Re: [Elecraft] [K3] Noise from P3
Hi Graham Yes. With or without that cable seems to make no difference. Regards John G4ZTR -Original Message- From: Graham Kimbell G3TCT [mailto:g3...@lineone.net] Sent: 24 March 2011 20:49 To: John Lemay Cc: elecraft@mailman.qth.net Subject: Re: Re: [Elecraft] [K3] Noise from P3 On 19:59, John Lemay wrote: > Well, I have undertaken a lot of work to address this problem:- > > John have you tried disconnecting the RS232 connection between K3 and P3? Graham G3TCT __ Information from ESET NOD32 Antivirus, version of virus signature database 5983 (20110324) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __ Information from ESET NOD32 Antivirus, version of virus signature database 5983 (20110324) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.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] [K3] Noise from P3
No apparent noise from the P3 on 144.225 here, either. The P3 is resting against the "feet" on the right side of the K3. My antenna is 100' away at 65' and was pointing at the shack. Bob K5SM __ 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] [K3] Noise from P3
On 19:59, John Lemay wrote: > Well, I have undertaken a lot of work to address this problem:- > > John have you tried disconnecting the RS232 connection between K3 and P3? Graham G3TCT __ 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] [K3] Noise from P3
On 3/24/2011 1:04 AM, John Lemay wrote: > In fact if anything it is a little worse this morning, > but these are not lab measurements. FWIW -- the P3 display is a VERY good indicator of voltage at the IF, and you can easily set it to read out in dB, and with very high resolution. I'd say take it up with Elecraft. It should not be thus. :) I'll bet this thread has already gotten their attention. N1AL is on the P3 design team, and has been following it. Wayne and Eric both pay attention to this list. 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] [K3] Noise from P3
Well, I have undertaken a lot of work to address this problem:- 1. taken apart the P3 and doubly made certain that contact between the various chassis parts is good. 2. taken apart the K3 and paid particular attention to the contact areas around the rear panel and IF output area. 3. placed ferrites at both ends of the DC lead to the P3. 4. used the P3 on a separate power supply. 5. placed ferrites on the IF lead between the P3 and K3. The problem remains. In fact if anything it is a little worse this morning, but these are not lab measurements. So, Dxing on 2m with the P3 running is a non-starter for me. John G4ZTR -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Jim Brown Sent: 24 March 2011 06:03 To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Noise from P3 On 3/23/2011 9:39 PM, David Pratt wrote: > That being so, Alan, is there any value in supplying screened cable for > the power lead rather than the twin 'bell wire' used at present? Not if it is common mode current, coupled from signal common onto the V- wire. Go to my website and study the material on "The Pin One Problem." While it is written about audio interconnects, it applies directly here to the V- lead. http://audiosystemsgroup.com/publish.htm Shielding only matters with respect to DIFFERENTIAL circuit (that is, RFI between V+ and V-). 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 __ Information from ESET NOD32 Antivirus, version of virus signature database 5980 (20110324) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __ Information from ESET NOD32 Antivirus, version of virus signature database 5980 (20110324) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.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] [K3] Noise from P3
On 3/23/2011 9:39 PM, David Pratt wrote: > That being so, Alan, is there any value in supplying screened cable for > the power lead rather than the twin 'bell wire' used at present? Not if it is common mode current, coupled from signal common onto the V- wire. Go to my website and study the material on "The Pin One Problem." While it is written about audio interconnects, it applies directly here to the V- lead. http://audiosystemsgroup.com/publish.htm Shielding only matters with respect to DIFFERENTIAL circuit (that is, RFI between V+ and V-). 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] [K3] Noise from P3
On Thu, 2011-03-24 at 04:39 +, David Pratt wrote: > In a recent message, Alan Bloom writes > > >The shells of the coax and the RS-232 connectors are grounded directly > >to the chassis. Sounds like it must be the power cable. > > That being so, Alan, is there any value in supplying screened cable for > the power lead rather than the twin 'bell wire' used at present? Maybe a little, but I suspect that wrapping a few turns through a ferrite core would be much more effective. Alan > 73 de David G4DMP __ 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] [K3] Noise from P3
In a recent message, Alan Bloom writes >The shells of the coax and the RS-232 connectors are grounded directly >to the chassis. Sounds like it must be the power cable. That being so, Alan, is there any value in supplying screened cable for the power lead rather than the twin 'bell wire' used at present? 73 de David G4DMP -- + - - - - - - - - - - - - - - - - + | David M Pratt, Kippax, Leeds. | | Website: http://www.g4dmp.co.uk | + - - - - - - - - - - - - - - - - + __ 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] [K3] Noise from P3
On Wed, 2011-03-23 at 19:35 -0700, Jim Brown wrote: > On 3/23/2011 1:30 PM, John Lemay wrote: > > Yes, I can "home in" on the noise with great certainty ! > > That indicates that the noise is being radiated by the P3 or something > attached to it, and picked up on your antenna (and not picked up on K3 > wiring). I can see the noise on mine if I hook a clip lead to the ANT3 (144 MHz) connector and place it close to the display. But I doubt you could hear that on an external antenna. The opening in the front panel is much smaller than 1/2 wavelength on 2 meters, so the far field should be greatly attenuated and the near field falls off rapidly with distance. > The comments by others that ferrites on the power cable killed the noise > suggest that that cable is doing the radiating. Now, I wouldn't rule out > the coax as a radiator if someone has choked the power cable and still > heard noise -- with RFI, always assume that there could be more than one > coupling mechanism. The shells of the coax and the RS-232 connectors are grounded directly to the chassis. Sounds like it must be the power cable. Alan N1AL > Again, let me emphasize that a ferrite core is a low Q parallel resonant > circuit. Most single #31 or #43 cores are, by virtue of their size and > shape, cause a single turn to resonate close to 2M, while more turns > move the resonance down to lower frequencies. This a problem on 2M is > better solved with multiple cores rather than multiple turns, whereas > problems on 6M are better solved with two turns and on the HF bands with > more turns. > > 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] [K3] Noise from P3
On 3/23/2011 1:30 PM, John Lemay wrote: > Yes, I can "home in" on the noise with great certainty ! That indicates that the noise is being radiated by the P3 or something attached to it, and picked up on your antenna (and not picked up on K3 wiring). The comments by others that ferrites on the power cable killed the noise suggest that that cable is doing the radiating. Now, I wouldn't rule out the coax as a radiator if someone has choked the power cable and still heard noise -- with RFI, always assume that there could be more than one coupling mechanism. Again, let me emphasize that a ferrite core is a low Q parallel resonant circuit. Most single #31 or #43 cores are, by virtue of their size and shape, cause a single turn to resonate close to 2M, while more turns move the resonance down to lower frequencies. This a problem on 2M is better solved with multiple cores rather than multiple turns, whereas problems on 6M are better solved with two turns and on the HF bands with more turns. 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] [K3] Noise from P3
Hm . . . what about SCOTCHTINT, or somesuch other rf shielding window film, over the display, between the clear bezel and the chassis? Brgds, Dave, N3HE -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-Noise-from-P3-tp6201047p6202021.html Sent from the Elecraft mailing list archive at 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] [K3] Noise from P3
Interesting ! I'll try some more ferrite tomorrow . John -Original Message- From: David Pratt [mailto:da...@g4dmp.fsnet.co.uk] Sent: 23 March 2011 21:31 To: Ken Roberson; John Lemay Cc: elecraft@mailman.qth.net; j...@audiosystemsgroup.com Subject: Re: [Elecraft] [K3] Noise from P3 *** Thank you to everyone for their kind help. *** I am pleased to report that putting a ferrite 'clamp-on' core at each end of the 12V power lead has completely cured the problem. Because the cable is quite thin, I managed to wind two turns round each core. I wonder whether a screened power cable might have been an alternative answer? Maybe I shall try that tomorrow. Incidentally, before fitting the cores I did notice that placing a finger near the screen did increase the noise. 73 de David G4DMP -- + - - - - - - - - - - - - - - - - + | David M Pratt, Kippax, Leeds. | | Website: http://www.g4dmp.co.uk | + - - - - - - - - - - - - - - - - + __ Information from ESET NOD32 Antivirus, version of virus signature database 5978 (20110323) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __ Information from ESET NOD32 Antivirus, version of virus signature database 5978 (20110323) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.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] [K3] Noise from P3
