AN OSCILLOGRAPH FOR TEN THOUSAND CYCLES 



77 



Fig. 1 — The rapid record oscillograph. 



quency. The odd numbered modes of vibration may not be exact 

 multiples of the fundamental because their frequency is influenced by 

 the beam stiffness of the string. With a relatively short, wide ribbon, 

 for example, the third resonance peak may be considerably higher 

 than 3Fo. The increase in sensitivity in the neighborhood of the 

 various resonance points is accompanied, as with other electrically 



1000 



2 



I 800 



u 600 



200 



2400 2500 2600 



2700 2800 2900 3000 3100 3200 3300 

 FREQUENCY IN CYCLES PER SECOND 



3400 3500 3600 



Fig. 2 — Variation in impedance near fundamental resonance frequency with Image 

 amplitude constant at 2 mm., peak to peak. 



