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KE7AQL
07-15-2008, 01:31 AM
I need to wind some toroids for a project that I'm working on and have a few cores laying around.
Is there any way to identify what the ferrite mix is (ie. 43, 63, etc)?

KB2YYR
07-15-2008, 01:36 AM
Not easily, no. About the best you can do is wind a known number of turns on it and accurately measure the inductance. That will get you in the ballpark. If you can measure the inductance across a range of excitation frequencies, so much the better.

WB2WIK
07-15-2008, 01:53 AM
I need to wind some toroids for a project that I'm working on and have a few cores laying around.
Is there any way to identify what the ferrite mix is (ie. 43, 63, etc)?

::Cores are often color coded to help you identify the mix; unfortunately, many aren't and even with those that are, you'd have to know the manufacturer of the core to trace back exactly what the color means.

When I "buy" cores (thankfully, they're pretty cheap!) I buy them according to the mix, diameter and thickness and once I get them I always "color code" them myself to remind me later what the heck I have. I use small dots of colored paint. Mix 43 would be yellow-orange, two dots side by side. Mix 75 would be violet-green, two dots side by side, etc. That way, even many years later, I know what I have.

WB2WIK/6

KR2D
07-15-2008, 02:35 AM
A few years ago, I read a web page that explained how to the identify ferrite mix with a MFJ antenna analyzer. Of course I didn't bookmark it. When I bought an analyzer, I wanted to ID the ferrites in my junk box, and now I can't find the web site.

Not helpful, I know. But maybe someone out there knows of that web page and can provide a link.

AB8RO
07-15-2008, 02:59 AM
A few years ago, I read a web page that explained how to the identify ferrite mix with a MFJ antenna analyzer. Of course I didn't bookmark it. When I bought an analyzer, I wanted to ID the ferrites in my junk box, and now I can't find the web site.

Not helpful, I know. But maybe someone out there knows of that web page and can provide a link.

Here ya go, from my old stomping grounds.

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

M0DSZ
07-15-2008, 07:00 AM
http://www.alan.melia.btinternet.co.uk/toroids.htm

Have a look at this site. It is important to distinguish between iron-dust and ferrite cores, if you're using any kind of power the ferrite will probably saturate easily, produce non-linearity and harmonics, become hot and even disintegrate.

Typical manufacturers are Amidon, Ferroxcube, Fair Rite and Micrometals. Amidon use colour codes for their dust toroids and the same code is emulated by some lesser manufacturers. In the case of unmarked, colourless toroids, as contributors have already said, try a few turns at various frequencies and see what happens. Bear in mind that some materials are deliberately lossy and designed for EMC reduction, still quite useful though on power leads for that purpose.

WB2UAQ
07-15-2008, 04:44 PM
Once you get a core of known mix, use the MFJ unit, measure it and record what found for future reference. The color coding is good too.

I have had good results ID'ng cores by measuring their physical dimensions with a caliper and then using a low freq LC bridge (the common 1 kHz types, not sure if the cheap multimeter types would be of any use) with some turns applied to the core, measure the inductance and calculate the AsubL (inductance factor) (from the number of turns and inductance measured). Then go to the catalogs and match the AsubL you calculated against the core size you measured. The initial perms are determined at low freqs so using 1 KHz works very well.

73,
Pete

KE5FRY
07-15-2008, 06:24 PM
Am I correct in assuming that the ones i have that are magnetic are powdered iron and the non-magnetic ones ferrite?

ZL3GSL
08-07-2008, 03:28 AM
No. ;)

Ferrites, and iron powder are both ferromagnetic.

Non-magnetic toroids might be "grade 0", made of phenolic, to be used as a former when you need a toroidal coil with a core mu of 0. :cool:

KB1KIX
08-09-2008, 01:40 AM
I've been looking through things before I throw them away and taking the cores and a few other odd parts here and there and storing them.

