Installing and putting a SINAUT modem into operation
6.4 MD2 dedicated line modem
SINAUT ST7 Station control system - System Manual
System Manual, 05/2007, C79000-G8976-C178-06
259
Transmission speeds and frequencies of the MD2 modem
Table 6-19 Transmission speeds and frequencies of the MD2 modem
Transmission
speed (bps)
Center frequency
[Hz]
Frequency
deviation Δf (Hz)
Lower keying
frequency (Hz)
Upper keying
frequency (Hz)
1200
1700
400
1300
2100
2400
2850
450
2400
3300
9600 / 19,200
27,200
6400
20,800
33,600
Attenuation values of the MD2 modem
Table 6-20 Attenuation values dependent on the transmission speed and wire diameter
Attenuation per km (dB) at wire diam. (mm)
Transmission
speed (bps)
0.6
0.8
0.9
1.2
1.4
Attenuation
per LTOP
(dB)
Insertion
loss per
tapping point
(dB)
Line terminated with Z = 600 ohms
1200
1.5
1.15
0.9
0.65
0.55
0.2
0.4
2400
1.85
1.4
1.1
0.75
0.6
0.2
0.2
Line terminated with Z = 150 ohms
9600 / 19,200
4.3
3.2
2.6
1.8
1.5
1.0
0.2
The values in the table above are guidelines for communication lines without loading coils of
the type 2 x 2 x A J-Y(St)Y (A = core diameter in mm).
Maximum range of the MD2 modem
Table 6-21 Maximum range dependent on the transmission speed and wire diameter
Maximum range (km)
Transmit level –6 dB
*)
Transmit level 0 dB
*)
Transmission
speed (bps)
With LTOP
Without LTOP
With LTOP
Without LTOP
Core diameter 0.6 mm
1200
21.7 – NTP x 0.6
22 – NTP x 0.3
25.7 – NTP x 0.6
26 – NTP x 0.3
2400
17.6 – NTP x 0.4
17.8 – NTP x 0.2
20.8 – NTP x 0.4
21 – NTP x 0.2
9,600 / 19,200
7.2 – NTP x 0.6
7.6 – NTP x 0.1
8.6 – NTP x 0.6
9 – NTP x 0.1
Core diameter 0.8 mm
1200
28.3 – NTP x 0.7
28.6 – NTP x 0.4
33.5 – NTP x 0.7
33.9 – NTP x 0.4
2400
23.2 – NTP x 0.5
23.5 – NTP x 0.2
27.5 – NTP x 0.5
27.8 – NTP x 0.2
9600 / 19,200
9.6 – NTP x 0.7
10.3 – NTP x 0.1
11.5 – NTP x 0.7
12.1 – NTP x 0.1