Vega 1211 User Manual

Model 1211 Dictaphone Back Plane

PCB

Technical Manual

P.N. 803881

1 Description:

The 1211 Dictaphone backplane PCB offers a quick connection solution for 3 slots of the 1211 type 10 card cage.
Up to 4 back planes can be installed on one 1211 card cage. The 1505 and 1360 cards I/O connections are
connected to a 25-pair Centronics style connector.

2 Theory of Operation:

Balanced audio pairs are applied to 1505 RX inputs on slots 1 and 3 of each 3-card group. The inputs are summed
and sent to TX output’s 1 and 3 and passed through a passive notch filter mounted on the 1360 card mounted in slot
number 2.

3 Installation:

Simply align the backplane PCB over 3 edge connectors, press into place and solder the wire wrap pins to the PCB.

4 Connectors:

4.1 25-Pair Centronics

CS= Card Slot
PIN # Signal PIN # Signal
1 RX #1, 4-wire circuit 1(CS 1)
3 RX #2, 4-wire circuit 1(CS 1)
5 Notch Filter output, 4-wire circuit 1(CS 2)
7 RX #3, 4-wire circuit 2(CS 1)
9 RX #4, 4-wire circuit 2(CS 1)
11 Notch Filter output, 4-wire circuit 2(CS 2)
13 RX #1, 4-wire circuit 3(CS 3)
15 RX #2, 4-wire circuit 3(CS 3)
17 Notch Filter output, 4-wire circuit 3(CS 2)
19 RX #3, 4-wire circuit 4(CS 3)
21 RX #4, 4-wire circuit 4(CS 3)
23 Notch Filter output, 4-wire circuit 4(CS 2)

26 RX #1, 4-wire circuit 1(CS 1)
28 RX #2, 4-wire circuit 1(CS 1)
30 Notch Filter output, 4-wire circuit 1(CS 2)
32 RX #3, 4-wire circuit 2(CS 1)
34 RX #4, 4-wire circuit 2(CS 1)
36 Notch Filter output, 4-wire circuit 2(CS 2)
38 RX #1, 4-wire circuit 3(CS 3)
40 RX #2, 4-wire circuit 3(CS 3)
42 Notch Filter output, 4-wire circuit 3(CS 2)
44 RX #3, 4-wire circuit 4(CS 3)
46 RX #4, 4-wire circuit 4(CS 3)
48 Notch Filter output, 4-wire circuit 4(CS 2)

4.2 Power connections

TB1 is provided for power buss connections from a +12Vdc source, TP connections are provided for parallel
connections between additional backplane PCB’s.

+12Vdc = TB1 pin 1, TP1 and TP11
Ground = TB1 pin 2, TP2 and TP12
Earth GND = TB1 pin 3, TP3 and TP13

TELEX Communications, Inc.

Vega Signaling Products

8601 East Cornhusker Highway, Lincoln, Nebraska, 68507

Phone: [phone] Fax: [phone]

E-mail: [e-mail], Web: www.vega-signaling.com

September 30, 2003