ISDN termination resistor ShiverPeaks BS74231-4SW — 2 × 8/8 ohm, 4 parallel

The ShiverPeaks ISDN termination resistor BS74231-4SW is designed for line termination in ISDN installations to ensure proper impedance matching and minimise signal reflections. Configured as two sets of 8/8 ohm resistances with four parallel elements, this passive component provides a stable termination option for telecom lines and interfaces where precise loading is required. The unit is compact, easy to install and intended for use in telecom equipment, PBX interfaces and ISDN line maintenance tasks.

Advantages

The termination resistor offers a stable, passive impedance match that helps maintain signal integrity on ISDN lines and reduces echo and reflections. Its two-set configuration with multiple parallel elements allows consistent loading across line pairs and supports straightforward installation and replacement in rack or field systems. The compact design minimises space requirements and simplifies integration with existing telecom hardware.

Suitable for

• ISDN line termination and testing
• PBX interface wiring and maintenance
• Telecom equipment repair and bench testing
• Field technicians performing line diagnostics

Key specifications

• Configuration: two sets of resistive elements, each set 8/8 ohm arrangement
• Parallel elements: four parallel resistive branches for each set
• Type: passive resistive termination for digital telephone lines
• Intended application: ISDN line impedance matching
• Form factor: compact module suitable for inline or panel mounting

How to use

Install the termination resistor at the end of the ISDN line or at the designated test point in accordance with the telecom wiring layout. Ensure proper isolation of the line before connecting the resistor and verify polarity and pair alignment where applicable. Secure the unit mechanically and make electrical connections using appropriate connectors or solder points to maintain low contact resistance. After installation, perform line tests to confirm correct impedance and stable signal transmission.

Recommendations

Use the resistor only for ISDN and compatible digital line terminations; avoid applying voltages or signals outside standard telecom ranges. Verify line conditions and environmental ratings before prolonged field deployment, and replace the unit if physical damage or corrosion is present. For critical systems, validate performance with a line analyzer to confirm proper termination.