Re: [Elecraft] Microham Microkeyer II, RFI in mike with my K3
On 2/17/2016 2:05 AM, Jim Brown wrote: > > Perhaps that's what you're selling now, and if it is, that's great. The microHAM supplied cables have been the same from the very start. Again, schematics are on the web site. The cables consist of special multi-cable bundles with six individually shielded coaxial cables and one shielded four wire cable in a common jacket. The outer jacket is cut back and the individual cables "fan out" to the appropriate jacks on the transceiver end. The mic cable is separate and in the case of the DB37-EL-K3R is two individually shielded coaxial cables. Again, the cables/interfaces work without RFI if the installation uses good engineering practice. No active external interface will be 100% "RFI free" if the user fails to keep the RF voltage well below the levels of the desired signals (~5 mV for dynamic mic audio). 73, ... Joe, W4TV On 2/17/2016 2:05 AM, Jim Brown wrote: Joe, Perhaps that's what you're selling now, and if it is, that's great. But what I described is what is at W6OAT. As it happens, I rode into San Francisco tonight with him to meet a visiting JA contester for dinner. He confirmed that what I wrote was an accurate description of what's in his station. He's agreed to grab a few photos that I'll be happy to send you if you would like to refresh your memory. 73, Jim K9YC On Tue,2/16/2016 5:54 AM, Joe Subich, W4TV wrote: Jim, On 2/16/2016 2:04 AM, Jim Brown wrote: Indeed, it would darn near impossible to do it right without starting from scratch withunit a properly made cable from the MicroHam unit to the radio, with each signal path having its own coaxial cable. Please confine your comments to areas where you are knowledgeable. The microHAM cables *DO* use a separate coaxial cable (or shielded twisted pair) for each signal path. The shields are connected to the shell of the respective connector on each end of the cable. With properly designed transceivers, this design will minimize RFI issues. When good engineering practice is used in the station installation - including antenna systems - there should be no RFI problems with a properly implemented microKEYER II, MK2R+ or micro2R system. Schematics for every microHAM cable are available from the support area at www.microham.com or www.microHAM-USA.com/support.html. 73, ... Joe, W4TV __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Microham Microkeyer II, RFI in mike with my K3
Joe, Perhaps that's what you're selling now, and if it is, that's great. But what I described is what is at W6OAT. As it happens, I rode into San Francisco tonight with him to meet a visiting JA contester for dinner. He confirmed that what I wrote was an accurate description of what's in his station. He's agreed to grab a few photos that I'll be happy to send you if you would like to refresh your memory. 73, Jim K9YC On Tue,2/16/2016 5:54 AM, Joe Subich, W4TV wrote: Jim, On 2/16/2016 2:04 AM, Jim Brown wrote: Indeed, it would darn near impossible to do it right without starting from scratch withunit a properly made cable from the MicroHam unit to the radio, with each signal path having its own coaxial cable. Please confine your comments to areas where you are knowledgeable. The microHAM cables *DO* use a separate coaxial cable (or shielded twisted pair) for each signal path. The shields are connected to the shell of the respective connector on each end of the cable. With properly designed transceivers, this design will minimize RFI issues. When good engineering practice is used in the station installation - including antenna systems - there should be no RFI problems with a properly implemented microKEYER II, MK2R+ or micro2R system. Schematics for every microHAM cable are available from the support area at www.microham.com or www.microHAM-USA.com/support.html. 73, ... Joe, W4TV On 2/16/2016 2:04 AM, Jim Brown wrote: Bernhard, It's NOT common mode, it's the simple fact that the audio interface is a mess. The antenna on the roof transmitting high power is doing its job, putting a lot of RF in the shack. If it didn't (based on proxmiity), it would be a lousy antenna. The problem is that the interface (wiring plus electronics plus termination) does not reject RF because it fails to conform to fundamental principles that reject RF. That is, every cable must be a transmission line, every shield must be terminated at the shielding enclosure of the equipment at both ends, and every equipment chassis must have a short, fat, bond to