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Why 23 khz?

In the last week or so I've noticed multiple stations "listening" to 23 khz. At first I just thought it was a typo but after seeing other users there perhaps its more than that. And always 23 khz. I've kicked a few of the instances and they have come right back. Altho this example is from China, the others haven't been. No user info of course....

RX0"(no identity)" (, Shenzhen,China) 23.00 kHz iq z0 0:04:30 1:25:46

Just curious if others have noticed this? I can't imagine for what purpose they would attempt to extract anything out of the solar inverter noise I have on 23 khz!

73 Don



  • Ha,

    Maybe they don't know it is just that ?

    It is quite strong and it does sound fairly spectacular, so it must be conveying a secret message, right yeh...

    If the frequency range is unusable due to the noise, why not just mask it ?

    Alternatively add a DX label saying interference and use the new signal bandwidth option to indicate the spectral occupancy of the noise.



  • The solar noise isn't present during night time when the charge circuit isn't allowed to be active.

    The IP has been showing up quite often, the location(s) can be from anywhere in the world but the IP stays the same. They camp on 23 in the IQ mode for as long as the timing allows. They will reconnect if I kick them.

    Anyway I have put this in the user writeable blacklist section so we'll see if they change ips or just go away....

  • I noticed someone sitting on 23kHz on my unlisted KiwiSDR a number of times for a few hours until I finally kicked them from the server one day. Always with a different IP address and location shown. Once it was China, another time it was Korea, a US Territory after that...

    Ever since I kicked them that one time, I haven't noticed it again. I haven't seen it since April.

  • Same here lately, usually China. They'll sit there until I kick them. I did notice a strange sporadic "warbling" signal on 19kHz when they were present, which wasn't interference, or local.

    Wav file here:

    It didn't seem like they were trying to listen to that, though. There was nothing I could hear on 25kHz when they were on.

  • FWIW... NAA @ 24 KHz is in Cutler Maine and close to my Maine system

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