It is FT82-75 and the resistance is only 5 KOhm, so the mix is accurate.

I will have to make use of them in wideband tranmission transformers.
Can you folks suggest a frequency range?

I can get ferrite #61 or #63, but iron core only comes in mix #2 or #6
locally.

Thanks for all the help!




Table 2
Typical Resistances of Small Ferrite Beads/Toroids

Material / Resistance
43 10 MOhm
61 30 MOhm
63 30 MOhm
64 30 MOhm
72 30 MOhm
73 20 KOhm to 100KOhm
75 5 KOhm to 20KOhm
The OP said it was ferrite. Assuming he is referring to an Amidon
product 75 is a ferrite mix:

MATERIAL ' J '/75 ( µ = 5000 ) Low volume resistivity and low core
loss from 1 KHZ to 1MHz. Used for pulse transformers and low level
wide band transformers. Excellent frequency attenuation from 0.5 MHZ
to 20 MHz. Available in toroidal form and ferrite beads as standard
off the shelf in stock. Also available in pot cores, RM cores, E & U
cores as custom ordered parts with lead time for delivery.

I'd say this was quite unsuitable for his purpose. It would be OK for
a wide-band transformer, as he suggests.

Leon