I have a whole bin full of 'em that I really want to identify.

Of course, purchasing them from Diz (The Toroid King) also works.....

I also picked up the little kit from "QRPMe". Rex sells a plastic handle that is wicked nice for when you have to wind them small suckers. If I ever lose or break this thing.... it will be a sad day. Makes winding them a whole lot easier.

Jonathan

PD7MAA
09-14-2008, 04:55 PM
I need to wind some toroids for a project that I'm working on and have a few cores laying around.
Is there any way to identify what the ferrite mix is (ie. 43, 63, etc)?
From my club president PA0EJH:
If you need to find out if a toroid is ok for your project:
put 3 turns of wire on the unknown ring and attach them to a signal generator .Then wind 3 turns on the other side and attach these to your scope. The sinus of the signal schould be the same on each side .If not the toroid is not designed for your frequency.
This is the best way to identify rings of unknown origine.
73s John

PD7MAA
09-22-2008, 03:09 PM
1 Wind 3 turns of wire on the unknown toroid
2 measure the induction in uH
3 Multiply the outcome by 1000
4 devide the outcome by the square of the windings ( 9 )

73s John

K9FV
09-22-2008, 06:21 PM
1 Wind 3 turns of wire on the unknown toroid
2 measure the induction in uH
3 Multiply the outcome by 1000
4 devide the outcome by the square of the windings ( 9 )

73s John

John, I really hate to show my lack of knowledge here, but what does the answer give you? the mix - i.e. 43, 61, etc? Or a number to allow you to look up the mix?

on edit: Should this be at a special freq? 2 mhz? 1 khz? My inductance meter is at 1 khz (I think), but the MFJ259B can be at much higher freqs.

73 de Ken H.

PD7MAA
09-22-2008, 07:35 PM
John, I really hate to show my lack of knowledge here, but what does the answer give you? the mix - i.e. 43, 61, etc? Or a number to allow you to look up the mix?

on edit: Should this be at a special freq? 2 mhz? 1 khz? My inductance meter is at 1 khz (I think), but the MFJ259B can be at much higher freqs.

73 de Ken H.

Hello Ken
Amidon mix numbers explaine the AL
My intention is to help OM's with unknown toroids. By knowing the AL the OM can choose the perfect match for a certain frequency or , as you mentioned , find out the mix. Products of Amidon can normaly easy be recognized by size and coulor...
To check the inductance i use a AADE inductance meter.
73s John

K9FV
09-22-2008, 09:01 PM
Awww, dummy me - now I see what you are doing John. take the reading in microhenry, multiply 1000 to get the reading in henrys, then devide by the turns squared to get the value in henrys for a single turn of wire.

Shucks, sometimes I can't see the forest for the trees.

That AADE sure is nice. I just build my meter last week. Sure does give a LOT better readings for capacitance and inductance than the MFJ-259B. Just too hard to cancel out the lead inductance/capacitance in the MFJ.

edit: BTW John, using the AADE meter, why put 3 turns of wire thru, then calculate? Why not just pass a single turn of wire thru and measure that - would that be less accurate?

73 de Ken H.
K9FV

KL7AJ
09-22-2008, 10:44 PM
Not easily, no. About the best you can do is wind a known number of turns on it and accurately measure the inductance. That will get you in the ballpark. If you can measure the inductance across a range of excitation frequencies, so much the better.


Actually, this method will get you not only in the ballpark, but to first base. The variation in permeability between cores of the same material is often greater than the error in this calculation. :)

eric

PD7MAA
09-25-2008, 11:09 AM
Interesting Tool :

http://www.dl5swb.de/html/mini_ring_core_calculator.htm



73s John

K9FV
09-26-2008, 11:43 PM
That is perhaps the best program I've seen for torids John, that's a good one. Kitsandparts.com has some pretty good info also.

I also downloaded the beacon program - simple and neat!

