6627	2011-09-10 11:39:41	dnorbury	Toroid identification
Message	Date	From	Subject
I got hold of a bunch of toroids of three different sizes. I've looked at the catalogs of the major suppliers (Amidon, Fair Rite, Micrometals, etc.) but can't find the sizes listed that match mine. They are yellow/clear in color and the dimensions are: 1. OD = .500, ID = .290 and HT = .260. 2. OD = .805, ID = .480 and HT = .270. (close to T80-6?) 3. OD = 1.065, ID = .555 and HT = .320. Any idea of the manufacturer and part numbers? If I can't find this out I will just wind some turns on each and figure out the approximate specs but it would be nicer to get the complete set of data from the manufacturer. Thanks for your help, Dave KD6A
6629	2011-09-10 13:44:14	Leon Heller	Re: Toroid identification

6630	2011-09-10 14:21:49	dnorbury	Re: Toroid identification
Leon, You're right, of course. I am hoping that the sizes of the toroids would help identify the (likely) manufacturer and part numbers and therefore the specs. I could then verify them with a sample winding and inductance measurement. Dave KD6A
6631	2011-09-10 15:35:48	Andy	Re: Toroid identification
It might not be true, but I've heard it said that Fair-Rite makes most ferrite toroids, and companies like Amidon are mainly re-sellers. Micrometals might be another manufacturer. I've also seen it said that the materials are color-coded, but this might not apply to all vendors equally. That being said, I'm afraid I'm not much help. W8DIZ's Kitsandparts website gives the colors and sizes of the ones he sells. For the Micrometals cores, the listed color codes are: -1 Blue/clear -2 Red/clear -3 Gray/clear -6 Yellow/clear -7 White/clear -10 Black/clear -12 Green/white -15 Red/white -17 Blue/yellow -0 Tan These are not the Fair-Rite mixes (43, 61, etc.), which seem to be various shades of black. Andy
6634	2011-09-11 00:26:48	John Kolb	Re: Toroid identification
Dave, color yellow/clear - did you mean the cores are Yellow on the painted sides and dark gray on the unpainted side. I have a sample bag of Microsoft T50-26B toroids which measure about 0.505 OD, 0.290 ID, and 0.260 HT, and would match your dimensions. These are Yellow on three sides and white on the bottom. The"B" in the part number indicates an alternate height. A T50-26 without the "B" would be 0.190 HT, http://www.micrometals.com/pcparts/torcore2.html If Micrometals made a T50-6B (yellow/clear), it would probably have the dimensions you measure, but can't find one using their search function in their catalog. Could have been a special product. There's a T51-6B http://www.micrometals.com/rfparts/rftoroid3.html but the ID and HT don't match. Note that Micrometals yellow/clear cores I've seen are typically well painted on the top but OD and ID edges tend to be splattered rather thinly. I've also seen yellow/white cores in switching power supplies, and believe these to be ferrite rather than the powered iron of Micrometals cores. John KK6IL At 11:39 AM 9/10/2011, Dave wrote: >I got hold of a bunch of toroids of three different sizes. I've >looked at the catalogs of the major suppliers (Amidon, Fair Rite, >Micrometals, etc.) but can't find the sizes listed that match mine. >They are yellow/clear in color and the dimensions are: > >1. OD = .500, ID = .290 and HT = .260. >2. OD = .805, ID = .480 and HT = .270. (close to T80-6?) >3. OD = 1.065, ID = .555 and HT = .320. At 03:35 PM 9/10/2011, Andy wrote: >It might not be true, but I've heard it said that Fair-Rite makes most >ferrite toroids, and companies like Amidon are mainly re-sellers. >Micrometals might be another manufacturer. > >I've also seen it said that the materials are color-coded, but this >might not apply to all vendors equally. > >That being said, I'm afraid I'm not much help. > >W8DIZ's Kitsandparts website gives the colors and sizes of the ones he >sells. For the Micrometals cores, the listed color codes are: > >-1 Blue/clear >-2 Red/clear >-3 Gray/clear >-6 Yellow/clear >-7 White/clear >-10 Black/clear >-12 Green/white >-15 Red/white >-17 Blue/yellow >-0 Tan > >These are not the Fair-Rite mixes (43, 61, etc.), which seem to be >various shades of black. > >Andy > > >------------------------------------ > >Yahoo! Groups Links > > >
6635	2011-09-11 05:14:46	dnorbury	Re: Toroid identification
John, I think you got it. I was calling the colors yellow/white assuming the white was to be interpreted as "clear" since I saw no yellow/white listed under the RF toroid list. My mistake for not checking the power toroid listing! From that list it appears that the three are T50-26B, T80-26 and T106-26A. I guess now I'm into switching power supplies rather than RF! Thanks for the help, Dave KD6A
6637	2011-09-11 10:02:19	Ashhar Farhan	Re: Toroid identification
Wind 20 turns on the and plug it into a oscillator with known capacitance. Measure the frequency and back calculate the inductance and divide it by 400 to get inductance per turn squared. That's the main thing you need to know. You will also want to know the Q. A simple jig with two capacitors and a signal generator will give you that measure (refer to emrfd's test meaurements chapter). I have used nylon tap washers, brass rings and even air core toroids with this technique. A little bit of measurements will take you a long way in classifying your collection of toroids and other RF coils. - farhan
6638	2011-09-11 11:29:09	William Carver	Re: Toroid identification
In my experience YELLOW-WHITE cores are -26 material. They are powdered iron, but are high permeability used for switching and AC powerline filters. YELLOW, clear on the bottom, have always been -6 material. Highest Q material over 5-15 MHz. W7AAZ