*** Thank you to everyone for their kind help. *** I am pleased to report that putting a ferrite 'clamp-on' core at each end of the 12V power lead has completely cured the problem. Because the cable is quite thin, I managed to wind two turns round each core. I wonder whether a screened power cable might have been an alternative answer? Maybe I shall try that tomorrow. Incidentally, before fitting the cores I did notice that placing a finger near the screen did increase the noise. 73 de David G4DMP -- + - - - - - - - - - - - - - - - - + | David M Pratt, Kippax, Leeds. | | Website: http://www.g4dmp.co.uk | + - - - - - - - - - - - - - - - - + __ 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] [K3] Noise from P3
John, my findings are the same as yours. I only have a single 4 element beam, mounted about 25 feet above the shack on the apex of the roof. The noise reduces significantly when the beam is pointing away from the shack. I hear the noise when the P3 is on and fully connected to the K3 and PC but I also hear it when the P3 is on with no connection to the K3 or PC, other than the dc feed from the K3. 73 to all Geoff G3UCK - Original Message - From: "John Lemay" To: Cc: Sent: Wednesday, March 23, 2011 8:18 PM Subject: Re: [Elecraft] [K3] Noise from P3 > I've spent a bit more time investigating this noise, following my initial > response to David. > > The noise sounds rather like a buzz saw. It is quite audible on the K3 > speaker, it is strong enough to move the S meter, and it's visible on the > P3. There is not just one frequency, but the noise is every 19kHz (approx) > across the band. > > The noise goes away if:- > > 1. I turn the P3 off > 2. I remove the 2m antenna > > The noise reduces if:- > > 1. I disconnect the BNC at the K3 IF Out connector. > > I already have chokes on the DC lead to the P3. > > I think at this stage I should also make it clear that I have a highly > sensitive 2m system with masthead preamplifier, and four eight element > yagis > which are at present quite close to ground level. > > Regards > > John G4ZTR __ 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] [K3] Noise from P3
Yes, I can "home in" on the noise with great certainty ! -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Jim Brown Sent: 23 March 2011 20:23 Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Noise from P3 On 3/23/2011 1:18 PM, John Lemay wrote: > I think at this stage I should also make it clear that I have a highly > sensitive 2m system with masthead preamplifier, and four eight element yagis > which are at present quite close to ground level. Does the strength of the noise vary as you rotate the antenna? 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 __ Information from ESET NOD32 Antivirus, version of virus signature database 5978 (20110323) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __ Information from ESET NOD32 Antivirus, version of virus signature database 5978 (20110323) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.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] [K3] Noise from P3
On 3/23/2011 1:18 PM, John Lemay wrote: > I think at this stage I should also make it clear that I have a highly > sensitive 2m system with masthead preamplifier, and four eight element yagis > which are at present quite close to ground level. Does the strength of the noise vary as you rotate the antenna? 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] [K3] Noise from P3
I've spent a bit more time investigating this noise, following my initial response to David. The noise sounds rather like a buzz saw. It is quite audible on the K3 speaker, it is strong enough to move the S meter, and it's visible on the P3. There is not just one frequency, but the noise is every 19kHz (approx) across the band. The noise goes away if:- 1. I turn the P3 off 2. I remove the 2m antenna The noise reduces if:- 1. I disconnect the BNC at the K3 IF Out connector. I already have chokes on the DC lead to the P3. I think at this stage I should also make it clear that I have a highly sensitive 2m system with masthead preamplifier, and four eight element yagis which are at present quite close to ground level. Regards John G4ZTR -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Jim Brown Sent: 23 March 2011 19:20 Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Noise from P3 On 3/23/2011 11:56 AM, John Lemay wrote: > It seems to me that the noise is being radiated by the screen itself, and no > amount of cabinet scraping will reduce this. That's entirely possible -- but it's also possible that the cables are involved. Many RFI problems have more than one cause, or more than one component, or a combination of causes, both of which must be present for the RFI to happen. In this example, a hand or finger next to the display allows RF to capacity-couple to the body, and the resulting RF current radiates the noise. Take the fingers away, and if there's still noise, another coupling mechanism may be present. On the other hand, I've never felt the urge to have my fingers next to the P3 screen. :) I don't operate 2M for weak signal work, because I'm blocked by a high ridge to all of North America, so I can't comment on noise from my own display. :) I don't recall details of the P3 construction, nor the display, but the display is a potential break in shielding, and even a potential RFI source. Ideally, the display should be bonded to the shielding enclosure and be constructed in a manner that there is no break in the shielding, and any current driving the display should flow in a loop with very small area to minimize any magnetic field. 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 __ Information from ESET NOD32 Antivirus, version of virus signature database 5978 (20110323) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __ Information from ESET NOD32 Antivirus, version of virus signature database 5978 (20110323) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.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] [K3] Noise from P3
