You can't make this stuff up

jksjks
in Signals Received

As many of you know, I (ironically) live inside a Faraday cage. Half way up a 10 story apartment building. Very, very little reception from my active antennas. I haven't even had them setup in several years. That's why I'm always asking for your help when I need to do testing with on-air signals.

Anyway, I'm up early, like I am every morning, and sit down to start the days debugging. Then I see this in the log from the Kiwi I left running overnight:

Sun Apr 16 19:30:45 00:13:36.158 0123  3 PSKReporter spot FT8 18102.903  ZL1IM RF82 -9  72km Sun Apr 16 19:30:30 2023
Sun Apr 16 19:32:13 00:15:04.336 0123    PSKReporter upload 1 spots (and info desc) to udp://74.116.41.13:4739
Sun Apr 16 19:36:15 00:19:06.154 0123 2  PSKReporter spot FT8 14075.184  OM7JG JN98 -13 17819km Sun Apr 16 19:36:00 2023
Sun Apr 16 19:37:08 00:19:59.115 0123    PSKReporter upload 1 spots (and info desc) to udp://74.116.41.13:4739
Sun Apr 16 19:46:30 00:29:21.107 0123 2  PSKReporter spot FT8 14074.991  R3RZ LO12 -15 16073km Sun Apr 16 19:46:15 2023
Sun Apr 16 19:47:13 00:30:03.838 0123    PSKReporter upload 1 spots (and info desc) to udp://74.116.41.13:4739

WTH? 17819 km? There are no antennas connected to any of my Kiwis. I go look. Oh yes, that one still has a one meter coax connected from the green antenna input block to the signal generator. Only it's not currently plugged into the gen and the grounding clip has fallen off the Kiwi end. So I essentially have a one meter wire probe on the antenna input. I bring up the FT8 extension and, sure enough, amid the S7 switching power supply noise there's a CQ DX from Japan on 17 meters. It's grey line propagation hours. And that, plus the line-of-sight I have to the horizon (over the ocean) in that direction probably explains everything..


FT8.unexpected_reception.2.png


FT8.unexpected_reception.1.png


Comments

  • n6gnn6gn

    We do indeed have pretty impressive grayline/chordal reports. If you had spectral spreadingvalues for some of those I'd not be surprised to see some exceptionally low values as well.

    Amazing indeed !

    Glenn n6gn

  • G8JNJG8JNJ

    It just goes to show how effective the digital modes such as WSPR & FT8 can be, especially on the HF bands.

    I have still received spots from others when running a transmitter into a fully screened test load via double screened coax, as there was still enough radiation from the transceiver (and signal ingress) to be able to hear stations and be spotted.

    It also demonstrates how easy it is for unwanted noise from items within the property to enter the receive chain.

    Regards,

    Martin

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