Ghost FT8 signals lower in frequency, but CW decodes fine

[Yuri]

Hi Yuri! 

Could you help me configure the setup between HDSDR and the SDC waterfall? I keep seeing ghosting/mirroring of FT8/FT4 signals lower down the frequency. I am using VB-Audio Virtual Cable. Interestingly, CW decoding works perfectly fine.

  Everything is set to 192000 Hz / 24-bit everywhere, and this issue does not appear on the HDSDR waterfall itself. 

73! Yuri EB5A 

[UT4LW Yuri Pavlov]

Hi

If you see mirrored stripes on the skimmer's waterfall, it means that the stream entering the skimmer is not an IQ stream. Alternatively, the audio devices transmitting it may have corrupted the stream.

Check the audio device settings in your operating system: there should be two settings for each cable (input and output) with a resolution of at least 192 kHz × 24-bit.

четверг, 23 июля 2026 г. в 17:21:45 UTC+3, ea5...@gmail.com:

[Yuri]

What frequencies should I set for LO and Tune in HDSDR? I’ve double-checked my sound card settings and set everything to 192kHz/24-bit.

  The mirroring effect is especially clear here.  

[Yuri]

Hi,

  

Everything works great after installing VAC. Set the output to 192kHz/32bit. What settings are actually enough to see a 100kHz range without overloading the CPU?  

73! Yuri EB5A