Ken H>

W8JI
09-27-2008, 12:03 PM
I need to wind some toroids for a project that I'm working on and have a few cores laying around.
Is there any way to identify what the ferrite mix is (ie. 43, 63, etc)?

Measuring the slope of reactance or impedance doesn't work to sort most ferrite cores.

What you have to do is wind a few turns on the core, enough to get a releiable reading for the measurement device you are using, and then sweep frequency until X=R. Reactance equals resistance.

What you will find is various cores have X=R at certain frequencies, this is where the loss tangent and reactance cross, or the Q=1 frequency.

For example 73 Material X and R cross at around 2 MHz. 43 materials cross up in VHF.

If you are using an MFJ-259 try to do this with enough turns so that the R is 50-100 ohms at the crossing frequency. Keep the core RIGHT AT the connector!!!!

If you are looking at low mu powdered iron cores, then you can just measure inductance. Using just a few turns, maybe a half-dozen, look at the value of inductance and the slope of inductance with frequency. The Q will probably be too high to use reliably unless you have a professional instrument. You can calculate AL and try to match it to a core, but this is not very reliable because several different types have similar AL's.

Actually a very low ui core is difficult to sort out. High ui mixes are pretty easy.

73 Tom

(Only LIDS mix politics, religion, and radio.)

K9FV
09-28-2008, 03:27 AM
Thank you for the info Tom - I will be playing with your suggestions over the next few days and see if I can make it work.

This is just one of the areas where I'm always interested in learning something new.

73 de Ken H>
K9FV

4L4AGU
11-03-2010, 04:43 PM
I've got ATU from some military HF transceiver. All ATU cores are yellow in color, one side is painted black, and each core has 3 color dots on it. Colors vary, and are like pink-pink-grey and so on. As I guess, this is some common marking system, but googling reveals nothing, maybe anyone has idea what system is that?

VK2TIL
11-03-2010, 08:11 PM
No iron- or ferrite-material identification system that I've ever seen.

Might be the inductance value; this is sometimes marked as dots or bands.

EIA/military codes;

http://www.pronine.ca/indcode.htm

4L4AGU
11-04-2010, 12:58 PM
I think you're right, dots mean inductance, since there are no coils with same amount of wire on it and same color code. When checked carefully, I can see that black coloring of the cores is not actually black, but dark navy green:

KD0CAC
11-04-2010, 02:10 PM
I've seen at least one or more threads about identifying cores , have to go back to see if I can find , to link .
I have been collecting a box of them also after reading a few books like Reflections III , figured I could make some of my own with an IDing process .

G3TXQ
11-04-2010, 02:10 PM
I think you're right, dots mean inductance, since there are no coils with same amount of wire on it and same color code. When checked carefully, I can see that black coloring of the cores is not actually black, but dark navy green:

The inductance values on many auto-tuners go in binary steps - that may help you unravel the colour-coding. At a guess they might use the same colour-coding as resistors.

Are you sure it's a military tuner - I'v not seen much military equipment that uses SO239 connectors?

Steve G3TXQ

G3TXQ
11-04-2010, 02:13 PM
The inductance values on many auto-tuners go in binary steps - that may help you unravel the colour-coding. At a guess they might use the same colour-coding as resistors.

Are you sure it's a military tuner - I'v not seen much military equipment that uses SO239 connectors?

PS: On second thoughts, that looks like relay-switched output filters rather than an autotuner

Steve G3TXQ

4L4AGU
11-04-2010, 05:15 PM
Yes, I'm 100% sure. This is car mounted CОDАN. But it was submerged into water, destroyed, so it's impossible to determine the model. Two MRF455 and balun are also kept there, but transistors look like blown up.

Technically, this may be not ATU, just I don't know how to say it properly in English, tunable output circuit for antenna matching?

VK2TIL
11-04-2010, 08:23 PM
I agree with 'TXQ; looks like a set of relay-switched filters to follow a solid-state power amplifier.

