Topband: Unknown Pulse Signal Wiping out 1900-1925 kHz

Michael Clarson wv2zow at
Tue Dec 9 10:35:17 EST 2014

All: Turned on my radio to listen to the ARRL 160, and saw "it". First
thought was "what piece of crap in my house is doing THAT".  But as we now
know, its something big. Since CODAR was suggested, I compared it to CODAR
around 4.8 MHz. Similar, but not the same. BW is similar, but the CODAR I
saw sweeps high to low about once every 1.5 seconds where this sweeps low
to high about 3 times per second. CODAR looks to be one carrier (with some
pulse-ish modulation) while this one looks to be two carriers, one delayed
by a short time interval (maybe 100 ms.) and starting at a slightly (aprox.
200 Hz) higher frequency. Carriers modulated with a fast rise time
waveform, giving us the raspy sound. Hope this info helps us figure out
what this is. 73, Mike, WV2ZOW

On Tue, Dec 9, 2014 at 9:55 AM, Roger D Johnson <n1rj at> wrote:

> Here is a YouTube video of a CODAR signal. Doesn't sound like what I'm
> hearing
> at all!
> 73, Roger
> _________________
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