Table of Contents
Advertisement
Transmit Level Adjustment (Continued)
3.
Connect pins 6, 7, and 9 together with
jumper PIN 5159491. (See the switched
board [PSN] illustration for the location of
the pins.) This turns on 'request to send'
and unclamps the transmitter.
Switched Lines (World Trade):
World Trade note for switched lines:
Before
adjusting the transmit card, it is necessary to
complete the line plate strapping. The line plate,
located above the cable tower inside the back
Attach a jumper from pin 4 to pin 5 with
jumper PIN 816645 to turn on 'data set
ready'.
cover of the system, is shipped from the plant
strapped for the lowest dc current (strapped between
U11andU10).
4.
Connect TB 1-3 on the line plate to the black
line terminal on the db meter.
CAUTION
Voltage is present on the line plate from the
5.
Connect TB 1-4 on the line plate to the red
line terminal on the db meter.
telephone lines.
To adjust the line plate for the proper strapping:
1.
Remove the card from the B2 socket on the
1200 bps integrated modem board. Removal
of this card activates the line 'connect
data set to line' and also activates the relay
on the line plate.
2.
Connect a dc voltmeter across TP1 (+) and
TP2 (-) on the line plate. (Refer to 10.3.1.1,
WT PSN Line Plate and Cable Connections,
for the locations of TP1 and TP2.)
3.
Change the strapping on the line plate by
moving the jumper from U11-U10 to
successive adjacent positions (U 1 0-U09,
U09-U08, etc) until the voltage is within
the range of 0.5 Vdc to 1.7 Vdc.
4.
If the installation does not use a handset,
attach a jumper from U2 to U3 on the line
plate; if it does use a handset, attach a
jumper from U1 to U2. (See the WT PSN
line plate illustration for the location of
the pins.)
After the line plate strapping has been completed,
the transmit level adjustment can be made by:
1.
Turning off system power.
2.
Remove PSN card from socket B2.
6.
Place the BRDG, 600,324 switch in the
B R DG position.
7.
Turn on system power.
8.
Adjust R3 potentiometer on the transmit
card for -9 dbm unless otherwise specified
by the local telephone company. Add +1
dbm to the PTT value for loss of amplitude
in the line plate.
9.
Remove the board jumpers that were installed
in step 3.
10.
Replace card in B2.
Switched Board (PSN)
9
•
7
•
6
•
5
•
4
Gate C
Transmit Card (C1)
Transmit level has an
[j[JLJ
R1
R2 R3
\
'\ Space Frequency
(sealed)
Mark Frequency
(sealed)
Odb
• A· Jumper
Jumper A is required for full adjustment range.
Remove the jumper for networks that restrict
the transmit level attenuation to a level of
less than -2 db (WT).
Data Communications
10-5
Advertisement
Table of Contents