every other equipment chassis. Yes, the signal is audio, but the interference is RF, and it takes proper transmission line techniques to reject that RF. I have VERY limited experience with MicroHam, but the jumble of wires that I encountered with the MicroHam unit at W6OAT violated all principles of good engineering practice for operation in a high RF environment. It was nothing more than a multipin connector with a lot of wires soldered to that connector. Indeed, it would darn near impossible to do it right without starting from scratch withunit a properly made cable from the MicroHam unit to the radio, with each signal path having its own coaxial cable. I have no idea if that describes ALL MicroHam units, but it does describe Rusty's. And don't ask the model number -- I was so disgusted by what I saw that I just rolled my eyes. 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to j...@audiosystemsgroup.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Microham Microkeyer II, RFI in mike with my K3
Joe, I can only confirm what Jim has written and this undermines my findings. Putting ferrites in the Original Microham cables improves the situation but does not solve it. I got feedback with similar problems when antennas are in close proximity, again only with Microham interfaces. Others work Be happy when in works in your environment. Lets close this thread, I found my solution that works but lost confidence in the Microkeyer II. 73s Bernhard -Ursprüngliche Nachricht- Von: Joe Subich, W4TV [mailto:li...@subich.com] Gesendet: Dienstag, 16. Februar 2016 14:55 An: elecraft@mailman.qth.net Betreff: Re: [Elecraft] Microham Microkeyer II, RFI in mike with my K3 Jim, On 2/16/2016 2:04 AM, Jim Brown wrote: > Indeed, it would darn near impossible to do it right without starting > from scratch withunit a properly made cable from the MicroHam unit to > the radio, with each signal path having its own coaxial cable. Please confine your comments to areas where you are knowledgeable. The microHAM cables *DO* use a separate coaxial cable (or shielded twisted pair) for each signal path. The shields are connected to the shell of the respective connector on each end of the cable. With properly designed transceivers, this design will minimize RFI issues. When good engineering practice is used in the station installation - including antenna systems - there should be no RFI problems with a properly implemented microKEYER II, MK2R+ or micro2R system. Schematics for every microHAM cable are available from the support area at www.microham.com or www.microHAM-USA.com/support.html. 73, ... Joe, W4TV On 2/16/2016 2:04 AM, Jim Brown wrote: > Bernhard, > > It's NOT common mode, it's the simple fact that the audio interface is a > mess. The antenna on the roof transmitting high power is doing its job, > putting a lot of RF in the shack. If it didn't (based on proxmiity), it > would be a lousy antenna. The problem is that the interface (wiring plus > electronics plus termination) does not reject RF because it fails to > conform to fundamental principles that reject RF. That is, every cable > must be a transmission line, every shield must be terminated at the > shielding enclosure of the equipment at both ends, and every equipment > chassis must have a short, fat, bond to every other equipment chassis. > Yes, the signal is audio, but the interference is RF, and it takes > proper transmission line techniques to reject that RF. > > I have VERY limited experience with MicroHam, but the jumble of wires > that I encountered with the MicroHam unit at W6OAT violated all > principles of good engineering practice for operation in a high RF > environment. It was nothing more than a multipin connector with a lot of > wires soldered to that connector. Indeed, it would darn near impossible > to do it right without starting from scratch withunit a properly made > cable from the MicroHam unit to the radio, with each signal path having > its own coaxial cable. > > I have no idea if that describes ALL MicroHam units, but it does > describe Rusty's. And don't ask the model number -- I was so disgusted > by what I saw that I just rolled my eyes. > > 73, Jim K9YC > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Microham Microkeyer II, RFI in mike with my K3
