Powdered Ferrite???

Where in the U.S. can i purchase powdered ferrite in
order to make very large ferrite rod antennas?

 

Are you talking about production quantities or just a few?
How many thousand pounds a month?
The stuff isn't very hard to make from the raw oxides with a kiln.

 

What i want to do is fill the inside of various lengths of pvc pipe with
a mixture of powdered ferrite & epoxy glue. The company "Stormwise"
sells the above already made but the items are expensive. John Popelish"

 

I don't know offhand if you can even buy it retail due to
the health issues involved in working with certain ferrites.

Do you care about its specific B/H properties? Why not
just salvage a shitload of ferrite cores from say "dead" AM
radios and grind them up yourself? A small ball mill is
about as hard to put together as a small cement mixer. In
fact, you can use a cement mixer and a bunch of ball
bearings (you do have to bust up the cores a bit first).

Mark L. Fergerson

 

John, any pointers or links on how to do this? (I have
a small kiln.) Is there some ceramic binder involved,
or is the oxide sintered directly? I assume this requires
a black magnetic iron oxide, not the red stuff?

Just curious, no immediate needs.

Thanks!


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com

 

Fine. So what is the answer?

 

I would have to dig into my records for the exact recipe, but I
remember making nickel zinc ferrite by ball milling red iron oxide,
green nickel oxide and white zinc oxide, together, and firing the
powder in a pottery kiln in ceramic crucibles. The sintered powder
was black and a lot coarser than the starting powder and had measured
magnetic properties very similar to commercial nickel zinc ferrite.
After a second ball milling and screening I used it in an epoxy matrix
as a non contact temperature sensor (utilizing the curie temperature
of the material and an inductive pickup).

I still have some of it.

 

Is there really a need for epoxy glue here?
Shouldn't it work just as well if those pvc pipes are packed full with a
powder of ferrite material?

 

How about buying a bunch of large pot cores of the material you want and
stack them together.
Mike

 

I thought of that, but he seems bent on grinding them up, or rolling his own.

BTW, TV deflection yokes have large chunks of Ferrite. If your operating at
low enough frequencies.