[RFI] Power Over Ethernet from Switch Mode Power supplies

[Chuck Gooden]

I am currently experiencing RFI issues on 40 meters and below. Some, but 
not all, of these issues are due to the Power over ethernet (POE) 
switches that I am using.  I have two POE switches and 2 Wirelass Access 
Points (WAP).  The switches are powered by a 48 volt 1.3 amp switching 
power supply and can supply power to 4 of the 8 ports.  I currently only 
use the POW on the switch to power a network cloud key controller.  The 
WAP's also have a 48 V switching power supply connected to an ethernet 
power inserted. So in this configuration I am using 3 of the switching 
power supplys.

I am considering redoing my network wiring so I connect the two WAP's to 
one of the switches (#1) and power my second switch from one of the POE 
ports also on the switch.  This will involve running more ethernet CAT5 
cable but will get rid of 3 SMP power supplies.

I would like to replace the switching supply with a linear power supply 
with a 48 vdc 3 amp supply but the lowest cost one I see runs about 
$150.  I have found a cheaper switching supply for $16.40  see

https://www.digikey.com/product-detail/en/mean-well-usa-inc/RPS-60-48/1866-4074-ND/7706100&?gclid=CjwKCAjwsIbpBRBNEiwAZF8-z7KemHIR0-Y6iHlnUyYMFaKFOUEIM5mTTqovlNSTq89bJMvSkC7jfRoCRcAQAvD_BwE 


If you follow the link to the datasheet you will see the conductive and 
radiated emissions meets EN55011 class B, but that does not seem very 
acceptable from what I found on the ethernet as to the levels for a 
class B device.

Is there any steps that I can take with this power supply to reduce the 
radiated and conductive emissions if any?  Like mounting it in a metal 
EMI case, Torrids on both the input and output leads, more capacitance 
on the output, etc.

Chuck K9LC