The Tektronix CT4 is a passive high-current transformer that extends the measurement capabilities of compatible Tektronix oscilloscope current probes. This clip-on, split-core accessory accepts conductors up to 1.5 inches in diameter and enables measurement of currents far exceeding base probe limits. The CT4 operates with two selectable transformation ratios—20:1 and 1000:1—supporting pulsed currents to 20,000 A and continuous currents to 2,000 A peak-to-peak. Bandwidth ranges from 0.5 Hz to 20 MHz depending on the associated probe, making it suitable for low-frequency transient analysis through RF applications.
Technical Specifications
Bandwidth
• With TCP202, A6302, or A6312: 0.5 Hz to 20 MHz
• With A6302XL: 0.5 Hz to 17 MHz
• With P6021: 120 Hz to 20 MHz
Current Measurement
• Maximum pulsed current: 20,000 A
• Continuous current: 2,000 A peak-to-peak
• Transformation ratios: 20:1 and 1000:1
• Conductor diameter: Up to 1.5 inches
• CT4 amp-second product: 5 ampere-seconds
Voltage Measurement
• 3,000 V peak (1,000 V RMS CAT III) on bare conductors
• 14 kV with included high-voltage bushing
– Key Features
• Split-core, clip-on design eliminates conductor disconnection
• Insulated core and shield assemblies
• Dual transformation ratios for flexible measurement ranges
• Optional DC bucking coil (015-0190-00) nullifies steady-state DC saturation up to 300 A
– Typical Applications
The CT4 measures high-magnitude transient and steady-state currents in power distribution, motor control, switching power supplies, and industrial test environments where standard current probes lack sufficient range or bandwidth.
– Compatibility & Integration
Compatible with P6021, A6302, A6302XL, A6312, and TCP202 probes. Not compatible with P6022 or A6303. Maximum low-frequency performance (0.5 Hz) requires the AM 503S amplifier with TM 500 or TM 5000 Series mainframes; AM5030 requires TM 5000 Series mainframe.