I own several DigiKeyer II's and a Micro2R and I have never noticed any RFI issue. I have done nothing special in my installation to avoid RFI, but I do eventually intend to bond all of my equipment per K9YC's site. I have not used the Micro2R with an Elecraft on SSB yet (except into a dummy load), but I have used it with other transceivers. I did use the Micro2R for K3S headphone audio in last weekends RTTY contest. John KK9A Joe Subich, W4TV lists at subich.com Tue Feb 16 08:54:42 EST 2016 Previous message (by thread): [Elecraft] Microham Microkeyer II, RFI in mike with my K3 Jim, On 2/16/2016 2:04 AM, Jim Brown wrote: > Indeed, it would darn near impossible to do it right without starting > from scratch withunit a properly made cable from the MicroHam unit to > the radio, with each signal path having its own coaxial cable. Please confine your comments to areas where you are knowledgeable. The microHAM cables *DO* use a separate coaxial cable (or shielded twisted pair) for each signal path. The shields are connected to the shell of the respective connector on each end of the cable. With properly designed transceivers, this design will minimize RFI issues. When good engineering practice is used in the station installation - including antenna systems - there should be no RFI problems with a properly implemented microKEYER II, MK2R+ or micro2R system. Schematics for every microHAM cable are available from the support area at www.microham.com or www.microHAM-USA.com/support.html. 73, ... Joe, W4TV __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Microham Microkeyer II, RFI in mike with my K3
Jim, On 2/16/2016 2:04 AM, Jim Brown wrote: Indeed, it would darn near impossible to do it right without starting from scratch withunit a properly made cable from the MicroHam unit to the radio, with each signal path having its own coaxial cable. Please confine your comments to areas where you are knowledgeable. The microHAM cables *DO* use a separate coaxial cable (or shielded twisted pair) for each signal path. The shields are connected to the shell of the respective connector on each end of the cable. With properly designed transceivers, this design will minimize RFI issues. When good engineering practice is used in the station installation - including antenna systems - there should be no RFI problems with a properly implemented microKEYER II, MK2R+ or micro2R system. Schematics for every microHAM cable are available from the support area at www.microham.com or www.microHAM-USA.com/support.html. 73, ... Joe, W4TV On 2/16/2016 2:04 AM, Jim Brown wrote: Bernhard, It's NOT common mode, it's the simple fact that the audio interface is a mess. The antenna on the roof transmitting high power is doing its job, putting a lot of RF in the shack. If it didn't (based on proxmiity), it would be a lousy antenna. The problem is that the interface (wiring plus electronics plus termination) does not reject RF because it fails to conform to fundamental principles that reject RF. That is, every cable must be a transmission line, every shield must be terminated at the shielding enclosure of the equipment at both ends, and every equipment chassis must have a short, fat, bond to every other equipment chassis. Yes, the signal is audio, but the interference is RF, and it takes proper transmission line techniques to reject that RF. I have VERY limited experience with MicroHam, but the jumble of wires that I encountered with the MicroHam unit at W6OAT violated all principles of good engineering practice for operation in a high RF environment. It was nothing more than a multipin connector with a lot of wires soldered to that connector. Indeed, it would darn near impossible to do it right without starting from scratch withunit a properly made cable from the MicroHam unit to the radio, with each signal path having its own coaxial cable. I have no idea if that describes ALL MicroHam units, but it does describe Rusty's. And don't ask the model number -- I was so disgusted by what I saw that I just rolled my eyes. 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Microham Microkeyer II, RFI in mike with my K3
