Re: [Elecraft] K3S Audio buzz on transmit, especially AM
Ahh indeed. Several hours at W7RN with a new router trying random things was less than productive. A more structured, several step effort at home yielded the solution, which was primarily router pilot error. 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County On 4/27/2019 1:02 PM, Rick WA6NHC wrote: What they are saying is that it is best to break things down into logical clear steps, isolating as much as possible to prove or eliminate cause and effect. The issue are that some folks don't know enough to do this and some have issues trying to be logical; running in circles while others often seek the easy way(s) out. No slur is meant or intended, people have different abilities or we wouldn't need groups like this. This is all best done while the XYL is at the spa or otherwise unavailable for a few hours. ;-) __ 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] K3S Audio buzz on transmit, especially AM
Hi Nick, You've done a good job organizing your tests and test results. One more question: how far is your transmitting antenna from your ham shack and other nearby homes? Very telling is this comment at the end of your email: "Transmitting into a dummy load *while* turning off all nearby power supplies and lights with the KX3 immediately adjacent the dummy load: nice, pristine signal" That certainly points to EMC issues in your environment. When you're ready for additional tests, first go back to your pristine signal case. Then -- one by one -- turn additional radio accessories and household on and reconnect them. Repeat your test each time you change something. I strongly suspect that you have a common EMI condition in your ham shack, probably elsewhere in your home and possibly in adjacent homes known as "RF FLOODING." What the heck is RF Flooding? When a strong RF signal enters a non-linear device (semiconductors most commonly, but also ferrites near saturation) that also carries other signals (most commonly AC power, but also computer related signals such as Ethernet), the non-linear device will mix the two signals together and reradiate them (including harmonics of the RF signal) on the wires connected to the non-linear device. Multi-operator and SO2R operator contest stations have experienced RF Flooding interference for decades, but the problem has become much worse as semiconductor devices have proliferated. Switching power supplies are among the worst offenders, especially wall-warts. If you have a RF flooding problem it will be especially apparent on the second and third harmonic of your transmitted signal. On the harmonic frequencies the buzz sidebands may be stronger than the transmitted harmonic. So what to do about it? If you don't intend to operate multi-operator or SO2R contests from your QTH, there's no reason to fix the problem at all. The buzz sidebands probably don't radiate more than a few hundred feet from your QTH. In that case its simply been an EMC learning experience about the consequences of introducing a strong RF field into a houseful of electronics. 73 Frank W3LPL - Original Message - From: "Nicklas Johnson" To: "elecraft" Sent: Saturday, April 27, 2019 6:31:53 PM Subject: Re: [Elecraft] K3S Audio buzz on transmit, especially AM I don't think that "collecting data" and "process of elimination" are particularly ANTI-methodical either. But the fact is that most people will never encounter this kind of problem and don't spend their days practicing how to troubleshoot it, so they seek advice from people who do have experience. Thus this email thread, which began with my thinking I'd developed an audio fault in the rig and seeking advice, but successive tests have pointed in other directions. To answer Jim's earlier question, yes, it does appear that transmitting an unmodulated AM carrier from the K3S into anything resembling an antenna yields a buzz on the KX3 receiver (and vice-versa). The buzz is NOT audible when listening to the K3S's own TX monitor. And to answer Frank's question, the PG transformer in our front yard for the underground utilities is approximately 30 horizontal feet over and 6 vertical feet down from the station. The distance to the utilities that run through the back of our lot is approximately 60 feet. I spent the morning reviewing (again) materials on grounding and bonding over my morning coffee to see if there's something important I missed, and I also found by repeating it that an earlier test I'd done had given me a misleading/contradictory result-- transmitting into a dummy load immediately adjacent the KX3 receiving it produces a nice, clean signal. I was misled before by the KX3 picking up a different buzz (probably off a wall wart) in the shack when performing this test earlier. (It also helped in this case to put the KX3 into CW mode to detect the unmodulated AM carrier.) FWIW, this morning I also disconnected the bonding between the station's ground rod and the house's utility power and also disconnected the DTV antenna run into the house (which shares the same coax grounding/surge protection bus outside, but of course could find another path to ground over the coax shield via either one of the TV receivers). Doing so eliminated any *direct * connection with the utility power, as I'm still running purely on battery power. This had NO effect on the received buzz. At this point I'm pretty sure this is an environmental issue and not a problem with either rig, so it's probably not appropriate for me to continue to pester the list about it. Thank you again to everyone who offered suggestions and advice. But for posterity, and in case anyone comes along searching the list while debugging a similar problem, here's a list of all the other things that I tried to isolate the probl
Re: [Elecraft] K3S Audio buzz on transmit, especially AM
What they are saying is that it is best to break things down into logical clear steps, isolating as much as possible to prove or eliminate cause and effect. The issue are that some folks don't know enough to do this and some have issues trying to be logical; running in circles while others often seek the easy way(s) out. No slur is meant or intended, people have different abilities or we wouldn't need groups like this. This is all best done while the XYL is at the spa or otherwise unavailable for a few hours. ;-) Here is one example for your situation: A critical and valid test to find the source of your radio problem is to run the radio on battery (no solar, no other wiring including ground) into a dummy load (completely isolated from everything, including any metal table that might be in use) with the house mains (and any outbuildings) turned completely OFF. Set up the test receiver in the same manner (nothing but different battery for power and another dummy load). This is to determine if it's the radio or the home environment (no stray induction). If everything is clean, it's probably not the radio but to make sure... The second portion of that test would be to repeat on different bands or frequencies within the band to eliminate 'fundamental overload' or unexpected mixing of the receiver (which should also be on a dummy load, proximity is likely enough to hear the signal). Is it band related or single band, on one frequency only or all? At only certain output power levels (bad internal amp? A 100 watt K3 has a series of three amps)? If the radio is clean, skip the next step. The third step (if the problem still exists) is to provide physical isolation of the receiver (another room even if both are on dummy loads) to note any changes (overload or coupling is no longer likely). If the problem remains, it's a radio issue (don't discount a receiver issue so you can confirm the issue with a second receiver). Then based on these results, if it's all clean, (therefore not a radio issue so more testing is required to find the actual cause) one then determines a potential cause as you re-power the house (breaker by breaker). In other words, when does it return? In the best case, flipping only one breaker on, testing, turning that breaker off and moving to the next breaker; then bringing multiple breakers on in combinations (interaction of home devices?). At which point/s does the issue return? Single breaker means examine everything powered on that circuit, mixed breakers is much more of a challenge to find the cause. Recall that house wiring often appears 'random' so it may be a challenge to find what each circuit powers. If the problem doesn't return with turning on all the breakers, the search continues. Note changes as you reconnect to the rest of the world (add antennas, control cables, etc) to your station. Through more testing, at which point does the issue return? Then reset all the clocks in the house as you ponder the results. With an antenna connected, this series of tests also gives you a good baseline for RF noise reduction if the home generates noise (it's guaranteed that it will). In your case, just for giggles, make SURE that ALL the tmp connectors in the K3(s) are properly connected as well (re-seat them) and re-tighten all screws and bolts as well (Murphy lives). While it's opened up, make sure no case paint is in the way of any bonding too, no corrosion, roaming parts etc. and look for obvious failures (disconnected wires, frays or pinched wire all without the smell of escaped smoke). And lastly, a complete reset (groan) is an option, sometimes things are not what they show to be or are expected to be (stuck bits, EEPROM belches...). Made when the radio is functioning correctly, you DO have a current backup of settings to use, no? If not, you manually make what changes are required (MANY of them, hence the groan) THEN make a backup. Now if there is a need to call for further assistance (Elecraft help line, your Elmer or here), one has (dis)proven some of the possibilities to present the issue. While others may disagree in this content, this is but one path to follow. GL, Rick nhc On 4/27/2019 11:31 AM, Nicklas Johnson wrote: I don't think that "collecting data" and "process of elimination" are particularly ANTI-methodical either. But the fact is that most people will never encounter this kind of problem and don't spend their days practicing how to troubleshoot it, so they seek advice from people who do have experience. Thus this email thread, which began with my thinking I'd developed an audio fault in the rig and seeking advice, but successive tests have pointed in other directions. To answer Jim's earlier question, yes, it does appear that transmitting an unmodulated AM carrier from the K3S into anything resembling an antenna yields a buzz on the KX3 receiver (and vice-versa). The buzz is
