Line 4W Selection; Line 4W Reverse Selection; Figure 5-2 - 4-Wire Line Circuit Block Diagram - AMERITECH AM5 Instruction Manual

AM5(e) Classic Instruction Manual
T1
Electronic
Line-Hold
Circuit
RX
Jack
OFF
or
HOOK
Terminals
RX
(on hook)
R1
T
Electronic
TX/2W
Jack Line-Hold
or
Circuit
Terminals
OFF
HOOK
(on hook)
TX/2W
R
Circuitry shown for LINE 4W Position. In 4W REVerse position T and R are exchanged with T1 and R1.
Figure 5–2 — 4-Wire Line Circuit Block Diagram
5.2 FUNCTIONAL DIAGRAMS OF AM5(e) CLASSIC
Figures 5-2 and 5-3 are Block Diagrams of the 4-Wire and 2-Wire line terminating
circuitry. The following sub-sections describe the LINE circuit functions in terms of
front-panel keys and the LEDs that show their selection.
5.2.1 LINE 4W selection: In the 4-Wire configuration (Figure 5-2),
signal flow is from the SEND functions out of the unit via the
TX/2W jack (or rear-panel T and R terminals). Signal flow
from the tested circuit is into the RX jack (or rear-pane T1 and
R1 terminals) and into the MEASURE functions.
5.2.2 LINE 4W REVerse selection: When in the 4-Wire REVerse
configuration, the MEASURE and SEND functions are
switched to the TX/2W and RX jacks, respectively (as
indicated in note on Figure 5-2). The 4W REVerse setting is
also useful for making receive-only measurements on a
TX/2W line. Refer to NOTE at 5.2.11.
November 19, 1997
(18-0047)
RX
Impedance
TERM
Selections
BRDG
RX
600
200 K
450
300
75
67.5
600 1200Ω
450
900Ω
300 600Ω
75 150Ω
TX/2W
Impedance
Selections
67.5 135Ω
Page 5-2
LINE FUNCTIONS
Frequency,
Level,
Noise
MEASURE
Selections
200 K
NTG
MEASURE
Signal
Generator
SEND
Selections
QUIET
SEND
3/1/93
4W
REV
4W
2W
2.16µf
2W
LI NE