I came across two ferrite toroids with the measurements of 35mm
diameter, the hole in the middle is 21mm and it is 13mm thick. On the
packet it says that the ferrite material is L15. Does anybody know if
L15 is equivalent to 43 or 61 ferrite material? I have searched the
net but have been unable to find any information. Any information
would be appreciated. Cheers.

wrote:
I came across two ferrite toroids with the measurements of 35mm
diameter, the hole in the middle is 21mm and it is 13mm thick. On the
packet it says that the ferrite material is L15. Does anybody know if
L15 is equivalent to 43 or 61 ferrite material? I have searched the
net but have been unable to find any information. Any information
would be appreciated. Cheers.


Where did they come from? Sounds like it may have been from a kit.


Charlie.

--
M0WYM
www.radiowymsey.org

wrote:
I came across two ferrite toroids with the measurements of 35mm
diameter, the hole in the middle is 21mm and it is 13mm thick. On the
packet it says that the ferrite material is L15. Does anybody know if
L15 is equivalent to 43 or 61 ferrite material? I have searched the
net but have been unable to find any information. Any information
would be appreciated. Cheers.


Here's how to check them:

http://www.w8pgw.org/node/303

Charlie.

--
M0WYM
www.radiowymsey.org

I haven't got an antenna analyser to do the above checks. The toroids
came in a box of stuff from a hamfest. They are in a packet which has
the brand name "Duratech" printed on it.

wrote:
I haven't got an antenna analyser to do the above checks. The toroids
came in a box of stuff from a hamfest. They are in a packet which has
the brand name "Duratech" printed on it.


If you have any means at all of mesuring
inductance, you can go he

http://en.wikipedia.org/wiki/Inductor
Inductor - Wikipedia, the free encyclopedia

Find the formula (#6) for the inductance
of a toroidal ring. Enter the
appropriate values and solve for u
(permeability of the core). Then look at
ferrites and iron power core properties
with the calculated permeability at the
test frequency. You'll probably find
several core materials that fit.

I think that's about all that can be done.

Chuck

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On Fri, 01 Jun 2007 11:03:30 -0700, wrote:

I haven't got an antenna analyser to do the above checks.

Do you have a SWR meter?

73's
Richard Clark, KB7QHC

i do would that help me with my mess of ferrites?

On Jun 1, 1:08 pm, Richard Clark wrote:
On Fri, 01 Jun 2007 11:03:30 -0700, wrote:
I haven't got an antenna analyser to do the above checks.

Do you have a SWR meter?

73's
Richard Clark, KB7QHC

wrote:
i do would that help me with my mess of ferrites?
...

1) Is your junk drawer supply good?

2) Got a freq counter?

If you answered yes to the above, build a simple 1 transistor
oscillator. Wrap a few turns on the toroid, and shunt it with a know
capacitance. Read the freq of the oscillator, using a chart available
on the web, note the capacitive reactance of the cap value in ohms.

Since capacitive reactance = inductive reactance in ohms at resonance,
it is now a simple matter to translate in the inductive reactance of the
torrid coil into uh/mh--using the osc freq and a chart from the web ...

Warmest regards,
JS


Since

On Sun, 03 Jun 2007 12:13:50 -0700, wrote:

i do would that help me with my mess of ferrites?

On Jun 1, 1:08 pm, Richard Clark wrote:
On Fri, 01 Jun 2007 11:03:30 -0700, wrote:
I haven't got an antenna analyser to do the above checks.

Do you have a SWR meter?

Hi Herbert,

Pass a wrap of wire around the material if it is a bar, or through it
if it is a toroid. Connect this to the output of the SWR meter. Hit
it with a short blip of power and note the SWR. You have the
multiple/divisor of 50 Ohms. Give it two wraps, or two passes and
repeat for more clues. Repeat at the frequencies of interest. Make a
chart.

Try to keep the power low and application short so you don't burn your
fingers.

73's
Richard Clark, KB7QHC

wrote in news:1180713268.474138.279890
@w5g2000hsg.googlegroups.com:

I came across two ferrite toroids with the measurements of 35mm
diameter, the hole in the middle is 21mm and it is 13mm thick. On the
packet it says that the ferrite material is L15. Does anybody know if
L15 is equivalent to 43 or 61 ferrite material? I have searched the
net but have been unable to find any information. Any information
would be appreciated. Cheers.


Search Jaycar's site for a LO1238. If that is what you have, you could ask
them for data.

Owen