Thank you. I do not yet posess the equipment to find the resonant frequecy of anything, although I might try to make a CRT osscilloscope in the future. The tube I got is from LND, inc. It is model LND-712, but I was originally going to use the CI-3BG until I heard of its terrible sensitivity. Is there any way I can find the resonant frequency without the osscilloscope? Personally, I have never seen transformers in flashlights, but I can't say I've taken many apart.
-Flam