Bernhard, It's NOT common mode, it's the simple fact that the audio interface is a mess. The antenna on the roof transmitting high power is doing its job, putting a lot of RF in the shack. If it didn't (based on proxmiity), it would be a lousy antenna. The problem is that the interface (wiring plus electronics plus termination) does not reject RF because it fails to conform to fundamental principles that reject RF. That is, every cable must be a transmission line, every shield must be terminated at the shielding enclosure of the equipment at both ends, and every equipment chassis must have a short, fat, bond to every other equipment chassis. Yes, the signal is audio, but the interference is RF, and it takes proper transmission line techniques to reject that RF. I have VERY limited experience with MicroHam, but the jumble of wires that I encountered with the MicroHam unit at W6OAT violated all principles of good engineering practice for operation in a high RF environment. It was nothing more than a multipin connector with a lot of wires soldered to that connector. Indeed, it would darn near impossible to do it right without starting from scratch withunit a properly made cable from the MicroHam unit to the radio, with each signal path having its own coaxial cable. I have no idea if that describes ALL MicroHam units, but it does describe Rusty's. And don't ask the model number -- I was so disgusted by what I saw that I just rolled my eyes. 73, Jim K9YC On Mon,2/15/2016 10:43 PM, bernhard.ho...@bmw.de wrote: Hi Guy, Fully agree with your statement, but as stated I have chokes in all Coax, rotor and control cables. I am using double shielded USB cables, extra grounding for each device…no idea what else could be don. Regarding the 2 Ohm, there is a recommendation by Microham to check that the USB / Molex connector resistance should not exceed 5 Ohm otherwise your PC has a USB/Chassis grounding problem. I had RFI in the Microham already with 300Wtts…now I can run 1200Watts without any problems with is over the legal limit over here anyway! Several HAMs observed problems with the Microham and in combination with K3/other rigs. The cheap homebrew USB/Soundcard interface works now, that’s all what counts. 73 Bernie DL5RDP Von: guyk...@gmail.com [mailto:guyk...@gmail.com] Im Auftrag von Guy Olinger K2AV Gesendet: Montag, 15. Februar 2016 18:15 An: Horst Bernhard, MZ-LR; Elecraft Reflector Betreff: [Elecraft] Microham Microkeyer II, RFI in mike with my K3 Hi Bernie, If you are running QRO over your roof, your RFI proofing needs to be perfect. Your situation is only exceeded in nastiness by being next door to a 50 kW AM station and maybe not then. Your induced common mode RF voltages on conductors can be double and triple the desired signal voltages on the cables and ridiculously more than microphone voltages. One CAN get lucky and get by, but if one does it's only by dumb blind luck and any change to cable routing or position and count of station equipment can disable or polute electronic functions. If you succumb to the temptation to attribute the changes to the last thing changed or moved, you will be sent down the rabbit hole to join company with Alice and the Mad Hatter where nothing makes sense any more. This can include complaints to manufacturers straight from Wonderland requiring apologies afterward. Been there, done that. Know whereof I speak. It is quite probable that replacing the box changed cable specifics. Any connection that is not a tenth of an ohm or less needs to be replaced or repaired. I have no idea where you got 2 ohms as a satisfactory connection resistance. Maybe the USB signal itself will tolerate that under otherwise non-stressed circumstances but it's far away out of bounds for RFI proofing. In your case, QRO on the roof, you need to take maximum anti-RF measures on **ALL** conductors in the shack. Otherwise just changing orientation of cables may remove or incite RFI, or worse makes RFI intermittent leading to suspicions of poltergeist. I have finally gotten to the point where all retail audio cables need to be replaced with soldered coax or shielded pairs with WOVEN shields. ESPECIALLY audio cables terminated in RCA plugs which typically have the cheapest shields known to man. No retail manufacturer is testing them for RFI susceptibility in rooftop QRO conditions. There is a good selection of shielded pair and coax cable with Teflon dielectric/insulation and woven shields easily soldered to *quality* RCA plugs or other connectors without melting the wire. I know that QRO on the roof is all that's available for many folks. Just understand that's the very stiffest possible demand on all RFI proofing issues. No cheapies, no short cuts, no omissions allowed in the protocol. 73, Guy K2AV On Monday, February 15, 2016, > wrote: Dear all, just an update..the Microham M
Re: [Elecraft] Microham Microkeyer II, RFI in mike with my K3
