RTS SSA-424 User manual

9350-7638-000 Rev A, 11/98
™
USER INSTRUCTIONS
SSA-424
DUAL DIGITAL HYBRID
ADAM™, ADAM™ CS, AND ZEUS™ INTERCOM SYSTEMS
POWER
4W LEVEL
REF SEL
LEVEL
SET SYSTEM A
4W
2W
TO
TO
2
BAL
1
12
BAL
TW CHAN SEL
-10dB 0dB +4dB
+8dB
+12dB
-15 -12 -9 -6 0 +3 +6 +9 +12-3
4W LEVEL
REF SEL
LEVEL
SET SYSTEM B
4W
2W
TO
TO
2
BAL
1
12
BAL
TW CHAN SEL
-10dB 0dB +4dB
+8dB
+12dB
-15 -12 -9 -6 0 +3 +6 +9 +12-3
SSA-424
TM

2User Instructions, SSA-424 Dual Digital Hybrid
PROPRIETARY NOTICE
The RTS product information and design disclosed herein were
originated by and are the property of Telex Communications, Inc.
Telex reserves all patent, proprietary design, manufacturing, repro-
duction, use and sales rights thereto, and to any article disclosed
therein, except to the extent rights are expressly granted to others.
COPYRIGHT NOTICE
Copyright 1998 by Telex Communications, Inc. All rights re-
served. Reproduction in whole or in part without prior written per-
mission from Telex is prohibited.
UNPACKING AND INSPECTION
Immediately upon receipt of the equipment, inspect the shipping
container and the contents carefully for any discrepancies or dam-
age. Should there be any, notify the freight company and the dealer
at once.
WARRANTY INFORMATION
RTS products are warranted by Telex Communications, Inc. to be
free from defects in materials and workmanship for a period of
three years from the date of sale.
The sole obligation of Telex during the warranty period is to pro-
vide, without charge, parts and labor necessary to remedy covered
defects appearing in products returned prepaid to Telex. This war-
ranty does not cover any defect, malfunction or failure caused be-
yond the control of Telex, including unreasonable or negligent
operation, abuse, accident, failure to follow instructions in the
Service Manual or the User Manual, defective or improper associ-
ated equipment, attempts at modification and repair not authorized
by Telex, and shipping damage. Products with their serial numbers
removed or effaced are not covered by this warranty.
To obtain warranty service, follow the procedures entitled "Proce-
dure For Returns" and "Shipping to Manufacturer for Repair or
Adjustment".
This warranty is the sole and exclusive express warranty given with
respect to RTS products. It is the responsibility of the user to deter-
mine before purchase that this product is suitable for the user's in-
tended purpose.
ANY AND ALL IMPLIED WARRANTIES, INCLUDING
THE IMPLIED WARRANTY OF MERCHANTABILITY
ARE LIMITED TO THE DURATION OF THIS EXPRESS
LIMITED WARRANTY.
NEITHER TELEX NOR THE DEALER WHO SELLS RTS
PRODUCTS IS LIABLE FOR INCIDENTAL OR CONSE-
QUENTIAL DAMAGES OF ANY KIND.
CUSTOMER SUPPORT
Technical questions should be directed to:
Customer Service Department
RTS/Telex,
2550 Hollywood Way, Suite 207
Burbank, CA 91505 U.S.A.
Telephone: [phone]
Fax: [phone]
RETURN SHIPPING INSTRUCTIONS
PROCEDURE FOR RETURNS
If a repair is necessary, contact the dealer where this unit was pur-
chased.
If repair through the dealer is not possible, obtain a RETURN
AUTHORIZATION from:
Customer Service Department
Telex Communications, Inc.
Telephone: [phone]
Fax: [phone]
DO NOT RETURN ANY EQUIPMENT DIRECTLY TO THE
FACTORY WITHOUT FIRST OBTAINING A RETURN
AUTHORIZATION.
Be prepared to provide the company name, address, phone number,
a person to contact regarding the repair, the type and quantity of
equipment, a description of the problem and the serial number(s).
SHIPPING TO MANUFACTURER FOR REPAIR OR
ADJUSTMENT
All shipments of RTS products should be made via United Parcel
Service or the best available shipper, prepaid. The equipment
should be shipped in the original packing carton; if that is not
available, use any suitable container that is rigid and of adequate
size. If a substitute container is used, the equipment should be
wrapped in paper and surrounded with at least four inches of excel-
sior or similar shock-absorbing material. All shipments must be
sent to the following address and must include the Return Authori-
zation.
Factory Service Department
Telex Communications, Incorporated
West 1st Street
Blue Earth, MN 56013 U.S.A.
Upon completion of any repair the equipment will be returned via
United Parcel Service or specified shipper collect.

