The relationship between the pulse generator frequency, the capacitance, and the inductance follows the formula for series resonance from Wikipedia LC Circuit :

2 (pi) f L = 1 / ( 2 (pi) f C )

where f = frequency in Hertz, L is inductance in Henrys, and C is the capacitance in Farads


f = 1 / ( 2 (pi) sqrt( L C ) )

C = 1 / ( L * ( 2 (pi) f )^2 )

L = 1 / ( C * ( 2 (pi) f )^2 )

For example, if frequency is 42800 Hz and capacitance is 0.1uF,

L = 1 / ( 0.1e-6 * ( 2 * pi * 42800 )^2 )

L = 130uH

Steps to take:

* Hang the tubes by thread, or you can also hold the tubes 22.4% from the end between thumb and index finger.  Strike with a small piece of wood or rubber to determine the acoustic frequency of the tubes using a computer with a microphone, or a magnetic pickup device (guitar pickup) and an oscilloscope, or a frequency counter (or a musical instrument tuner if you are so lucky to have one).  See for some software tools which may help.

* Tune the pipes to the same acoustic tone using physical means, grind the lower pitched tubes to be the same as the highest pitched tube.  Use caution to never take off too much metal at once, you can’t put it back.  It may be desirable for the tubes pitch to be a harmonic of 42.8KHz (21.4KHz, 10.7KHz, 5350Hz, 2675Hz, and the ultra elite 1337 Hz).

* when all of the tubes ring the same note, this is the frequency to target with the pulse generator

* assemble the capacitor.  Hang the tubes in such a way as to allow the most acoustic movement in the center of the pipe, with the tubes held 22.4% from the ends.

* measure the capacitor with a capacitance meter

* given the frequency and capacitance above, calculate the inductance required

* determine existing inductance in the circuit by measuring the inductance of the secondary power coil with an inductance meter

* wind two wires onto a coil such that each wire is one half remaining inductance (so total inductance will be the secondary power + each wire of the two-strand coil)

* assemble cell

* adjust pulse frequency to specification (tube tone), then adjust for maximum output

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