Topband: Strange 160m intruder

[John Kaufmann]

I have been observing an intruder whose behavior is unlike anything I have
seen before.  It consists of a comb spectrum of CW tones in the 160m band.
They pulse on and off at a regular interval.  There is never any form of
identification transmitted by it.

 

Thanks to my Elecraft P3 panadapter, I have determined that this intruder is
actually composed of two distinct sets of tones that are synchronized.  I
have posted a YouTube video of the P3 display here:
https://www.youtube.com/watch?v=-OaA1CBH_Xk.

 

In the video you can see the display is centered on one tone at 1822.9 kHz,
and it is synchronized with other tones spaced approximately, but not
exactly, every 50 kHz.  They all pulse on and off together.

 

The second set of tones pulses on when the first set pulses off, and vice
versa.  These tones are spaced about midway between the tones in the first
set.

 

>From my QTH in eastern MA, the direction of arrival is WSW and I can hear it
all night and all day.  The signals are very steady with no QSB, so it must
be something within groundwave distance of me.

 

A few months ago, I posted a report of a similar intruder on 1814 kHz.  I
never determined what that was, and nobody else could hear it.  That one has
disappeared but perhaps this new one is related to it, because the direction
of arrival is the same.  Also both are about the same strength and audible
24 hours a day.

 

Does anyone recognize what kind of intruder this might be?

 

73, John W1FV