Well, I wound 6 turns of #26 enamel magnet wire onto on of the surplus
toroids. It measures an whopping 714uH on my Almost All Digital Electronics
LC meter.

The toroid measures a bit less than 1 inch OD but definitely more than
0.94". I don't have a set of calipers here but it looks to be about 0.97"
based on the ruler I have. The ID is about 0.50 inches. The thickness is
about 0.34". These dimensions don't seem to be standard. By the way, here
is the listing for these toroids:

http://www.goldmine-elec-products.co...p?number=G6683

This inductance seems way too high - either I'm getting a false reading or
else this not a good material to make RF transformers / inductors with?

I'm mostly working with 2 to 30 Mhz so I am looking for some stuff for that
range.

thanks all,

Dave





"William E. Sabin" wrote in message
news:OR2Yg.1021387$084.658192@attbi_s22...
I keep a modest collection of many useful types of cores that I bought
from
Amidon, from their excellent complete Catalog. The initial expense was a
couple of hundred dollars about 15 years ago, but I know exactly what I
have, and I save a lot of time and trouble. When I run low on some type I
order replacements. I store them in plastic zipper bags with labels. For
home experimenting it is a very good way to go. I also have an ancient
Boonton Q meter and an ancient surplus HP Vector Impedance Meter.

Bill W0IYH

"dave" wrote in message
...
Hi all,

Is there an easy way to test surplus toroids as to what mix they might
be?
I have some here with no markings (plain black powder) and I would like
to
see what frequency ranges they would be useful at. I guess I would have
to
wind up a transformer and plot the frequency response?

Dave