[Elecraft] HF noise.....10 M

[Fred Townsend]

If memory serves me right there is a ICM band between 10 and 11 meters that would be a logical place for an welder.  Assuming they are using a power oscillator the signal could be quite broad band and unstable just like a microwave oven. It also sounds like a foreign design. I think a call to the FCC is in order.

Fred, AE6QL


-----Original Message-----
>From: Dan Maase AC6DM via Elecraft <elecraft at mailman.qth.net>
>Sent: Oct 14, 2014 8:06 PM
>To: elecraft at mailman.qth.net
>Subject: Re: [Elecraft] HF noise.....10 M
>
>These "weeblies" are all over the 10 meter band  here in northern Calif
>Monday through Saturday; gone on Sunday.   Best I can find is that they are
>radiated emissions from HF ultrasonic welders (used to seal plastic
>packaging, emboss car mats, etc.)  They sound like they are a high power
>oscillator which changes frequency during the welding operation; starting
>high and decreasing in frequency as the weld is accomplished.  Such welders
>are not supposed to operate in the ten meter band in the US, so I suspect
>they are "rogue", operating international.
>Dan
>AC6DM
>
>
>Anyone have any idea what those "weeblies" are on ten meters?   They 
>typically start high in frequency and flitter past the receiver then stop 
>abruptly.  They sound like a very unstable oscillator,
>
>
>
>--
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