Re: [Elecraft] K3S Audio buzz on transmit, especially AM
On 4/27/2019 11:31 AM, Nicklas Johnson wrote: To answer Jim's earlier question, yes, it does appear that transmitting an unmodulated AM carrier from the K3S into anything resembling an antenna yields a buzz on the KX3 receiver (and vice-versa). The buzz is NOT audible when listening to the K3S's own TX monitor. OK. Try this test. Running from a battery, no connection to anything grounded, TX into an antenna and listen on the KX3 running on internal batteries, also not connected to anything grounded. Do you hear buzz? If not, walk around until you do. If you do, walk around until it's loudest. What this test is doing is probing for some source of passive intermod. It could be in your own home, or it could be somewhere else. And try this test. Transmit into an antenna and have someone listen to your signal. I see that you're only 36 miles from me, so perhaps I could do that on 75M if you have a suitable antenna. I haven't seen an answer for my question about DC voltage under RX and TX conditions. 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
Re: [Elecraft] K3S Audio buzz on transmit, especially AM
I don't think that "collecting data" and "process of elimination" are particularly ANTI-methodical either. But the fact is that most people will never encounter this kind of problem and don't spend their days practicing how to troubleshoot it, so they seek advice from people who do have experience. Thus this email thread, which began with my thinking I'd developed an audio fault in the rig and seeking advice, but successive tests have pointed in other directions. To answer Jim's earlier question, yes, it does appear that transmitting an unmodulated AM carrier from the K3S into anything resembling an antenna yields a buzz on the KX3 receiver (and vice-versa). The buzz is NOT audible when listening to the K3S's own TX monitor. And to answer Frank's question, the PG transformer in our front yard for the underground utilities is approximately 30 horizontal feet over and 6 vertical feet down from the station. The distance to the utilities that run through the back of our lot is approximately 60 feet. I spent the morning reviewing (again) materials on grounding and bonding over my morning coffee to see if there's something important I missed, and I also found by repeating it that an earlier test I'd done had given me a misleading/contradictory result-- transmitting into a dummy load immediately adjacent the KX3 receiving it produces a nice, clean signal. I was misled before by the KX3 picking up a different buzz (probably off a wall wart) in the shack when performing this test earlier. (It also helped in this case to put the KX3 into CW mode to detect the unmodulated AM carrier.) FWIW, this morning I also disconnected the bonding between the station's ground rod and the house's utility power and also disconnected the DTV antenna run into the house (which shares the same coax grounding/surge protection bus outside, but of course could find another path to ground over the coax shield via either one of the TV receivers). Doing so eliminated any *direct * connection with the utility power, as I'm still running purely on battery power. This had NO effect on the received buzz. At this point I'm pretty sure this is an environmental issue and not a problem with either rig, so it's probably not appropriate for me to continue to pester the list about it. Thank you again to everyone who offered suggestions and advice. But for posterity, and in case anyone comes along searching the list while debugging a similar problem, here's a list of all the other things that I tried to isolate the problem, none of which had any effect: - Complete disconnection of all other inputs and outputs on the K3S other than the antenna. - Turning off all nearby power supplies. - Setting the input to any other selection (front panel, rear panel, line in) - Setting the line input level to 0, verifying that front and rear panel gains were set to "low" - Running solely on battery power without the solar charge controller - TX EQ settings- cutting the low end completely - Taking the receiver outdoors, away from power supplies - Trying a different transmit antenna (ie, making sure I wasn't having problems with a damaged dipole having the house neutral wiring as one leg) - Temporarily disconnecting the station ground - Temporarily disconnecting the utility bonding from the station's ground rod - Reversing the direction: transmitting with the KX3 into a portable antenna and receiving with the K3S also produced a much more significant buzz What DID yield some useful data: - Transmitting into a dummy load *while* turning off all nearby power supplies and lights with the KX3 immediately adjacent the dummy load: nice, pristine signal - Checking the TX monitor on the K3S: only white noise with the line input and the monitor output turned to maximum while transmitting. What I have yet to do, and will require some more time and effort to organize and implement: - Going portable or to another QTH to test again - Getting a signal report from a distant station to see if this is a local reception problem, or something actually getting into the transmitted signal. Nick On Sat, 27 Apr 2019 at 01:19, Jim Brown wrote: > On 4/26/2019 10:44 PM, donov...@starpower.net wrote: > > Y our emails leave the impression that your approach > > isn't very methodical. > > Yes, but that lack of methodical troubleshooting is the result of most > hams being weak on the fundamentals of fields and passive IM, instead > seeing problems in the light of RFI and mythical concepts like "ground > loops." > > The two causes I've come around to smelling in this problem are passive > IM (which Frank reminded me of) and power-related fields. And Frank's > advice is right on. > > 73, Jim K9YC > > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post:
Re: [Elecraft] K3S Audio buzz on transmit, especially AM
On 4/26/2019 10:44 PM, donov...@starpower.net wrote: Y our emails leave the impression that your approach isn't very methodical. Yes, but that lack of methodical troubleshooting is the result of most hams being weak on the fundamentals of fields and passive IM, instead seeing problems in the light of RFI and mythical concepts like "ground loops." The two causes I've come around to smelling in this problem are passive IM (which Frank reminded me of) and power-related fields. And Frank's advice is right on. 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
Re: [Elecraft] K3S Audio buzz on transmit, especially AM
Hi Nick, Since there are many unknowns and concerns about the EMI and magnetic environment at your home QTH, it might be revealing to repeat your basic tests (battery and dummy load) at a friend's QTH. Maybe you also have a friend who owns a K3 or K3S. Forget about resetting your transceiver. Your varied descriptions point to EMI or one (or more) strong magnetic fields as the source of your difficulties. How far is the "big green transformer" from your ham shack? Have you ever attempted to perform this type of troubleshooting in the past? Y our emails leave the impression that your approach isn't very methodical. A friend with troubleshooting experience could be of great help in getting you organized for a successful result. 73 Frank W3LPL - Original Message - From: "Nicklas Johnson" To: "elecraft" Sent: Saturday, April 27, 2019 1:53:27 AM Subject: Re: [Elecraft] K3S Audio buzz on transmit, especially AM Sorry for the additional email, but this is particularly interesting: it occurred to me that I'd never tried the reverse setup, so I put the KX3 in transmit mode and 0.1W on AM in another room, and set the K3S on receive. And sure enough, the K3S immediately started picking up S40 of buzzing noise. However if I tune the K3S to an AM broadcast station or WWV, no buzz. So either both the K3S and KX3 are being affected on transmit in the same way (which seems implausible but not impossible), or possibly something else is going on at my QTH. On the P3, I definitely see the noise when the KX3 is transmitting from the other room. Now I wish I had a scope so I could see what the AM carrier generated by the KX3 and K3S looks like so I could tell if this is something that's happening inside the transmitter, or something that is happening because of some outside influence mixing powerline noise with the AM carrier. The important thing to me is that the carrier I'm putting out there is clean... if there's some local mixing that happens that means I can't listen to my own transmission without a buzz, I can live with that. One kind of curious thing is that there's also a superimposed "squeaky wheel" sound at random intervals detectable when the KX3 is transmitting an AM carrier, and not otherwise, and also not when listening to WWV or AM broadcast, which vaguely seems to correlate with how windy it is at any given moment. Could all of this be a "rusty bolt" effect from something in the vicinity? Nick On Fri, 26 Apr 2019 at 18:11, Nicklas Johnson wrote: > A few more data points: > > Changing TX EQ, including cutting the first 4 bands all the way down to > -16 had no effect on the received signal. > > Plugging in some headphones, turning the TX Monitor up all the way, I > don't detect the hum in the TX monitor signal either in TX test mode, > transmitting into a dummy load, or even transmitting into the antenna with > very low power. If I turn up the Line In level, I just hear expected white > noise on the TX monitor. So at least as far along the path as the TX > monitor, there's