To see it from another side (actually means the same) , a transformer does not "

*have an impedance*" by itself, but converts/translates a speaker impedance into a higher impedance seen by the plate.

What they actually offer is a fixed primary, and a tapped secondary with 6 taps, which offer different *voltage* ratios and *impedance* ratios.

They might very well just print the voltage ratios and let you do the Math, or print just a couple values.

They were incredibly honest (or suffer OCD

) and offered a

** full** table covering

**all** possibilities,

*even the most impractical ones* , such as .09 ohms or 0.43 or 21 ohms

Personally I prefer extra data to pick from and not having to guess "mystery data".

Those weird values are what your calculator will show if you actually do the Math, tap by tap; it's good that they show all at once and you pick closest possible.

Fine, since load impedance is not

**that **critical; 20% upor down is completely inaudible.

So keep that datasheet, even photocopy it as a backup ... and if you lose it, no big deal, you'll have to feed primary, say, 40V to 120V , measure voltage at secondaries and recalculate it yourself