beginner wrote:

Yes it is definitely a core T82-75 from the labeling on the package.
Which parameter specifies that it has low resistivity?
Can this be used as a transmission line transformer of a balanced mixer?

Which ferrite material works well for the AM band around 1 MHz?

I can get core #43, 61, and 63.

Thanks for the input folks.

Go to the makers catalog (available as a big PDF) at:
http://www.fair-rite.com/fr_catalog-14thed_rev3.pdf
and read about the various types (starting with the parametric
comparison on page 4, including the frequency recommendations under
the low flux density row). Type 43 is normally used in RFI absorbing
devices but has pretty good properties for indictors for low flux
applications up to 10 MHz. Type 60 is recommended for up to 100 MHz,
and type 63 isn't a Fair-Rite type listed in this catalog. In the
same table type 75 is limited to .75 MHz for low flux applications.
Based on this table, alone, I would probably try the type 43.

--
John Popelish

Which ferrite material works well for the AM band around 1 MHz?


Here's what seems like a hi-Q a crystal set using toroids:
http://www.crystalradio.net/contest/paul.html

It uses "two toroid cores, Palomar Engineering T-130, broadcast band
frequency material". Unfortunately it doesn't say the kind of core, but from
the number of turns and the capacitance I figured that it must be type 26
(yellow/white). I think this is a rather uncommon kind of material, it has
one of the highest mu's, 75, compared to mu=10 for type 2 and mu=8 for type
6. Anybody with experience with this kind of material?

Sverre
LA3ZA