Type 31 Material Split Core ID 25mm OD 56mm Length 43mm

Snap-On Ferrite Core (Mix 31) – HF Common-Mode Choke & DC Line Noise Suppressor

Product Overview

The Fair-Rite 0431177081 Snap-On Ferrite Core is a high-performance EMI/RFI suppression solution designed to eliminate unwanted noise in HF (1-30 MHz) radio setups and DC power lines in automotive and shack environments. Made from Fair-Rite’s Mix 31 ferrite material, this core effectively reduces common-mode interference and high-frequency noise, improving signal clarity and system stability.

This snap-on clamp design allows for quick and easy installation without needing to disconnect cables, making it a hassle-free solution for radio operators, automotive enthusiasts, and EMI-sensitive applications.

Key Features

✅ High-Performance Mix 31 Material – Optimized for noise suppression in the 1 MHz to 300 MHz range, ideal for HF, VHF, and low UHF interference reduction.
✅ Snap-On Design for Easy Installation – No need to cut cables; simply clamp it around existing wires.
✅ Versatile Usage – Works on coaxial cables, DC power lines, and audio/control cables in radio shacks, cars, and industrial setups.
✅ Compact & Durable Construction – Made from premium ferrite for long-lasting EMI suppression.
✅ Reusable & Adjustable – Can be repositioned or removed as needed without damaging cables.

Applications & Use Cases

1. HF Common-Mode Choke for Coaxial Cables

• Reduces unwanted RF interference and common-mode currents on HF antennas.
• Improves signal purity and reception in ham radio, SDR, and SWL setups.
• Ideal for baluns and feedline chokes in HF/VHF radio installations.
• Best used near the antenna feedpoint or at the transceiver end of coaxial cables.

Recommended Use: Snap onto coax cables (1-6 turns for stronger suppression).

2. Noise Suppressor for DC Power Lines (Automotive & Shack Applications)

• Eliminates alternator whine, ignition noise, and switching power supply interference in vehicle and radio power systems.
• Improves performance of mobile radios, inverters, and sensitive electronics.
• Effective on 12V/24V DC lines in cars, trucks, RVs, and amateur radio stations.

Recommended Use:
✔ Place as close to the radio or power input as possible for best results.
✔ Use multiple turns (6-15) if space allows for greater noise reduction.

Technical Specifications

• Material: Fair-Rite Mix 31
• Frequency Range: 1 MHz – 300 MHz
• Inner Diameter: 25.14mm
• Outer Diameter: 56.4mm
• Length: 42.95mm
• Impedance: 160Ω at 10 MHz, 370Ω at 100 MHz (approx.)
• Clamping Mechanism: Snap-On (Releasable)

Why Choose this core?

✔ Proven Performance – Trusted by amateur radio operators, automotive engineers, and EMI professionals.
✔ Multi-Purpose Suppression – Works for HF chokes, DC line filtering, and general EMI suppression.
✔ Quick Installation – No special tools required – just snap it onto the cable.
✔ Cost-Effective Solution – Reduces interference without expensive shielding or grounding modifications.