alt Hacker NewsShortwave radio is more challenging than you might imagine.
Near to the transmitter it's received by ground wave, further it's scattered off the ionosphere. In-between it's undetectable due to the skip zone. This might also explain why Amelia Earhart went missing [1]
Coverage is obtained from multipath and reflections. Leading to variable strength and timing. Not as bad as DXing on HF with low power but much harder than you might imagine.
Fine for someone to transcribe some numbers but useless for people trying to identify sources.
So locally you get an apparent direction to the source which is clearly not the source.
Add to that the complex local terrain and a well placed number stations can be very difficult to locate with precision.
Edit: unrelated but interesting there are some mysteries in HF transmission including long delayed echoes where a signal takes far longer than reasonable to travel out and back over several seconds [0] which given its travelling light milliseconds is a conundrum.
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My father regailed tales of his college years where it was a game to have a HAM radio operator start broadcasting and to have teams try to find where they were hiding, first.
More challenging? Not really. It does require multiple boots on the ground to do it.
Thanks that was quite illuminating. I knew about ionospheric reflections to be a problem but not the others.
I would guess that the combined EU/NATO counterintelligence forces could find the station if they wanted to, especially for the rough location in the article.
EDIT: apparently the source is on a U.S. military base in Germany (other posts on this topic). Looks like its "ours" then.