Hi Guy, Fully agree with your statement, but as stated I have chokes in all Coax, rotor and control cables. I am using double shielded USB cables, extra grounding for each device…no idea what else could be don. Regarding the 2 Ohm, there is a recommendation by Microham to check that the USB / Molex connector resistance should not exceed 5 Ohm otherwise your PC has a USB/Chassis grounding problem. I had RFI in the Microham already with 300Wtts…now I can run 1200Watts without any problems with is over the legal limit over here anyway! Several HAMs observed problems with the Microham and in combination with K3/other rigs. The cheap homebrew USB/Soundcard interface works now, that’s all what counts. 73 Bernie DL5RDP Von: guyk...@gmail.com [mailto:guyk...@gmail.com] Im Auftrag von Guy Olinger K2AV Gesendet: Montag, 15. Februar 2016 18:15 An: Horst Bernhard, MZ-LR; Elecraft Reflector Betreff: [Elecraft] Microham Microkeyer II, RFI in mike with my K3 Hi Bernie, If you are running QRO over your roof, your RFI proofing needs to be perfect. Your situation is only exceeded in nastiness by being next door to a 50 kW AM station and maybe not then. Your induced common mode RF voltages on conductors can be double and triple the desired signal voltages on the cables and ridiculously more than microphone voltages. One CAN get lucky and get by, but if one does it's only by dumb blind luck and any change to cable routing or position and count of station equipment can disable or polute electronic functions. If you succumb to the temptation to attribute the changes to the last thing changed or moved, you will be sent down the rabbit hole to join company with Alice and the Mad Hatter where nothing makes sense any more. This can include complaints to manufacturers straight from Wonderland requiring apologies afterward. Been there, done that. Know whereof I speak. It is quite probable that replacing the box changed cable specifics. Any connection that is not a tenth of an ohm or less needs to be replaced or repaired. I have no idea where you got 2 ohms as a satisfactory connection resistance. Maybe the USB signal itself will tolerate that under otherwise non-stressed circumstances but it's far away out of bounds for RFI proofing. In your case, QRO on the roof, you need to take maximum anti-RF measures on **ALL** conductors in the shack. Otherwise just changing orientation of cables may remove or incite RFI, or worse makes RFI intermittent leading to suspicions of poltergeist. I have finally gotten to the point where all retail audio cables need to be replaced with soldered coax or shielded pairs with WOVEN shields. ESPECIALLY audio cables terminated in RCA plugs which typically have the cheapest shields known to man. No retail manufacturer is testing them for RFI susceptibility in rooftop QRO conditions. There is a good selection of shielded pair and coax cable with Teflon dielectric/insulation and woven shields easily soldered to *quality* RCA plugs or other connectors without melting the wire. I know that QRO on the roof is all that's available for many folks. Just understand that's the very stiffest possible demand on all RFI proofing issues. No cheapies, no short cuts, no omissions allowed in the protocol. 73, Guy K2AV On Monday, February 15, 2016, > wrote: Dear all, just an update..the Microham Microkeyer II has definitely a problem with RF! I replaced the Microkeyer with a homebrew USB and soundcard interface (Built in 2008) and made new cable distribution box..And the problems are gone. I have S-NO 280 on the microkeyer..hope the newer ones are better. But definitely not my kind of solution for that cost! 73s Bernie DL5RDP -Ursprüngliche Nachricht- Von: Joe Subich, W4TV [mailto:li...@subich.com] Gesendet: Freitag, 12. Februar 2016 14:15 An: elecraft@mailman.qth.net<mailto:elecraft@mailman.qth.net> Betreff: Re: [Elecraft] Microham Microkeyer II, RFI in mike with my K3 > As I recall, I used pin 7 for the mic ground and pin 8 for the PTT > ground. In a brief test it worked ok into a dummy load. Is this not > correct? That is correct although with the K3/K3S since the Elecraft mic RFI change it should not matter (both pin 7 and pin 8 are connected to the "ground" foil on the front panel circuit board). Early K3 front panels included an RF choke in the mic *and* PTT returns which made the "pin 1 problem" much worse. With the RF choke removed (bypassed) the issue is significantly reduced but there may still be a problem if the overall station installation has any "RF on the coax." 73, ... Joe, W4TV On 2/12/2016 7:59 AM, j...@kk9a.com<mailto:j...@kk9a.com> wrote: > This week I wired rewired my MicroHAM Micro2R cables for K3S's. As I > recall, I used pin 7 for the mic ground and pin 8 for the PTT ground.
