 This is particularly common at night when signals from adjacent frequencies travel long distances due to skywave  .
<meaning-changed>  This is particularly common at night when signals from adjacent frequencies travel long distances due to skywave  .
 This is particularly common at night when signals from adjacent frequencies travel long distances due to skywave . Modern SDR-based receivers can eliminate this by utilizing a brick-wall filter narrower than the channel spacing, that reduces signals outside the passband to inconsequential levels .