[KX3/PX3] Bonding
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I figured out most of my problems with all the spikes on the PX3 - the switching P/S in my iMac. To a lesser extent, I can hear the MFJ-4125 switching P/S I use to power the KX3 and PX3. I cannot remember if I tried looking at the spectrum using the Astron RS-35 as a power source and plugging in the 4125 or not. I will try that today. I did use the RX SHFT and was able to move a huge spike off the carrier. Does RX SHFT still nullify the roofing filter or was that fixed in a F/W update?
I’m pretty sure I can bond the KX3, PX3, and MFJ-4125 but I don’t have a *clue* how to bond the iMac. It’s a late 2012 27” iMac. It’s an all-in-one with *no* external screws. It’s the model with the “pregnant” bulge in the back. However, if it means I have to go to a Windows computer, I’ll live with the noise or build a Hackintosh. I also use this computer for other things - editing video, etc. I *did* try my wife’s Mac Book Pro with the power supply plugged in and I did not notice the P/S noise on the PX3; however, her computer is not powerful enough to edit video unless you have time to wait. ;) Just to make sure I understand what I need to do: 1. Bond the KX3 to the power supply. 2. Bond the KX3 to the PX3. 3. Bond the KX3 to the computer (somehow). 4. Bond the KX3 to the sound card (in my case, a Focusrite 2i2). Trying to use ASCII to draw, I’m guessing it should look like this: PX3————KX3———MFJ-4125 / \ / \ iMac Focusrite 2i2 My KX3 antenna connection goes to a 4-way switch to switch between my OCF, NVIS, vertical, and dummy load. Does the KX3 need to be bonded to that as well? All of the feed lines run up through the wall, into the attic, and out a soffit vent to surge protectors attached to a ground rod. That ground rod is bonded to house ground. The OCF and the NVIS are on a fiberglass pole in the middle of the back yard. There is no ground rod there. The vertical is over to the side and is bonded to a ground rod there. That ground rod is not bonded but, from my reading, it should be. Does this look/sound right? Please be critical. I cannot learn unless you tell me where I screwed up. I have pretty thick skin. ;) 73, Joel - W4JBB ______________________________________________________________ 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 Message delivered to [hidden email] |
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Here is the authority on the issue. http://audiosystemsgroup.com/RFI-Ham.pdf
Have you put ferrite on the cables from the iMac and the switching power supply? You've used "star" grounding around the KX3. Try bonding everything to everything - you want to provide a low-impedance parallel path from case to case everywhere there is a connection. So, there should be a bond between the soundcard and the iMac and the soundcard and power supply. Also the iMac and soundcard to the PX3. Your diagram should look more like a spider web. Are the interconnecting cables grounded to the chassis or the circuit board? You'll have to open some things up and see if there is the "pin 1 problem" where the cable's ground is on the circuit board and not the chassis. I would look for a YouTube video on how to open up that iMac. I am sure someone has posted one. K4ia Buck Honor Roll 335 8BDXCC On 6/5/2016 8:03 AM, Joel Black wrote: > I figured out most of my problems with all the spikes on the PX3 - the switching P/S in my iMac. To a lesser extent, I can hear the MFJ-4125 switching P/S I use to power the KX3 and PX3. I cannot remember if I tried looking at the spectrum using the Astron RS-35 as a power source and plugging in the 4125 or not. I will try that today. I did use the RX SHFT and was able to move a huge spike off the carrier. Does RX SHFT still nullify the roofing filter or was that fixed in a F/W update? > > I’m pretty sure I can bond the KX3, PX3, and MFJ-4125 but I don’t have a *clue* how to bond the iMac. It’s a late 2012 27” iMac. It’s an all-in-one with *no* external screws. It’s the model with the “pregnant” bulge in the back. However, if it means I have to go to a Windows computer, I’ll live with the noise or build a Hackintosh. I also use this computer for other things - editing video, etc. > > I *did* try my wife’s Mac Book Pro with the power supply plugged in and I did not notice the P/S noise on the PX3; however, her computer is not powerful enough to edit video unless you have time to wait. ;) > > Just to make sure I understand what I need to do: > > 1. Bond the KX3 to the power supply. > 2. Bond the KX3 to the PX3. > 3. Bond the KX3 to the computer (somehow). > 4. Bond the KX3 to the sound card (in my case, a Focusrite 2i2). > > Trying to use ASCII to draw, I’m guessing it should look like this: > > PX3————KX3———MFJ-4125 > / \ > / \ > iMac Focusrite 2i2 > > > My KX3 antenna connection goes to a 4-way switch to switch between my OCF, NVIS, vertical, and dummy load. Does the KX3 need to be bonded to that as well? All of the feed lines run up through the wall, into the attic, and out a soffit vent to surge protectors attached to a ground rod. That ground rod is bonded to house ground. The OCF and the NVIS are on a fiberglass pole in the middle of the back yard. There is no ground rod there. The vertical is over to the side and is bonded to a ground rod there. That ground rod is not bonded but, from my reading, it should be. > > Does this look/sound right? Please be critical. I cannot learn unless you tell me where I screwed up. I have pretty thick skin. ;) > > 73, > Joel - W4JBB > ______________________________________________________________ > 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 > Message delivered to [hidden email] ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Joel Black-2
Joel,
Good progress. Yes, the roofing filter is not usable with the 8kHz shift engaged. This is not a firmware problem, it is a hardware problem. Think of it this way - the "IF" for the KX3 is at baseband (audio frequency range), and that is where the roofing filter works - in other words, it is an audio range filter, but installed at the IF rather than in the audio chain. When the 8kHz shift is engaged, the "IF" changes to 8kHz and that is too high for the audio range roofing filter. On the bonding, you are on the right path. Bond along the path of your audio cables or along the paths of the coax. You imply that you have several ground rods driven. Unless they are connected back to the house Utility Ground rod, you may have a safety issue on your hands. All ground rods should be connected to the Utility Ground by #6 (minimum) or #4 (preferred) copper wire. See the Safety chapter in the later ARRL Handbooks. A fault in the AC wiring of your home or green-wire grounded appliances can cause a significant potential difference between isolated grounds, perhaps even lethal. 73, Don W3FPR On 6/5/2016 8:03 AM, Joel Black wrote: > Does RX SHFT still nullify the roofing filter or was that fixed in a F/W update? > > > My KX3 antenna connection goes to a 4-way switch to switch between my OCF, NVIS, vertical, and dummy load. Does the KX3 need to be bonded to that as well? All of the feed lines run up through the wall, into the attic, and out a soffit vent to surge protectors attached to a ground rod. That ground rod is bonded to house ground. The OCF and the NVIS are on a fiberglass pole in the middle of the back yard. There is no ground rod there. The vertical is over to the side and is bonded to a ground rod there. That ground rod is not bonded but, from my reading, it should be. > > Does this look/sound right? Please be critical. I cannot learn unless you tell me where I screwed up. I have pretty thick skin. ;) > > 73, > Joel - W4JBB > ______________________________________________________________ > 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 > Message delivered to [hidden email] ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Elecraft mailing list
Can’t do that - with the iMac the power supply is built in…it’s an all-in-one.
