B. Operator Performance Checks
Table B.2. Required Performance Check Equipment for CT100HF and CT100B with SMA
Option
Item MOHR part number
Precision 50 Ω terminator CT100-AC-ER50-S
Connector, SMA male to BNC female CT100-AC-ISMBF
Shorting cap CT100-AC-ISS
50 Ω 36 in. reference cable CT100-AC-W536-S
Additionally, a device capable of taking accurate pulse measurements with documented calibration
will be required, and, if working with a CT100B [BNC], an open terminator will be needed. Coaxial
adapters with low TDR reflections (< 5 Ω) are required in any cases where adapters are used.
B.3. Getting Ready
Go to MENU → Settings → Display and make sure Standard Menu is toggled on. This ensures
Cable Length can be accessed in the Main menu.
Disconnect any cables from the front BNC or SMA connector. Connect the instrument to the
external 24 V power supply connected to a standard 3-prong AC source.
Allow the unit to warm up until it displays a steady temperature.
B.4. Operator Performance Checks
B.4.1 Jitter, Noise, Rise Time, and Sampling Efficiency Checks
1. Connect a 50 ohm terminator to the CT100B front panel cable connector.
2. Select the MENU → Settings → Diagnostics menu item to enter the Diagnostics submenu.
3. Select Jitter. After a moment, a results window appears with a list of measurements.
The value for Jitter used in the specification for a CT100B is Jitter P2P. The value for Noise is
Noise P2P.
The value for the 20-80% and 10-90% Reflected Rise Times are both displayed as 20-80 Rise and
10-90 Rise, respectively.
B.4.2 Output Impedance Check
1. Disconnect any cables from the CT100B front panel cable connector.
2. Position a cursor before the falling edge of the trace (or before the second rise on an SMA
connector).
3. Position the second cursor well to the right of the falling edge (or second rise on an SMA
connector).
4. Attach the 50 ohm terminator to the CT100B.
5. The difference in ohms between the two cursors is a measure of the deviation of output
impedance from 50 ohms.
116 CT100B TDR Cable Analyzers Operator’s Manual
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