1) For conducted emissions, should the EMI mode be always set to DC coupling? We noticed when set to AC there would be a high noise floor on the frequencies below 1 MHz.
2) For radiated emissions, Should we keep the EMI mode at AC coupling?
3) It's constantly asking us to keep the receiver aligned. Is this normal? It takes 5-10min to do the full alignment.
Hello, Zack!
For reference, this is the product in question:
http://www.keysight.com/en/pdx-x201870-pn-N9038A/mxe-emi-receiver-3-hz-to-44-ghz?nid=-32508.1150210&cc=US&lc=eng&pm=ov&state=0
On that product page, if you go to "Resource Center" and find tab "Application Notes", there is one titled "Making EMI Compliance Measurements - Application Note". Click on it, and it'll prompt you to fill in some information, then you can download it.
In the AppNote, it considers conducted emissions testing to be between 9 kHz and 30 MHz, and radiated emissions from 30 MHz to 1 GHz (or higher, like stated.)
Hope this helps!
Bertie