The toroids are almost certainly #6 iron-powder material; they are yellow and look like these;

http://img541.imageshack.us/img541/9085/material6photo.jpg (http://img541.imageshack.us/i/material6photo.jpg/)

4L4AGU
11-04-2010, 08:29 PM
Yes, they look exactly like ones you've posted. But from where you determine it's #? are there any charts? that PCB also contains other cores, smaller ones, green color and with blue side. One of such cores is used for SWR meter as I guess, so it'll be nice to know it's material also.

VK2TIL
11-04-2010, 11:40 PM
There's quite a lot of information on iron & ferrite materials on the 'net; you have to dig a little, though.

Here are some links;

A "legacy" VK site by the former VK Amidon agents;

http://users.catchnet.com.au/~rjandusimports/index.html

(The colours are on page 3).

Fair-Rite catalogue; a good read;

http://www.fair-rite.com/newfair/index.htm

Ferroxcube manual; ditto;

http://www.ferroxcube.com/appl/info/HB2009.pdf

You can get DL5SWB's excellent calculator here;

http://www.dl5swb.de/html/mini_ring_core_calculator.htm

It shows the colours for iron-powder materials.

It's unfortunate that ferrite materials are not colour-coded.

I address this problem by marking ferrites as soon as I receive an order; I use my own code of coloured dots made with enamel paint.

The other thing I do is never use unmarked/unknown materials!

Ferrites are not expensive (even in VK) if bought in quantity from 'DIZ;

http://www.kitsandparts.com/

I think that using unknown material is risking problems; there is enough that can go wrong with my experiments without adding unknown core characteristics to the equation.

4L4AGU
11-05-2010, 04:08 AM
Thanks a lot. By 3rd page you mean this?:

http://users.catchnet.com.au/~rjandusimports/ip_mat_1.html

according to it, #6 should be yel/clr, what does clr means, "clear" ?

Soviet marking system was much easier and better. Each core had letters on it, like 2000 HH, where number shows permeability and 2 letter suffix - material and working frequency.

I also downloaded ring core calculator. It does have color information, but the combination for my cores aren't shown, except green/blue one, which is being told to be low frequency one. Which is not correct for my case, according to ATU schematics. I have seen low freq. green/blue cores, they are mounted on computer motherboards.

In fact, I own huge number of soviet cores, starting from mini ones, with less than half inch diameter, ending with huge ones, 5 inch and more in diameter each. I just wanted to test these "foreign" cores, how they compare to soviet ones.

VK2TIL
11-05-2010, 05:22 AM
Apologies re "page 3"; I was thinking of something else.

The page you linked shows the colours; "clr" means clear as you deduced. This just says that part of the coating is clear; the yellow, red etc are the colours that identify the mix.

#2 (red) and #6 (yellow) are probably the most-used iron-powder types, at least in amateur work; other mixes are not commonly encountered (by me anyway :) ).

The whole field of mixes, particularly ferrite mixes, is a minefield; different makers have different systems and cross-references are uncommon. There is one here;

http://users.catchnet.com.au/~rjandusimports/xref_mat.html

based on ui but this does not mean that "equivalent" materials are truly identical. I doubt that precise cross-referencing is possible.

Part of the problem is that there is some "art" as well as science in the making of ferrites. The physical processes (grinding, sintering etc) are complex and different makers do things in different ways, thereby producing mixes that are not quite the same as an "equivalent" mix from another maker.

Here is some more detailed information that might interest you;

https://www.amidoncorp.com/pages/specifications

If you really must use unknown mixes, earlier posts in this thread (which was started quite some time ago) describe some ways of identifying the mix.

4L4AGU
11-05-2010, 09:33 AM
Well, I want to built relatively compact tuner for longwire antennas. Since I already own compact HF switch and capacitor, and these coils are wound with increasing number of turns, as I've counted them, they are 4-5-7-10-13-15-17-19-24 turns, all on same size of core. So they should make good set of coils for matching device. Also, I've checked smaller cores at daylight, and they are gray color, not green, as I thought before.

