Telex AUDIOCOM BP-2000 - Manual (Page 16)

Unbalanced Intercom Channel:
Output Level: 200 mVrms ±10%
Input Impedance: 150 W ±5%
Bridging Impedance: greater than 10,000 W
Call Signalling:
Send: 12
±3 VDC
Receive: 4 VDC minimum
HEADPHONE AMPLIFIER:
Voltage Gain:
27
±3 dB from the line
Maximum Output:
60 mW into 150
W
Frequency Response:
200 Hz to 8 kHz with no more than 4 dB deviation
Audible Alert:
1 kHz, at the headset
Total Harmonic Distortion:
Less than 2% at 50 mW from the line
Sidetone:
20 dB minimum range, adjustable
15