Spurs on 15m from new laptop
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Replaced my laptop/shack computer recently with a Dell XPS 15 laptop. Now I have spurs every ~3 KHz across 15m. Any suggestions on getting rid of or minimizing them?
Tnx, Barry W2UP |
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Received several emails suggesting the power supply. Spurs are still there when running on battery.
Barry W2UP |
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This post was updated on .
OK. Just found the problem. It's monitor-related.
Same monitor (HP 2311x) as used with last 'puter with no problems. Only difference is this computer uses an HDMI cable. Last computer used an SVGA cable. When I unplug the HDMI cable, noise stops. I'll wrap the HDMI cable with some ferrites. If that doesn't work, Think I'll pick up an HDMI to VGA adaptor and see if that fixes it. Any other thoughts? Tnx, Barry W2UP P.S. Apologies replying to my own post, but all the replies so far have come directly to me. P.P.S Update - 3 ferrites on cable, noise gone! |
Re: Spurs on 15m from new laptop
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Hi Barry,
You might want to try a different HDMI cable with better shielding, like this one http://www.amazon.co.uk/AmazonBasics-Quad-Shielded-High-Speed-Cable/dp/B002C1BHIO I haven't tried it myself but they claim it's "quad shielded".. But it could also be the monitor's HDMI decoding circuit creating the spurs in which case it probably won't help. Try moving the cable around? 73, Thomas M0TRN On 15 May 2012 15:37, Barry <[hidden email]> wrote: > OK. Just found the problem. It's monitor-related. > > Same monitor (HP 2311x) as used with last 'puter with no problems. Only > difference is this computer uses an HDMI cable. Last computer used an SVGA > cable. > > When I unplug the HDMI cable, noise stops. I'll wrap the HDMI cable with > some firrits. If that doesn't work, Think I'll pick up an HDMI to VGA > adaptor and see if that fixes it. Any other thoughts? > > Tnx, > Barry W2UP > > P.S. Apologies replying to my own post, but all the replies so far have > come > directly to me. > > -- > View this message in context: > http://elecraft.365791.n2.nabble.com/Spurs-on-15m-from-new-laptop-tp7555872p7555876.html > Sent from the Elecraft mailing list archive at Nabble.com. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: Spurs on 15m from new laptop
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In reply to this post by Barry
Than looks like is an internal notebook problem, I am wondering how they get FCC certification? I would advise to return it back due compliance issue..my 2 cents
VE3GNO Daniel ________________________________ From: Barry <[hidden email]> To: [hidden email] Sent: Tuesday, May 15, 2012 10:13:49 AM Subject: Re: [Elecraft] Spurs on 15m from new laptop Received several emails suggesting the power supply. Spurs are still there when running on battery. Barry W2UP -- View this message in context: http://elecraft.365791.n2.nabble.com/Spurs-on-15m-from-new-laptop-tp7555872p7555875.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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One of my favorite "bitches" about some of the "digital types". A lot of
them DO NOT UNDERSTAND "analog radio"! Therefore they are unaware of the trash and hash digital gear is capable of emitting in copious quantities! Running the source down can be a big problem. Trying to do something about it can be heart rending! 73, Sandy W5TVW -----Original Message----- From: VE3GNO Daniel Sent: Tuesday, May 15, 2012 9:46 AM To: [hidden email] Subject: Re: [Elecraft] Spurs on 15m from new laptop Than looks like is an internal notebook problem, I am wondering how they get FCC certification? I would advise to return it back due compliance issue..my 2 cents VE3GNO Daniel ________________________________ From: Barry <[hidden email]> To: [hidden email] Sent: Tuesday, May 15, 2012 10:13:49 AM Subject: Re: [Elecraft] Spurs on 15m from new laptop Received several emails suggesting the power supply. Spurs are still there when running on battery. Barry W2UP -- View this message in context: http://elecraft.365791.n2.nabble.com/Spurs-on-15m-from-new-laptop-tp7555872p7555875.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2425/4999 - Release Date: 05/14/12 ______________________________________________________________ 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 |
