K3: Are the birdies really birdies
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There's a very interesting item in December's QST "The Doctor is In" feature (page 48 right column). Receiver birdies turned out to be caused by a noisy router. I have learned to live with 10 meter birdies on my K3. But lately I've been active on 12 meters and there is an S5 birdie at about 24900KHz. So after reading the article I started unplugging cables on my wireless router (which is in another room from my K3). Whoa, what's this? Birdies come and go as I unplug the router power line or unplug the CAT 5 cable going to the shack. Ditto in the shack. If I unplug the CAT 5 from the wall or from the PC the birdie on 12 meters disappeared. Moving on to 10 meters I discovered that all of the prominent birdies also disappeared. I haven't done a thorough investigation but I suspect they might all be gone.
Of course that was only step one. I still need an internet connection on my shack PC so I'm currently experimenting. Snap-on ferrite cores had no effect. Moving the shack CAT 5 cable away from other radio related cables is having a positive effect. Next I'm going to try a shielded CAT 5 cable from the wall to the shack PC. But of course the cable wiring in the wall to the router is not shielded so I don't have high hopes of solving it in this way. But at least I'm on the right track and I'm sure I'll find something that works eventually. 73, Mike K2MK |
Re: K3: Are the birdies really birdies
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Mike,
OK, you are finding good information about the source of the "birdies" (which are not really birdies, but real signals). If you can locate your antenna away from the router and ethernet cables, your problem will diminish. My computer network is confined to the inside of a stucco covered house with its steel mesh coating, so I (sort-of) live in a shielded box. The antennas are located at least 80 feet from the house, so I hear few of those troublesome radiation effects from the computer netowrk devices. The downside is that I cannot connect my laptop to the network access point if I am more than 25 feet from the house. So, if you can, locate the antennas as far away from the noise source as possible, and if that is not possible, use ferrites and other shielding means to lower the radiation into your receiving antenna. This is not a K3 (K2, K2, YaseuKenCom) problem, but it is a situation that must be dealt with if one is to continue to enjoy the benefits of networking and internet access provided by routers and switches and access points, they all generate RF that our sensitive receiver can hear. 73, Don W3FPR On 11/16/2010 6:02 PM, Mike K2MK wrote: > There's a very interesting item in December's QST "The Doctor is In" feature > (page 48 right column). Receiver birdies turned out to be caused by a noisy > router. I have learned to live with 10 meter birdies on my K3. But lately > I've been active on 12 meters and there is an S5 birdie at about 24900KHz. > So after reading the article I started unplugging cables on my wireless > router (which is in another room from my K3). Whoa, what's this? Birdies > come and go as I unplug the router power line or unplug the CAT 5 cable > going to the shack. Ditto in the shack. If I unplug the CAT 5 from the wall > or from the PC the birdie on 12 meters disappeared. Moving on to 10 meters I > discovered that all of the prominent birdies also disappeared. I haven't > done a thorough investigation but I suspect they might all be gone. > > Of course that was only step one. I still need an internet connection on my > shack PC so I'm currently experimenting. Snap-on ferrite cores had no > effect. Moving the shack CAT 5 cable away from other radio related cables is > having a positive effect. Next I'm going to try a shielded CAT 5 cable from > the wall to the shack PC. But of course the cable wiring in the wall to the > router is not shielded so I don't have high hopes of solving it in this way. > But at least I'm on the right track and I'm sure I'll find something that > works eventually. > > 73, > Mike K2MK 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 Mike K2MK
Hi Mike,
They're not birdies, but real signals. See what happens when you disconnect your antenna. If they were birdies, therefore originating from within the radio, you'll still hear them. I have two routers in my house, and both wreak havoc for me! I still haven't found a good way to minimize their impact. 