no hum or buzz introduced. > > Switching the receiver (a KX3) to USB mode and using one leg of a > buddistick as an antenna so I can walk around, the noise received around > the house and outside is around S4 when transmitting about 100mW into the > antenna, though it varies some as I walk around. > > I do have a set of power lines running through my back yard, and where I > live in San Mateo, you're always near somebody's wiring for something, > unfortunately... my neighbor's south wall is possibly as far as 8 feet away > from my north wall, etc. > > It looks like two phases running along the top, then a transformer to two > phases and a neutral along the bottom, to which people's houses are > connected. > > We also have underground utilities on our street, including a big green > transformer that sits in the corner of our front lawn. > > I think the next test will be to take the K3S and the KX3 some distance > away from all of these things and see if the hum goes away, and if it does, > then figure out what thing the K3S needs to get away from in particular. > If it's the powerlines in my back yard or the transformer in my front yard, > then that'll be a difficult problem. > > Nick > > > > On Fri, 26 Apr 2019 at 17:28, Bob McGraw K4TAX > wrote: > >> Yes but the EQ is in the digital path. The EQ should be done there, >> preferably after the MIC input. The AM BW does not attenuate the end like >> the SSB filter. >> >> I suggest -16 dB on the first 3 bands. >> >> Bob, K4TAX >> >> >> Sent from my iPhone >> >> > On Apr 26, 2019, at 6:38 PM, Nicklas Johnson wrote: &g
Re: [Elecraft] K3S Audio buzz on transmit, especially AM
On 4/26/2019 7:48 PM, Frank Krozel wrote: Try switching to a linear supply? No, ALL power supplies with cap input filter have harmonics. But the problem is FAR, FAR larger than equipment in the shack. Nick -- what kind of mic do you use with your rig? Is it an electret or a dynamic? Another way of asking -- do you have turn on bias to make it work? Does the buzz get worse with the mic plugged in? Does turning up the mic gain make it louder? 73, Jim __ 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] K3S Audio buzz on transmit, especially AM
On 4/26/2019 6:11 PM, Nicklas Johnson wrote: Plugging in some headphones, turning the TX Monitor up all the way, I don't detect the hum in the TX monitor signal either in TX test mode, transmitting into a dummy load, or even transmitting into the antenna with very low power. If I turn up the Line In level, I just hear expected white noise on the TX monitor. So at least as far along the path as the TX monitor, there's no hum or buzz introduced. I'm confused, Nick. Under what conditions DO you hear the buzz? Antenna connected to the K3S? Switching the receiver (a KX3) to USB mode and using one leg of a buddistick as an antenna so I can walk around, the noise received around the house and outside is around S4 when transmitting about 100mW into the antenna, though it varies some as I walk around. I'm more confused. When you have been listening to your signal and hearing the buzz, HOW were you listening to it? Were you listening on the KX3? If you transmit 5-10W into a dummy load you should be able to hear your signal in a KX3 sitting next to it with NO antenna. Does the buzz only happen when you're listening on the KX3 and there's an antenna connected to the K3S? That brings up the possibility of passive intermod. We'll talk about that after we've gotten the symptoms straight. 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
Re: [Elecraft] K3S Audio buzz on transmit, especially AM
Try switching to a linear supply? Sincerely, Frank Krozel t: 1-630-924-1600 fr...@electronicinstrument.com BSEE, AASEET, FCC Lic.# PG-18-19178, KG9H Electronic Instrument Associates - Central, Inc. ...since 1971 w: www.electronicinstrument.com d/l our linecard at http://www.electronicinstrument.com/lc.pdf > On Apr 26, 2019, at 9:46 PM, Nicklas Johnson wrote: > > Before I forget, thank you to everyone who has responded thusfar with ideas > and suggestions. This one is a real head-scratcher, and I appreciate > everyone bouncing ideas around with me. > > If the problem is in fact originating with power line neutral distortion, > what, if anything could I actually do about it, beyond what I've already > done in running on battery power? I can't really move my 'shack' in this > case. > > I did find the "squeaky wheel" at least. It was the end of one of the > aluminum straps of an antenna mast chimney mount brushing against a copper > ground wire in the wind. A pair of tin snips solved that problem. This > bit was kind of fascinating-- if I held a copper wire against the aluminum > strap, and position the antenna of the KX3 nearby, I could receive some > broadcast AM station on the 51.123 MHz carrier I was transmitting from > inside the house (it's pretty close to a multiple of 810kHz, so if I had to > guess, it was likely KGO I was getting). > > I also found the noise gets a hell of a lot louder near the back gutter of > the house (which runs parallel to the power lines that run through the back > yard), though this could just be because the antenna of my KX3 was coupling > to it. > > Yet to be determined is whether the noise is a local thing only affecting > reception (e.g., some kind of passive intermod), or if in fact it becomes > part of the signal I'm sending up to the ionosphere. To really figure that > one out, I probably will need to make an actual distant AM contact and ask > someone to tell me how it sounds... this may be no small feat with the way > the sun is behaving lately, but I'll keep trying. > > Nick > >> On Fri, 26 Apr 2019 at 19:18, Bob McGraw K4TAX wrote: >> >> I think Jim's concern, expressed earlier, about power line neutral >> distortion components is valid. And it may be originating in "the big green >> transformer" in the yard. >> >> Bob, K4TAX >> >> >> Sent from my iPhone >> >>> On Apr 26, 2019, at 8:53 PM, Nicklas Johnson wrote: >>> >>> Sorry for the additional email, but this is particularly interesting: it >>> occurred to me that I'd never tried the reverse setup, so I put the KX3 >> in >>> transmit mode and 0.1W on AM in another room, and set the K3S on receive. >>> And sure enough, the K3S immediately started picking up S40 of buzzing >>> noise. However if I tune the K3S to an AM broadcast station or WWV, no >>> buzz. So either both the K3S and KX3 are being affected on transmit in >> the >>> same way (which seems implausible but not impossible), or possibly >>> something else is going on at my QTH. >>> >>> On the P3, I definitely see the noise when the KX3 is transmitting from >> the >>> other room. >>> >>> Now I wish I had a scope so I could see what the AM carrier generated by >>> the KX3 and K3S looks like so I could tell if this is something that's >>> happening inside the transmitter, or something that is happening because >> of >>> some outside influence mixing powerline noise with the AM carrier. The >>> important thing to me is that the carrier I'm putting out there is >> clean... >>> if there's some local mixing that happens that means I can't listen to my >>> own transmission without a buzz, I can live with that. >>> >>> One kind of curious thing is that there's also a superimposed "squeaky >>> wheel" sound at random intervals detectable when the KX3 is transmitting >> an >>> AM carrier, and not otherwise, and also not when listening to WWV or AM >>> broadcast, which vaguely seems to correlate with how windy it is at any >>> given moment. Could all of this be a "rusty bolt" effect from something >> in >>> the vicinity? >>> >>> Nick >>> >>> >>> On Fri, 26 Apr 2019 at 18:11, Nicklas Johnson wrote: A few more data points: Changing TX EQ, including cutting the first 4 bands all the way down to -16 had no effect on the received signal. Plugging in some headphones, turning the TX Monitor up all the way, I don't detect the hum in the TX monitor signal either in TX test mode, transmitting into a dummy load, or even transmitting into the antenna >> with very low power. If I turn up the Line In level, I just hear expected >> white noise on the TX monitor. So at least as far along the path as the TX monitor, there's no hum or buzz introduced. Switching the receiver (a KX3) to USB mode and using one leg of a buddistick as an antenna so I can walk around, the noise received around the house and outside is around S4 when transmitting about
Re: [Elecraft] K3S Audio buzz on transmit, especially AM
Before I forget, thank you to everyone who has responded thusfar with ideas and suggestions. This one is a real head-scratcher, and I appreciate everyone bouncing ideas around with me. If the problem is in fact originating with power line neutral distortion, what, if anything could I actually do about it, beyond what I've already done in running on battery power? I can't really move my 'shack' in this case. I did find the "squeaky wheel" at least. It was the end of one of the aluminum straps of an antenna mast chimney mount brushing against a copper ground wire in the wind. A pair of tin snips solved that problem. This bit was kind of fascinating-- if I held a copper wire against the aluminum strap, and position the antenna of the KX3 nearby, I could receive some broadcast AM station on the 51.123 MHz carrier I was transmitting from inside the house (it's pretty close to a multiple of 810kHz, so if I had to guess, it was likely KGO I was getting). I also found the noise gets a hell of a lot louder near the back gutter of the house (which runs parallel to the power lines that run through the back yard), though this could just be because the antenna of my KX3 was coupling to it. Yet to be determined is whether the noise is a local thing only affecting reception (e.g., some kind of passive intermod), or if in fact it becomes part of the signal I'm sending up to the ionosphere. To really figure that one out, I probably will need to make an actual distant AM contact and ask someone to tell me how it sounds... this may be no small feat with the way the sun is behaving lately, but I'll keep trying. Nick On Fri, 26 Apr 2019 at 19:18, Bob McGraw K4TAX wrote: > I think Jim's concern, expressed earlier, about power line neutral > distortion components is valid. And it may be originating in "the big green > transformer" in the yard. > > Bob, K4TAX > > > Sent from my iPhone > > > On Apr 26, 2019, at 8:53 PM, Nicklas Johnson wrote: > > > > Sorry for the additional email, but this is particularly interesting: it > > occurred to me that I'd never tried the reverse setup, so I put the KX3 > in > > transmit mode and 0.1W on AM in another room, and set the K3S on receive. > > And sure enough, the K3S immediately started picking up S40 of buzzing > > noise. However if I tune the K3S to an AM broadcast station or WWV, no > > buzz. So either both the K3S and KX3 are being affected on transmit in > the > > same way (which seems implausible but not impossible), or possibly > > something else is going on at my QTH. > > > > On the P3, I definitely see the noise when the KX3 is transmitting from > the > > other room. > > > > Now I wish I had a scope so I could see what the AM carrier generated by > > the KX3 and K3S looks like so I could tell if this is something that's > > happening inside the transmitter, or something that is happening because > of > > some outside influence mixing powerline noise with the AM carrier. The > > important thing to me is that the carrier I'm putting out there is > clean... > > if there's some local mixing that happens that means I can't listen to my > > own transmission without a buzz, I can live with that. > > > > One kind of curious thing is that there's also a superimposed "squeaky > > wheel" sound at random intervals detectable when the KX3 is transmitting > an > > AM carrier, and not otherwise, and also not when listening to WWV or AM > > broadcast, which vaguely seems to correlate with how windy it is at any > > given moment. Could all of this be a "rusty bolt" effect from something > in > > the vicinity? > > > > Nick > > > > > > > >> On Fri, 26 Apr 2019 at 18:11, Nicklas Johnson wrote: > >> > >> A few more data points: > >> > >> Changing TX EQ, including cutting the first 4 bands all the way down to > >> -16 had no effect on the received signal. > >> > >> Plugging in some headphones, turning the TX Monitor up all the way, I > >> don't detect the hum in the TX monitor signal either in TX test mode, > >> transmitting into a dummy load, or even transmitting into the antenna > with > >> very low power. If I turn up the Line In level, I just hear expected > white > >> noise on the TX monitor. So at least as far along the path as the TX > >> monitor, there's no hum or buzz introduced. > >> > >> Switching the receiver (a KX3) to USB mode and using one leg of a > >> buddistick as an antenna so I can walk around, the noise received around > >> the house and outside is around S4 when transmitting about 100mW into > the > >> antenna, though it varies some as I walk around. > >> > >> I do have a set of power lines running through my back yard, and where I > >> live in San Mateo, you're always near somebody's wiring for something, > >> unfortunately... my neighbor's south wall is possibly as far as 8 feet > away > >> from my north wall, etc. > >> > >> It looks like two phases running along the top, then a transformer to > two > >> phases and a neutral along the bottom, to which
Re: [Elecraft] K3S Audio buzz on transmit, especially AM
EQ should have nothing to do with solving the problem. EQ just masks it. Sent from my iPad > On Apr 26, 2019, at 6:56 PM, Bob McGraw K4TAX wrote: > > I recall commenting earlier. What TX EQ values are being used for AM. ? > > Bob, K4TAX > > > Sent from my iPhone > >> On Apr 26, 2019, at 5:48 PM, Nicklas Johnson wrote: >> >> My desk in this case sits adjacent a wall, and there's only a shower on the >> other side of that wall. I did turn off everything in the vicinity of the >> desk and all the lights in the room (I've in fact heard a very similar hum >> from the switching power supply for my mixer, and my first thought was it >> was this that was being picked up), but I didn't turn off the computer on >> the other side of the room. In this case it will be easier to move the rig >> outdoors with a battery than it will be to turn that computer off for the >> moment. It would have to be an impressively/obnoxiously strong magnetic >> field from that side of the room to influence the transformers inside the >> rig 8 feet away, but it's worth trying and simple enough to rule it out. >> >> Nick >> >>> On Fri, 26 Apr 2019 at 14:51, Don Wilhelm wrote: >>> >>> In addition to operating from a battery isolated from the solar system, >>> I would recommend that you do a quick test - remove all cables from the >>> K3S except the power cable and a coax to a dummy load. Power down all >>> power supplies in your station, including any desk lamps. >>> Go into Transmit by tapping the XMIT button. >>> Is the hum still present? If not, then start connecting things to your >>> K3S one at a time, doing the same test after each thing connected. >>> >>> Of course, if the hum is present with nothing connected, contact >>> supp...@elecraft.com - but I cannot imagine a hum with harmonics of 60 >>> Hz being induced if you take away all the 60 Hz operated sources in the >>> area. >>> >>> 73, >>> Don W3FPR >>> >>> -- >> *N6OL* >> Saying something doesn't make it true. Belief in something doesn't make it >> real. And if you have to lie to support a position, that position is not >> worth supporting. >> __ >> 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] K3S Audio buzz on transmit, especially AM
Sounds like some internal RF feedback. Sent from my iPad > On Apr 26, 2019, at 11:43 AM, Nicklas Johnson wrote: > > This morning just for yuks, I also temporarily disconnected the ground from > the rig entirely while also connecting only to a dummy load, so there could > be no path to ground at all, let alone multiple paths. No change. > > I guess the next things I'll probably try are a full factory reset, and > then perhaps popping it open to make sure nothing has come unseated. But > first I'll drop a line to Elecraft support too. I've seen a number of > people post about similar problems that either magically resolved > themselves or ended up being a fault on the audio board. > > Nick > > >> On Thu, 25 Apr 2019 at 23:27, Nicklas Johnson wrote: >> >> Again, the problem persists with all inputs completely disconnected and >> the mic gain set at 0. And running solely on a battery into a dummy load. >> >> Nick >> >> On Thu, Apr 25, 2019, 10:10 PM Jim Brown >> wrote: >> On 4/25/2019 8:15 PM, Nicklas Johnson wrote: Physically touching the case or grabbing the barrel of the front panel >>> mic connector actually does cause the buzz to get just a little softer. >>> >>> I suspect either a bonding problem or a problem with the wiring of the >>> mic. >>> I generally use solar/battery power, though my ground is bonded to my utility ground. >>> >>> I suggest that you carefully study either N0AX's recent ARRL book on >>> grounding and bonding, or the slides for talks I've given at Visalia and >>> Pacifion. >>> >>> 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 >>> >> > > -- > *N6OL* > Saying something doesn't make it true. Belief in something doesn't make it > real. And if you have to lie to support a position, that position is not > worth supporting. > __ > 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] K3S Audio buzz on transmit, especially AM
I think Jim's concern, expressed earlier, about power line neutral distortion components is valid. And it may be originating in "the big green transformer" in the yard. Bob, K4TAX Sent from my iPhone > On Apr 26, 2019, at 8:53 PM, Nicklas Johnson wrote: > > Sorry for the additional email, but this is particularly interesting: it > occurred to me that I'd never tried the reverse setup, so I put the KX3 in > transmit mode and 0.1W on AM in another room, and set the K3S on receive. > And sure enough, the K3S immediately started picking up S40 of buzzing > noise. However if I tune the K3S to an AM broadcast station or WWV, no > buzz. So either both the K3S and KX3 are being affected on transmit in the > same way (which seems implausible but not impossible), or possibly > something else is going on at my QTH. > > On the P3, I definitely see the noise when the KX3 is transmitting from the > other room. > > Now I wish I had a scope so I could see what the AM carrier generated by > the KX3 and K3S looks like so I could tell if this is something that's > happening inside the transmitter, or something that is happening because of > some outside influence mixing powerline noise with the AM carrier. The > important thing to me is that the carrier I'm putting out there is clean... > if there's some local mixing that happens that means I can't listen to my > own transmission without a buzz, I can live with that. > > One kind of curious thing is that there's also a superimposed "squeaky > wheel" sound at random intervals detectable when the KX3 is transmitting an > AM carrier, and not otherwise, and also not when listening to WWV or AM > broadcast, which vaguely seems to correlate with how windy it is at any > given moment. Could all of this be a "rusty bolt" effect from something in > the vicinity? > > Nick > > > >> On Fri, 26 Apr 2019 at 18:11, Nicklas Johnson wrote: >> >> A few more data points: >> >> Changing TX EQ, including cutting the first 4 bands all the way down to >> -16 had no effect on the received signal. >> >> Plugging in some headphones, turning the TX Monitor up all the way, I >> don't detect the hum in the TX monitor signal either in TX test mode, >> transmitting into a dummy load, or even transmitting into the antenna with >> very low power. If I turn up the Line In level, I just hear expected white >> noise on the TX monitor. So at least as far along the path as the TX >> monitor, there's no hum or buzz introduced. >> >> Switching the receiver (a KX3) to USB mode and using one leg of a >> buddistick as an antenna so I can walk around, the noise received around >> the house and outside is around S4 when transmitting about 100mW into the >> antenna, though it varies some as I walk around. >> >> I do