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 Don Wilhelm-4 wrote: > > 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 > -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-Are-the-birdies-really-birdies-tp5745866p5746083.html Sent from the [K3] 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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