Re: Spurs on 15m from new laptop
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In reply to this post by VE3GNO Daniel
On 12-05-15 10:46 AM, VE3GNO Daniel wrote:
> I am wondering how they get FCC certification? I would advise to return > it back due compliance issue..my 2 cents Some years back I was working for a company that had an RF based hand-held real-time data collection system used in focus groups. The hand-held devices and the base station both had type approval for use in Canada and the US. After using the devices for a few years the company wanted to use the devices in the UK so the units were submitted for UK type approval. Both base station and hand-held failed the approval process. The hand-held transmitted in the 49MHz band using a 16.6xx MHz crystal running in third overtone (ie. 16.6xx times 3 = ~49MHz). It failed because of emissions exceeding allowed limits for the 900MHz(!) band. As soon as I connected the spectrum analyzer I saw spurs every 16.6xx MHz in to the GHz range. The person that designed it must never have used an SA or they shouldn't have let it get past the prototype stage. Fortunately I found a simple solution. I changed the 7404 used in the crystal oscillator with a 74U04 (unbuffered) and all the spurs dropped in strength from being equal to the fundamental to barely measurable. The hand-held passed on the second submission for UK approval. This made me realize that FCC type approval doesn't mean a lot as a unit can still put out a lot of of unwanted RF emissions and simple circuit changes can often clean up a design if someone cares at all. The FCC type approval process is nowhere near as strict as it should be but it is still better than not having an approval process at all. The one noise source I have at home is the high efficiency furnace that creates a tremendous amount of broadband RF noise when it goes in to a heating cycle during the winter months. I'm sure it was type approved too. :-P -- Cheers! Kevin. http://www.ve3syb.ca/ |"Nerds make the shiny things that distract Owner of Elecraft K2 #2172 | the mouth-breathers, and that's why we're | powerful!" #include <disclaimer/favourite> | --Chris Hardwick ______________________________________________________________ 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 |
Re: Spurs on 15m from new laptop
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In reply to this post by Barry
Send them firrits after 'em - that'll fix 'er!
73, Pete N4ZR The World Contest Station Database, updated daily at www.conteststations.com The Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com, spots at telnet.reversebeacon.net, port 7000 and arcluster.reversebeacon.net, port 7000 On 5/15/2012 10:37 AM, Barry wrote: > OK. Just found the problem. It's monitor-related. > > Same monitor (HP 2311x) as used with last 'puter with no problems. Only > difference is this computer uses an HDMI cable. Last computer used an SVGA > cable. > > When I unplug the HDMI cable, noise stops. I'll wrap the HDMI cable with > some firrits. If that doesn't work, Think I'll pick up an HDMI to VGA > adaptor and see if that fixes it. Any other thoughts? > > Tnx, > Barry W2UP > > P.S. Apologies replying to my own post, but all the replies so far have come > directly to me. > > -- > View this message in context: http://elecraft.365791.n2.nabble.com/Spurs-on-15m-from-new-laptop-tp7555872p7555876.html > Sent from the Elecraft mailing list archive at Nabble.com. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: Spurs on 15m from new laptop
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In reply to this post by Barry
On 5/15/2012 7:37 AM, Barry wrote:
> I'll wrap the HDMI cable with some firrits. Don't wrap the cable with ferrites, WIND turns of the cable through a ferrite core. #31 or #43 material work fine, at least five turns through a 2.4-in o.d. toroid, at least three turns through a clamp-on that's at least 1 inch long. More advice in tutorial form -- http://audiosystemsgroup.com/RFI-Ham.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 |
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I have a bunch of the split ferrites with a hole to fit RG-213 coax on hand. Got 2 turns through the hole and used 3 of them with complete elimination of the noise.
Barry W2UP .
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