NF FRA5097, Instruction Manual

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3.5 Examples of basic operations
FRA5097 3-34
e) Connecting cable length and routing
The FRA5097 signal line and chassis are isolated. However, at high frequency, current can
easily flow between the cable outer conductor (shield) and ground due to stray capacitance. If
the connecting cable is long, oscillation can occur due to such properties as cable inductance and
isolation capacitance, disturbing frequency response and possibly preventing measurement.
In this type of case, such measures as shortening the cable or inserting a common mode choke in
the cable can provide improvement. For example, a clamp type ferrite core, such as used for
correcting noise, can be attached to the cable.
Cable routing and coupling between cables can change the impedance to ground and thus appear
like a variation in characteristics. In this type of case, minimizing cable junctions and securing
the cable location can improve measurement consistency.