have a set of power lines running through my back yard, and where I >> live in San Mateo, you're always near somebody's wiring for something, >> unfortunately... my neighbor's south wall is possibly as far as 8 feet away >> from my north wall, etc. >> >> It looks like two phases running along the top, then a transformer to two >> phases and a neutral along the bottom, to which people's houses are >> connected. >> >> We also have underground utilities on our street, including a big green >> transformer that sits in the corner of our front lawn. >> >> I think the next test will be to take the K3S and the KX3 some distance >> away from all of these things and see if the hum goes away, and if it does, >> then figure out what thing the K3S needs to get away from in particular. >> If it's the powerlines in my back yard or the transformer in my front yard, >> then that'll be a difficult problem. >> >> Nick >> >> >> >> On Fri, 26 Apr 2019 at 17:28, Bob McGraw K4TAX >> wrote: >> >>> Yes but the EQ is in the digital path. The EQ should be done there, >>> preferably after the MIC input. The AM BW does not attenuate the end like >>> the SSB filter. >>> >>> I suggest -16 dB on the first 3 bands. >>> >>> Bob, K4TAX >>> >>> >>> Sent from my iPhone >>> On Apr 26, 2019, at 6:38 PM, Nicklas Johnson wrote: Flat, except I turned the first one down a few notches, which doesn't really do much in my case because both the microphone and mixer that I >>> use (when they're actually connected) roll off below 150 and 80 Hz respectively. It had previously been suggested to me that rolling off >>> low frequency cruft is a good idea for AM and SSB. Nick > On Fri, 26 Apr 2019 at 15:57, Bob McGraw K4TAX >>> wrote: > > I recall commenting earlier. What TX EQ values are being used for AM. >>> ? > > Bob, K4TAX > > > Sent from my iPhone > >> On Apr 26, 2019, at 5:48 PM, Nicklas Johnson wrote: >> >> My desk in this case sits adjacent a wall, and there's only a shower >>> on > the >> other side of that wall. I did turn off everything in the vicinity of > the >> desk and
Re: [Elecraft] K3S Audio buzz on transmit, especially AM
Sorry for the additional email, but this is particularly interesting: it occurred to me that I'd never tried the reverse setup, so I put the KX3 in transmit mode and 0.1W on AM in another room, and set the K3S on receive. And sure enough, the K3S immediately started picking up S40 of buzzing noise. However if I tune the K3S to an AM broadcast station or WWV, no buzz. So either both the K3S and KX3 are being affected on transmit in the same way (which seems implausible but not impossible), or possibly something else is going on at my QTH. On the P3, I definitely see the noise when the KX3 is transmitting from the other room. Now I wish I had a scope so I could see what the AM carrier generated by the KX3 and K3S looks like so I could tell if this is something that's happening inside the transmitter, or something that is happening because of some outside influence mixing powerline noise with the AM carrier. The important thing to me is that the carrier I'm putting out there is clean... if there's some local mixing that happens that means I can't listen to my own transmission without a buzz, I can live with that. One kind of curious thing is that there's also a superimposed "squeaky wheel" sound at random intervals detectable when the KX3 is transmitting an AM carrier, and not otherwise, and also not when listening to WWV or AM broadcast, which vaguely seems to correlate with how windy it is at any given moment. Could all of this be a "rusty bolt" effect from something in the vicinity? Nick On Fri, 26 Apr 2019 at 18:11, Nicklas Johnson wrote: > A few more data points: > > Changing TX EQ, including cutting the first 4 bands all the way down to > -16 had no effect on the received signal. > > Plugging in some headphones, turning the TX Monitor up all the way, I > don't detect the hum in the TX monitor signal either in TX test mode, > transmitting into a dummy load, or even transmitting into the antenna with > very low power. If I turn up the Line In level, I just hear expected white > noise on the TX monitor. So at least as far along the path as the TX > monitor, there's no hum or buzz introduced. > > Switching the receiver (a KX3) to USB mode and using one leg of a > buddistick as an antenna so I can walk around, the noise received around > the house and outside is around S4 when transmitting about 100mW into the > antenna, though it varies some as I walk around. > > I do have a set of power lines running through my back yard, and where I > live in San Mateo, you're always near somebody's wiring for something, > unfortunately... my neighbor's south wall is possibly as far as 8 feet away > from my north wall, etc. > > It looks like two phases running along the top, then a transformer to two > phases and a neutral along the bottom, to which people's houses are > connected. > > We also have underground utilities on our street, including a big green > transformer that sits in the corner of our front lawn. > > I think the next test will be to take the K3S and the KX3 some distance > away from all of these things and see if the hum goes away, and if it does, > then figure out what thing the K3S needs to get away from in particular. > If it's the powerlines in my back yard or the transformer in my front yard, > then that'll be a difficult problem. > >Nick > > > > On Fri, 26 Apr 2019 at 17:28, Bob McGraw K4TAX > wrote: > >> Yes but the EQ is in the digital path. The EQ should be done there, >> preferably after the MIC input. The AM BW does not attenuate the end like >> the SSB filter. >> >> I suggest -16 dB on the first 3 bands. >> >> Bob, K4TAX >> >> >> Sent from my iPhone >> >> > On Apr 26, 2019, at 6:38 PM, Nicklas Johnson wrote: >> > >> > Flat, except I turned the first one down a few notches, which doesn't >> > really do much in my case because both the microphone and mixer that I >> use >> > (when they're actually connected) roll off below 150 and 80 Hz >> > respectively. It had previously been suggested to me that rolling off >> low >> > frequency cruft is a good idea for AM and SSB. >> > >> > Nick >> > >> >> On Fri, 26 Apr 2019 at 15:57, Bob McGraw K4TAX >> wrote: >> >> >> >> I recall commenting earlier. What TX EQ values are being used for AM. >> ? >> >> >> >> Bob, K4TAX >> >> >> >> >> >> Sent from my iPhone >> >> >> >>> On Apr 26, 2019, at 5:48 PM, Nicklas Johnson wrote: >> >>> >> >>> My desk in this case sits adjacent a wall, and there's only a shower >> on >> >> the >> >>> other side of that wall. I did turn off everything in the vicinity of >> >> the >> >>> desk and all the lights in the room (I've in fact heard a very similar >> >> hum >> >>> from the switching power supply for my mixer, and my first thought >> was it >> >>> was this that was being picked up), but I didn't turn off the >> computer on >> >>> the other side of the room. In this case it will be easier to move >> the >> >> rig >> >>> outdoors with a battery than it will be to turn that computer off for >>
Re: [Elecraft] K3S Audio buzz on transmit, especially AM
A few more data points: Changing TX EQ, including cutting the first 4 bands all the way down to -16 had no effect on the received signal. Plugging in some headphones, turning the TX Monitor up all the way, I don't detect the hum in the TX monitor signal either in TX test mode, transmitting into a dummy load, or even transmitting into the antenna with very low power. If I turn up the Line In level, I just hear expected white noise on the TX monitor. So at least as far along the path as the TX monitor, there's no hum or buzz introduced. Switching the receiver (a KX3) to USB mode and using one leg of a buddistick as an antenna so I can walk around, the noise received around the house and outside is around S4 when transmitting about 100mW into the antenna, though it varies some as I walk around. I do have a set of power lines running through my back yard, and where I live in San Mateo, you're always near somebody's wiring for something, unfortunately... my neighbor's south wall is possibly as far as 8 feet away from my north wall, etc. It looks like two phases running along the top, then a transformer to two phases and a neutral along the bottom, to which people's houses are connected. We also have underground utilities on our street, including a big green transformer that sits in the corner of our front lawn. I think the next test will be to take the K3S and the KX3 some distance away from all of these things and see if the hum goes away, and if it does, then figure out what thing the K3S needs to get away from in particular. If it's the powerlines in my back yard or the transformer in my front yard, then that'll be a difficult problem. Nick On Fri, 26 Apr 2019 at 17:28, Bob McGraw K4TAX wrote: > Yes but the EQ is in the digital path. The EQ should be done there, > preferably after the MIC input. The AM BW does not attenuate the end like > the SSB filter. > > I suggest -16 dB on the first 3 bands. > > Bob, K4TAX > > > Sent from my iPhone > > > On Apr 26, 2019, at 6:38 PM, Nicklas Johnson wrote: > > > > Flat, except I turned the first one down a few notches, which doesn't > > really do much in my case because both the microphone and mixer that I > use > > (when they're actually connected) roll off below 150 and 80 Hz > > respectively. It had previously been suggested to me that rolling off > low > > frequency cruft is a good idea for AM and SSB. > > > > Nick > > > >> On Fri, 26 Apr 2019 at 15:57, Bob McGraw K4TAX > wrote: > >> > >> I recall commenting earlier. What TX EQ values are being used for AM. ? > >> > >> Bob, K4TAX > >> > >> > >> Sent from my iPhone > >> > >>> On Apr 26, 2019, at 5:48 PM, Nicklas Johnson wrote: > >>> > >>> My desk in this case sits adjacent a wall, and there's only a shower on > >> the > >>> other side of that wall. I did turn off everything in the vicinity of > >> the > >>> desk and all the lights in the room (I've in fact heard a very similar > >> hum > >>> from the switching power supply for my mixer, and my first thought was > it > >>> was this that was being picked up), but I didn't turn off the computer > on > >>> the other side of the room. In this case it will be easier to move the > >> rig > >>> outdoors with a battery than it will be to turn that computer off for > the > >>> moment. It would have to be an impressively/obnoxiously strong > magnetic > >>> field from that side of the room to influence the transformers inside > the > >>> rig 8 feet away, but it's worth trying and simple enough to rule it > out. > >>> > >>> Nick > >>> > On Fri, 26 Apr 2019 at 14:51, Don Wilhelm > >> wrote: > > In addition to operating from a battery isolated from the solar > system, > I would recommend that you do a quick test - remove all cables from > the > K3S except the power cable and a coax to a dummy load. Power down all > power supplies in your station, including any desk lamps. > Go into Transmit by tapping the XMIT button. > Is the hum still present? If not, then start connecting things to > your > K3S one at a time, doing the same test after each thing connected. > > Of course, if the hum is present with nothing connected, contact > supp...