Hello all, Jim is right the ferrite cores will fix the problem, Been there done that about two months ago . Ferrite on all input and outputs. 73 all K5DNL --- --- On Wed, 3/23/11, Jim Brown wrote: > From: Jim Brown > Subject: Re: [Elecraft] [K3] Noise from P3 > To: elecraft@mailman.qth.net > Date: Wednesday, March 23, 2011, 1:31 PM > On 3/23/2011 10:09 AM, David Pratt > wrote: > > Removing the 2 metre antenna also > removes the noise. > > How far is your 2M antenna from your P3? > > A suggestion. Try adding several clamp-on ferrite cores to > the power > cable and the BNC, placing them as close to the P3 as > practical. These > should be a SINGLE TURN for 2M (that is, simply clamped > onto the cable), > two turns for 6M. IF these cables are radiating the trash, > the cores can > help reduce it. > > 73, Jim K9YC > > 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] [K3] Noise from P3
On 3/23/2011 11:56 AM, John Lemay wrote: > It seems to me that the noise is being radiated by the screen itself, and no > amount of cabinet scraping will reduce this. That's entirely possible -- but it's also possible that the cables are involved. Many RFI problems have more than one cause, or more than one component, or a combination of causes, both of which must be present for the RFI to happen. In this example, a hand or finger next to the display allows RF to capacity-couple to the body, and the resulting RF current radiates the noise. Take the fingers away, and if there's still noise, another coupling mechanism may be present. On the other hand, I've never felt the urge to have my fingers next to the P3 screen. :) I don't operate 2M for weak signal work, because I'm blocked by a high ridge to all of North America, so I can't comment on noise from my own display. :) I don't recall details of the P3 construction, nor the display, but the display is a potential break in shielding, and even a potential RFI source. Ideally, the display should be bonded to the shielding enclosure and be constructed in a manner that there is no break in the shielding, and any current driving the display should flow in a loop with very small area to minimize any magnetic field. 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] [K3] Noise from P3
Thank you for adding the needed emphasis. I really took pains to be sure lots of metal to metal. Bill K9YEQ -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Jim Brown Sent: Wednesday, March 23, 2011 1:52 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Noise from P3 On 3/23/2011 11:47 AM, Bill wrote: > I should not think the mains 50 cycle should matter. It would seem to > be more of a radiation issue. That is what makes me ask about the > cabinet prep. Yes. And your comment about the importance of scraping the paint is right on too. If there's paint between the connector and the chassis, there's no shield connection. 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] [K3] Noise from P3
It seems to me that the noise is being radiated by the screen itself, and no amount of cabinet scraping will reduce this. John G4ZTR -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Jim Brown Sent: 23 March 2011 18:52 To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Noise from P3 On 3/23/2011 11:47 AM, Bill wrote: > I should not think the mains 50 cycle should matter. It would seem to be > more of a radiation issue. That is what makes me ask about the cabinet > prep. Yes. And your comment about the importance of scraping the paint is right on too. If there's paint between the connector and the chassis, there's no shield connection. 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 __ Information from ESET NOD32 Antivirus, version of virus signature database 5978 (20110323) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __ Information from ESET NOD32 Antivirus, version of virus signature database 5978 (20110323) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.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] [K3] Noise from P3
On 3/23/2011 11:47 AM, Bill wrote: > I should not think the mains 50 cycle should matter. It would seem to be > more of a radiation issue. That is what makes me ask about the cabinet > prep. Yes. And your comment about the importance of scraping the paint is right on too. If there's paint between the connector and the chassis, there's no shield connection. 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] [K3] Noise from P3
