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My setup is the following:

  • terratec SDR dongle directly plugged into my laptop
  • the dongle shows up in gqrx as Realtek RTL2838UHIDH
  • coax cable out to the balcony, not laid in any loops
  • via an adapter, the "antenna" is plugged into the coax
  • The antenna is a ~2m length of copper cable, about 2mm², taped to a piece of wood, roughly upright

Here's what I see and hear in gqrx:

  • I can listen to shortwae radio (100 MHz), though quality is bad
  • When I look outside of the frequency range, I ocassionaly see signals that look like thin lines (not the wavey shape of the radio broadcasts), with the frequency set to this and decoding set to one of the cw settings, I hear a beep
  • I've not looked a CB bands, the lower limit of the terratec seems to be ~52MHz

I'm in Germany. I've looked at some ham radio / Amateurfunk bands, Flugfunk / Airtraffic (admittedly only in the evening) and skimmed through frequencies inbetween, with the idea that I should see something on the waterfall.

My suspicions why I don't receive anything are:

  • something about my antenna setup doesnt work (works poorly around 100 MHz and not at all at higher frequencies)
  • the terratec is just not good at all
  • My setup is okayish, just nobody uses radio at the times I listen
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    $\begingroup$ 100 MHz is not shortwave, but VHF (as German: nicht Kurzwelle, sondern UKW)! But that's just terminology, it doesn't really change your question :) $\endgroup$ Commented Jun 15, 2023 at 21:22
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    $\begingroup$ Broadcast stations as the ones you receive are typically very strong where people actually live. Is it possible that you have the RF receiver gain turned all the way down in GQRX, so that you can barely see these stations and are too insensitive to see weaker signals at all? $\endgroup$ Commented Jun 15, 2023 at 21:24
  • $\begingroup$ (also, yeah, your antenna isn't great; it's missing some kind of ground plane, and as far as you describe it, would be a low-efficiency quarter-wave monopole for 4·2m=8m , i.e. 37.5 MHz; how well it works at odd multiples, i.e. 3·37.5 MHz = 112.5 MHz, 5·37.5 MHz = 187.5 MHz and in between depends on very many "parasitic" factors that will be hard to quantify) $\endgroup$ Commented Jun 15, 2023 at 21:26
  • $\begingroup$ For receiver gain I use the hardware AGC, before I wouldnt even receive broadcast stations. What are bands outside of radio that are somewhat populated? My next step would be to connect the other pole of the antenna calbe to the balcony railing as a ground plane, and cut "antennas" for quarter wave for some reasonable bands. What are bands outside of radio that are somewhat populated? $\endgroup$
    – mart
    Commented Jun 16, 2023 at 6:58
  • $\begingroup$ I can update the question with my gqrx settings this evening $\endgroup$
    – mart
    Commented Jun 16, 2023 at 6:59

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