@elecraft.com - but I cannot imagine a hum with harmonics of > 60 > Hz being induced if you take away all the 60 Hz operated sources in > the > area. > > 73, > Don W3FPR > > -- > >>> *N6OL* > >>> Saying something doesn't make it true. Belief in something doesn't > make > >> it > >>> real. And if you have to lie to support a position, that position is > not > >>> worth supporting. > >>> __ > >>> 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:
Re: [Elecraft] K3S Audio buzz on transmit, especially AM
On 4/26/2019 5:28 PM, Bob McGraw K4TAX wrote: I suggest -16 dB on the first 3 bands. My standard recommendation for ham radio is to start with max cut of 50, 100, and 200 Hz bands, 6 dB of cut of the 400 Hz band, and get signal reports. Do this in TXEQ. What sounds "right" will depend on your voice and your mic, so take this as a starting point. 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
Re: [Elecraft] K3S Audio buzz on transmit, especially AM
A pro audio colleague, Neil Muncy, now deceased, specialized in chasing down hum and buzz in home studios. One mechanism he ran into several times was "triplen" harmonic current on the incoming neutral or ground, and I worked with him on one of them. These harmonic currents are the result of distortion of the current waveform on power lines,which in turn is caused by current in anything with a capacitor input power supply drawing most of the current at positive and negative peaks of the AC cycle. Most power lines outside our home are some form of 3-phase, and in these systems, any harmonic divisible by 3 ADDS in the neutral rather than cancelling. The most prominent components are 180 Hz, 360 Hz, 540 Hz, 720 Hz, and so on, and they are heard as "buzz" rather than hum. Few of us have 3-phase power in our homes, but a power distribution system called "high leg Delta" or "wild leg" is VERY widely used in neighborhoods where the customers are a mix residential and light industrial. This system is a Delta, but with one leg of the Delta center-tapped. The 3-phase customers are fed from the Delta, and single-phase customers from the center-tapped transformer. Single phase customers get phase-phase-neutral. The 3-phase customers get no neutral, but they generate lots of triplen harmonics that go to ground via the neutral bond in single-phase homes. My home in the Santa Cruz Mountains, is fed single-phase power (120-0-120) by high-leg Delta. Depending on lots of factors, that triplen current can get pretty large, and the magnetic field can couple into any magnetic loop, into any unshielded transformer, and into magnetic guitar pickups! That's where Neil came in. How strong the pickup is depends on the routing of the neutral and ground wire carrying that triplen current. Another colleague working on the design of audio for a major TV studio in NYC found very high triplen currents in a vertical riser in the high rise building housing the studio, right next to the main mix console. MAJOR problem -- it got into almost all the gear and low level mic wiring in the room! As to the accuracy of your FFT frequencies -- FFT's are computed in "bins" with their width dependent on the FFT parameters for any given measurement/display width. If bins are fairly wide, the frequencies you're reading could easily be triplen harmonics. 73, Jim K9YC On 4/26/2019 3:38 PM, Nicklas Johnson wrote: they're more or less 120Hz apart, but they start at a weird place-- 350 isn't a multiple of 60 or 120, but that particular spur and the 470 and 830 Hz spurs are all pretty exact, though of course it's not impossible that there's some FFT error in determining those frequencies and they're actually 360, 480, and 840. __ 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] K3S Audio buzz on transmit, especially AM
Yes but the EQ is in the digital path. The EQ should be done there, preferably after the MIC input. The AM BW does not attenuate the end like the SSB filter. I suggest -16 dB on the first 3 bands. Bob, K4TAX Sent from my iPhone > On Apr 26, 2019, at 6:38 PM, Nicklas Johnson wrote: > > Flat, except I turned the first one down a few notches, which doesn't > really do much in my case because both the microphone and mixer that I use > (when they're actually connected) roll off below 150 and 80 Hz > respectively. It had previously been suggested to me that rolling off low > frequency cruft is a good idea for AM and SSB. > > Nick > >> On Fri, 26 Apr 2019 at 15:57, Bob McGraw K4TAX wrote: >> >> I recall commenting earlier. What TX EQ values are being used for AM. ? >> >> Bob, K4TAX >> >> >> Sent from my iPhone >> >>> On Apr 26, 2019, at 5:48 PM, Nicklas Johnson wrote: >>> >>> My desk in this case sits adjacent a wall, and there's only a shower on >> the >>> other side of that wall. I did turn off everything in the vicinity of >> the >>> desk and all the lights in the room (I've in fact heard a very similar >> hum >>> from the switching power supply for my mixer, and my first thought was it >>> was this that was being picked up), but I didn't turn off the computer on >>> the other side of the room. In this case it will be easier to move the >> rig >>> outdoors with a battery than it will be to turn that computer off for the >>> moment. It would have to be an impressively/obnoxiously strong magnetic >>> field from that side of the room to influence the transformers inside the >>> rig 8 feet away, but it's worth trying and simple enough to rule it out. >>> >>> Nick >>> On Fri, 26 Apr 2019 at 14:51, Don Wilhelm >> wrote: In addition to operating from a battery isolated from the solar system, I would recommend that you do a quick test - remove all cables from the K3S except the power cable and a coax to a dummy load. Power down all power supplies in your station, including any desk lamps. Go into Transmit by tapping the XMIT button. Is the hum still present? If not, then start connecting things to your K3S one at a time, doing the same test after each thing connected. Of course, if the hum is present with nothing connected, contact supp...@elecraft.com - but I cannot imagine a hum with harmonics of 60 Hz being induced if you take away all the 60 Hz operated sources in the area. 73, Don W3FPR -- >>> *N6OL* >>> Saying something doesn't make it true. Belief in something doesn't make >> it >>> real. And if you have to lie to support a position, that position is not >>> worth supporting. >>> __ >>> 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 >>> >> >> > > -- > *N6OL* > Saying something doesn't make it true. Belief in something doesn't make it > real. And if you have to lie to support a position, that position is not > worth supporting. > __ > 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] K3S Audio buzz on transmit, especially AM
Flat, except I turned the first one down a few notches, which doesn't really do much in my case because both the microphone and mixer that I use (when they're actually connected) roll off below 150 and 80 Hz respectively. It had previously been suggested to me that rolling off low frequency cruft is a good idea for AM and SSB. Nick On Fri, 26 Apr 2019 at 15:57, Bob McGraw K4TAX wrote: > I recall commenting earlier. What TX EQ values are being used for AM. ? > > Bob, K4TAX > > > Sent from my iPhone > > > On Apr 26, 2019, at 5:48 PM, Nicklas Johnson wrote: > > > > My desk in this case sits adjacent a wall, and there's only a shower on > the > > other side of that wall. I did turn off everything in the vicinity of > the > > desk and all the lights in the room (I've in fact heard a very similar > hum > > from the switching power supply for my mixer, and my first thought was it > > was this that was being picked up), but I didn't turn off the computer on > > the other side of the room. In this case it will be easier to move the > rig > > outdoors with a battery than it will be to turn that computer off for the > > moment. It would have to be an impressively/obnoxiously strong magnetic > > field from that side of the room to influence the transformers inside the > > rig 8 feet away, but it's worth trying and simple enough to rule it out. > > > > Nick > > > >> On Fri, 26 Apr 2019 at 14:51, Don Wilhelm > wrote: > >> > >> In addition to operating from a battery isolated from the solar system, > >> I would recommend that you do a quick test - remove all cables from the > >> K3S except the power cable and a coax to a dummy load. Power down all > >> power supplies in your station, including any desk lamps. > >> Go into Transmit by tapping the XMIT button. > >> Is the hum still present? If not, then start connecting things to your > >> K3S one at a time, doing the same test after each thing connected. > >> > >> Of course, if the hum is present with nothing connected, contact > >> supp...@elecraft.com - but I cannot imagine a hum with harmonics of 60 > >> Hz being induced if you take away all the 60 Hz operated sources in the > >> area. > >> > >> 73, > >> Don W3FPR > >> > >> -- > > *N6OL* > > Saying something doesn't make it true. Belief in something doesn't make > it > > real. And if you have to lie to support a position, that position is not > > worth supporting. > > __ > > 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 > > > > -- *N6OL* Saying something doesn't make it true. Belief in something doesn't make it real. And if you have to lie to support a position, that position is not worth supporting. __ 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] K3S Audio buzz on transmit, especially AM
