[RFI] EMI solution - ethernet cord

Aaron Kreider aaron at campusactivism.org
Tue Feb 5 18:51:23 EST 2013

I tracked down a source of EMI to an incoming ethernet cord.

It appears that the EMI came from the router (a terrible EMI producer) 
into my computer and then possibly via the USB cable into the QS1R.

I was getting very weak narrow band signals (around 10 db over noise), 
across the entire shortwave band, around every 60 khz.   I figured it 
was caused by a switched power supply -- however this is not true!  So 
if you see EMI - try unplugging your ethernet.

I fixed it with torroids.

My router also seems to have extremely different levels of EMI on each 
port.  Another port was 20-30 db worse.  It is a Medialink Wireless N 4 
port router.  It gets great reviews except from radio enthusiasts.

I still have some noise that looks like switched power supplies, but it 
is a lot weaker.


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