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Interesting tones on 20m

Discussion in 'Ham Radio Discussions' started by N8SAN, Dec 3, 2018.

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  1. KC9YGN

    KC9YGN Platinum Subscriber Platinum Subscriber QRZ Page

    Easiest way to tell is to run a transceiver off a battery or inverter and then kill power to the entire house by throwing the main breaker. That will tell you immediately if it's something in the house or something external.
     
    K6LPM likes this.
  2. K6CLS

    K6CLS Ham Member QRZ Page

    Big signal on 14.212... yep, Ethernet.

    Replace your old unshielded router. Put ferrites on both ends of every cat5 jumper.
     
  3. KC9YGN

    KC9YGN Platinum Subscriber Platinum Subscriber QRZ Page

    I'm curious about this because I've never run into ethernet interference before. Every room in the house wired with CAT-6, plus the garage has at least one ethernet jack, some like my office have several, all running to a 24 port Cisco router, plus WiFI, and I've never run into interference from my network. How common is this?
     
  4. K6CLS

    K6CLS Ham Member QRZ Page

    Good questions.

    Cat 6 is somewhat overdone for home use, are you really going to do 10Gbps around the house? And gosh it's heavy and less flexible, a bear to install. Well, now you have it, so enjoy it.

    Cat6 twisted pair is slightly better than cat5, which does a pretty good job of being a self cancelling transmission line.

    I found my older cheaper routers and switches would radiate out the RJ45 ports. They are cheap, unshielded, and those old routers had plastic cases. My WRT54Gs were among the worst. Had so much fun hacking those, ahh memories.

    Your Cisco switch uses top quality RJ45 shells and has nice metal box.

    So, I would not expect any RFI from your network.

    I believe the 14.212 is on 100Mbps only. Yes there are regular birdies up and down the band. I forget, maybe every 50kHz or so? Question for the OP.

    Gbps links do not appear to make birdies on HF.

    WiFi is on 2.4 and 5.7 GHz, so waaay higher than HF.

    Enjoy your clean spectrum!
     
    KC9YGN likes this.
  5. WZ7U

    WZ7U Subscriber QRZ Page

    I've heard something like that for years on 20m when the band goes out. Never had routers, ethernet or any of that stuff around till very recently. I always attributed it to birdies in the radio.
     
  6. N8SAN

    N8SAN XML Subscriber QRZ Page

    It's cold and winter here in Michigan, so certainly not sprinklers.
    interesting you're saying something similar on 10m. 20m is my main go to, so it's kinda annoying to have it humming along! Hope to be able to check out some of the birdies this weekend. I don't get any time down there weekday mornings.
    Might be interesting to Setup a time lapse cam watching the scope, leave the rig on all night and see when they appear. I'd have to turn off the screen saver....

    61kHz spacing, At least on mine.
     
    Last edited: Dec 5, 2018
  7. W0AEW

    W0AEW Ham Member QRZ Page

    How loud are the signals if you connect your rig to a dummy load?
     
  8. KC9YGN

    KC9YGN Platinum Subscriber Platinum Subscriber QRZ Page

    Thanks for the info. That explains it. I admit that our system here is definitely overkill for a home installation but there is some rational behind it. I used to be a technician for a company that sold and serviced point of sale systems for grocery stores, and if we wanted to avoid future service calls over trivial matters we learned it paid to go with the best quality equipment we could talk the customer into buying. The upfront cost was more, yes, but it more than paid for itself in fewer problems and service calls down the road. And any kind of downtime could cost the company huge amounts of money in lost sales. Plus my eldest son is an engineer in IT department for a major retailer and while upfront cost of equipment is important, any kind of downtime because of equipment problems costs the company huge amounts of money. So we both look at not just the initial cost of equipment but also at long term performance and reliability of a system.

    The Cat-6 cable was used because I got it almost for free, remnants of spools from a networking project that were too short for full runs. The Cisco equipment was free, they were throwing it away because it didn't work so my son snagged it and repaired it. If I remember right it was an issue with the power supply. Cost less than $15 in parts plus a couple of hours of time to fix it.

    Thanks for the response!
     
    K6CLS likes this.
  9. K6LPM

    K6LPM XML Subscriber QRZ Page

    Luckily 20 mtrs here is the least affected and seems that 15 is most affected although 17 used to be afflicted pretty bad by a neighbors security camera/dvr combo and its wallwart power supply. The combination of all 3 together really messed with 17. No longer a problem now that someone stole his security camera.... Jk:D actually no longer problem all four of them are gone.
     
  10. W0AEW

    W0AEW Ham Member QRZ Page

    Shhhh.
     

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