FT8 Comb Filtering?

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  • Question
  • Updated 2 months ago
  • (Edited)
Recently I've been seeing what looks like some sort of comb filtering in the FT8 waterfall. Has anyone seen this? What do you think is going on?

Here's a screen shot:

Photo of Geoff - AB6BT

Geoff - AB6BT

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Posted 2 months ago

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Photo of Jim  KJ7S

Jim KJ7S

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reminds me of solar inverter noise, does it by chance go away after dark?
Photo of Geoff - AB6BT

Geoff - AB6BT

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Similar just after sunset:
Photo of Geoff - AB6BT

Geoff - AB6BT

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And now it looks like this:

(Edited)
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Rob N4GA

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That's cool. Following...
Photo of Dave Gipson

Dave Gipson

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I screenshot this today. it occurs across the bands, some to a lesser extent.
 The top two passes are with Audio BW of 1.kK, next two down are 2.0K, next two are 3.0k and the bottom ones are at 6.0k. 

I'm thinking it may be a local interference but... it seems to be relates to the filters, each one of them.

Any ideas?