High frequency apparatus, design, construction and practical application; a practical treatise for electrical engineers, electricans, physicians, students and experimenters (1920)
Curtis, Thomas Stanley · New York, Norman W. Henley publishing company · leaf 61
hespeed govern the tone or pitch of the note imparted to thespark. With 12 points and a motor running at 1,800 R.P.M.the tone of the spark is musical and pleasant to the ear;this is in striking contrast to the crackling or crashingspark of the stationary gap. While this feature is ofgreater…
Electric apparatus and appliances
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