[Boatanchors] Transformer marking question

[Jim Haynes]

I suspect those are military identification numbers, but I don't know
what they mean.  The military has lots of overlapping schemes for applying
identification numbers to things.  There are the 11-digit stock numbers,
and then references to standards like MIL-W-20812 things, and then there
is a scheme for electronic parts - I remember seeing resistors with
numbers starting with R where the various parts tell you the resistance
and wattage rating and precision and material it is made of.

On Mon, 8 Jun 2009, J. Forster wrote:
> They are manufacturers part numbers. Who made the things?
>
> AFAIK, there are no industry standard part numbers for transformers, like
> for tubes or other parts. Only the lead color codes are standard.
>
>> Some transformers have markings like
>> TF4Q02YY, TF4R2IYY, etc.
>> Anybody know what these mean?
>> de HL1FB/WW6N