0R ferrite beads ... are they real ??

[softfoot]

I've been in electronics for some years but I was looking at a design that called for a 0R ferrite bead in a power supply line.

Zero ohm impeadance   You can buy them on eBay for example but are they an inductor at all ??

It strikes me that they are in essence a wire link rather like the 0R resistors you often find in a schematic to facilitate testing or controlling options.

Have I got the wrong end of the stick here

TIA,
Confused Dave

[Vovk_Z]

They have some resistanse of cause. It can be about 5-20 mOhm (+-) depends on wire size, look at datasheet (I'm talking abou wired ferrite beards). They have inductance too - it is about 0.5-1.0 uH (at 100 kHz).
And there is a type without wires - just small ferrite tubes.

[Unixon]

I guess something like a BL01/BL02/BL03 ferrite jumper (e.g. BL01RN1A1D2B) is implied.

[brabus]

They act as a short circuit in DC, but significantly increase their impedance in certain frequency bands, specified in the datasheet. Be careful though: they do not work as inductors, as they dissipate the energy rather than storing it.
This exact behavior is desired in order to dampen any disturbance in the target band.

[Siwastaja]

It's a completely meaningless specification.

The designer meant something, but wrote down something else. You can only ask the designer.

Ferrite beads are different and they should be specified with part numbers, or at least with the basic stack of parameters like impedance @ 100MHz, DC resistance, and maximum current. Saturation current would be necessary as well but as the manufacturers fail to provide that, designers can't specify it either.