[Elecraft] OT: Digital Signals on 20M

[Joe Planisky]

I've been monitoring these signals for a few days now.  They seem to  
run for long periods without a break, although I have heard a few  
times when they stopped for a few seconds.

I've always seen them in pairs spaced about 15kHz apart.  I don't have  
the bandwidth to be able to tell if the pairs are related but I kind  
of suspect they are.  Each signal seems to consist of two groups of  
tones with the groups spaced about 1.5kHz apart.  Each group consists  
of 8 tones, each about 100Hz apart.  The tones alternate between the  
groups (i.e. one tone from group A, followed by one tone from group  
B).  Each tone seems to be on for about 10mS with a gap of about 34mS  
between tones.

They're never extremely strong here in southern Oregon,  maybe S5 or  
S7.  I've also heard them on 40m.

73
--
Joe KB8AP


On Mar 27, 2009, at 8:44 AM, Kenneth Moorman wrote:

> For the past several days I have been seeing a couple of powerful  
> digital
> signals, S9+, between 14.018 to 14.032MHz.  They seem to be  
> comprised of 4
> or 5 discrete frequencies rapidly moving around in a bandwidth of  
> about
> 2Khz.  When working with a narrow filter it is possible to work  
> through
> them, with difficulty.  With a wide filter, 2.8KHz set to the center  
> of
> their bandwidth it sounds like a group of castanets clicking away with
> slightly different tones.  I might have just discounted them but for  
> the
> fact that I have just recently gotten a "poor man's" panadapter  
> using a
> Rockmite and Z10000 amp from Clifton Labs with the Rocky software  
> monitoring
> my K3's IF output.  These two signals have been here every time I  
> get on 20M
> and are quite impressive in the amount of bandwidth they occupy.  I  
> have not
> seen this on any other band.  Forgive my ignorance of digital modes,  
> but I
> just don't recall hearing this sort of signal before.  Can anyone  
> let me
> know what this might be?
>
> Ken, NU4I
>
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