Arris Cable Modem Sings Like a Wagnerian Soprano

Bill Alpert

In my never ending quest to remove RFI noise sources from my shack, I discovered (while snooping with an AM broadcast radio) that my cable modem is creating a loud high pitch whine audible in on the AM band. It's quite loud with the radio 18 inches away from the source. All my radio gear is also close by.

This is a Charter (Spectrum) supplied modem, (they told me it was an improvement over the previous Motorola modem) and I'm wondering if I invest in my own unit, could it help things. Can you recommend a better (quieter) cable modem?

Another idea is to wrap it in faraday foil. Could that help? I already have wound its power cord through a torroid.

73 de Bill / KG6NRV


Hi Bill

When I had my last shack I had a similar problem with a set top box in the house radiating  garbage......also a problem with a router. I ended up grounding both of them to the station ground and it reduced interference quite a bit.  I might try this as a  first shot. Hope this helps.

Regards & 73