Anyone know why he used 15"?
Pulse stacking??? Stacked pulses create a pulse sweep???
The wavelength of the seventh harmonic of 35.7 is almost devisable by 47.1" ( 15" x 3.14) could be pulse stacking....
I cant find any reason for 15"
maybe he had some of these laying around his speaker shop?
I don't think there is any particular reason the he used 15" - probably like you suggested - he had speaker rings available
pi - 3.14159265
3.14159265 * 15"
= 47.12388975"
330011.23513859464" wavelength of 35.7806khz
47144.462162656377" 7th harmonic of wavelength of 35.7806khz
47144.462162656377" / 47.12388975"
= 1000.4365601559107
---------------------------------------------------------------------------
almost a function of 1000 and evenly divisible
or....
47144.462162656377" / 1000
= 47.144462162656377"
47.144462162656" / 3.14159265
= 15.00654840233866"
15.00654840233866" at 1000
???
or...
for exactly 15"
15 * 3.14159265
= 47.12388975"
47.12388975" * 7000
= 329867.22825"
329867.22825" is the wave length of : 35.805386563275khz ??? did i get that right?
Collector diameter equals power ? 15" tpu is x1000 ? < actually that would be inverse as a 7.5" tpu would be a function of 2000
>> a lot of interesting reading on transformer theory and the 7th harmonic <<
propagation velocity and wavelength are variable depending on the properties of the medium - often much slower than C
length/widh suggestion here ???
http://www.scribd.com/doc/24526174/Eric-Dollard-The-Oscillating-Current-Transformer
The coil in the photo is 15 x 4 - 280 turns
Due to its self capacitanceit is less than 35khz , but a pair of wire clippers and a bout 6 hours of test-clip-test-clip-test-clip can fix that
Or - get it to its closest divisible and calculate a cap to correct it. < It came out at 96.5khz so it needed a 400pf cap