RFI on K3s
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On Mon,6/20/2016 4:38 PM, K9MA wrote:
> Beware ground loops! Horse puckey -- ground loops do not exist, and this very false concept has caused hams to do completely wrong things to solve problems with hum, buzz, and RFI. http://k9yc.com/GroundingAndAudio.pdf 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 Message delivered to [hidden email] |
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In reply to this post by K9MA
I've been told that the "loop" part of "ground loop" is a misnomer. I
think the real problem is when a "chassis" connection doesn't really go to the conductive enclosure but rather follows on into the "ground" in the circuitry, which is probably better termed "common". In the olden days, finding a connection to the "chassis" [i.e. enclosure] was a snap. They were big, heavy, and obvious. Not so much today. Finding the "chassis" connection on a laptop can be a challenge. 73, Fred K6DGW Sparks NV Washoe County DM09dn On 6/20/2016 4:38 PM, K9MA wrote: > Beware ground loops! > > 73, > > Scott. K9MA ______________________________________________________________ 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 Jim Brown-10
Call them what you will, connecting a bunch of station components to a common DC power return has to be done very carefully. I've found that often the easiest solution is isolated power sources. Some accessories seem to be designed with the assumption of ground isolation using a dedicated wall wart.
But I'm not going to argue about it. 73, Scott. K9MA ---------- Scott Ellington --- via iPad > On Jun 20, 2016, at 7:26 PM, Jim Brown <[hidden email]> wrote: > >> On Mon,6/20/2016 4:38 PM, K9MA wrote: >> Beware ground loops! > > Horse puckey -- ground loops do not exist, and this very false concept has caused hams to do completely wrong things to solve problems with hum, buzz, and RFI. > > http://k9yc.com/GroundingAndAudio.pdf > > 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 > 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 'DGB'
Get some no. 10 stranded wire at Home Depot (etc.), double it over, put one end in a vise and the other in the chuck of your electric drill and twist away. Not shielded, but much better than parallel wires. I suppose you could strip some RG-8 if you really wanted to shield it.
Vic 4X6GP > On 20 Jun 2016, at 22:54, DGB <[hidden email]> wrote: > > > Jim ... where does one find #10 twisted pair? Is it shielded? > > thanks 73 Dwight NS9I > >> On 6/20/2016 12:59 PM, Jim Brown wrote: >>> On Mon,6/20/2016 10:33 AM, James Walker wrote: >>> Is it normal to register voltage as low as I’m seeing on my K-3? >> >> What you're seeing sounds like IR drop in the DC cable. How long is the DC cable between the K3 and the power supply? What wire gauge? Is there any equipment (like distribution panel) in between? >> >> This is a great application for a short length of #10 twisted pair between the PSU and rig. >> >> 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 > 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 Ramon Tristani-2
If that question was directed at me, the answer is that my issues were not
using my K3 and I only needed to turn off the tuner supply. 73, Alan. G4GNX -----Original Message----- From: Ramon Tristani Sent: Monday, June 20, 2016 6:14 PM To: G4GNX Cc: [hidden email] Subject: Re: [Elecraft] RFI on K3s How can you detect the drifting if RF if Iyou have to turn off the K-3 and the P3? ______________________________________________________________ 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 Vic Rosenthal
Works great!
Do it all the time. Father showed me how 50 years ago, the same way Vic describes it ;o) On Tue, 21 Jun 2016 07:44:19 +0300, you wrote: >Get some no. 10 stranded wire at Home Depot (etc.), double it over, put one end in a vise and the other in the chuck of your electric drill and twist away. Not shielded, but much better than parallel wires. I suppose you could strip some RG-8 if you really wanted to shield it. > >Vic 4X6GP > >> On 20 Jun 2016, at 22:54, DGB <[hidden email]> wrote: >> >> >> Jim ... where does one find #10 twisted pair? Is it shielded? >> >> thanks 73 Dwight NS9I >> >>> On 6/20/2016 12:59 PM, Jim Brown wrote: >>>> On Mon,6/20/2016 10:33 AM, James Walker wrote: >>>> Is it normal to register voltage as low as Im seeing on my K-3? >>> >>> What you're seeing sounds like IR drop in the DC cable. How long is the DC cable between the K3 and the power supply? What wire gauge? Is there any equipment (like distribution panel) in between? >>> >>> This is a great application for a short length of #10 twisted pair between the PSU and rig. >>> >>> 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 >> 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] ______________________________________________________________ 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]
Amateur Radio Operator N5GE
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In reply to this post by Vic Rosenthal
Also, the Elecraft supplied DC zip cord can be twisted by hand pretty
easily. RFI from wall-wart SMPS supplies might be improved by twisting their cords... 73, Drew AF2Z On 06/21/16 00:44, Vic Rosenthal wrote: > Get some no. 10 stranded wire at Home Depot (etc.), double it over, put one end in a vise and the other in the chuck of your electric drill and twist away. Not shielded, but much better than parallel wires. I suppose you could strip some RG-8 if you really wanted to shield it. > > Vic 4X6GP > >> On 20 Jun 2016, at 22:54, DGB <[hidden email]> wrote: >> >> >> Jim ... where does one find #10 twisted pair? Is it shielded? >> >> thanks 73 Dwight NS9I >> ______________________________________________________________ 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 N5GE
