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Today's v1.694 update is hopefully a working version of the failed v1.691,692 release of a few days ago.
See the first post of the "v1.694" thread below for the CHANGE_LOG notes.
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Not really interesting.

Its definitely CW but digital. Couldn't ID it on the wiki either.


  • Not sure about that one, it looks a bit like interference, but it's difficult to tell from your screen grab.

    Is it present 24/7 ?

    Can you remind me of your KiWi URL so that I can take a listen myself ?


    Martin - G8JNJ
  • I'd share it but that signal actually either blew my kiwi or my power supply. I'm working on testing the supply now. I left the system on that channel it poof it went.
  • OK, that's not good.

    However I'm sure it was just coincidence that it happened to be tuned to that frequency when it went faulty.

    Hope you fix it without too much difficulty.


    Martin - G8JNJ
  • yeah def coincidence but also can't find the multimeter when you need it too :) I'm going to hack off one of my precious raspberry pi power supplies to see for sure
  • Whew that was close its back up and the signal still there

    Also Id put it online in the repo but when you sign up it demands a call sign. I don't have my ham license so I don't have one so I can't register it.
  • Just heard it transmit again its definitely digital.. periodically changes it tones
  • As a non-ham you can make up a callsign for registration on
    See the instructions:
  • @Lonecrow

    There is a workaround for non amateurs described in the KiWi quick start guide

    "Registration on
    On the tab are the parameters for registration. To obtain an API key go to and fill-out the form. You will be emailed a key to be entered into the API key field.

    Currently the form requires a ham radio callsign to be entered. But a lot of Kiwi customers will of course not be hams. We suggest creating a "pseudo" callsign following the conventions used by the WSPR extension. Namely using a callsign of "SWL" (abbreviation for shortwave listener) followed by your grid square, either 4 or 6 characters. We've tried this and it seems to work and, like a callsign, is useful in that it gives an indication of where you are in the world"


    Martin G8JNJ
  • Ahh thanks my kiwi should be back up now. I was picking up some odd interference. I've noticed since I discovered the 12 v was too much for miniwhip the overload is gone. But since I switched to 5v at the lna I get periodic noise floor noise and the clear and then noise and then clear. Like when you touch the antenna wire and can impact the overall quality of the background. Its like the auto gain is going a little haywire?

    We just got our permit on our tower so I will be moving it to its permanent location soon and I'll register it that way with a permanent ip / hostname. Thanks for the info.

    back to the topic at hand.. signal still going strong - and I cant' locate it by TDOA
  • Yeh, I see the variation in signal levels, somethings not right with the antenna, the KiWi doesn't have any auto gain control.

    I heard the signal, but to be honest it sounds like local interference. I think sorting out the antenna problem is the first priority, then see if you can minimise the wideband interference. I suspect that your mystery signal may be an artifact associated with some of the other interfering signals I can see / hear on your KiWi.

    Unfortunately reducing unwanted interference tends to be a full time occupation in its own right, as soon as you get rid of one lot, you then hear a weaker set that was previously hidden :-(


    Martin - G8JNJ
  • fyi this is what I've been getting

    I know separate problems I may post in another forum about it.

  • Can you hear it on any other KiWi's that are near to you ?

    If you can't, it's likely to be local interference, especially on the higher frequency bands.


    Martin -G8JNJ
  • Yes can confirm someone about 100km away seeing it too
  • Hmm, that look like interference too.

    If you zoom out you can see lots of reguarly spaced signals that are almost certainly local interference.

    I'm not saying that it isn't genuine, but I'm still not convinced.

    The 15-25MHz region is generally fairly quiet and you don't hear many genuine signals unless propagation is good, especially wihen using a Mini.Whip type antenna, as they typically run out of steam on frequencies above anout 10MHz. This frequency range is also prone to Ethernet and other computer related interference, and the signals can sound modulated and come and go like genuine signals, depending upon what data is flowing at the time.

    When you hear modulation on this frequency your KiWi, does it exactly match the other KiWi ?


    Martin - G8JNJ
  • in PA sees it a few others as well but it gets weaker the further you go.