On 3/23/2011 10:54 AM, Ron D'Eau Claire wrote: > If it's not being picked up by the antenna there must be some other path > into the K144XV perhaps through an open ground between units, etc. A Pin One Problem on either end of the BNC or power cables (that is, at the P3 or K3) could couple around the antenna. In chasing RF noise coupled from a noisy SteppIR power supply, I'm chasing exactly such a coupling mechanism that is quite strong on 12M. At this point, I'm not CERTAIN that the K3 has a Pin One problem on its power connector and accessory power connector, but tentative results suggest it -- chokes on those cables reduces the noise! What does this mean from a circuit design point of view? The V+ AND V- lines should both be RF bypassed to the chassis, AND should have a choke between those conductors and interior circuitry. The V- conductor is the one most usually overlooked. What RFI guru Henry Ott calls "the hidden schematic lurking behind the ground symbol." Of course, the BNC connector shells should be solidly screwed to the shielding enclosure at both ends. Note that this sort of problem might also be caused by an open shield on the coax running between the P3 and the K3. I have two P3s. The BNC cable shipped with one of them was bad. 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] [K3] Noise from P3
David, I should not think the mains 50 cycle should matter. It would seem to be more of a radiation issue. That is what makes me ask about the cabinet prep. I have mine sitting on the right side of K3. Bill K9YEQ -Original Message- From: David Pratt [mailto:da...@g4dmp.fsnet.co.uk] Sent: Wednesday, March 23, 2011 12:30 PM To: Bill Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Noise from P3 Thank you, Bill, interesting. As the problem has also been reported by John G4ZTR I wonder whether it could be due to our 50Hz mains supply. 73 de David G4DMP In a recent message, Bill writes > >David, > >I tried this and found no similar issue. > >Bill >K9YEQ > >-Original Message- > >While operating on SSB on 144.225 MHz using the internal K144VX >transverter I am getting broadband noise around that frequency when I switch on my P3. >The noise is quite strong, about S7, and shows clearly on the P3 >screen. If I move the P3 about six inches away from the K3 the noise disappears. >Removing the 2 metre antenna also removes the noise. > >I would be grateful if anyone else with a K144XV and a P3 would check >to see if they get the same problem? > -- + - - - - - - - - - - - - - - - - + | David M Pratt, Kippax, Leeds. | | Website: http://www.g4dmp.co.uk | + - - - - - - - - - - - - - - - - + __ 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] [K3] Noise from P3
On 3/23/2011 10:09 AM, David Pratt wrote: > Removing the 2 metre antenna also removes the noise. How far is your 2M antenna from your P3? A suggestion. Try adding several clamp-on ferrite cores to the power cable and the BNC, placing them as close to the P3 as practical. These should be a SINGLE TURN for 2M (that is, simply clamped onto the cable), two turns for 6M. IF these cables are radiating the trash, the cores can help reduce it. 73, Jim K9YC 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] [K3] Noise from P3
It's audible here only if I put my fingers on the P3 screen and find the most sensitive spot, but it's never strong. It's completely inaudible without touching the P3's screen. Disconnected the 2-meter antenna and touched a short wire to the ANT3 connector and it got very loud, suggesting that it's noise being picked up by the antenna, at least for me. My 2-meter antenna is on the roof about 15 feet above the rig. If it's not being picked up by the antenna there must be some other path into the K144XV perhaps through an open ground between units, etc. Ron AC7AC -Original Message- David Yes, I do. Try placing your hand immediately in front of the P3 screen and it will act as an aerial, making the situation quite a bit worse. John G4ZTR -Original Message- While operating on SSB on 144.225 MHz using the internal K144VX transverter I am getting broadband noise around that frequency when I switch on my P3. The noise is quite strong, about S7, and shows clearly on the P3 screen. If I move the P3 about six inches away from the K3 the noise disappears. Removing the 2 metre antenna also removes the noise. I would be grateful if anyone else with a K144XV and a P3 would check to see if they get the same problem? Many thanks 73 de David G4DMP -- + - - - - - - - - - - - - - - - - + | David M Pratt, Kippax, Leeds. | | Website: http://www.g4dmp.co.uk | + - - - - - - - - - - - - - - - - + __ 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] [K3] Noise from P3
David, My P3 is on the side of my K3 with the handle. I also have the K144XV. I'm not able to duplicate what you describe. Tom N5GE On Wed, 23 Mar 2011 17:09:07 +, David Pratt wrote: >While operating on SSB on 144.225 MHz using the internal K144VX >transverter I am getting broadband noise around that frequency when I >switch on my P3. The noise is quite strong, about S7, and shows clearly >on the P3 screen. If I move the P3 about six inches away from the K3 the >noise disappears. Removing the 2 metre antenna also removes the noise. > >I would be grateful if anyone else with a K144XV and a P3 would check to >see if they get the same problem? > >Many thanks > >73 de David G4DMP __ 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] [K3] Noise from P3