[Elecraft] Microham Microkeyer II, RFI in mike with my K3
Hi Bernie, If you are running QRO over your roof, your RFI proofing needs to be perfect. Your situation is only exceeded in nastiness by being next door to a 50 kW AM station and maybe not then. Your induced common mode RF voltages on conductors can be double and triple the desired signal voltages on the cables and ridiculously more than microphone voltages. One CAN get lucky and get by, but if one does it's only by dumb blind luck and any change to cable routing or position and count of station equipment can disable or polute electronic functions. If you succumb to the temptation to attribute the changes to the last thing changed or moved, you will be sent down the rabbit hole to join company with Alice and the Mad Hatter where nothing makes sense any more. This can include complaints to manufacturers straight from Wonderland requiring apologies afterward. Been there, done that. Know whereof I speak. It is quite probable that replacing the box changed cable specifics. Any connection that is not a tenth of an ohm or less needs to be replaced or repaired. I have no idea where you got 2 ohms as a satisfactory connection resistance. Maybe the USB signal itself will tolerate that under otherwise non-stressed circumstances but it's far away out of bounds for RFI proofing. In your case, QRO on the roof, you need to take maximum anti-RF measures on **ALL** conductors in the shack. Otherwise just changing orientation of cables may remove or incite RFI, or worse makes RFI intermittent leading to suspicions of poltergeist. I have finally gotten to the point where all retail audio cables need to be replaced with soldered coax or shielded pairs with WOVEN shields. ESPECIALLY audio cables terminated in RCA plugs which typically have the cheapest shields known to man. No retail manufacturer is testing them for RFI susceptibility in rooftop QRO conditions. There is a good selection of shielded pair and coax cable with Teflon dielectric/insulation and woven shields easily soldered to *quality* RCA plugs or other connectors without melting the wire. I know that QRO on the roof is all that's available for many folks. Just understand that's the very stiffest possible demand on all RFI proofing issues. No cheapies, no short cuts, no omissions allowed in the protocol. 73, Guy K2AV On Monday, February 15, 2016, > wrote: > Dear all, > > just an update..the Microham Microkeyer II has definitely a problem with > RF! > I replaced the Microkeyer with a homebrew USB and soundcard interface > (Built in 2008) and made new cable distribution box..And the problems are > gone. > > I have S-NO 280 on the microkeyer..hope the newer ones are better. But > definitely not my kind of solution for that cost! > > 73s > Bernie > DL5RDP > > -Ursprüngliche Nachricht- > Von: Joe Subich, W4TV [mailto:li...@subich.com] > Gesendet: Freitag, 12. Februar 2016 14:15 > An: elecraft@mailman.qth.net > Betreff: Re: [Elecraft] Microham Microkeyer II, RFI in mike with my K3 > > > > As I recall, I used pin 7 for the mic ground and pin 8 for the PTT > > ground. In a brief test it worked ok into a dummy load. Is this not > > correct? > > That is correct although with the K3/K3S since the Elecraft mic RFI > change it should not matter (both pin 7 and pin 8 are connected to > the "ground" foil on the front panel circuit board). > > Early K3 front panels included an RF choke in the mic *and* PTT returns > which made the "pin 1 problem" much worse. With the RF choke removed > (bypassed) the issue is significantly reduced but there may still be a > problem if the overall station installation has any "RF on the coax." > > 73, > >... Joe, W4TV > > > On 2/12/2016 7:59 AM, j...@kk9a.com wrote: > > This week I wired rewired my MicroHAM Micro2R cables for K3S's. As I > > recall, I used pin 7 for the mic ground and pin 8 for the PTT ground. In > a > > brief test it worked ok into a dummy load. Is this not correct? > > > > John KK9A > > > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to k2av@gmail.com -- Sent via Gmail Mobile on my iPhone __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Microham Microkeyer II, RFI in mike with my K3
just an update..the Microham Microkeyer II has definitely a problem > with RF! microKEYER II does not have a problem with RF. You must have an exceptional problem with common mode RF on your feedline(s) and that would impact *any* interface in the mic line. > I replaced the Microkeyer with a homebrew USB and soundcard > interface (Built in 2008) and made new cable distribution box..And > the problems are gone. Unless your homebrew interface includes mic handling circuits with a wide range preamp, your test in meaningless. Any change in cable length can make significant differences in RFI as it moves the high voltage point. 73, ... Joe, W4TV On 2/15/2016 2:20 AM, bernhard.ho...