Canon fax basic 2000 サービスマニュアル

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4. TELEPHONE LINE BAND & SIGNAL 

SPECTRUM

Although the bandwidth of regular telephone lines is 300 to 3400 Hz, the

upper limit is 3000 Hz for submarine coaxial cables for international com-

munications. This is for the efficient use of high-cost cables.

Fig. A-12   Telephone Line Bandwidth and Signal Spectrum

1850

1650

0 300

1000

2000

3000 3400

1100

1300

CNG

FC(J

apan

only)

1800

1700

2100

CED

Telephone line
frequency
characteristics

T

ransmittance

(dB)

Frequency

(Hz)

Frequency

(Hz)

Frequency

(Hz)

Frequency

(Hz)

Tonal signals

Signal

le

v

e

l

(dBm)

Signal

le

v

e

l

(dBm)

Signal

le

v

e

l

(dBm)

G3 procedure signals
(binary signals)
(FSK)

G3 image signals
4800,2400bps
(PSK)

G3 image signals
9600,7200bps
(QAM)

Signal

le

v

e

l

(dBm)

Frequency

(Hz)