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Author Topic: Odd Signal / QRM 43 meters 0858z  (Read 1326 times)

Offline ChrisSmolinski

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Odd Signal / QRM 43 meters 0858z
« on: September 11, 2012, 1233 UTC »
This is something I have noticed for many months, since I started recording overnight on the SDR. I think the waterfall shows it best:



Time runs down, ie: it starts at the top of the image, at about 0858z, and stops about 2/3 of the way down, at 0905z.

This signal appears roughly around this time (0900z is presently 5 AM local time), I'll need to more carefully observe when I notice it, to see if it is really following any kind of a schedule.  It sure looks like a switch mode PSU of some kind. It's only on for a few minutes, and I don't seem to notice it at other times of the day. Any ideas?
Chris Smolinski
Westminster, MD
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cmradio

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Re: Odd Signal / QRM 43 meters 0858z
« Reply #1 on: September 12, 2012, 0506 UTC »
Very clean lines. Harmonics are too perfect for a SMPS, which would be stronger of the odd harmonics (square wave).

Vat ees dat? ???

Peace!

Offline ChrisSmolinski

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Re: Odd Signal / QRM 43 meters 0858z
« Reply #2 on: September 12, 2012, 1042 UTC »
It appeared again this morning, from 0842z to 0852z. The pattern looks almost the same, the difference is that since it was on for a longer time, the drift in the frequencies near the end is less (the lines are closer to vertical, but still slanting/drifting some)
Chris Smolinski
Westminster, MD
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Offline refmo

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Re: Odd Signal / QRM 43 meters 0858z
« Reply #3 on: September 12, 2012, 2200 UTC »
Coffee maker would be my guess.....
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