Practical Ferrite Guide for HF

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

Tea

Cappuccino

Espresso
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


Typically
(NiZn) dark grey or black
Amidon
and Fair-rite
Eg.
materials 61 and 43

Typically (MnZn) shiny black
Amidon
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
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