Topband: Speaking of Noises...

[Jim - WS6X]

I too, am curious as to the source. I heard it for many years in Central California; hear it at my current QTH in Central Shenandoah Valley; and heard it last weekend at NR4M.
I describe it as a scratchy sound, sometimes with a bit of tonality. Always 4 pulses (although I don't think I've ever heard the 4 followed by 3 as Bill describes.). I've never timed the interval between the groups of 4, but it is fairly infrequent. I'll hear it throughout the evening when I'm at the radio for long periods. It is loud enough on 160 here in VA that it will wipe out all but the strongest signals. I will have to pay more attention to details and record when I hear it.
I wish I was better at phonics, but what I hear has distinct articulation:
"Gugghk  gugghk gugghk gugghk". 😊
Jim, WS6X

1. Speaking of noises... (Bill Tippett)
Message: 1
Date: Wed, 21 Feb 2018 12:48:20 -0500
From: Bill Tippett <btippett at alum.mit.edu>
To: topband <topband at contesting.com>
Subject: Topband: Speaking of noises...

Does anyone know the source of periodic wideband buzzes that sound like
this:

buzzz..buzzz..buzzz..buzzz (i.e. 4X then pause)  buz..buz..buz (3X ~10 dB down).

I believe this may be some sort of ionospheric sounder but I've heard this for decades, including when I was in Colorado.  Hopefully someone knows what's generating this.

73,  Bill  W4ZV