T32MI K3 rig problem
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IZ1CRR
Maury, Regarding the 40M problem with Derek's K3, it may be related to stray 40M RF getting into the radio when it is keyed. If this is the cause, an easy fix may be to create an imaginary ground on it by connecting a 1/4 wave long (around 10.56 Meters or 34.6 feet) wire to the ground screw on the back of the K3. The high impedance end of the 1/4 wave wire is transformed to a low impedance at the radio. This should reduce any stray RF around the radio. It is a simple thing to try and may fix the problem. I would be interested to hear if it fixes the 40 Meter problem. I had no difficulty in working T32MI on CW & SSB with 100 Watts and a wire antenna from my QTH in Virginia, my IOTA number 964. They are a great operators! 73, Rich - K1HTV Retired from VOA = = = >From a post of the K3 Reflector from Roland, DC1RS 2010-03-28 08:30 This morning local time (Saturday 21:00 gmt) we started our journey to Caroline island. Estimate 5 days sailing. Almost 9,000 Qs in our logs from the 3 days on Malvern. Derek's beloved Elecraft K3 has a problem! On 40m only, the instant the rig is keyed, even at min power, it switches off as if the supply plug is disconnected. After an indeterminate delay power is restored and the rig can be used on other bands. Any ideas, please contact Maury, IZ1CRR (iz1crr @ tin.it). 73 Derek ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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How do they know it's the radio and not the power supply shutting off?
-----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Rich - K1HTV Sent: Monday, March 29, 2010 7:46 PM To: [hidden email] Cc: [hidden email] Subject: [Elecraft] T32MI K3 rig problem IZ1CRR Maury, Regarding the 40M problem with Derek's K3, it may be related to stray 40M RF getting into the radio when it is keyed. If this is the cause, an easy fix may be to create an imaginary ground on it by connecting a 1/4 wave long (around 10.56 Meters or 34.6 feet) wire to the ground screw on the back of the K3. The high impedance end of the 1/4 wave wire is transformed to a low impedance at the radio. This should reduce any stray RF around the radio. It is a simple thing to try and may fix the problem. I would be interested to hear if it fixes the 40 Meter problem. I had no difficulty in working T32MI on CW & SSB with 100 Watts and a wire antenna from my QTH in Virginia, my IOTA number 964. They are a great operators! 73, Rich - K1HTV Retired from VOA = = = >From a post of the K3 Reflector from Roland, DC1RS 2010-03-28 08:30 This morning local time (Saturday 21:00 gmt) we started our journey to Caroline island. Estimate 5 days sailing. Almost 9,000 Qs in our logs from the 3 days on Malvern. Derek's beloved Elecraft K3 has a problem! On 40m only, the instant the rig is keyed, even at min power, it switches off as if the supply plug is disconnected. After an indeterminate delay power is restored and the rig can be used on other bands. Any ideas, please contact Maury, IZ1CRR (iz1crr @ tin.it). 73 Derek ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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They don't, but if it is triggered by RF, the proposed suggestion is simple one
and worth trying with available parts. Rich - K1HTV -----Original Message----- From: Bob Naumann [mailto:[hidden email]] Sent: Monday, March 29, 2010 21:00 PM To: 'Rich - K1HTV'; [hidden email] Cc: [hidden email] Subject: RE: [Elecraft] T32MI K3 rig problem How do they know it's the radio and not the power supply shutting off? -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Rich - K1HTV Sent: Monday, March 29, 2010 7:46 PM To: [hidden email] Cc: [hidden email] Subject: [Elecraft] T32MI K3 rig problem IZ1CRR Maury, Regarding the 40M problem with Derek's K3, it may be related to stray 40M RF getting into the radio when it is keyed. If this is the cause, an easy fix may be to create an imaginary ground on it by connecting a 1/4 wave long (around 10.56 Meters or 34.6 feet) wire to the ground screw on the back of the K3. The high impedance end of the 1/4 wave wire is transformed to a low impedance at the radio. This should reduce any stray RF around the radio. It is a simple thing to try and may fix the problem. I would be interested to hear if it fixes the 40 Meter problem. I had no difficulty in working T32MI on CW & SSB with 100 Watts and a wire antenna from my QTH in Virginia, my IOTA number 964. They are a great operators! 73, Rich - K1HTV Retired from VOA = = = >From a post of the K3 Reflector from Roland, DC1RS 2010-03-28 08:30 This morning local time (Saturday 21:00 gmt) we started our journey to Caroline island. Estimate 5 days sailing. Almost 9,000 Qs in our logs from the 3 days on Malvern. Derek's beloved Elecraft K3 has a problem! On 40m only, the instant the rig is keyed, even at min power, it switches off as if the supply plug is disconnected. After an indeterminate delay power is restored and the rig can be used on other bands. Any ideas, please contact Maury, IZ1CRR (iz1crr @ tin.it). 73 Derek ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by k1htv
