61mm Ferrite Toroid Core 2pcs, 2.4"x1.4"x0.5" Toroidal Ring for Ham Radio Balun Unun, Common Mode Choke EMI RFI Noise Filter, HF Antenna Solar Inverter

Ferrite Toroid Core OD= 2.40 in / 61.0 mm ID= 1.40 in / 35mm Ht = 0.50 in / 12.7 mm AL=6800±25﹪nH/N2（TESTING METHOD：f=1KHz,U=0.3V,25±3℃,N=20Ts） The magnetic ring can play a very good anti-interference effect, it can prevent the display signal from intruding into the equipment and other problems. Suitable for all kinds of electronic equipment and wire/ power cord/platoon line/data line/signal line/USB line/AC line/DC line/audio line/ cable/ connection line/digital camera line and more.

• 【Precision 61mm Ferrite Toroid Core — 2pcs per Pack】 OD 2.40"(61mm) × ID 1.40"(35mm) × H 0.50"(12.7mm). Uncoated ferrite core, ±0.5mm dimensional tolerance. AL ≈ 6800nH/N² ±25% (tested at 1kHz, 0.3V, 20Ts). Smooth edges, no burrs, ready for winding.
• 【Tested for 9:1 Unun & Common Mode Chokes at HF】 | Works in verified builds: a 9:1 unun for a 29ft random wire antenna, and coax-wound chokes for reducing RF noise on HF bands (40m/20m/10m). One user reported clean 450Ω-to-40Ω impedance matching at feed point using a NanoVNA.
• 【Effectively Suppresses EMI/RFI in Multiple Setups】 | Field-tested by users for: filtering RF noise from solar panel inverters, reducing electromagnetic interference on AC power lines, and cleaning up signal interference on USB, coax, and network cables. Multiple builds confirmed working without modification.
• 【Securely Packed & Dimensional Checked】 | Each pair is individually packed to prevent chipping during transit. All cores are pre-checked for dimensions and magnetic permeability before shipping. If a core shows unusual induction values upon arrival, contact us for replacement.
• 【Simple to Use — Wire and Wind】 | Works with standard coax (RG58/RG8X), magnet wire, and common HF transceivers. No modification needed for basic unun or choke builds. PTFE tape not included; core fits standard coax winding patterns.