[Milsurplus] Programmable Osc. Booster : Western Electric 227B

[David Stinson]

While the programmable oscillators we've been discussing 
will push the receiver fine, driving the transmitter 6L6 power
oscillator takes a little more "push."   
I built a simple Class-D MOSFET stage with a 4:1 
autotransformer UNUN output.  It drives the set well.
Here's the circuit:

http://home.netcom.com/~arc5/oscbrd.jpg

One "kink":  the toroid I used was a "junkbox" find.
I don't know it's specs.  The first two I tried were too
"lossy."  This one works well but I need to find out 
what the heck it is so I can get some more.

Anyone know how to classify an unknown toroid?
If not, what toroid do you think would work as well?

73 DE Dave AB5S