I recall commenting earlier. What TX EQ values are being used for AM. ? Bob, K4TAX Sent from my iPhone > On Apr 26, 2019, at 5:48 PM, Nicklas Johnson wrote: > > My desk in this case sits adjacent a wall, and there's only a shower on the > other side of that wall. I did turn off everything in the vicinity of the > desk and all the lights in the room (I've in fact heard a very similar hum > from the switching power supply for my mixer, and my first thought was it > was this that was being picked up), but I didn't turn off the computer on > the other side of the room. In this case it will be easier to move the rig > outdoors with a battery than it will be to turn that computer off for the > moment. It would have to be an impressively/obnoxiously strong magnetic > field from that side of the room to influence the transformers inside the > rig 8 feet away, but it's worth trying and simple enough to rule it out. > > Nick > >> On Fri, 26 Apr 2019 at 14:51, Don Wilhelm wrote: >> >> In addition to operating from a battery isolated from the solar system, >> I would recommend that you do a quick test - remove all cables from the >> K3S except the power cable and a coax to a dummy load. Power down all >> power supplies in your station, including any desk lamps. >> Go into Transmit by tapping the XMIT button. >> Is the hum still present? If not, then start connecting things to your >> K3S one at a time, doing the same test after each thing connected. >> >> Of course, if the hum is present with nothing connected, contact >> supp...@elecraft.com - but I cannot imagine a hum with harmonics of 60 >> Hz being induced if you take away all the 60 Hz operated sources in the >> area. >> >> 73, >> Don W3FPR >> >> -- > *N6OL* > Saying something doesn't make it true. Belief in something doesn't make it > real. And if you have to lie to support a position, that position is not > worth supporting. > __ > 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] K3S Audio buzz on transmit, especially AM
My desk in this case sits adjacent a wall, and there's only a shower on the other side of that wall. I did turn off everything in the vicinity of the desk and all the lights in the room (I've in fact heard a very similar hum from the switching power supply for my mixer, and my first thought was it was this that was being picked up), but I didn't turn off the computer on the other side of the room. In this case it will be easier to move the rig outdoors with a battery than it will be to turn that computer off for the moment. It would have to be an impressively/obnoxiously strong magnetic field from that side of the room to influence the transformers inside the rig 8 feet away, but it's worth trying and simple enough to rule it out. Nick On Fri, 26 Apr 2019 at 14:51, Don Wilhelm wrote: > In addition to operating from a battery isolated from the solar system, > I would recommend that you do a quick test - remove all cables from the > K3S except the power cable and a coax to a dummy load. Power down all > power supplies in your station, including any desk lamps. > Go into Transmit by tapping the XMIT button. > Is the hum still present? If not, then start connecting things to your > K3S one at a time, doing the same test after each thing connected. > > Of course, if the hum is present with nothing connected, contact > supp...@elecraft.com - but I cannot imagine a hum with harmonics of 60 > Hz being induced if you take away all the 60 Hz operated sources in the > area. > > 73, > Don W3FPR > > -- *N6OL* Saying something doesn't make it true. Belief in something doesn't make it real. And if you have to lie to support a position, that position is not worth supporting. __ 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] K3S Audio buzz on transmit, especially AM
I did in fact wonder the same thing myself-- whether the solar controller could be injecting some noise or just making some noise, so when I did the battery test, I disconnected the battery from the controller and ran directly from the battery to the rig. I couldn't tell you a dB level of the buzz without having some more accurate equipment to measure it, but it's very noticeable relative to my voice when testing. It was enough to make me think I had either RF feedback or a ground loop giving me grief. There could be something to be learned from the predominant frequencies present in the buzz... they're more or less 120Hz apart, but they start at a weird place-- 350 isn't a multiple of 60 or 120, but that particular spur and the 470 and 830 Hz spurs are all pretty exact, though of course it's not impossible that there's some FFT error in determining those frequencies and they're actually 360, 480, and 840. Curious, though, is that running on a battery, there's nothing to inject a 60Hz or 120Hz noise directly, especially not once I disconnected the rig ground from the ground rod outside. Which makes me wonder if the buzz is just something in the house that's mixing with the carrier and re-radiating. For my next trick, this weekend I think I'll take everything outside on a picnic table, away from house wiring, etc., and see if that changes anything, or I might start with just the receiver outdoors and away from house wiring, and then move on to both if needed. Nick On Fri, 26 Apr 2019 at 14:37, K8TE wrote: > The word that struck my attention is "solar" and the possibility of that > controller causing noise. When you were connected to just the battery and > dummy load, was the battery disconnected from the solar system? And, at > what level was the buzz relative to a full power carrier? > > Every transmitter has some noise on its signal. Specifications and FCC > rules in some cases call for a specific ratio. I can't imagine a factory > reset solving a problem like this. Be certain you have saved your > configuration first. Solving issues like this is not magic, but sometimes > a > mystery. > > 73, Bill, K8TE > -- *N6OL* Saying something doesn't make it true. Belief in something doesn't make it real. And if you have to lie to support a position, that position is not worth supporting. __ 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] K3S Audio buzz on transmit, especially AM
That makes sense too. The transformers are unshielded, so are sitting ducks for strong nearby magnetic fields. K6XX ran into this early on running RTTY from a big amp PSU very close to a K3. The coupling was so strong that it went into regeneration! 73, Jim K9YC On 4/26/2019 3:16 PM, donov...@starpower.net wrote: I had this same problem years ago before purchasing my first K3. It turned out to magnetic field coupling between my HyGain T2X control box and an audio transformer in the transceiver. __ 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] K3S Audio buzz on transmit, especially AM
I had this same problem years ago before purchasing my first K3. It turned out to magnetic field coupling between my HyGain T2X control box and an audio transformer in the transceiver. As Don suggested, be sure all power supplies including computers, UPSs and lamps are turned off during the test. If this doesn't work, take to K3S to a friends QTH and repeat the test 73 Frank W3LPL - Original Message - From: "Don Wilhelm" To: elecraft@mailman.qth.net Sent: Friday, April 26, 2019 9:51:15 PM Subject: Re: [Elecraft] K3S Audio buzz on transmit, especially AM In addition to operating from a battery isolated from the solar system, I would recommend that you do a quick test - remove all cables from the K3S except the power cable and a coax to a dummy load. Power down all power supplies in your station, including any desk lamps. Go into Transmit by tapping the XMIT button. Is the hum still present? If not, then start connecting things to your K3S one at a time, doing the same test after each thing connected. Of course, if the hum is present with nothing connected, contact supp...@elecraft.com - but I cannot imagine a hum with harmonics of 60 Hz being induced if you take away all the 60 Hz operated sources in the area. 73, Don W3FPR On 4/26/2019 5:36 PM, K8TE wrote: > The word that struck my attention is "solar" and the possibility of that > controller causing noise. When you were connected to just the battery and > dummy load, was the battery disconnected from the solar system? And, at > what level was the buzz relative to a full power carrier? > > Every transmitter has some noise on its signal. Specifications and FCC > rules in some cases call for a specific ratio. I can't imagine a factory > reset solving a problem like this. Be certain you have saved your > configuration first. Solving issues like this is not magic, but sometimes a > mystery. > __ 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] K3S Audio buzz on transmit, especially AM
I think you may have hit on it, Bill. Say it's a pulse-regulated controller on the battery is on the soft side. BTW -- most solar charge controllers put out a lot of RF noise. The only good pulsing controllers I've found are the MPPT controllers made by Genasun. https://sunforgellc.com/genasun/#gen_product_row Another question to help diagnose the problem if it's the battery -- what's the DC voltage at the battery in RX mode? In TX mode? What does the K3 internal voltmeter read for RX and TX? 73, Jim K9YC 73, On 4/26/2019 2:36 PM, K8TE wrote: The word that struck my attention is "solar" and the possibility of that controller causing noise. When you were connected to just the battery and dummy load, was the battery disconnected from the solar system? __ 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] K3S Audio buzz on transmit, especially AM
