---
product_id: 444008308
title: "FT-240-43 Ferrite Toroid Core – Mix 43 for RFI Suppression & HF Baluns (2.4\" OD, High Permeability) (PACK OF 1)"
brand: "amidon"
price: "A$91"
currency: AUD
in_stock: true
category: "Amidon"
url: https://www.desertcart.com.au/products/444008308-ft-240-43-ferrite-toroid-core-mix-43-for-rfi
store_origin: AU
region: Australia
---

# Supports up to 1 kW power handling 2.4" OD large core for multi-turn winding High permeability µi ≈ 850 for strong RFI suppression FT-240-43 Ferrite Toroid Core – Mix 43 for RFI Suppression & HF Baluns (2.4" OD, High Permeability) (PACK OF 1)

**Brand:** amidon
**Price:** A$91
**Availability:** ✅ In Stock

## Summary

> 🔧 Elevate your RF game with the FT-240-43 — where power meets precision!

## Quick Answers

- **What is this?** FT-240-43 Ferrite Toroid Core – Mix 43 for RFI Suppression & HF Baluns (2.4" OD, High Permeability) (PACK OF 1) by amidon
- **How much does it cost?** A$91 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.com.au](https://www.desertcart.com.au/products/444008308-ft-240-43-ferrite-toroid-core-mix-43-for-rfi)

## Best For

- amidon enthusiasts

## Why This Product

- Trusted amidon brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Multi-Use Marvel:** Ideal for 1:1, 4:1, 9:1 baluns, common-mode chokes, End Fed and OCF antennas, plus appliance RFI suppression.
- • **Thermally Stable:** Maintains consistent performance even under intense operating conditions—no signal dropouts here.
- • **Generous Core Size:** 2.4" outer diameter fits multiple turns of RG-8, RG-213, or speaker wire for versatile coil designs.
- • **Powerhouse Performance:** Handles up to 1 kW power, perfect for high-demand HF baluns and impedance transformers.
- • **Broadband RFI Shielding:** Mix 43 ferrite material expertly blocks interference from 20 MHz to 250 MHz, keeping your signals crystal clear.

## Overview

The FT-240-43 Ferrite Toroid Core by Amidon is a high-permeability, large-diameter ferrite core designed for effective RFI suppression and HF balun construction. Operating efficiently across 20 MHz to 250 MHz, it supports up to 1 kW power and offers excellent thermal stability, making it a trusted choice for RF engineers and hobbyists aiming to optimize antenna and EMI filter performance.

## Description

The FT-240-43 Ferrite Toroid Core is a high-performance solution for reducing radio frequency interference (RFI) and building efficient impedance transformers. Made with Mix 43 material, this toroid is ideal for applications in the 20 MHz to 250 MHz range, making it a favorite among ham radio operators, RF engineers, and electronics hobbyists. Its large 2.4-inch outer diameter and high initial permeability (µi ≈ 850) allow for multiple turns of coaxial cable or wire, enabling effective common-mode chokes and broadband EMI filters. Whether you're constructing HF baluns, suppressing appliance noise, or improving antenna performance, the FT-240-43 delivers consistent results with excellent thermal stability and power handling up to 1 kW. OD(A) = 2.40 in / 61.0 mm +/- 1.30 mm ID(B) = 1.40 in / 35.55 mm +/- 0.85 mm Ht(C) = 0.50 in / 12.7 mm +/- 0.50 mm AL=1075 +/- 20 % uH=(AL*Turns2)/1000 Temperature Stability (ppm /°C) = 12500 Color Code = shiny black Application Freq Range Wideband Transformers 5 - 400 MHz Power Transformers 0.5 - 30 MHz RFI Suppression 5 - 500 MHz