Now I'll try to determine their inductance, and let's see if they can provide enough inductance for my needs.

W8JI
11-08-2010, 10:40 AM
I identify cores with a MFJ259 by winding a few turns and looking for the frequency where R=X c values. That would be where Q is 1.

Then I look on a list of cores for the point where the reactance and resistance curves cross at or near the same frequency.

If the Q=1 point is out of range, I look at turns and reactance and try to match a known core.

I have the same impedance measuring test set most manufacturers use to evaluate core materials, but most cases the MFJ259 works good enough.

4L4AGU
11-09-2010, 10:34 AM
I have digital LCR bridge, so I think I'll use it on core with largest amount of windings.

KD0CAC
11-09-2010, 05:07 PM
I've been a number of repair business , and having parts on hand , new & used have many advantages , if can keep things organized [ part of that is values ] saves time & money .
Then the way I see myself & many others look at ham radio is an experimenters hobby , so learning by testing is a big part of it .
I would have say there are many aspects to using used / NOS , what ever , that if you have to ask then just haven't found any reasons , yet .

EI3JU
11-09-2010, 08:54 PM
Why waste the time?

Time spent learning and broadening the mind is never wasted.

KM1H
11-10-2010, 02:13 AM
Today its so easy and relatively inexpensive to own test equipment that was only a dream 20-25 years ago.

I use a hand held digital LCR meter to get in the ballpark with 10T wound usually. Then knowing the L I can transpose the formula to come up with the Al value. I dont even bother searching for a comparison in the catalogs. If its not a known Micrometals or Fairite anything else is a crapshoot. With companies like TDK and Siemens its a task not worth the effort as what you have is likely to not be in any catalog.

A Q Meter is a huge help to evaluate any cores usefulness in a project, I use a military TS-617C/U which is the next to last of the series and not an earlier Boonton clone with all its problems. It was all of $40 on Fleabay a few years ago and works great.

Carl
KM1H

4L4AGU
11-10-2010, 08:56 PM
Why waste the time? Toroids don't cost much.


Internet really erases differences between countries. Yes, cores for you may be easy to buy, but here in Georgia, only few people in whole country, know what is produced by Amidon, for example.

Sure, I can easilly buy in online shops, but there are certain restrictions again - ham gear is generally sold in small, specific online shops, which either accept only paypal (which is impossible to legally have in Georgia), or they require shipping address to be same as billing address, which is also problematic for me. Some of them may accept wire transfer, but one time fee for such transfer will be around $60 - too expensive for $5 core.

So, if anyone knows any online store, that accepts foreign credit cards, and will ship to St. Paul, MN (address of my forwarder), please let me know.

VK2TIL
11-10-2010, 09:13 PM
Perhaps you could first contact Dieter W8DIZ;

http://www.kitsandparts.com/

I've found "DIZ" to be a good bloke and very helpful; his prices are low, too! :)

I appreciate that you have currency problems but you may be able to work something out with him.

4L4AGU
11-11-2010, 06:24 AM
Yes, but as mentioned, he only accepts paypal :)

It's very strange - digikey.com - huge supplier of all parts, I can buy from them without any problems, does not have any stand-alone cores, only RF choke ones.

VK2TIL
11-11-2010, 06:56 AM
"Yes, but as mentioned, he only accepts paypal :)".

But have you actually talked to (ie e-mailed) the man; sometimes a polite approach can find a way to achieve an end.

Components are often difficult to get here in VK; your situation is certainly worse than ours but friendly personal contact with an overseas person has often solved many problems for me.

4L4AGU
11-11-2010, 10:28 AM
Sure, I'll mail him, but, according to previous experience, most sellers won't bother with such problems - another $10 or $20 sale is not significant for them.

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