "amp" we are talking about disabling the KPA3 in the CONFIG
menu by putting it in bypass to see if the spur is related to the K3's internal AMP, not an external amp. Steve N4LQ [hidden email] ----- Original Message ----- From: "David Gilbert" <[hidden email]> To: "Toni Lindén" <[hidden email]> Cc: <[hidden email]> Sent: Sunday, October 04, 2009 12:13 PM Subject: Re: [Elecraft] K3 bad TX I don't understand ... if you used two different K3's and the same amp (I assume for both K3's), how does that remove the amp as a possible cause of the spurs? I don't think you narrow anything down to the K3 until you check the results into a dummy load. If you have two K3's, transmit into a dummy load with one while you check for spurs with the other. 73, Dave AB7E Toni Lindén wrote: > I was using SO2R with pair of K3s' and had similar reports with both > radios, so I guess it's not the amp issue. The bands where I got > reports were 20M and 15M (on 10M were no propagation and maybe 40M and > 80M were too noisy to notice the 2nd sigs). > > All antennas are OK and no difference was noted with antennas. > > 73 de Toni, OH2UA > > > >> Tke the amp out of the equation and see if you still have the issue. Try >> a >> different antenna and check the SWR. I would suspect one of those to be >> the >> issue. At least it will eliminate some variables. >> >> Dan AB3EN >> >> > > Toni Lindén wrote: > >> Hi! >> >> I was trying K3 for first time in SAC contest a couple of weeks ago. >> >> During the contest I got multiple reports that besides of my run >> frequency, I also had other reasonable strong signals "around the >> band". >> >> It cleared out that I had at least one other signal about 7kHz away >> from my actual freq. It was quite strong, maybe 40dBs down from my >> running freq. >> >> Have anyone else had similar problems and do you have any suggestion >> how to fix this? >> >> I was using only about 60 to 70 watts drive for the amp and amp was >> not pushed over. The same appears on both, CW and SSB. Radio has the >> most resent FWs available via K3 utility SW. >> >> I'm planning to take K3 with me to CU2 for CQWW, but after getting >> such a bad reports about "my 2nd pileup" on the same band, I'm not >> sure if I'm willing to make such an interference to others on CQWW... >> >> So if anyone has any advice, I'm more than pleased to hear! >> >> >> 73 de Toni, OH2UA >> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Toni Lindén
Ahhh ... I didn't think of that. Thanks for the clarification! 73, Dave AB7E [hidden email] wrote: > I think he means the K3 amp issue - the amp in the K3. > > > <quote author='David Gilbert'> > > I don't understand ... if you used two different K3's and the same amp > (I assume for both K3's), how does that remove the amp as a possible > cause of the spurs? I don't think you narrow anything down to the K3 > until you check the results into a dummy load. If you have two K3's, > transmit into a dummy load with one while you check for spurs with the > other. > > 73, > Dave AB7E > > > > Toni Lindén wrote: > >> I was using SO2R with pair of K3s' and had similar reports with both >> radios, so I guess it's not the amp issue. The bands where I got >> reports were 20M and 15M (on 10M were no propagation and maybe 40M and >> 80M were too noisy to notice the 2nd sigs). >> >> All antennas are OK and no difference was noted with antennas. >> >> 73 de Toni, OH2UA >> >> >> >> >>> Tke the amp out of the equation and see if you still have the issue. Try >>> a >>> different antenna and check the SWR. I would suspect one of those to be >>> the >>> issue. At least it will eliminate some variables. >>> >>> Dan AB3EN >>> >>> >>> >> Toni Lindén wrote: >> >> >>> Hi! >>> >>> I was trying K3 for first time in SAC contest a couple of weeks ago. >>> >>> During the contest I got multiple reports that besides of my run >>> frequency, I also had other reasonable strong signals "around the >>> band". >>> >>> It cleared out that I had at least one other signal about 7kHz away >>> from my actual freq. It was quite strong, maybe 40dBs down from my >>> running freq. >>> >>> Have anyone else had similar problems and do you have any suggestion >>> how to fix this? >>> >>> I was using only about 60 to 70 watts drive for the amp and amp was >>> not pushed over. The same appears on both, CW and SSB. Radio has the >>> most resent FWs available via K3 utility SW. >>> >>> I'm planning to take K3 with me to CU2 for CQWW, but after getting >>> such a bad reports about "my 2nd pileup" on the same band, I'm not >>> sure if I'm willing to make such an interference to others on CQWW... >>> >>> So if anyone has any advice, I'm more than pleased to hear! >>> >>> >>> 73 de Toni, OH2UA >>> >>> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> >> >> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > </quote> > Quoted from: http://n2.nabble.com/K3-bad-TX-tp3763903p3764377.html > > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Just to demonstrate that the K3 TX spectrum is excellent, I have uploaded some plots to flickr
starting at http://www.flickr.com/photos/ad6xy/3980006295/ with the ones between up to http://www.flickr.com/photos/ad6xy/3980007573/ showing the close in spectrum at 100W output on 14.2 MHz for a CW tone - it has no obvious spurii except those close to the carrier above -90dBc. The close in plot shows the usual 50Hz mains spurs plus some at 400Hz but even these are 60 dB down. I am not sure if the K3 is better than the analyser. I did some 2-tone tests to see if it could be that, they are in the following 4 pictures but again, there is nothing wrong and indeed the results are rather good for a 12V PA. It is interesting the K3 is cleaner close in at 50W than at 10W. That is because of the bypassing of the PA below 12W. I thought this had been corrected to 10W when the big PA was limited to 100W but not so. Mike |
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In reply to this post by David Gilbert
I can find +/- 6.33 kHz on my K3 on 20m, but it's down in excess of 100 db.