73, James K2QI On Tue, Nov 16, 2010 at 6:02 PM, Mike K2MK <[hidden email]> wrote: > > There's a very interesting item in December's QST "The Doctor is In" > feature > (page 48 right column). Receiver birdies turned out to be caused by a noisy > router. I have learned to live with 10 meter birdies on my K3. But lately > I've been active on 12 meters and there is an S5 birdie at about 24900KHz. > So after reading the article I started unplugging cables on my wireless > router (which is in another room from my K3). Whoa, what's this? Birdies > come and go as I unplug the router power line or unplug the CAT 5 cable > going to the shack. Ditto in the shack. If I unplug the CAT 5 from the wall > or from the PC the birdie on 12 meters disappeared. Moving on to 10 meters > I > discovered that all of the prominent birdies also disappeared. I haven't > done a thorough investigation but I suspect they might all be gone. > > Of course that was only step one. I still need an internet connection on my > shack PC so I'm currently experimenting. Snap-on ferrite cores had no > effect. Moving the shack CAT 5 cable away from other radio related cables > is > having a positive effect. Next I'm going to try a shielded CAT 5 cable from > the wall to the shack PC. But of course the cable wiring in the wall to the > router is not shielded so I don't have high hopes of solving it in this > way. > But at least I'm on the right track and I'm sure I'll find something that > works eventually. > > 73, > Mike K2MK > -- > View this message in context: > http://elecraft.365791.n2.nabble.com/K3-Are-the-birdies-really-birdies-tp5745866p5745866.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 > -- 73 de James K2QI President UNARC/4U1UN ______________________________________________________________ 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 Mike K2MK
On Nov 16, 2010, at 3:02 PM, Mike K2MK wrote: > Moving the shack CAT 5 cable away from other radio related cables is having a positive effect. Next I'm going to try a shielded CAT 5 cable from the wall to the shack PC. I can attest to the effectiveness of shielded Ethernet cables (for me anyway). After fighting with Ethernet noise, I finally swapped out all the Ethernet switches in the house with ones that have metal enclosures (Netgear GS series), and replaced all UTP CAT-5 cables to STP CAT-6 cables. The shielded switches by themselves didn't do much until I went to the STP cables. I couldn't find shielded CAT-5 at the local Fry's and just went with CAT-6. I believe the critical difference is STP (shielded twisted pair) vs UTP (unshielded) and not the difference of going from CAT-5 to CAT-6. If you can't find shielded Ethernet switches, perhaps at least look for ones where the RJ-45 jack has the metal tab that connects to the shield of the STP CAT cable. I still have a box full of unshielded CAT-5 cables that I have been using for controlling remote antenna switches and such :-). Going to WiFi can also help, but some WiFi routers, like the early Apple Airport Express, are themselves very RF noisy in the HF region. I don't know if the newer AirPort Express are any better since I had banned the Apple AirPort Express from this QTH :-). 73 Chen, W7AY ______________________________________________________________ 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: K3: Are the birdies really birdies
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I long ago diagnosed several of my RFI problems on ethernet devices
throughout the house. I tried everything to get rid of it including making special ethernet jumpers I put at the source devices with ferrite and by-pass capacitors between the offending pair of wires (the TX/RX wires). Of course the caps worked, but since the ethernet signal is AC, it also killed the network, LOL! Shielded cable on long runs that is grounded at both ends definitely makes a big difference...at least it did for me. It doesn't get rid of it entirely, but it helps. Some devices are worse than others, and of course it's more pronounced on some bands than others. On Tue, Nov 16, 2010 at 4:05 PM, Kok Chen <[hidden email]> wrote: > > On Nov 16, 2010, at 3:02 PM, Mike K2MK wrote: > > > Moving the shack CAT 5 cable away from other radio related cables is > having a positive effect. Next I'm going to try a shielded CAT 5 cable from > the wall to the shack PC. > > I can attest to the effectiveness of shielded Ethernet cables (for me > anyway). > > After fighting with Ethernet noise, I finally swapped out all the Ethernet > switches in the house with ones that have metal enclosures (Netgear GS > series), and replaced all UTP CAT-5 cables to STP CAT-6 cables. The > shielded switches by themselves didn't do much until I went to the STP > cables. > > I couldn't find shielded CAT-5 at the local Fry's and just went with CAT-6. > > I believe the critical difference is STP (shielded twisted pair) vs UTP > (unshielded) and not the difference of going from CAT-5 to CAT-6. If you > can't find shielded Ethernet switches, perhaps at least look for ones where > the RJ-45 jack has the metal tab that connects to the shield of the STP CAT > cable. > > I still have a box full of unshielded CAT-5 cables that I have been using > for controlling remote antenna switches and such :-). > > Going to WiFi can also help, but some WiFi routers, like the early Apple > Airport Express, are themselves very RF noisy in the HF region. I don't > know if the newer AirPort Express are any better since I had banned the > Apple AirPort Express from this QTH :-). > > 73 > Chen, W7AY > > > > > ______________________________________________________________ > 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 Kok Chen
Try hosting the neighborhood wireless RAP at the top of your tower [in
