Rx Off Hook Selection; Rx Term Or Brdg Selection - AMERITECH AM5 Instruction Manual

AM5(e) Classic Instruction Manual
5.2.6 TX/2W 135
The SEND impedances are selected by the left
TX/2W front-panel switch, and the corresponding
LEDs are lighted for each impedance selection.
5.2.7 TX/2W OFF HOOK selection: The electronic
equivalent of a loading coil (OFF HOOK) is selected
by the right TX/2W switch.
5.2.8 RX 135 , 150 , 600 , 900 , 1200
MEASURE impedances are selected by the left RX
front-panel switch, if TERM has been selected by the
right RX switch. If BRDG has been selected, the
impedance selector
impedance is 50 KΩ or greater. Calculation of dBm
and dBrn is based on the impedance selected (see
5.2.10).
5.2.9 RX OFF HOOK selection: The electronic equivalent
of a loading coil (OFF HOOK) is selected by the
middle RX switch. The holding coil presents a DC
resistance of 200 Ω or less while maintaining a high-
impedance to AC.
5.2.10 RX TERM or BRDG selection: The MEASURE impedances are selected by the
left RX front-panel switch, only if TERMinate has been selected by the right RX
switch. If BRDG (Bridging) has been selected, the impedance selector is
disconnected and the impedance at the RX jack is 50 KΩ or greater.
NOTE: dBm and dBrn readings displayed are calculated on the setting of the RX impedance
switch, even though the network has been disconnected by the BRDG selection or because one of
the LINE 2W selections has been made. The formula used is:
Where:
November 19, 1997
(18-0047)
, 150 , 600 , 900 , 1200
is disconnected
dBm = 10 log (E 2 X 1000)
E = Voltage across the circuit
R = Termination selection for the circuit
Page 5-4
LINE FUNCTIONS
selections:
selections: The
900
and the
600
150
135
R
900 1200
600
150
OFF
135
HOOK
TX/2W
1200
TERM
OFF BRDG
HOOK
RX