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Spurs showing up?

rfoust
rfoust Member ✭✭
Any idea what is causing these spurs? They show up across the entire spectrum. If I unplug the antenna, it goes away. I moved the antenna to the 2nd port and they show up there too. This is on a 6700. imageimage

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Comments

  • Stu Phillips - K6TU
    Stu Phillips - K6TU Member ✭✭
    edited May 2020
    You have my sympathy - some where in your neighbor hood someone is using switched variable speed controller - most likely on an AC unit, pool or well pump.

    Start by seeing whether its on your own property = run a battery powered receiver on your antenna and then turn off your main circuit breaker.  If it goes away, now start with all secondary breakers off, reset the main breaker and then start turning on circuits one at a time until the noise reappears.

    If its not on your property, then you need to start DFing and searching to find the property and then speak (very nicely) to the owner and see if you can get the problem isolated.  You may need to get the FCC involved to help you.

    These problems are nasty... here's my saga of woe and how I found and got the problem fixed.

    Stu K6TU

    http://1vc.typepad.com/ethergeist/2010/02/rfi-hunters.html
  • rfoust
    rfoust Member ✭✭
    edited March 2017
    Thanks Stu! I'll see if I can track down the source.
  • Stu Phillips - K6TU
    Stu Phillips - K6TU Member ✭✭
    edited May 2020
    Robbie, If it's not on your property and you have overhead power lines, it's likely being radiated from them. From the strength it's likely within a mile of you. Let me know if you need help tracking this down and resolving the problem. I've dealt with a lot of this stuff... It's an epidemic. Stu K6TU
  • rfoust
    rfoust Member ✭✭
    edited March 2017
    Unfortunately, I live in the largest subdivision in my city. Houses (and even businesses) are everywhere around me. Guess I'm gonna have to use your blog posts as a guide and come up with a game plan to track it down. I'll try to rule out my own house first. It's gonna be a busy week so I probably won't get to search much until next weekend.
  • rfoust
    rfoust Member ✭✭
    edited March 2017
    The spurs seem to be drifting very slightly over time. I can scroll back on the waterfall and see it. They drift in sync sometimes left, sometimes right.
  • George KF2T
    George KF2T Member ✭✭✭
    edited February 2019
    Robbie, it's a toughie sometimes. Stu's advice is solid. On my QRZ page, I have a list of things that helped mitigate interference from my house & property. Like you, I'm in a pretty dense subdivision, so it's impossible to get rid of it all, but you CAN make good progress. I think it was Tim (W4TME) that said it - the best thing about the Flex radios is the pan display. It's also the worst. You can really see all the junk in the air. Drove me crazy trying to cut it down to size. Good luck!!

    Geo/KF2T

  • rfoust
    rfoust Member ✭✭
    edited March 2017
    Wow, found it! I tuned my HT to a frequency where one of the spurs was, and pointed it around in all directions just from where I'm sitting. When I pointed it at a samsung 20" lcd monitor that my wife uses on her desk (I just set it up for her this weekend), the noise got loud. So, I turned it off, and the spurs dropped a lot, but didn't completely go away. So, I unplugged the monitor from the wall, and the spurs completely disappeared. Guess I have to get her a new monitor. I'm glad it was something in my house.
  • Stan VA7NF
    Stan VA7NF President Surrey Amateur Radio Communications Member ✭✭
    edited February 2017

    A good chance the spurs came from the wall wart.  There are plug-in suppressors and ferrites on the power lead that may make enough of a difference.  Besides 20" monitors are not that expensive. 

    Did you just purchase the monitor or set up one you had around?  If a new purchase, return it claiming FCC 15 and start over (bring your HT and check the new ones)

  • rfoust
    rfoust Member ✭✭
    edited March 2017
    It was one I've had for a few years.  I was using it as one of my primary monitors but I got a bigger one to replace it.  I had noticed weird noise/spur problems before and could never really locate the source.  But for some reason when I relocated this monitor (different desk, different outlet), the problem got much worse.  If I can find another power supply that matches the same specs, I'll try to use that and see if it fixes the problem.  But yeah, monitors are cheap now.
  • Tim - W4TME
    Tim - W4TME Administrator, FlexRadio Employee admin
    edited March 2017
    Also make sure you do not have the RF preamp enabled for bands 20m and below.
  • AE0MW
    AE0MW Member ✭✭
    edited January 2017
    Wow, that looks a lot like the noise I have!

    I haven't been able to chase mine down yet, I finally decided to chase mine down and it's gotten a lot quieter in the last 2-3 months.

    In my case I've verified it's not in my house... AC units, pools and well pumps are all possibilities in my area.

    Just for comparison sake, here's what mine looks like.
  • Dave - WB5NHL
    Dave - WB5NHL Member ✭✭
    edited December 2014
    Good catch. I wonder if an LED would be an improvement over LCD monitors. LCD monitors have a cold cathode tubes used for backilghting the display. Because of the high voltage gas discharge they are inherently noisy. It would seem LED monitors might be less noisy.


  • rfoust
    rfoust Member ✭✭
    edited March 2017
    Actually, this one is a led monitor. I just swapped it out with a slightly older LCD apple and there is no noise. I'm pretty sure it's the power brick, not the monitor itself. Having said that, your theory may very well be correct with led/lcd noise levels. Wonder if anyone has done any lab measurements for stuff like that. One thing is for sure, it sure is easy to see noise/spurs on a panadapter/waterfall. When I just had a knob radio, I had no idea what those weird noises were and if it repeated at an interval, etc. Could have been aliens trying to communicate as far as I knew.
  • Robert -- N5IKD
    Robert -- N5IKD Member ✭✭
    edited March 2015
    I had some under-cabinet LED lighting in the kitchen that was raising the noise floor significantly. I had the same LED lighting in the shack with no impact on the radio.

    I discovered that the difference was the power supply. The power supply in the kitchen was in a metal case but created a lot of RF. The power supply in the shack is in a plastic case and does not impact the radio.
  • rfoust
    rfoust Member ✭✭
    edited December 2016
    Ok I'm gonna show my ignorance here. Is rf preamp the same as rf gain? If so, looks like it is set to zero. Otherwise, I can't find a preamp button.
  • KY6LA_Howard
    KY6LA_Howard La Jolla, CA. Paris and Sablet FranceMember ✭✭✭
    edited December 2014
    RF Preamp is NOT RF Gain.. it should be set to zero on 20M

    There really is not a RF Gain Control...Rather you set the AGC-T - Automatic Gain Control Threshold to limit the noise in the receiver..it is found under the Speaker Icon where you set AGC
  • Jon_KF2E
    Jon_KF2E Member ✭✭
    edited July 2018
    If you have a yagi antenna you can use it to point you to the interference. I have a three element SteppIR and when I had interference similar to what you are seeing, I used it to lead me to the problem. First find the band with the most interference. Then swing your antenna 360 degrees. The interference will peak and that will be the direction to the problem. It can tell you whether a problem is in your house or your neighbors. My problem was a battery charger in my garage.

    Jon...kf2e



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