    My question would be how would you try to figure out what signal it is? What program would you use? You'd need to pipe the audio into virtual audio cable into a program and just try all the decoders?
  • @ Lonecrow

    Looking back over some past notes, I think it's likely to be noise from Ethernet data. I was reminded about this when I tried my KiWi around 18MHz and found some weak signals similar to what you are observing, as I'd previously manged to reduce these to a fairly low level.

    If you look at some of the screenshots that I'd attached to my post, they look a lot like what you are seeing and hearing.

    The exact frequencies at which some of these signals are strongest will depend upon your Ethernet cable lengths and any switch / hub you are using.

    Make up some simple 'sniffer' probes to use with your KiWi in order to locate local noise sources.

    Copied from Keith Armstrong's excellent EMC notes.


    Martin - G8JNJ
  • Ooops, I should also have added this YouTube link which shows you how to use them.

    Although this shows them being used with a printed circuit board, you can do the same thing with power supplies, cables, PC's etc.

    Just be aware that the KiWi takes time to process the signals, so there will be a delay of 1-2 seconds between you moving the probe and seeing a change occur on the waterfall or spectrum display.


    Martin - G8JNJ
  • edited August 2018
    Funny you should show that oscilloscope I've been looking at buying one on ebay (used) and start learning how to use them. Setting up your own probe sounds like a fun project. I think it could be related to ethernet because right now I'm keeping the actual unit in the same corner as the wifi, the router, the modem and basically a switch with all my ethernet coming in.

    But the fact that specific signal comes in on other kiwi's nearby and then gone the further I go makes me think it actually is a signal.

    If it is ethernet I could do some speed tests and confirm because the more traffic the more modulation I should see.
  • @Lonecrow

    The oscilloscope you see in the video is actually a spectrum analyser. It shows the amplitude (strength) of the signal with respect to time, like a much faster and much more expensive version of the KiWi spectrum display.

    It's just handy that the KiWi contains its own built in piece of test kit :-)


    Martin - G8JNJ
  • Built in? Meaning I could just hook the antenna to the probe and use the sdr to find the signal?
  • Yes that's the idea.

    When you run the probe near the offending item(s) you should see the same sort of pattern on the KiWi as you would observe if the same interference was present when you had your antenna connected.

    The signal levels may be different, but the frequency spacing between the 'comb' of unwanted signals should look roughly the same.

    Chances are you will find lots of possible interfering signals, but just concentrate on the strongest and the ones that best match first, you can sort the others out once you have initially cleared up the worst ones.


    Martin - G8JNJ
  • Found the problem with the popping on and off. The actual power supply was a switching power supply I used. Put a new one in and it seems to be constant.
  • Also still cannot pinpoint the location of this signal because there are not enough receivers nearby for the tdoa. It definitely is within 200km of me. I've look at neighboring kiwis and they see it. I've seen other people from around the world log in and take a look.
  • Been playing around with combinations of kiwis and tdoa and I managed to get a hit in the PA area but it didn't provide a heat map.°00'00.0"N+79°00'00.0"W/@41.69487,-78.6521691,8.5z/data=!4m5!3m4!1s0x0:0x0!8m2!3d42!4d-79

    Right on the border between NY an PA state.

    But narrowing it further ... its 18.6625Mhz and I've been searching the net for anything and not finding anything.

    I checked some of the websdr's as well to see if anyone else picks it up and nothing nearby that listens to that.
  • Closest thing I've found in the right range is this

    I've been through the entire sigidwiki and thats the best match. Its definitely PSK. If its a Russian "diplomatic" channel that would be quite interesting inside US soil.
  • Hello there! I am newbie here,can anyone tell me whats going here.

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  • @evawilson11

    It's a mixture of topics related to the KiWi WEB SDR.

    This thread is mainly related to trying to identify an mystery signal heard by Lonecrow that may, or may not, turn out to be local interference rather than a genuine signal.


    Martin - G8JNJ
  • Definitely not local interference :) Others picking it up the exact same but less strong and in some cases stronger nearby on other Kiwi units. The waveform best matches some Russian diplomatic channel.
  • I know you can build those probes but I'm having a hard time finding an assortment of them. I'm looking into getting a wireless scope for my lab. Know a good place to buy the commercial versions?
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