TDR Cable Tester (With FRA)

Cable Parameters & Fault Locator


  • Acquisition bandwidth: 1 GHz
  • FRA: Frequency Response Analyzer
  • Step signal rise time: less than 1 nS
  • Range : 50 cm to 1000 km (1.5 feet to 620 miles)
  • Accuracy: 1%
  • default loss measured at: 1 MHz, 2 MHz, 3 MHz, 6 MHz, 12 MHz, 24 MHz, 50 MHz
  • FRA and loss measurements for frequencies up to 50 MHz
  • Fully automatic
  • Intuitive graphical interface
  • Adjustable velocity correction factor
  • Measures length, impedance, capacitance, inductance, resistance, and loss
  • Finds shorts in the cable
  • Test all common cable types
  • Automatically finds the location of faults
  • Frequency accuracy: 50 ppm
  • Live cables option (contact the factory)
  • Integrated full featured oscilloscope and spectrum analyzer to analyze live cables
    • 1 GHz input bandwidth
    • 1 Channel
    • Internal Trigger Capability
  • Integrated full featured arbitrary generator for various cable excitation
    • 50 MHz output frequency
    • Arbitrary signals/ standard functions
    • 0 V to +3.5 V (7 Vpp) output range

ST985 Video Description

Product Description

ST985 is a unique TDR cable analyzer, with an integrated FRA, designed for various cables with lengths of 50 cm to more than 1000 km. It automatically tests for shorts, measures cable’s length, impedance, resistance, capacitance, inductance, as well as the transmission loss through the cable. The measurement results are then displayed both for the entire length of the cable, and also for the unit length; available in feet or meters. The TDR acquisition bandwidth is around 1 GHz, and the stimulating step signal rise time is less than 1 nS. This allows for the precise measurements of cable parameters. For velocity factors different from the default value of 0.67, the user can enter the proper value in a corresponding text box to compensate for any related errors. Once one end of the cable is connected to CH2, the measuring process takes place and is displayed on the screen, both numerically and graphically. All the measurements are done automatically by setting the time base of the TDR analyzer and the frequency of the applied step signal to make it appropriate for the length of the cable. To view the general behavior of the cable, the time-base of the unit can be changed to see a bigger span of the reflected wave. Clicking the auto button will make the process automatic again. After the length of the cable is determined, connecting the open end of the cable to CH1 allows for the automatic measurement of the capacitance, inductance, resistance, and signal loss through the-cable. CH1 input of the instrument is a full featured 1 GHz bandwidth oscilloscope and spectrum analyzer to analyze live cables. Similarly, the integrated generator can also be used as a full featured 50 MHz arbitrary signal generator for cable excitation. To examine some of the features of the product, install the demo application-software and review the comprehensive video tutorials.

Typical Application Plots

TDR Cable Tester and Analyzer, TDR Transmission Loss Measurement

TDR Transmission Loss Measurement

TDR Cable Analyzer ST985, Analyzing cable’s length, impedance, resistance, capacitance, inductance, & transmission loss

Analyzing cable’s length, impedance, resistance, capacitance, inductance, & transmission loss

Please visit the photo gallery to view additional application plots.

Analog Arts Inc. MA USA  info@