Thank you, Bill, interesting. As the problem has also been reported by John G4ZTR I wonder whether it could be due to our 50Hz mains supply. 73 de David G4DMP In a recent message, Bill writes > >David, > >I tried this and found no similar issue. > >Bill >K9YEQ > >-Original Message- > >While operating on SSB on 144.225 MHz using the internal K144VX transverter >I am getting broadband noise around that frequency when I switch on my P3. >The noise is quite strong, about S7, and shows clearly on the P3 screen. If >I move the P3 about six inches away from the K3 the noise disappears. >Removing the 2 metre antenna also removes the noise. > >I would be grateful if anyone else with a K144XV and a P3 would check to see >if they get the same problem? > -- + - - - - - - - - - - - - - - - - + | David M Pratt, Kippax, Leeds. | | Website: http://www.g4dmp.co.uk | + - - - - - - - - - - - - - - - - + __ 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] [K3] Noise from P3
I tried the hand thing and still no change. There is obviously a difference between our setups. I assembled my P3. I also followed the cabinet paint cleaning scheme with my dremel tool to be sure the cabinet sides were well bonded. Did you do this? Bill K9YEQ -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of John Lemay Sent: Wednesday, March 23, 2011 12:18 PM To: 'David Pratt'; elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Noise from P3 David Yes, I do. Try placing your hand immediately in front of the P3 screen and it will act as an aerial, making the situation quite a bit worse. John G4ZTR -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of David Pratt Sent: 23 March 2011 17:09 To: elecraft@mailman.qth.net Subject: [Elecraft] [K3] Noise from P3 While operating on SSB on 144.225 MHz using the internal K144VX transverter I am getting broadband noise around that frequency when I switch on my P3. The noise is quite strong, about S7, and shows clearly on the P3 screen. If I move the P3 about six inches away from the K3 the noise disappears. Removing the 2 metre antenna also removes the noise. I would be grateful if anyone else with a K144XV and a P3 would check to see if they get the same problem? Many thanks 73 de David G4DMP -- + - - - - - - - - - - - - - - - - + | David M Pratt, Kippax, Leeds. | | Website: http://www.g4dmp.co.uk | + - - - - - - - - - - - - - - - - + __ 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 __ Information from ESET NOD32 Antivirus, version of virus signature database 5978 (20110323) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __ Information from ESET NOD32 Antivirus, version of virus signature database 5978 (20110323) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.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 __ 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] [K3] Noise from P3
David, I tried this and found no similar issue. Bill K9YEQ -Original Message- While operating on SSB on 144.225 MHz using the internal K144VX transverter I am getting broadband noise around that frequency when I switch on my P3. The noise is quite strong, about S7, and shows clearly on the P3 screen. If I move the P3 about six inches away from the K3 the noise disappears. Removing the 2 metre antenna also removes the noise. I would be grateful if anyone else with a K144XV and a P3 would check to see if they get the same problem? Many thanks 73 de David G4DMP __ 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] [K3] Noise from P3
David Yes, I do. Try placing your hand immediately in front of the P3 screen and it will act as an aerial, making the situation quite a bit worse. John G4ZTR -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of David Pratt Sent: 23 March 2011 17:09 To: elecraft@mailman.qth.net Subject: [Elecraft] [K3] Noise from P3 While operating on SSB on 144.225 MHz using the internal K144VX transverter I am getting broadband noise around that frequency when I switch on my P3. The noise is quite strong, about S7, and shows clearly on the P3 screen. If I move the P3 about six inches away from the K3 the noise disappears. Removing the 2 metre antenna also removes the noise. I would be grateful if anyone else with a K144XV and a P3 would check to see if they get the same problem? Many thanks 73 de David G4DMP -- + - - - - - - - - - - - - - - - - + | David M Pratt, Kippax, Leeds. | | Website: http://www.g4dmp.co.uk | + - - - - - - - - - - - - - - - - + __ 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 __ Information from ESET NOD32 Antivirus, version of virus signature database 5978 (20110323) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __ Information from ESET NOD32 Antivirus, version of virus signature database 5978 (20110323) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.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
[Elecraft] [K3] Noise from P3
While operating on SSB on 144.225 MHz using the internal K144VX transverter I am getting broadband noise around that frequency when I switch on my P3. The noise is quite strong, about S7, and shows clearly on the P3 screen. If I move the P3 about six inches away from the K3 the noise disappears. Removing the 2 metre antenna also removes the noise. I would be grateful if anyone else with a K144XV and a P3 would check to see if they get the same problem? Many thanks 73 de David G4DMP -- + - - - - - - - - - - - - - - - - + | David M Pratt, Kippax, Leeds. | | Website: http://www.g4dmp.co.uk | + - - - - - - - - - - - - - - - - + __ 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
