[K3] Noise from P3
Locked
12
12
 
|
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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
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: [hidden email] [mailto:[hidden email]] On Behalf Of David Pratt Sent: 23 March 2011 17:09 To: [hidden email] 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:[hidden email] 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
In reply to this post by David Pratt
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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
In reply to this post by John Lemay
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: [hidden email] [mailto:[hidden email]] On Behalf Of John Lemay Sent: Wednesday, March 23, 2011 12:18 PM To: 'David Pratt'; [hidden email] 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: [hidden email] [mailto:[hidden email]] On Behalf Of David Pratt Sent: 23 March 2011 17:09 To: [hidden email] 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:[hidden email] 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
In reply to this post by Bill K9YEQ
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 <[hidden email]> 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
In reply to this post by David Pratt
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 +0000, David Pratt <[hidden email]> 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Amateur Radio Operator N5GE
|
|
|
In reply to this post by John Lemay
CONTENTS DELETED
The author has deleted this message.
|
|
|
In reply to this post by David Pratt
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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
In reply to this post by David Pratt
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:[hidden email]] Sent: Wednesday, March 23, 2011 12:30 PM To: Bill Cc: [hidden email] 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 <[hidden email]> 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 >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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
In reply to this post by AC7AC
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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
In reply to this post by Bill K9YEQ
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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
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: [hidden email] [mailto:[hidden email]] On Behalf Of Jim Brown Sent: 23 March 2011 18:52 To: [hidden email] 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:[hidden email] 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
In reply to this post by Jim Brown-10
Thank you for adding the needed emphasis. I really took pains to be sure
lots of metal to metal. Bill K9YEQ -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Jim Brown Sent: Wednesday, March 23, 2011 1:52 PM To: [hidden email] 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
In reply to this post by John Lemay
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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
In reply to this post by Jim Brown-10
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 <[hidden email]> wrote: > From: Jim Brown <[hidden email]> > Subject: Re: [Elecraft] [K3] Noise from P3 > To: [hidden email] > 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:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
In reply to this post by Jim Brown-10
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: [hidden email] [mailto:[hidden email]] On Behalf Of Jim Brown Sent: 23 March 2011 19:20 Cc: [hidden email] 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:[hidden email] 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
Yes, I can "home in" on the noise with great certainty !
-----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Jim Brown Sent: 23 March 2011 20:23 Cc: [hidden email] 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:[hidden email] 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
In reply to this post by John Lemay
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" <[hidden email]> To: <[hidden email]> Cc: <[hidden email]> 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
In reply to this post by K5DNL
*** 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
«
Return to [K3]
|
1 view|%1 views
| Free forum by Nabble | Edit this page |