exchange for free, pretty-high speed Internet in an area with no DSL, no CATV, and no sewers. OK the last doesn't count]. Truthfully, the number of external signals I hear are fewer and of lower amplitude than I thought I would see, I know where they are, and I'm good at ignoring things ... ask my wife. 73, Fred K6DGW - Northern California Contest Club - CU in the 2011 Cal QSO Party 1-2 Oct 2011 - www.cqp.org On 11/16/2010 4:05 PM, Kok Chen wrote: > > I can attest to the effectiveness of shielded Ethernet cables (for me > anyway). > > After fighting with Ethernet noise, I finally swapped out all the > Ethernet switches in the house with ones that have metal enclosures > (Netgear GS series), and replaced all UTP CAT-5 cables to STP CAT-6 > cables. The shielded switches by themselves didn't do much until I > went to the STP cables. ______________________________________________________________ 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 K2QI
Hi,
I am still working on mine. My main problem is that I have yet to find a source of ferrites that are big enough to thread cables with connectors through (the snap-on ones are totally useless) and effective on HF. I have borrowed ferrites from the kits we have at work but they are only moderately effective below 30MHz (regulatory requirements are more severe at VHF so companies tend to focus on that). My "birdies" are definitely picked up by my antennas. When I switch to the dummy load, it's mostly dead quite although my MFJ tuner/switch/dummyload is not extremely well shielded. I am convinced that most of the radiation from the router is through the AC power house wiring. I say that because I do not have that much Ethernet cabling beyond the immediate vicinity of the router and the computer cluster close to it. The "birdies" are also worst on the antennas that are parallel with the long axis of the house - not unexpected if the AC wiring is the main radiator. AB2TC - Knut
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In reply to this post by Don Wilhelm-4
Don and James,
You are both correct. I was pretty sure the S5 router noise was a birdie as I had already switched to my dummy load. But now I disconnected the PL259 from the back of the K3 and the router noise on 12 meters is down to S1. So it is probably being picked up by the 4 cables between the K3, amplifier, power meter, antenna switch, and dummy load. The real birdies are still there with no antenna cable connected. I had done birdie reduction some time ago by rearranging the RF cables inside the K3 (and taping them in place with blue painter's tape). The real birdies are mostly S1 and S2 which is something I can live with. Thanks for the enlightenment. 73, Mike K2MK
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Re: K3: Are the birdies really birdies
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In reply to this post by Kok Chen
On 11/16/2010 4:05 PM, Kok Chen wrote:
> After fighting with Ethernet noise, I finally swapped out all the Ethernet switches in the house with ones that have metal enclosures (Netgear GS series), and replaced all UTP CAT-5 cables to STP CAT-6 cables. The shielded switches by themselves didn't do much until I went to the STP cables. There are two ways the noise escapes the box. One is direct radiation from the box. The other is common mode current on the Ethernet cable and sometimes even the power cable. You can make a BIG dent in the cable radiation by winding multiple turns of EVERY Ethernet cable through a #31 or #43 ferrite core. SINGLE TURNS (BEADS) WILL NOT WORK except on 6M and 2M. 5-7 turns on a 2.4-in o.d. toroid is a good starting point. Note that BOTH ENDS of any digital connection, including an Ethernet connection, can produce this trash, so if the Ethernet cable is longer than about 0.15 wavelengths at a frequency where you hear this stuff, you are likely to need chokes at both ends. The most common of the birdies coming from modems are around 14,030 kHz, 21,052 kHz, the bottom of 10M CW, and the bottom 100 kHz or so of 6M. There are also some on 30M. See my RFI tutorial for a list. I'm a CW guy, so those are the ones I hear. If you work SSB you get to identify your own. :) Note also that each Ethernet box has its own free-running clock, so each box is on a different frequency. It is very common to kill your own trash but still hear your neighbors. I did in my Chicago residential neighborhood. When chasing these birdies, kill power to your Ethernet box first to identify which is yours. Otherwise you'll chase your tail. Here in CA, I have no wired Ethernet at all, doing everything on WiFi. Works a treat, as our friends in the UK would say. 73, Jim Brown 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 |
Re: K3: Are the birdies really birdies
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In reply to this post by ab2tc
On 11/16/2010 4:23 PM, ab2tc wrote:
> I am still working on mine. My main problem is that I have yet to find a > source of ferrites that are big enough to thread cables with connectors > through (the snap-on ones are totally useless) and effective on HF. See Appendix One of 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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In reply to this post by Mike K2MK
Don't forget the PC and the monitor AND your new HD TV. Now that many are using flat panel monitors and have HD TV's you have a whole new set of frequencies to work around.
