Re: [Elecraft] K3S Receiver Spurious
On 12/5/2023 9:33 AM, Michael Tope wrote: I did move the Astron RS-35 that powers the K3S off my UPS a few weeks ago. See this note on a manufacturing issue that I found in several of my Astron supplies that can cause instability. The bond between the AC green wire, V-, is insulated from the chassis by paint at the mounting leg of the old-style terminal strip next to the V- terminal. The defect can be confirmed by an ohmmeter measurement between the green wire at the plug and the chassis. http://k9yc.com/PowerSupplyBondingAndAudioDistortion.pdf 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3S Receiver Spurious
Yes, I operate the station remotely, so there is a fair bit of stuff attached to the rig including a Windows PC. There probably isn't a good intentional bond between the computer chassis and the rig chassis. The current setup is "temporary", so I never got around to bonding everything to the copper bus bar that I have sitting around waiting to be put into service. The plan was to do all that once I finish remodeling the inside of the cabin where the station resides. At the rate things are going, however, I should probably go ahead and install the buss bar. "Temporary" is turning into years. That said, the receive spurious seems to be new. I would have noticed it before if it had been a longstanding problem. I did move the Astron RS-35 that powers the K3S off my UPS a few weeks ago. There was an issue where UPS output was dropping for no apparent reason. It doesn't appear to be the battery which holds the reduced load up fine if you pull the plug. I need to troubleshoot that further, but for now it seems to be working fine with the reduced load. It is a recent configuration change, so it's possible that the spurious is somehow related. 73, Mike W4EF On 12/3/2023 7:41 PM, David Gilbert wrote: Is your K3S connected to a computer (or some other significant piece of electronics), and if so, are they tightly and closely bonded together chassis wise? 73, Dave AB7E On 12/3/2023 8:11 PM, Michael Tope wrote: Hi All, I noticed when operating the ARRL 160 contest this weekend that my K3S has developed a nasty case of what appears to be some sort of LO spurious. When tuning across strong signals, I can now hear a low-level buzz (like phase noise reciprocal mixing) as I tune off them followed by a distinct tone peak 400 Hz off the fundamental frequency (as if there is a discrete spurious at that offset from the carrier frequency). I had noticed that a few days or weeks ago on one signal and dismissed it as being someone with a dirty transmit signal. After tuning across a number of strong signals on 160 and seeing the same phenomenon, it is clear that the problem is coming from my rig. I don't know if the problem is showing up on my transmit signal as I haven't received any reports that I have a dirty transmit signal. I just listened to my carrier on a WebSDR and it sounds clean and I don't see any sidebands on the waterfall, so I think it may be confined to receive only. So far I have been troubleshooting this remotely over the internet, so I haven't had a chance to twist knobs or look at the hidden menus carefully. Any ideas as to what might be causing this? Is there some problem common to the K3S that manifests itself like this? Thanks & 73, Mike W4EF... __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to w...@ca.rr.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3S Receiver Spurious
Is the noise blanker on? It might sound like this if there is repetitive noise being blanked by the NB. 73, Victor, 4X6GP Rehovot, Israel Formerly K2VCO CWops no. 5 http://www.qsl.net/k2vco/ On 04/12/2023 5:11, Michael Tope wrote: Hi All, I noticed when operating the ARRL 160 contest this weekend that my K3S has developed a nasty case of what appears to be some sort of LO spurious. When tuning across strong signals, I can now hear a low-level buzz (like phase noise reciprocal mixing) as I tune off them followed by a distinct tone peak 400 Hz off the fundamental frequency (as if there is a discrete spurious at that offset from the carrier frequency). I had noticed that a few days or weeks ago on one signal and dismissed it as being someone with a dirty transmit signal. After tuning across a number of strong signals on 160 and seeing the same phenomenon, it is clear that the problem is coming from my rig. I don't know if the problem is showing up on my transmit signal as I haven't received any reports that I have a dirty transmit signal. I just listened to my carrier on a WebSDR and it sounds clean and I don't see any sidebands on the waterfall, so I think it may be confined to receive only. So far I have been troubleshooting this remotely over the internet, so I haven't had a chance to twist knobs or look at the hidden menus carefully. Any ideas as to what might be causing this? Is there some problem common to the K3S that manifests itself like this? Thanks & 73, Mike W4EF... __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k2vco@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3S Receiver Spurious
Is your K3S connected to a computer (or some other significant piece of electronics), and if so, are they tightly and closely bonded together chassis wise? 73, Dave AB7E On 12/3/2023 8:11 PM, Michael Tope wrote: Hi All, I noticed when operating the ARRL 160 contest this weekend that my K3S has developed a nasty case of what appears to be some sort of LO spurious. When tuning across strong signals, I can now hear a low-level buzz (like phase noise reciprocal mixing) as I tune off them followed by a distinct tone peak 400 Hz off the fundamental frequency (as if there is a discrete spurious at that offset from the carrier frequency). I had noticed that a few days or weeks ago on one signal and dismissed it as being someone with a dirty transmit signal. After tuning across a number of strong signals on 160 and seeing the same phenomenon, it is clear that the problem is coming from my rig. I don't know if the problem is showing up on my transmit signal as I haven't received any reports that I have a dirty transmit signal. I just listened to my carrier on a WebSDR and it sounds clean and I don't see any sidebands on the waterfall, so I think it may be confined to receive only. So far I have been troubleshooting this remotely over the internet, so I haven't had a chance to twist knobs or look at the hidden menus carefully. Any ideas as to what might be causing this? Is there some problem common to the K3S that manifests itself like this? Thanks & 73, Mike W4EF... __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] K3S Receiver Spurious
Hi All, I noticed when operating the ARRL 160 contest this weekend that my K3S has developed a nasty case of what appears to be some sort of LO spurious. When tuning across strong signals, I can now hear a low-level buzz (like phase noise reciprocal mixing) as I tune off them followed by a distinct tone peak 400 Hz off the fundamental frequency (as if there is a discrete spurious at that offset from the carrier frequency). I had noticed that a few days or weeks ago on one signal and dismissed it as being someone with a dirty transmit signal. After tuning across a number of strong signals on 160 and seeing the same phenomenon, it is clear that the problem is coming from my rig. I don't know if the problem is showing up on my transmit signal as I haven't received any reports that I have a dirty transmit signal. I just listened to my carrier on a WebSDR and it sounds clean and I don't see any sidebands on the waterfall, so I think it may be confined to receive only. So far I have been troubleshooting this remotely over the internet, so I haven't had a chance to twist knobs or look at the hidden menus carefully. Any ideas as to what might be causing this? Is there some problem common to the K3S that manifests itself like this? Thanks & 73, Mike W4EF... __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
