The built-in EMI filter is used for specific 
measurement situations such as EMI average 
detection, where a higher level of sensitivity is 
required compared to the standard 
configuration. When turned on, the RBW is set 
to -6dB, indicated by an asterisk (*). 
When any measurement functions are turned 
on (see page 123 for details), the EMI filter is 
automatically disabled. Conversely if the EMI 
filter is turned on, any measurement functions 
are turned off.