My PC LCD display went bad a few months ago, and being a good ham I salvaged as many good parts as possible. In addition to a GREAT +12, +5 VDC (@ 5 and 10 amps) and a bunch of good electrolytic' and useless SMD's I found several crystals, 2 with frequencies in the ham bands. One was 14.300 kHz and I can't recall the other right now. Rich |
Re: K3: Are the birdies really birdies
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In reply to this post by Mike K2MK
Mike,
My old Linksys router did this. After many attempts to attenuate the birdies, I took someone's suggestion and swapped it out to a new Netgear router. All my birdies left with the Linksys. That said, others have had no problems with the Linksys and still others had problems like mine with other Netgear router. My point is, when all else fails, "try another brand or model". Good luck. Terry, W0FM -----Original Message----- From: Mike K2MK [mailto:[hidden email]] Sent: Tuesday, November 16, 2010 5:03 PM To: [hidden email] Subject: [Elecraft] K3: Are the birdies really birdies There's a very interesting item in December's QST "The Doctor is In" feature (page 48 right column). Receiver birdies turned out to be caused by a noisy router. I have learned to live with 10 meter birdies on my K3. But lately I've been active on 12 meters and there is an S5 birdie at about 24900KHz. So after reading the article I started unplugging cables on my wireless router (which is in another room from my K3). Whoa, what's this? Birdies come and go as I unplug the router power line or unplug the CAT 5 cable going to the shack. Ditto in the shack. If I unplug the CAT 5 from the wall or from the PC the birdie on 12 meters disappeared. Moving on to 10 meters I discovered that all of the prominent birdies also disappeared. I haven't done a thorough investigation but I suspect they might all be gone. Of course that was only step one. I still need an internet connection on my shack PC so I'm currently experimenting. Snap-on ferrite cores had no effect. Moving the shack CAT 5 cable away from other radio related cables is having a positive effect. Next I'm going to try a shielded CAT 5 cable from the wall to the shack PC. But of course the cable wiring in the wall to the router is not shielded so I don't have high hopes of solving it in this way. But at least I'm on the right track and I'm sure I'll find something that works eventually. 73, Mike K2MK -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-Are-the-birdies-really-birdies-tp574 5866p5745866.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 |
Re: K3: Are the birdies really birdies
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In reply to this post by Mike K2MK
Birdies are mainly an issue for me on VHF+ where I am involved with
copying super-weak signals; bain of all eme stations. If 28-MHz is impacted I will have to work on that as I am running the K3 with transverters that output 28-32 MHz. Of course the output signal level may be high enough not to be troubled by birdies if they are low level. As sort of a chuckle, I have made myself a big birdie on 10-MHz with the addition of a OCXO 10-MHz station reference for locking PLL's in my transverters. Even though totally run in coax and with the OCXO inside a shielded enclosure, 10mw (+10 dBm) is a huge signal. No checking WWV while it is running (it runs continuously to keep it stable under 0.01-Hz; I have my new 1296-MHz transverter with output held to <1-Hz freq. error). I have not seen any harmonic or sub-harmonics so that is good, at least. 73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 144-800*w, 432-100w, 1296-testing*, 3400-winter? DUBUS Magazine USA Rep [hidden email] ====================================== *temp not in service ______________________________________________________________ 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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