3-10 Installation and Service Guide N5251-90001
System Installation
PNA, Controller, and Test Head Module Interconnections
PNA Series Microwave Network Analyzer System 
N5251A
Figure 3-1 2-Port Model Rear Panel Cabling
Cables shown in the graphic above are the same (5061-9038) except 
for the Test Set I/O cable (8120-6818).