That's listening with an antenna-less K2, the main signal showing 10 over 9, and the "spurs" below standard MDS, just barely detectable as a tone by ear in the RX noise with a narrow CW bandwidth. Are you using the internal speaker? Does the level vary if you push internal cables around inside? 73, Guy.. On Sun, Oct 4, 2009 at 12:59 PM, David Gilbert <[hidden email]>wrote: > > > Ahhh ... I didn't think of that. Thanks for the clarification! > > 73, > Dave AB7E > > > > [hidden email] wrote: > > I think he means the K3 amp issue - the amp in the K3. > > > > > > <quote author='David Gilbert'> > > > > I don't understand ... if you used two different K3's and the same amp > > (I assume for both K3's), how does that remove the amp as a possible > > cause of the spurs? I don't think you narrow anything down to the K3 > > until you check the results into a dummy load. If you have two K3's, > > transmit into a dummy load with one while you check for spurs with the > > other. > > > > 73, > > Dave AB7E > > > > > > > > Toni Lindén wrote: > > > >> I was using SO2R with pair of K3s' and had similar reports with both > >> radios, so I guess it's not the amp issue. The bands where I got > >> reports were 20M and 15M (on 10M were no propagation and maybe 40M and > >> 80M were too noisy to notice the 2nd sigs). > >> > >> All antennas are OK and no difference was noted with antennas. > >> > >> 73 de Toni, OH2UA > >> > >> > >> > >> > >>> Tke the amp out of the equation and see if you still have the issue. > Try > >>> a > >>> different antenna and check the SWR. I would suspect one of those to be > >>> the > >>> issue. At least it will eliminate some variables. > >>> > >>> Dan AB3EN > >>> > >>> > >>> > >> Toni Lindén wrote: > >> > >> > >>> Hi! > >>> > >>> I was trying K3 for first time in SAC contest a couple of weeks ago. > >>> > >>> During the contest I got multiple reports that besides of my run > >>> frequency, I also had other reasonable strong signals "around the > >>> band". > >>> > >>> It cleared out that I had at least one other signal about 7kHz away > >>> from my actual freq. It was quite strong, maybe 40dBs down from my > >>> running freq. > >>> > >>> Have anyone else had similar problems and do you have any suggestion > >>> how to fix this? > >>> > >>> I was using only about 60 to 70 watts drive for the amp and amp was > >>> not pushed over. The same appears on both, CW and SSB. Radio has the > >>> most resent FWs available via K3 utility SW. > >>> > >>> I'm planning to take K3 with me to CU2 for CQWW, but after getting > >>> such a bad reports about "my 2nd pileup" on the same band, I'm not > >>> sure if I'm willing to make such an interference to others on CQWW... > >>> > >>> So if anyone has any advice, I'm more than pleased to hear! > >>> > >>> > >>> 73 de Toni, OH2UA > >>> > >>> > >> ______________________________________________________________ > >> Elecraft mailing list > >> Home: http://mailman.qth.net/mailman/listinfo/elecraft > >> Help: http://mailman.qth.net/mmfaq.htm > >> Post: mailto:[hidden email] > >> > >> This list hosted by: http://www.qsl.net > >> Please help support this email list: http://www.qsl.net/donate.html > >> > >> > >> > > ______________________________________________________________ > > Elecraft mailing list > > Home: http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/mmfaq.htm > > Post: mailto:[hidden email] > > > > This list hosted by: http://www.qsl.net > > Please help support this email list: http://www.qsl.net/donate.html > > > > </quote> > > Quoted from: http://n2.nabble.com/K3-bad-TX-tp3763903p3764377.html > > > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by AD6XY
Yes, I've noticed that when looking at PSK31 IMD measurements. I'd really like the option not to disable the PA when going below 12W. Currently, running 10W PSK31 using my 100W transceiver really isn't an option, though fortunately it isn't something I often want to do.
Julian, G4ILO. K2 #392 K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html |
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