In addition to operating from a battery isolated from the solar system, I would recommend that you do a quick test - remove all cables from the K3S except the power cable and a coax to a dummy load. Power down all power supplies in your station, including any desk lamps. Go into Transmit by tapping the XMIT button. Is the hum still present? If not, then start connecting things to your K3S one at a time, doing the same test after each thing connected. Of course, if the hum is present with nothing connected, contact supp...@elecraft.com - but I cannot imagine a hum with harmonics of 60 Hz being induced if you take away all the 60 Hz operated sources in the area. 73, Don W3FPR On 4/26/2019 5:36 PM, K8TE wrote: The word that struck my attention is "solar" and the possibility of that controller causing noise. When you were connected to just the battery and dummy load, was the battery disconnected from the solar system? And, at what level was the buzz relative to a full power carrier? Every transmitter has some noise on its signal. Specifications and FCC rules in some cases call for a specific ratio. I can't imagine a factory reset solving a problem like this. Be certain you have saved your configuration first. Solving issues like this is not magic, but sometimes a mystery. __ 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] K3S Audio buzz on transmit, especially AM
The word that struck my attention is "solar" and the possibility of that controller causing noise. When you were connected to just the battery and dummy load, was the battery disconnected from the solar system? And, at what level was the buzz relative to a full power carrier? Every transmitter has some noise on its signal. Specifications and FCC rules in some cases call for a specific ratio. I can't imagine a factory reset solving a problem like this. Be certain you have saved your configuration first. Solving issues like this is not magic, but sometimes a mystery. 73, Bill, K8TE -- Sent from: http://elecraft.365791.n2.nabble.com/ __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3S Audio buzz on transmit, especially AM
I did listen and look at my K3S on my SDR receiver in AM mode. I do find there is a small amount of hum on the carrier. Then switching to LSB, I do not find the hum present. You may want to check the settings of your TX EQ. If you have any low frequency boost, that will contribute to the level of the hum. My operating values are: 50 Hz = -16 dB , 100 Hz = -16 dB , 200 Hz = -16 dB , 400 Hz = -6 dB, everything above that is set to 0 dB or flat. The mike is a Shure SM-58. In AM mode the hum is noted at 120 Hz, 240 Hz, and 360 Hz, all multiples of the 60 Hz line. At the same time, the hum level of the individual frequencies, worst case, is some 40 dB below 100% modulation. Some are 50 dB below 100% modulation with the worst case being 120 Hz. In working several AM stations over the past year or so, I've not had any comments regarding hum on the carrier. These tests were done with MIC level set to 0 and COM level set to 0. Everything else normal and connected to the radio. Different power levels, mike level and comp level made no difference in the amplitude of the hum components. 73 Bob, K4TAX On 4/26/2019 10:43 AM, Nicklas Johnson wrote: This morning just for yuks, I also temporarily disconnected the ground from the rig entirely while also connecting only to a dummy load, so there could be no path to ground at all, let alone multiple paths. No change. I guess the next things I'll probably try are a full factory reset, and then perhaps popping it open to make sure nothing has come unseated. But first I'll drop a line to Elecraft support too. I've seen a number of people post about similar problems that either magically resolved themselves or ended up being a fault on the audio board. Nick On Thu, 25 Apr 2019 at 23:27, Nicklas Johnson wrote: Again, the problem persists with all inputs completely disconnected and the mic gain set at 0. And running solely on a battery into a dummy load. Nick On Thu, Apr 25, 2019, 10:10 PM Jim Brown wrote: On 4/25/2019 8:15 PM, Nicklas Johnson wrote: Physically touching the case or grabbing the barrel of the front panel mic connector actually does cause the buzz to get just a little softer. I suspect either a bonding problem or a problem with the wiring of the mic. I generally use solar/battery power, though my ground is bonded to my utility ground. I suggest that you carefully study either N0AX's recent ARRL book on grounding and bonding, or the slides for talks I've given at Visalia and Pacifion. 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 __ 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] K3S Audio buzz on transmit, especially AM
This morning just for yuks, I also temporarily disconnected the ground from the rig entirely while also connecting only to a dummy load, so there could be no path to ground at all, let alone multiple paths. No change. I guess the next things I'll probably try are a full factory reset, and then perhaps popping it open to make sure nothing has come unseated. But first I'll drop a line to Elecraft support too. I've seen a number of people post about similar problems that either magically resolved themselves or ended up being a fault on the audio board. Nick On Thu, 25 Apr 2019 at 23:27, Nicklas Johnson wrote: > Again, the problem persists with all inputs completely disconnected and > the mic gain set at 0. And running solely on a battery into a dummy load. > >Nick > > On Thu, Apr 25, 2019, 10:10 PM Jim Brown > wrote: > >> On 4/25/2019 8:15 PM, Nicklas Johnson wrote: >> > Physically touching the case or grabbing the barrel of the front panel >> mic >> > connector actually does cause the buzz to get just a little softer. >> >> I suspect either a bonding problem or a problem with the wiring of the >> mic. >> >> > I generally use solar/battery power, though my ground is bonded to my >> > utility ground. >> >> I suggest that you carefully study either N0AX's recent ARRL book on >> grounding and bonding, or the slides for talks I've given at Visalia and >> Pacifion. >> >> 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 >> > -- *N6OL* Saying something doesn't make it true. Belief in something doesn't make it real. And if you have to lie to support a position, that position is not worth supporting. __ 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] K3S Audio buzz on transmit, especially AM
Again, the problem persists with all inputs completely disconnected and the mic gain set at 0. And running solely on a battery into a dummy load. Nick On Thu, Apr 25, 2019, 10:10 PM Jim Brown wrote: > On 4/25/2019 8:15 PM, Nicklas Johnson wrote: > > Physically touching the case or grabbing the barrel of the front panel > mic > > connector actually does cause the buzz to get just a little softer. > > I suspect either a bonding problem or a problem with the wiring of the mic. > > > I generally use solar/battery power, though my ground is bonded to my > > utility ground. > > I suggest that you carefully study either N0AX's recent ARRL book on > grounding and bonding, or the slides for talks I've given at Visalia and > Pacifion. > > 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 > __ 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] K3S Audio buzz on transmit, especially AM
On 4/25/2019 8:15 PM, Nicklas Johnson wrote: Physically touching the case or grabbing the barrel of the front panel mic connector actually does cause the buzz to get just a little softer. I suspect either a bonding problem or a problem with the wiring of the mic. I generally use solar/battery power, though my ground is bonded to my utility ground. I suggest that you carefully study either N0AX's recent ARRL book on grounding and bonding, or the slides for talks I've given at Visalia and Pacifion. 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
Re: [Elecraft] K3S Audio buzz on transmit, especially AM
That was my second thought, but then I disconnected everything, including the microphone, and it made no difference. Nick On Thu, Apr 25, 2019, 8:20 PM Grant Youngman wrote: > Microphone? Or anything in between the mic and the radio, if there is > anything? > > Grant NQ5T > K3 #2091 KX3 #8342 > > > > > > > Any other ideas? I'm running out of them. > > > > Nick > > > > -- > > *N6OL* > > Saying something doesn't make it true. Belief in something doesn't make > it > > real. And if you have to lie to support a position, that position is not > > worth supporting. > > __ > > 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] K3S Audio buzz on transmit, especially AM
Microphone? Or anything in between the mic and the radio, if there is anything? Grant NQ5T K3 #2091 KX3 #8342 > > > Any other ideas? I'm running out of them. > > Nick > > -- > *N6OL* > Saying something doesn't make it true. Belief in something doesn't make it > real. And if you have to lie to support a position, that position is not > worth supporting. > __ > 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] K3S Audio buzz on transmit, especially AM
I'm trying to track down a pretty obnoxious audio problem on AM, and to a much lesser extent on SSB. On transmit I get an audio buzz with the highest spikes on 350, 470, and 830 Hz. At first I thought I had a ground loop hum, so I disconnected everything from the K3s except the antenna and switched the power over to battery only. It made no difference. Other things that don't make any difference: lowering the mic/line input level to 0, changing the mic input among front panel, rear panel, line-in, changing frequency, changing output power all the way down to 0.1w, turning off all the lights and shutting off any other nearby equipment in the room, running into a dummy load with the receiver nearby. Physically touching the case or grabbing the barrel of the front panel mic connector actually does cause the buzz to get just a little softer. I generally use solar/battery power, though my ground is bonded to my utility ground. Any other ideas? I'm running out of them. Nick -- *N6OL* Saying something doesn't make it true. Belief in something doesn't make it real. And if you have to lie to support a position, that position is not worth supporting. __ 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
