System Related Operation 4 
Utility Menu Summary
U3606A User’s and Service Guide 121
If the power- on or complete self- test fails, the Error annunciator 
illuminates, and an error is stored in the error queue. See “Reading error 
messages”  on page 114 “Self- test”  on page 149  for more information on 
resolving the error.
Selecting a dBm reference resistance value
The dBm function is logarithmic, and is based on a calculation of power 
delivered to a reference resistance, relative to 1 mW. The following 
procedure shows you how to select an appropriate dBm reference 
resistance value.
1 To access the utility menu, press Shift > Utility.
2 The first utility menu item (Error) will be shown in the upper 
secondary display.
3 Press   or   until the menu item “db.rEF” is shown in the upper 
secondary display. The factory default dBm reference resistance value is 
600  Ω .
4 Press   or   to change the dBm reference resistance value  
(0001  Ω to 9999 Ω). See “Editing values” on page 110 for more 
information.
5 After selecting an appropriate dBm reference resistance value, press 
Shift > Save to save or press Shift > Exit to exit the edit mode without 
saving.
6 Press  Shift > Exit to exit the utility menu.