Topband: a box of ferrites

[Richard (Rick) Karlquist]

On 5/31/2017 8:26 PM, Michael Walker wrote:
> Thanks All
> 
> Sean, I have at least 3 printed opies of W1HIS's pdf and I totally forgot
> that was in the back.  It was that article that made me a choke everything
> convert.
> 

Nice article, but if you want the quick version, use a method
suggested by W8JI.  Determine the frequency at which R = |+jX|
and look at the Fair-Rite products web site to cross reference
to the closest material.  The R = |+jx| frequency should
correspond to where the u' and u" curves intersect.  Usually
good enough.  If two materials meet the criterion, then
the tiebreaker would be to look up the nearest Fair-Rite
shape to the one you have in the two materials and see which
material has the corresponding inductance to what you are
reading on the meter.

Rick N6RK