Instruction manual
Chapter 3 Replacing Assemblies
To Remove A3 1.5/3.0/5.0/12.4 GHz Channel Assembly (Option 
015/030/050/124)
Assembly-Level Service Guide 3-13
3
To Remove A3 1.5/3.0/5.0/12.4 GHz Channel 
Assembly (Option 015/030/050/124)
NOTE The 1.5 GHz Channel 2 Assembly is available only for the Agilent 53181A 
Frequency Counter.
1 Remove the cover.
See the section titled “To Remove the Cover” in this chapter.
2 Using the 14-mm deep-socket spin tight, remove the BNC nut (H3) from the 
optional Channel 3 (or Channel 2 for Agilent 53181A) input connector (Options 
015/030 only). For Option 050 or 124 remove the knurled nut using a pair of 
pliers.
3 Pull W1, which is the optional channel assembly cable, out of the Channel 3 (or 
2) opening in the front panel assembly as shown in Figure 3-8. For the Option 
050 or 124, the connector is part of the Option assembly.
CAUTION When reassembling A3 (Option 015/030) Assembly, ensure that cable W1 is not 
placed or folded on top of the input circuits of A1 Motherboard Assembly or is tucked 
behind A3 as the Counter may start reading or measuring noise.