## Features

- Mix 43 Ferrite Material Manufactured by Fair-Rite Designed for RFI suppression from 20 MHz to 250 MHz—ideal for HF radio and EMI filtering
- Large Core Dimensions 2.4" OD × 1.4" ID × 0.5" height—perfect for winding multiple turns of RG-8, RG-213, or speaker wire.
- High Power Handling Supports up to 1 kW—suitable for high-power HF baluns and impedance transformers.
- Versatile Applications Use in 1:1, 4:1, or 9:1 baluns, common-mode chokes, End Fed and OCF antennas, and appliance RFI suppression.
- High Initial Permeability (µi ≈ 850) Enables strong attenuation of unwanted signals with minimal insertion loss. Thermal Stability Maintains performance under demanding operating conditions.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B07Y6NQRGF |
| Are batteries included? | No |
| Best Sellers Rank | #211,202 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #78 in Ferrite Cores #21,874 in Lab & Scientific Products |
| Brand | Amidon |
| Country of Origin | USA |
| Date First Available | 22 February 2020 |
| Item Weight | 118 g |
| Item part number | FT-240-43 |
| Manufacturer | Amidon |
| Net Quantity | 2.0 Count |
| Number of Memory Sticks | 1 |
| Package Dimensions | 10.21 x 6.6 x 1.7 cm; 118 g |

## Images

![FT-240-43 Ferrite Toroid Core – Mix 43 for RFI Suppression & HF Baluns (2.4" OD, High Permeability) (PACK OF 1) - Image 1](https://m.media-amazon.com/images/I/21eTMRmSE6L.jpg)
![FT-240-43 Ferrite Toroid Core – Mix 43 for RFI Suppression & HF Baluns (2.4" OD, High Permeability) (PACK OF 1) - Image 2](https://m.media-amazon.com/images/I/31kaTAxchqL.jpg)
![FT-240-43 Ferrite Toroid Core – Mix 43 for RFI Suppression & HF Baluns (2.4" OD, High Permeability) (PACK OF 1) - Image 3](https://m.media-amazon.com/images/I/31pD3iabY0L.jpg)
![FT-240-43 Ferrite Toroid Core – Mix 43 for RFI Suppression & HF Baluns (2.4" OD, High Permeability) (PACK OF 1) - Image 4](https://m.media-amazon.com/images/I/410uE+VY90L.jpg)
![FT-240-43 Ferrite Toroid Core – Mix 43 for RFI Suppression & HF Baluns (2.4" OD, High Permeability) (PACK OF 1) - Image 5](https://m.media-amazon.com/images/I/81AqQXEUpeL.jpg)

## Questions & Answers

**Q: Are the north and south poles, axially (top and bottom) or diametrically (side to side)?**
A: Your question indicates that you assume this product is a magnet.  This product is not a magnet.  It is a ferrite core used to construct impedance matching transformers by winding wires repeatedly through the center and tightly wrapped around the edges of core.

**Q: works for dash cam radio interference???**
A: You can use the clip on type for that as well. Get good ones, not unknown cheap chinese.

**Q: Would this help with noise on AM radio? Wrap the antenna wire around and through this?**
A: If the antenna wire is just that a wire then you will only decrease the signal and the noise.  Find the source of the noise.  LED lights, wall plug-in power sources, or other electrical appliances.  If you find the source then maybe using  snap on ferrite cores.  They see these on Amazon also.  I found a source for my AM noise was a power supply for a blue tooth adapter I had.  After unplugging this the noise went away.  If you shield the antenna as using coax and running an outside antenna wire to get away from the noise that might work also, but that depending where you live might not be possible.

**Q: what is the dimater of the inner hole?**
A: I don't have an ID micrometer handy but an eyeball guess with a desk ruler is about 1 3/8 inch. If you need something more precise or in metric, I can figure that tomorrow.

## Frequently Bought Together

- FT-240-43 FT240-43 Ferrite Toroid Core 43 Material
- BNTECHGO 16 AWG Magnet Wire - Enameled Copper Wire - Enameled Magnet Winding Wire - 4 oz - 0.0492" Diameter 1 Spool Coil Red Temperature Rating 155℃ Widely Used for Transformers Inductors
- FT-140-43 Ferrite Toroid Core | 43 Material

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*Product available on Desertcart Australia*
*Store origin: AU*
*Last updated: 2026-02-07*