[Lowfer] Question about surplus toroids

[Mike WE0H]

The Yellow/White cores are -26 iron cores. Shiny black cores are mostly 
-43 ferrites. Go by color and you will figure out most of them that way. 
Some are going to be odd ducks and you end up using a single turn of 
wire and measuring the inductance for a guestimation. The nice 
Blue/Green cores found in most server power supplies work well at 600 
meters. I don't recall the spec, but I think it was -52 material. Use 
Mini Ring Core Calculator to see the colors verses what material there 
is out there. I save every ferrite and iron dust core I run across.

Mike
WE0H


Andy Bell wrote:
> I do a lot of computer repair and rebuilding, so I
> have quite a few old Mobo's and dead pwr supply's. My
> question is this: Are the toroids on the Mobo's and in
> the pwr supply's useful in any way, such as for
> winding a coil for a LOWfer xmtr ?? Also; how do you
> determine the type of an unknown toroid ? I assume by
> its dimensions rather than color ?? I've never fooled
> around with winding on toroids so any info and
> experiences will be appreciated. Thanks and 73.
> Andy - KU4XR