Dwight, here’s one example of a shield twisted pair: Belden 12/2 5000FE: http://www.showmecables.com/product/Belden-2-Conductor-12-Awg-Stranded-Shielded-Cable-Per-FT.aspx <http://www.showmecables.com/product/Belden-2-Conductor-12-Awg-Stranded-Shielded-Cable-Per-FT.aspx>
Twisted pair. Foil shielded. Ground. I looked at this and found a cheaper, non-plenum version from another brand (will get you the exact name in a separate post). So I’ve replaced all zip cable lines and many of the smaller Elecraft lines too. Trashed the noisy Samsung switching PS (14V DC) used for the Elecraft SVGA display and made a new shielded cable to the Powererx PS and on and on. Highly effective method to reduce RFI. Pretty convinced noise is not going to enter the system through these shielded cables. David A., KK6DA, Los Angeles > On Jun 21, 2016, at 6:44 AM, Amateur Radio Operator N5GE <[hidden email]> wrote: > > Works great! > > Do it all the time. Father showed me how 50 years ago, the same way > Vic describes it ;o) > > On Tue, 21 Jun 2016 07:44:19 +0300, you wrote: > >> Get some no. 10 stranded wire at Home Depot (etc.), double it over, put one end in a vise and the other in the chuck of your electric drill and twist away. Not shielded, but much better than parallel wires. I suppose you could strip some RG-8 if you really wanted to shield it. >> >> Vic 4X6GP >> >>> On 20 Jun 2016, at 22:54, DGB <[hidden email]> wrote: >>> >>> >>> Jim ... where does one find #10 twisted pair? Is it shielded? >>> >>> thanks 73 Dwight NS9I >>> >>>> On 6/20/2016 12:59 PM, Jim Brown wrote: >>>>> On Mon,6/20/2016 10:33 AM, James Walker wrote: >>>>> Is it normal to register voltage as low as Im seeing on my K-3? >>>> >>>> What you're seeing sounds like IR drop in the DC cable. How long is the DC cable between the K3 and the power supply? What wire gauge? Is there any equipment (like distribution panel) in between? >>>> >>>> This is a great application for a short length of #10 twisted pair between the PSU and rig. >>>> >>>> 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 >>> 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] > ARS N5GE > > ______________________________________________________________ > 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] David Ahrendts [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 K9MA
On Mon,6/20/2016 6:50 PM, K9MA wrote:
> Call them what you will, connecting a bunch of station components to a common DC power return has to be done very carefully. Yes, it does. The rules are quite simple, and are articulated in the Power Point slides I referenced by a link. It's nothing more complicated than proper bonding between equipment, and between that equipment and all grounded parts of a building. 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 Message delivered to [hidden email] |
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In reply to this post by Jim Brown-10
Hi Jimmy,
While I've not investigated it myself, I've been told by those who have that the bus conductors inside some of these boxes are not very robust. In my station, I've made my own cable splices using Power Pole connectors. One pair, as short as I can make it, goes directly to the K3, another goes to a Rig Runner box that feeds power to other boxes that don't draw much current (preamp for Beverages, antenna switching, SO2R box, etc.). 73, Jim K9YC On Mon,6/20/2016 6:54 PM, James Walker wrote: > You may have something there. I use a rig runner device to divide the > power supply output among several rigs. I’m going to try some rewiring > to get a shorter, more direct connection. Thanks. ______________________________________________________________ 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 Jim Brown-10
Tnx to all the input ... all my pwr leads in the shack are now twisted
(as is my mind) ... never had RFI to begin with! tnx 73 Dwight NS9I ______________________________________________________________ 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 Clay Autery
One can convert red/black zip wire pretty easily: zip wire separates
by pulling the red side away from the black so you end up with two separate wires (you can even leave the power-pole connector on one end). Then twist the two wires to obtain twisted-pair. No waste of those existing power cables. 73, Ed - KL7UW http://www.kl7uw.com "Kits made by KL7UW" Dubus Mag business: [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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Administrator
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Let's end this recurring thread for now in the interest of relieving email topic overload for others :-)
Its well exceeding our single OT posting limit and has a wealth of past posts on this topic in our nabble archives etc. 73, Eric (a.k.a. Mr. Moderator) elecraft.com --- Sent from my iPhone 6S > On Jun 22, 2016, at 7:48 AM, Edward R Cole <[hidden email]> wrote: > > One can convert red/black zip wire pretty easily: zip wire separates by pulling the red side away from the black so you end up with two separate wires (you can even leave the power-pole connector on one end). Then twist the two wires to obtain twisted-pair. No waste of those existing power cables. > > > 73, Ed - KL7UW > http://www.kl7uw.com > "Kits made by KL7UW" > Dubus Mag business: > [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] > 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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