@bmw.de wrote: Dear all, just an update..the Microham Microkeyer II has definitely a problem with RF! I replaced the Microkeyer with a homebrew USB and soundcard interface (Built in 2008) and made new cable distribution box..And the problemsare gone. I have S-NO 280 on the microkeyer..hope the newer ones are better. But definitely not my kind of solution for that cost! 73s Bernie DL5RDP -Ursprüngliche Nachricht- Von: Joe Subich, W4TV [mailto:li...@subich.com] Gesendet: Freitag, 12. Februar 2016 14:15 An: elecraft@mailman.qth.net Betreff: Re: [Elecraft] Microham Microkeyer II, RFI in mike with my K3 As I recall, I used pin 7 for the mic ground and pin 8 for the PTT ground. In a brief test it worked ok into a dummy load. Is this not correct? That is correct although with the K3/K3S since the Elecraft mic RFI change it should not matter (both pin 7 and pin 8 are connected to the "ground" foil on the front panel circuit board). Early K3 front panels included an RF choke in the mic *and* PTT returns which made the "pin 1 problem" much worse. With the RF choke removed (bypassed) the issue is significantly reduced but there may still be a problem if the overall station installation has any "RF on the coax." 73, ... Joe, W4TV On 2/12/2016 7:59 AM, j...@kk9a.com wrote: This week I wired rewired my MicroHAM Micro2R cables for K3S's. As I recall, I used pin 7 for the mic ground and pin 8 for the PTT ground. In a brief test it worked ok into a dummy load. Is this not correct? John KK9A __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Microham Microkeyer II, RFI in mike with my K3
On Sun,2/14/2016 11:20 PM, bernhard.ho...@bmw.de wrote: just an update..the Microham Microkeyer II has definitely a problem with RF! Without diving into the details, I helped W6OAT chase down RFI issues in his station. He had a MicroHam box with an "interface" to the radio that was a jumble of wires. Virtually NO attention had been paid to the fundamental concept of a transmission line in the interface between it and the radio. While that is acceptable at baseband (audio), it is monumentally foolish when RF is present (i.e. an antenna on the roof). Current flows in loops, whether at DC or at RF, and the loops form both antennas and magnetic loops whose coupling is proportional to the loop area. In the near field, magnetic coupling dominates, so the loop area can be a VERY big deal. EVERY signal path between devices must be treated as a transmission line of RFI is a potential issue. That means EVERY signal path should be a twisted pair or a coaxial pair, so that the path forms a transmission line. Any interface that does not do this is an invitation to RFI if the antenna is close enough, or if the power is high enough, or both. This is NOT an indictment of Microham -- at a CQP expedition a few years ago, a team member showed up with an interface betweeen is radio and his amp to key the amp that was an RCA to RCA cable with a single wire, no shield. Chassis to chassis was depended on for the return. That works fine at DC to key the amp, but the resulting current loop area gives that circuit VERY STRONG coupling to an RF field, both as a magnetic circuit and as an antenna. Noted RFI guru Henry Ott talks about understanding where ALL the current flows, which is revealed by "the hidden schematic lurking behind the ground symbol" that causes most issues with RFI and crosstalk. 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Microham Microkeyer II, RFI in mike with my K3
Dear all, just an update..the Microham Microkeyer II has definitely a problem with RF! I replaced the Microkeyer with a homebrew USB and soundcard interface (Built in 2008) and made new cable distribution box..And the problems are gone. I have S-NO 280 on the microkeyer..hope the newer ones are better. But definitely not my kind of solution for that cost! 73s Bernie DL5RDP -Ursprüngliche Nachricht- Von: Joe Subich, W4TV [mailto:li...@subich.com] Gesendet: Freitag, 12. Februar 2016 14:15 An: elecraft@mailman.qth.net Betreff: Re: [Elecraft] Microham Microkeyer II, RFI in mike with my K3 > As I recall, I used pin 7 for the mic ground and pin 8 for the PTT > ground. In a brief test it worked ok into a dummy load. Is this not > correct? That is correct although with the K3/K3S since the Elecraft mic RFI change it should not matter (both pin 7 and pin 8 are connected to the "ground" foil on the front panel circuit board). Early K3 front panels included an RF choke in the mic *and* PTT returns which made the "pin 1 problem" much worse. With the RF choke removed (bypassed) the issue is significantly reduced but there may still be a problem if the overall station installation has any "RF on the coax." 73, ... Joe, W4TV On 2/12/2016 7:59 AM, j...@kk9a.com wrote: > This week I wired rewired my MicroHAM Micro2R cables for K3S's. As I > recall, I used pin 7 for the mic ground and pin 8 for the PTT ground. In a > brief test it worked ok into a dummy load. Is this not correct? > > John KK9A > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Microham Microkeyer II, RFI in mike with my K3
