[RFI] 30 M Shuts Down Internet Cable Modem

[Dan Butler]

I live on the 15th floor of a 17 story apartment so "proper" grounding is not possible. I use an end fed multiband dipole which theoretically does not require RF grounding. However, I do have a multiple wire counterpoise hooked to the tuner. I recently converted from a 20/40 end fed dipole to the 6-80 end fed dipole, so have just started using the other bands. Now when I TX on 30 M (and occasionally 17 M) the internet cable modem which is in an adjacent room about 20 feet away, cuts off - all the lights go out, then it starts once the TX is finished. I placed a steel bowl over it and wrapped it in foil but it still cuts off. I disconnected the router cable and the cable input and it still cuts off. I presume I have some sort of power supply issue but not sure how to address that. 

Thanks in advance for any useful suggestions.

73, Dan 9V1DB