2N Helios Force - Technical Parameters; Telephone Parameters

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4. Technical Parameters
Telephone Parameters
Parameters Value Conditions
Minimum required off-hook line current 15 mA Off-hook
Minimum required on-hook line voltage 20 V Hang-up
DC voltage drop (off-hook) < 8 V < 16 V I = 25 mA
I = 50 mA
Lead current while hang-up < 25 μA U = 60 V
Off-hook AC impedance 220 Ω + 820 Ω 115 nF parallel 20 to 60 mA
Return loss > 10 dB 20 to 60 mA
Bandwidth 300 to 3500 Hz 20 to 60 mA
Ringing impedance > 2 kΩC = 1 μF 25 to 50 Hz
Ringing detector sensitivity 10 to 20 V 25 to 50 Hz
Time of response to ringing Variable 
Pulse dialling 40/60 ms 20 to 60 mA
DTMF level −6 and −8 dB± 2 dB 20 to 60 mA
DTMF detector sensitivity
Min. −40 dB
20 to 60 mA