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Re: Measured Q (was Homemade chokes)



In a message dated 8/12/00 6:43:12 PM Pacific Daylight Time, tesla-at-pupman-dot-com 
writes:

> 
>  I finally decided to measure the Q of my coil.  I have a measured DC 
> resistance
>  of 26.7 ohms.  According to E-T5, my coil's operating frequency is about
>  125kHz.  The inductance is calculated to be 33mH by WinTesla.  Putting this
>  into
>  the equations gives me a Q of 970!
>  
>  This number seems about 5 times too high, and my primary tuning isn't 
> terribly
>  finicky.  Is this high of a Q possible?
>  
>  Thanks,
>  
>  Mark B.

Mark,

You need to use the AC resistance which will be higher (maybe
3 or 4 times higher) due to the skin and proximity effects.  This
will result in the calculated Q being 3 or 4 times lower than what
you calculated.

John Freau