Feasibility study – loop in ground for rx only on low HF – small broadband RF transformer using medium µ ferrite core for receiving use – 50:200Ω

A simplified design for small broadband RF transformers using medium µ ferrite core for receiving use. The specific application is an impedance transformer for a nominally 200Ω antenna to a 50Ω receiver input. Intended frequency range is from 0.5 to 15MHz. The characteristic of typical medium µ ferrite mixes, particularly NiZn, are well suited to … Continue reading Feasibility study – loop in ground for rx only on low HF – small broadband RF transformer using medium µ ferrite core for receiving use – 50:200Ω

Online calculator of ferrite material permeability interpolations

Many of my articles call for finding the complex permeability of a ferrite components from manufacturer’s data. Let’s explore an example used in a recent article, Another small broadband RF transformer using medium µ ferrite core for receiving use – 50:450Ω. The core used was a Fair-rite ferrite core of #43 material, and the magnetising … Continue reading Online calculator of ferrite material permeability interpolations

Another small broadband RF transformer using medium µ ferrite core for receiving use – 50:450Ω

A simplified design for small broadband RF transformers using medium µ ferrite core for receiving use. The specific application is an impedance transformer for a nominally 450Ω antenna to a 50Ω receiver input. Intended frequency range is from 0.5 to 15MHz. The characteristic of typical medium µ ferrite mixes, particularly NiZn, are well suited to … Continue reading Another small broadband RF transformer using medium µ ferrite core for receiving use – 50:450Ω

Another small broadband RF transformer using medium µ ferrite core for receiving use – 50:3200Ω

A simplified design for small broadband RF transformers using medium µ ferrite core for receiving use. The specific application is an input transformer to a nominally 2kΩ receiver at around 9MHz (a panadapter). The characteristic of typical medium µ ferrite mixes, particularly NiZn, are well suited to this application. This article continues with the design … Continue reading Another small broadband RF transformer using medium µ ferrite core for receiving use – 50:3200Ω

ARRL guidance on design of ferrite cored inductors

The ARRL handbook for radio communications (Ward 2011) gives guidance on designing with ferrite cored inductors: Ferrite cores are often unpainted, unlike powdered-iron toroids. Ferrite toroids and rods often have sharp edges, while powdered-iron toroids usually have rounded edges. Because of their higher permeabilities, the formulas for calculating inductance and turns require slight modification. Manufacturers … Continue reading ARRL guidance on design of ferrite cored inductors

Thoughts on binocular ferrite core inductors at radio frequencies

Binocular ferrite cores are widely used, but not so widely understood. Understanding inductors is an important first step to understanding transformers are they are coupled inductors. The usual use of them is to make a winding of several turns around the central limb. One turn is a pass through both sides of the core around … Continue reading Thoughts on binocular ferrite core inductors at radio frequencies

A prototype small 4:1 broadband RF transformer using medium µ ferrite core for receiving use

Discussion at A method for design of small broadband RF transformers using medium µ ferrite core for receiving use was around a 9:1 transformer on a BN43-2402 core. In that design, 4t was proposed as a suitable winding for a nominal 50Ω primary. This article describes a 4:1 transformer needed for a project and based … Continue reading A prototype small 4:1 broadband RF transformer using medium µ ferrite core for receiving use

A method for design of small broadband RF transformers using medium µ ferrite core for receiving use

A simplified design for small broadband RF transformers using medium µ ferrite core for receiving use. The characteristic of typical medium µ ferrite mixes, particularly NiZn, are well suited to this application. This article continues with the design discussed at BN43-2402 balun example, but using a 4t primary and 12t secondary for a nominal 1:9 … Continue reading A method for design of small broadband RF transformers using medium µ ferrite core for receiving use