On Mon, 29 Mar 2010 20:45:49 -0400, Rich - K1HTV wrote:
>it may be related to stray 40M RF >getting into the radio when it is keyed. If this is the cause, an easy fix may >be to create an imaginary ground on it by connecting a 1/4 wave long (around >10.56 Meters or 34.6 feet) wire to the ground screw on the back of the K3. Horsepucky. If RF is getting into the K3, the radio has a design flaw. And it does -- improperly terminated shields, also known as "the pin 1 problem," which is a well known and well documented cause of RFI. The ONLY proper connection of a cable shield is ZERO LENGTH to the CHASSIS, and NOT through an RF choke! 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 |
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In reply to this post by k1htv
Hi Bob,
OK on seeing the problem of the K3 shutting down when the transmitter is keyed on 40 Meters. If there is a 40 Meter 'sensitivity-to-RF' problem with the K3, then there is a reason for it. It may take a super sleuth to discover the cause. It may be a component resonance problem within the radio such as a combination of a trace length and a bypass cap causing a parallel resonant circuit at 40M. Who knows. If the problem is being triggered by 40 Meter RF and the internal fix can not be found, then the user should be able to take some actions to reduce the problem. Stray RF can be reduced with a good RF ground at the radio, using a resonant antenna with low standing waves, adding coax chokes or installing ferrites on antenna coax feedline. Your mileage may vary :-). 73, Rich - K1HTV = = = -----Original Message----- From: Bob Naumann [mailto:[hidden email]] Sent: Monday, March 29, 2010 21:21 PM To: 'Rich - K1HTV' Subject: RE: [Elecraft] T32MI K3 rig problem I've seen this problem many times in the past - that's why I ask. I don't know the connection, but 40m seems to do this a lot. -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Rich - K1HTV Sent: Monday, March 29, 2010 8:06 PM To: 'Bob Naumann' Cc: [hidden email] Subject: Re: [Elecraft] T32MI K3 rig problem They don't, but if it is triggered by RF, the proposed suggestion is simple one and worth trying with available parts. Rich - K1HTV -----Original Message----- From: Bob Naumann [mailto:[hidden email]] Sent: Monday, March 29, 2010 21:00 PM To: 'Rich - K1HTV'; [hidden email] Cc: [hidden email] Subject: RE: [Elecraft] T32MI K3 rig problem How do they know it's the radio and not the power supply shutting off? -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Rich - K1HTV Sent: Monday, March 29, 2010 7:46 PM To: [hidden email] Cc: [hidden email] Subject: [Elecraft] T32MI K3 rig problem IZ1CRR Maury, Regarding the 40M problem with Derek's K3, it may be related to stray 40M RF getting into the radio when it is keyed. If this is the cause, an easy fix may be to create an imaginary ground on it by connecting a 1/4 wave long (around 10.56 Meters or 34.6 feet) wire to the ground screw on the back of the K3. The high impedance end of the 1/4 wave wire is transformed to a low impedance at the radio. This should reduce any stray RF around the radio. It is a simple thing to try and may fix the problem. I would be interested to hear if it fixes the 40 Meter problem. I had no difficulty in working T32MI on CW & SSB with 100 Watts and a wire antenna from my QTH in Virginia, my IOTA number 964. They are a great operators! 73, Rich - K1HTV Retired from VOA = = = >From a post of the K3 Reflector from Roland, DC1RS 2010-03-28 08:30 This morning local time (Saturday 21:00 gmt) we started our journey to Caroline island. Estimate 5 days sailing. Almost 9,000 Qs in our logs from the 3 days on Malvern. Derek's beloved Elecraft K3 has a problem! On 40m only, the instant the rig is keyed, even at min power, it switches off as if the supply plug is disconnected. After an indeterminate delay power is restored and the rig can be used on other bands. Any ideas, please contact Maury, IZ1CRR (iz1crr @ tin.it). 73 Derek ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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> OK on seeing the problem of the K3 shutting down when the
