Practical Ferrite Guide for HF

Core Category
1. Iron Powder Cores
2. Light Ferrite Cores
3. Strong Ferrite Cores



Permeability (μ)
μ = 3 - 20
μ = 100 - 1000
μ = 1000 - 10000
Loss in HF
Low loss
Medium loss
High loss
Photo examples

Typically colored
Amidon and Micrometals
Eg. materials 6 and 2

(NiZn) dark grey or black
and Fair-rite
materials 61 and 43

Typically (MnZn) shiny black
and Fair-rite
Eg. material 77
HF application

Tuned circuit
Low-pass filter
Inductor for tuner

Common mode (current) balun
Wide band RF transformer
Voltage balun

Interference filters for AC/DC power lines
in switched power supplies, inverters
and all kinds of IT lines

The important parameter is the permeability of a core to minimize RF losses in tuned
circuits, baluns, transformers
and to maximize the loss in interference filters. Refer to the manufacturer data sheet for the material permeability.

Iron powder cores Amidon | Micrometals
Ferrites Amidon | Fair-rite

2018-11-25 OH7SV
Back to OH7SV ham projects