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"Q" - weird... Not so high ??



Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>

Hi All,

I was frequency sweeping my small coil's terminal voltage response and
noticed something...  I am loading it with a 220k resistor and the 3pF HV
(Tek 5100) scope probe.  I am driving the primary circuit from the
wide-band low-Z amplifier.

http://hot-streamer-dot-com/TeslaCoils/Misc/SmallCoilRvF/P3030001.JPG
http://hot-streamer-dot-com/TeslaCoils/Misc/SmallCoilRvF/P3030021.jpg

The frequency response of the small coil swept from 200kHz to 300kHz looks
like:

http://hot-streamer-dot-com/temp/Tek00000.gif

Since the system has dual "humps", the "Q" is "weird"...

The center frequency is 229.8kHz and the two 1/SQRT(2) freqencies are at
216.5 and 242.5 kHz.  Thus the Q would appear to be only 8.84.  This system
is not terribly far from a CW coil setup.  This would imply that CW coils
have fairly low Q too!!  

Not the 100+ Q we usually assume for CW coils, but less than 10!?!...

Comments...

Cheers,

	Terry