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Seeing a lot of solid vertical lines on the spectrum scope of my ftdx10 and they’re really annoying.

I have a yaesu fp1023a powering and ftdx10. Doesn’t go away if I turn off every circuit in the house except the one powering my radio. Antenna is outside also. Gonna order a battery to see if it’s the power supply.

Anyone know what’s going on (new ham here)

enter image description here

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  • $\begingroup$ It's hard for me to tell, but it looks like the red lines are about 20 kHz apart. Switching power supplies and solar inverters are usually 25 kHz. Not too far off. Can anyone verify this? $\endgroup$ Jul 12, 2023 at 19:55
  • $\begingroup$ Does this occur 24 hours a day? $\endgroup$ Jul 12, 2023 at 19:58
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    $\begingroup$ @MikeWaters you’re good! 20khz is the spacing on 10m. I believe the same RFI is present on 80m but at 30khz spacing. It’s 24 hours a day. $\endgroup$
    – Chris G.
    Jul 13, 2023 at 14:48
  • $\begingroup$ I may be wrong but I don’t recall seeing it on 40 or 20m $\endgroup$
    – Chris G.
    Jul 13, 2023 at 14:53
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    $\begingroup$ I have a 40/20/10 efhw in a tree outside in an inverted vee. It’s a vibroplex Ef-quad $\endgroup$
    – Chris G.
    Jul 13, 2023 at 20:16

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Your S-meter is showing 0, so unless you have an attenuator in I don't think there's an actual noise problem here. There's just no signals in the band so the noise (which isn't all that strong) is all you see. If there were any signals they would probably stand out against the noise just fine.

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  • $\begingroup$ Good catch. I was focused on the waterfall. $\endgroup$ Jul 12, 2023 at 22:54
  • $\begingroup$ Can’t tell if I have the att on or if it’s ipo or amp1 because I maximized the waterfall (oops) but I have to notch out these signals when someone is transmitting near them if the tx station signal isn’t really big and strong. The notch filter distorts the audio pretty heavily sometimes depending on where the station is in relation to the RFI. $\endgroup$
    – Chris G.
    Jul 13, 2023 at 14:50
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Chris, WSPR is gonna be your friend. You can find if the band is opening by looking at WSPR maps, when you see contacts in your area, then you will know there will be some signals up. If things are happening, usually FT8 signals will be at 28.074 and maybe some SSB between 28.350-28.400. You can also wander down to the CB frequencies to look for US path openings. Sometimes the 11 meter band opens just before the 10 meter band.

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    $\begingroup$ Thanks, waiting on my wspr account to be activated. I check for 10m opening currently by pulling up a Websdr site about 100mi from my qth and looking for ft8 or ssb $\endgroup$
    – Chris G.
    Jul 13, 2023 at 14:51
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What you see is a train of pulses with a repetition frequency of about 20 kHz. The pulses are not quite wideband because they are absent above about 28.63 MHz. If you tune towards lower frequencies you can presumably find a low end for where these pulses occur. The wider the spectrum is, the better is the chance to remove these pulses with a high bandwidth noise blanker. If you have access to an oscilloscope going up to or above 30 MHz you might be able to see these pulses in the time domain. Maybe you would need a high pass filter to not saturate the oscilloscope wit strong signals from the lower bands.

You might be interested in these links:

https://www.youtube.com/watch?v=5asxOcRDdXo

http://sm5bsz.com/blanker.htm

http://sm5bsz.com/linuxdsp/blanker/wide.htm

http://sm5bsz.com/linuxdsp/rxiq/demo/blanker.htm

http://sm5bsz.com/linuxdsp/blanker/leonids.htm

http://sm5bsz.com/linuxdsp/blanker/leon2001/leon2001.htm

https://www.youtube.com/watch?v=qMd5y036HtA

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