Block a frequency

Recently im having issues of people using TOR browsers and hogging the kiwi, usually on the same frequency (27.005). Switching between DRM and AM (probably to try to keep to activity going).

Ive tried blocking all TOR exit nodes, but they seem to popup new ones daily.

Instead of blocking IP's, would it be possible to block a certain frequency instead? Im not sure if that would solve the issue, but it might be an easy try if this is possible.

I did a forum search but couldnt find anything on this ...

Thanks in advance.




  • Thanks John ... not sure how i missed that!

  • I took a look at that forum post and I must be daft - I see no explanation of how it's done -- apart from an explanation that is started in the middle of DX Labeling or something --

    Maybe someone could issue a post or link to where this is all described.

    Many thanks!

  • Zoom in enough that the passband covers a decent area of the screen (e.g. use the "max in" button, the one with two arrowheads pointing at each other, to select zoom level 10). Follow the directions in the entire section titled "DX/marker label editing" and create a new label.

    Important part: In the "DX label edit" panel that appears set the "Type" menu to "masked" (entry at the bottom of the list). When the "Add" or "Modify" button is pressed you will then see the effect of the masking at the frequency of the label.

  • For some of the guys complaining about bots logging in and monitoring a specific frequency, this method will fully thwart them! I was very annoyed by a nearly CONSTANT stream of totally un-decodable RTTY at 4005 KHz, so I created the "mask" to block it out. Works perfectly!

  • Masking is indeed a great feature.

    I had a recent issue with someone from Taiwan sitting on all seven KiwiSDRs here, monitoring CHU. Sometimes for 12 hours straight. As CHU is something legitimate users might want to listen to, masking was unfortunately not an option, so I had to resort to IP bans. He got around them a few times by changing IP, so it was a game of whack a mole for a while, but he finally took the hint, and has not come back.

  • What could be the purpose of using multiple channels to monitor CHU on a 1-2+ second delay?

  • IP Network propagation delay monitoring ? (looking for route changes, loading etc.)

    Harp atmospheric work ? (active feedback, or detection of remote use)

    Time reference for linking other recorded channels ? (HF military plane locations)

    EMP or storm detection ? (back to Harp)

    We assume the audio is the goal but they may be extracting other data, the "we are just listing to CHU" might just be a distraction.

    They still try ports on my firewall every two seconds 24/7/365, must be of some value other than listening to local radio "tunes".

  • I have some concerns now that third-party applications like MixW 4 have support to easily access the KiwiSDR network using their own user interface.

    I don't object to the concept. But I worry that placing an application interface between a popular program and our network might encourage a large number of users to access public KiwiSDRs without taking the time to learn and understand the limitations of our network.

    I've only had time to take a brief glance at MixW 4, but it seems to have a monitor function using the Kiwi network to answer the question: "How's my signal being received at the DX?" My first reaction is wanting to know if that monitor function has a built-in time limit so a careless user can't leave a connection hanging open without realizing the impact that has.

  • All valid concerns for sure. I also have constant attacks on my firewall, but I'm running mail and other services so I'm more of a target. For months I've had continuous attacks from bot nets. Same vectors, different IP each time. Bastards.

    Anyway, @jks, is there a specific user-agent or similar header that those services use which could trigger different permissions/timeouts on the kiwis? I'm not very familiar with MixW other than a quick perusal of the website - looks neat.


  • I have a different antenna on each KiwiSDR here, so perhaps they wanted to see how reception varied between antennas? Assuming they had some rational purpose in doing this, which might not be a valid assumption 😀

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