> transmitter is keyed > on 40 Meters. If there is a 40 Meter 'sensitivity-to-RF' > problem with the K3, > then there is a reason for it. It may take a super sleuth > to discover the cause. > It may be a component resonance problem within the radio > such as a combination > of a trace length and a bypass cap causing a parallel > resonant circuit at 40M. > Who knows. The RF should never be making it back inside the cabinet. All the super sleuth really has to do is look at external ports and find the bad bypassing, poor grounding of a shield, or ground loop. That shouldn't take much time, if it is a radio problem. > If the problem is being triggered by 40 Meter RF and the > internal fix can not be > found, then the user should be able to take some actions > to reduce the problem. > Stray RF can be reduced with a good RF ground at the > radio, using a resonant > antenna with low standing waves, adding coax chokes or > installing ferrites on > antenna coax feedline. Your mileage may vary :-). Although SWR can indirectly affect common mode current by changing voltages and currents at the antenna feedpoint, SWR by itself is unrelated to common mode RFI, as is resonance of the antenna. Common mode is caused by an improper feed system (bad antenna or feedline construction or design) or an antenna too close to the shack, and that can happen with equal severity if SWR is 1:1 or 100:1. The first thing to look at is the antenna system and what goes on around the feedpoint and feedline. The second thing is something wrong with I/O port design. http://www.w8ji.com/rfi_rf_grounding.htm 73 Tom ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Tom,
Your points are well taken. However, my original suggestion was how to possibly resolve the problem with available resources (wire) that the guys on rare East Kiribati IOTAs were experiencing when their K3 transmitted on 40 Meters. Hopefully the resident Elecraft 'super sleuth' will be able to recreate the problem and find a fix. 73, Rich - K1HTV -----Original Message----- From: Tom W8JI [mailto:[hidden email]] Sent: Tuesday, March 30, 2010 9:46 AM To: Rich - K1HTV; 'Bob Naumann' Cc: [hidden email] Subject: Re: [Elecraft] T32MI K3 rig problem > OK on seeing the problem of the K3 shutting down when the transmitter > is keyed on 40 Meters. If there is a 40 Meter 'sensitivity-to-RF' > problem with the K3, > then there is a reason for it. It may take a super sleuth to discover > the cause. > It may be a component resonance problem within the radio such as a > combination of a trace length and a bypass cap causing a parallel > resonant circuit at 40M. > Who knows. The RF should never be making it back inside the cabinet. All the super sleuth really has to do is look at external ports and find the bad bypassing, poor grounding of a shield, or ground loop. That shouldn't take much time, if it is a radio problem. > If the problem is being triggered by 40 Meter RF and the internal fix > can not be found, then the user should be able to take some actions to > reduce the problem. > Stray RF can be reduced with a good RF ground at the radio, using a > resonant antenna with low standing waves, adding coax chokes or > installing ferrites on antenna coax feedline. Your mileage may vary > :-). Although SWR can indirectly affect common mode current by changing voltages and currents at the antenna feedpoint, SWR by itself is unrelated to common mode RFI, as is resonance of the antenna. Common mode is caused by an improper feed system (bad antenna or feedline construction or design) or an antenna too close to the shack, and that can happen with equal severity if SWR is 1:1 or 100:1. The first thing to look at is the antenna system and what goes on around the feedpoint and feedline. The second thing is something wrong with I/O port design. http://www.w8ji.com/rfi_rf_grounding.htm 73 Tom ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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I had a similar problem on 40m that only occurred when transmitting RTTY.
The K3 would indicate an over current condition and automatically reduce power as a result. The PA also ran much hotter than on the other bands. So hot in fact that switching diode (D10) burned out on the original PA during the welcome preamble of a RTTY net that I was about to run, Gary was most helpful in getting me a replacement PA but this did not cure the problem. Having had problems with the USB adapters kicking out on 40m RTTY due to RFI in the past and curing this problem by placing chokes at both ends of the USB cables, I decided to give the same treatment to the K3. The cure was placing two toroids on the DC feed to the K3, one at the point where the DC cable leaves the power supply and the other just before the connection to the K3. Milton AD5XD ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Not sure whether this is it.
On some bands KPA3 exhibits a current runaway. Reducing power helps. In my case it was on 10m and after a trip to Elecraft, it was no longer a problem during CW or SSB operation. WQ7X traced this problem to an overheating IF trap a few weeks ago. There is a fix from Elecraft which involves different elements for the trap. Ignacy |
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From the T32 website:
K3 and more 2010-03-30 22:25 Thanks to those kind folk who offered suggestions to fix the 40m problem on my K3. Have opened the unit and examined but can't do much more until we reach Caroline. Our progress is good and we should be QRV as T32CI Thursday morning gmt. We plan 3 days activity there. 73 Derek 73 de Roland, DC1RS
K3/100 #1243, KFL3A-2.8K, KFL3A-2.1K, KFL3A-400, KRX3, KFL3A-2.8K, KFL3A-400, KAT3, KXV3A, LP-Pan
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