[RFI] ft240 Designation

[Grant Saviers]

No standards AFAIK, similar performance ferrites from different makers 
have different names.  Or one might say there are so many standards that 
every body can have their own.  One text will use one makers ID 
(letters) and another will use Fair-Rites numbers.  It's up to the 
engineer to figure that out and measure how "compatible" they are.

Many Fair-Rite part numbers do include their 2 digit ferrite type in the 
longer number as digit positions 3 & 4.

Making highly technical ferrites to precise specs is difficult. It's a 
messy business with wide manufacturing tolerances.  When we made memory 
cores most of the finished product failed final electrical test and went 
back into the ball mills.

Grant KZ1W

On 11/10/2021 12:01, Chuck Gooden wrote:
> Could someone explain where the FT240-31 designation for ferrites came 
> from.  I do not see this in the Fair-Rite catalog or any manufactures 
> that use this designation as a part number. If you Google "FT240-31" you 
> will be directed to a different part number made by Fair-rite
> 
> I realize that it means a 2.4 inch diameter torrid of type 31 material.
> 
> So is this an industry standard for classifying  the shape and size of 
> ferrite components, if so what is the standard?
> 
> Chuck K9LC
> 
> _______________________________________________
> RFI mailing list
> RFI at contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi