Canon fax basic 2000 Manuale Di Servizio
A–23
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2
3
4
5
6
A
çi
(2) Attenuation distortion
“Attenuation distortion” is the distortion that occurs as a result of inconsis-
tent transmission loss in the required frequency band.
Attenuation distortion occurs between EOs (end offices) and on non-
loaded subscriber lines. Humps may occur in the attenuation characteris-
tics of the subscriber line due to impedance mismatching.
Attenuation distortion occurs does not cause special problems in telephone
conversations. However, in the case of G3 facsimile transmission, image
signals can no longer be received properly and errors occur frequently if
the distortion is significant.
Fig. A-20 Attenuation Characteristics between EOs
Fig. A-18 Loading cable
Fig. A-19 Attenuation
Characteristics of Non-loading
Cable
L
L
L
L
L
L
S
S
S=Approx.1km
0
1
2
3
4
5
4
3
2
1
NL
(Non-loading)
Atten
uation
(dB)
L (Loading)
Frequency (kHz)
15
10
5
0
7
5
3
1
7
5
3
0.3
0
1.0
2.0
3.0
3.4
DC
TC
EO
DC
TC
EO
TC
EO
TC
EO
EO
EO
RC
DC
TC
EO
RC
DC
TC
EO
7 link
1
Atten
uation
(dB)
Frequency (kHz)
[Note] Numbers inside the graph indicate the
number of links in the case of the
organization below (Figure A-20).
organization below (Figure A-20).
5 link
3 link
1 link