On 5 Jun 2016, at 2:42 PM, Buck via Elecraft <[hidden email]> wrote: Here is the authority on the issue. http://audiosystemsgroup.com/RFI-Ham.pdf Have you put ferrite on the cables from the iMac and the switching power supply? You've used "star" grounding around the KX3. Try bonding everything to everything - you want to provide a low-impedance parallel path from case to case everywhere there is a connection. So, there should be a bond between the soundcard and the iMac and the soundcard and power supply. Also the iMac and soundcard to the PX3. Your diagram should look more like a spider web. Are the interconnecting cables grounded to the chassis or the circuit board? You'll have to open some things up and see if there is the "pin 1 problem" where the cable's ground is on the circuit board and not the chassis. I would look for a YouTube video on how to open up that iMac. I am sure someone has posted one. K4ia Buck Honor Roll 335 8BDXCC ______________________________________________________________ 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 Message delivered to [hidden email] |
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much noise comes from and iMac from the USB cables, beads will greatly
reduce the noise... Fred On 6/5/16 9:35 AM, John wrote: > Can’t do that - with the iMac the power supply is built in…it’s an all-in-one. > > > > > On 5 Jun 2016, at 2:42 PM, Buck via Elecraft <[hidden email]> wrote: > > Here is the authority on the issue. http://audiosystemsgroup.com/RFI-Ham.pdf > > Have you put ferrite on the cables from the iMac and the switching power supply? > > You've used "star" grounding around the KX3. Try bonding everything to everything - you want to provide a low-impedance parallel path from case to case everywhere there is a connection. So, there should be a bond between the soundcard and the iMac and the soundcard and power supply. Also the iMac and soundcard to the PX3. Your diagram should look more like a spider web. > > Are the interconnecting cables grounded to the chassis or the circuit board? You'll have to open some things up and see if there is the "pin 1 problem" where the cable's ground is on the circuit board and not the chassis. > > I would look for a YouTube video on how to open up that iMac. I am sure someone has posted one. > > K4ia > Buck > Honor Roll 335 > 8BDXCC > > > ______________________________________________________________ > 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 > Message delivered to [hidden email] -- Fred Moore email: [hidden email] [hidden email] phone: 321-217-8699 ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Joel Black-2
On 6/5/2016 5:03 AM, Joel Black wrote:
> I’m pretty sure I can bond the KX3, PX3, and MFJ-4125 but I don’t > have a *clue* how to bond the iMac. It’s a late 2012 27” iMac. It’s > an all-in-one with *no* external screws. It’s the model with the > “pregnant” bulge in the back. However, if it means I have to go to a > Windows computer, I’ll live with the noise or build a Hackintosh. I > also use this computer for other things - editing video, etc. No comment on the Hackintosh. :-) Finding the chassis in the "Golden Days of Ham Radio" was a trivial exercise, and all the "grounds" went to the chassis, which was universally conductive ... and usually heavy. Finding "chassis ground" in today's computers is somewhat different, and much harder. Occasionally, I've found the DE-9 or DB-25 hold-down nuts approximate a chassis ground, but not always, and even stuff from when I still felt young no longer has D<anything> connectors anyway. Beware also of the K9YC Pin One problem ... nowadays, even if there is what looks like a chassis, it may not be what you're looking for. > 1. Bond the KX3 to the power supply. 2. Bond the KX3 to the PX3. 3. > Bond the KX3 to the computer (somehow). 4. Bond the KX3 to the sound > card (in my case, a Focusrite 2i2). Theory says to ground [assuming you can find it] at one point and keep the straps from each device as short as possible. Point-to-point can create loop-throughs, again see K9YC's info at audiosystemsgroup.com Practice often differs from theory, however. 73, Fred K6DGW - Northern California Contest Club - CU in the Cal QSO Party 1-2 Oct 2016 - www.cqp.org ______________________________________________________________ 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 Message delivered to [hidden email] |
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