I just took a street view look around Redmond and I wonder if an air conditioning unit might be responsible for the noise?
I notice you have lots of suppliers and one offers Daikan units which I assume is Daikin?
I was asked to sort out interference to VHF comms on a local ferry operating here on the Solent and it turned out to be from a Daikin air conditioner. To reduce costs they’d bought a standard commercial unit rather than one with a marine spec.
The thing used a chopper chip type STR-L472 which radiated VHF interference that was rock steady with one spike right on top of their ship-shore channel.
You have a lot of unsightly mains distribution cables around there and these may be radiating noise but if you can find a portable VHF radio and one of your interfering signals is stable enough you might be able to pinpoint its source?
That particular pcb had tracking for lots of mains filtering but half was strapped over probably to reduce costs.
“But lots of other chopper power supplies are available”
main@SDR-Radio.groups.io [mailto:main@SDR-Radio.groups.io] On Behalf Of George Stein - NJ3H via groups.io
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