As I recall, I used pin 7 for the mic ground and pin 8 for the PTT ground. In a brief test it worked ok into a dummy load. Is this not correct? That is correct although with the K3/K3S since the Elecraft mic RFI change it should not matter (both pin 7 and pin 8 are connected to the "ground" foil on the front panel circuit board). Early K3 front panels included an RF choke in the mic *and* PTT returns which made the "pin 1 problem" much worse. With the RF choke removed (bypassed) the issue is significantly reduced but there may still be a problem if the overall station installation has any "RF on the coax." 73, ... Joe, W4TV On 2/12/2016 7:59 AM, j...@kk9a.com wrote: This week I wired rewired my MicroHAM Micro2R cables for K3S's. As I recall, I used pin 7 for the mic ground and pin 8 for the PTT ground. In a brief test it worked ok into a dummy load. Is this not correct? John KK9A __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Microham Microkeyer II, RFI in mike with my K3
This week I wired rewired my MicroHAM Micro2R cables for K3S's. As I recall, I used pin 7 for the mic ground and pin 8 for the PTT ground. In a brief test it worked ok into a dummy load. Is this not correct? John KK9A Bernhard.Horst at bmw.de Bernhard.Horst at bmw.de Fri Feb 12 01:43:33 EST 2016 Good morning gents... I have RFI in the mike since using the Microkeyer II from Mikroham. Mainly on 20m and the lower bands when transmitting with about 700watts and above. My antenna is about 5meters above the shack on the roof of my house (2 el Ultrabeam), but the effect also can be observed on the lower bands where the vertical is about 12 meters away from the shack. ==> Direct RFI? I am using the front mike jack on my K3 and Microkeyer - I have put a capacitor across USB and connector ground in the Microkeyer as recommended by Microham. - All devices are grounded on common ground and same wall plug. - I have extra grounded my PCs ground with USB ground as the resistance was not good enough..its now 2 Ohms USB between USB and connector ground. Also recommendation by Microham. - Bought an extra shielded USB cable and put ferrite cords on. - Mic line is shielded and ferrite cords in every cable and line - Common mode chokes at the antenna feedpoint and also at the end of the coax going into the shack. - Pin 8 of the mike jack is not connected. See http://elecraft.365791.n2.nabble.com/K3-quot-RF-Feedback-quot-and-microHAM-MK2R-or-microKEYER-II-td1080853.html Microham is stating on their website that it has to do with the wiring of the K3 mike lines in the frontpanel.. I am really lost and helpful for any ideas. Is there an alternative to Microham? Thinking about going back to my old USB interface, but integration of Radio, Software and Ultrabeam is really nice We had a similar issue on our clubstation and could cure it with ferrites...on a YAESU rig. Any hint is appreciated..and thanks for quick feedback as usual. Already dropped a line to Elecraft support if they have some hints... I am glad the effect does not show on CW :-) Many thanks in advance. Best 73s Bernie DL5RDP __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] Microham Microkeyer II, RFI in mike with my K3
Good morning gents... I have RFI in the mike since using the Microkeyer II from Mikroham. Mainly on 20m and the lower bands when transmitting with about 700watts and above. My antenna is about 5meters above the shack on the roof of my house (2 el Ultrabeam), but the effect also can be observed on the lower bands where the vertical is about 12 meters away from the shack. ==> Direct RFI? I am using the front mike jack on my K3 and Microkeyer - I have put a capacitor across USB and connector ground in the Microkeyer as recommended by Microham. - All devices are grounded on common ground and same wall plug. - I have extra grounded my PCs ground with USB ground as the resistance was not good enough..its now 2 Ohms USB between USB and connector ground. Also recommendation by Microham. - Bought an extra shielded USB cable and put ferrite cords on. - Mic line is shielded and ferrite cords in every cable and line - Common mode chokes at the antenna feedpoint and also at the end of the coax going into the shack. - Pin 8 of the mike jack is not connected. See http://elecraft.365791.n2.nabble.com/K3-quot-RF-Feedback-quot-and-microHAM-MK2R-or-microKEYER-II-td1080853.html Microham is stating on their website that it has to do with the wiring of the K3 mike lines in the frontpanel.. I am really lost and helpful for any ideas. Is there an alternative to Microham? Thinking about going back to my old USB interface, but integration of Radio, Software and Ultrabeam is really nice We had a similar issue on our clubstation and could cure it with ferrites...on a YAESU rig. Any hint is appreciated..and thanks for quick feedback as usual. Already dropped a line to Elecraft support if they have some hints... I am glad the effect does not show on CW :-) Many thanks in advance. Best 73s Bernie DL5RDP __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
