[RFI] external noise source identification

[Jim Brown]

On 12/21/2018 2:19 PM, bill K7WXW wrote:
> 015 K7WXW RFI 122118-3 (5MHz sweep, centered at 4.05MHz)
>     - 130' doublet (main antenna, power off, fiber power on)
> 016 K7WXW RFI 122118-3 (5MHz sweep, centered at 4.05MHz)
>     - 130' doublet (main antenna, power off, fiber power off) 

If it's there all the time, I'd suspect  CATV or DSL backhaul 
transmissions. If it's switched on and off and the pattern changes 
occasionally (because the TV is reproducing different DTV formats), 
maybe a Plasma TV. There's a discussion of both in the "chasing RFI" app 
note I wrote several years ago.

http://k9yc.com/KillingReceiveNoise.pdf

This might be a good use for NK7Z's long slow waterfall pictures. See 
his website -- it's a real treasure trove!

73, Jim K9YC