Re: Quarter Wavelength Frequency

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Gerry Reynolds" <gerryreynolds-at-earthlink-dot-net> 

Hi Ed,

Is L/D like H/D or is L the length of the coiled wire uncoiled and straigten
out? Is D is the diameter of the coil?  Could you define the geometry for
lamda (I believe it is the wavelength but not sure if it is the wavelenth of
the coiled wire or the straigtened out wire)?

Gerry R

 > Original poster: Ed Phillips <evp-at-pacbell-dot-net>
 >
 > For those who may be interested, I just ran the following calculations
 > using a program with quite accurate inductance calculation and a pretty
 > good series fitting Medhurst's data.
 >
 > L/D length of wire/lambda
 >
 > 0.5 0.228
 >
 > 1.0 0.298
 >
 > 1.5 0.343
 >
 > 2.0 0.374
 >
 > 3.0 0.413
 >
 > 4.0 0.435
 >
 > 5.0 0.449
 >
 > 7.0 0.466
 >
 > 10 0.478
 >
 > 100 0.49998
 >
 > 1000 0.50000
 >
 > This is for a coil with no added capacitance.  I've found the program
 > gives results within 2% of measured value over a fairly wide range of
 > L/D, so think the trend is significant.  As L/D gets large the ratio
 > goes to 1/2, just what one would expect with a straight wire.
 >
 > Any comments or does someone see an error here?  Antonio?  Paul?
 >
 > Ed
 >
 >