yo3gnd

@yo3gnd@lemmy.radio

• ⁨Comment⁩ on ⁨How do WSPR signals avoid frequency collisions?⁩ ⁨⁨2⁩ ⁨weeks⁩ ago⁩:

  They don’t.

  You randomly position yourself somewhere in the tiny sliver of a sub-band, and TX. An important bit of WSPR operation is to only transmit in 10-20% of the windows, not all of them. I guess it is a form of poor man’s TDMA.

  Another trick, also used by FT8 SWL mode: you decode a batch of signals, you regenerate their audio and subtract that from your RXed audio. This is called a pass. Repeat for a few passes, decode after each.

  Hidden signals discovered like this are not perfect and rely heavily on FEC, especially if something else masks them, but hey do show up.