Welch Allyn GSI 38 - Page 9

Signal Format
Continuous
- Signal steady as long as present bar is depressed
Pulsed
Pulse rate: 2.5 pulses/sec
Duty Cycle: 50%
Rise/Fall Time:
20 - 50 msec
On/Off Ration (between pulses): > 20 dB
Frequency Modulation
FM Rate: 5Hz
FM deviation: +/- 5%
Transducers
Headset: TDH-39 Earphones with 60 ohm impedance
Insert Phone:
Audiovox Model SM-N Earphone, Eartip, Eartip adapter and cord.
Output impedances and voltages on back panel
Left Phone 130 ohm 2.5 volts rms max open circuit
Right Phone 130 ohm 2.5 volts rms max open circuit in Audiometer mode
Insert Phone <1 ohm 2.5 volts rms max open circuit
Subject response input 47 kohm pull up to 5 volts
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