User Instructions, SSA-424 Dual Digital Hybrid 3
TABLE OF CONTENTS
1 DESCRIPTION AND SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1 GENERAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2 GENERAL FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3 FRONT AND BACK PANEL DESCRIPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.3.1 Front Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.3.2 Back Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.4 SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2 INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1 UNPACKING AND INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 MOUNTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3 4-WIRE AUDIO CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3.1 ADAM, ADAM CS or Zeus Audio Connection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3.2 Audio Connections for Other 4-Wire Communication Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.4 2-WIRE AUDIO CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.4.1 RTS TW Audio Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.4.2 Audiocom Audio Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.4.3 Clear-Com Audio Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.4.4 Other 2-wire Audio Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.5 4-WIRE CALL SIGNAL CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.5.1 Call Signal Connections for ADAM, ADAM CS, and Zeus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.5.2 Call Signal Connections for Other 4-Wire Communication Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.5.2.1 4-Wire Call Send and Call Enable/Inhibit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.5.2.2 4-Wire Call Receive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.6 2-WIRE CALL SIGNAL CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.6.1 Call Signal Connections for Audiocom, RTS TW and Clear-Com . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.6.2 Call Signal Connections for Other 2-wire Communication System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3 OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.1 GENERAL INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.2 OPERATING NOTES FOR ADAM, ADAM CS, AND Zeus Intercom SystemS. . . . . . . . . . . . . . . . . . . . . . . . 15
4 APPENDIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.1 INTERNAL ACCESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.2 MODE DIP SWITCH SETTINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.3 LEVEL DISPLAY CALIBRATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.4 CALL SIGNAL OPTION CARD INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4User Instructions, SSA-424 Dual Digital Hybrid
LIST OF FIGURES
Figure 1. SSA-424 Reference View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Figure 2. Rack mount configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Figure 3. Using a TW-5W to connect twoTW channels to the SSA424. . . . . . . . . . . . . . . . . . . . . . . 9
Figure 4. Using a JB-2 Junction Box to split a 2-channel Audiocom cable into two 1-channel cables. . . . . . . 9
Figure 5. Call signal connections for ADAM, ADAM CS, or Zeus Intercom Systems. . . . . . . . . . . . . . 11
Figure 6. Typical call send and call enable/inhibit connections for a 4-wire intercom system. . . . . . . . . . . 13
Figure 7. Call signal connections for 4-wire intercom systems other than ADAM, ADAM CS, and Zeus. . . . . 13
Figure 8. Location of level adjust trimmers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 9. Location of screws for disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 10. Locations of internal controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 11. The Call Signal Option Card after installaton in the SSA-424.. . . . . . . . . . . . . . . . . . . . . 17
LIST OF TABLES
Table 1. GPI Connector Pin-out (ADAM, ADAM CS, and Zeus) . . . . . . . . . . . . . . . . . . . . . . . . . 11
Table 2. UIO-256 GPI Inputs Connector (J7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Table 3. UIO-256 GPI Outputs Connector (J5). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Table 4. Mode DIP Switch Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

1 DESCRIPTION AND SPECIFICATIONS
1.1 GENERAL DESCRIPTION
The SSA-424 Dual Digital Hybrid interfaces two, 2-wire
intercom lines to two, 4-wire intercom lines. Unlike ear-
lier analog hybrids, the SSA-424 features advanced digital
signal processing to achieve automatic nulling of the
2-wire lines. Plus, each hybrid features convenient
peak-reading level meters to quickly match the levels be-
tween the lines that are being interfaced. The result is easy
and accurate setup. With the SSA-424, all need for test
tones, nulling adjustments and ducking adjustments have
been eliminated.
Compatible 2-wire intercom systems include RTS™ TW,
Audiocom®, and Clear-Com®. Compatible 4-wire inter-
com systems include Telex’s ADAM™, ADAM™ CS and
Zeus™ Digital Matrix Intercom Systems.
The SSA-424 is also available with optional call signal
interfacing. This option provides bidirectional call signal
compatibility between the 2-wire and 4-wire intercom
systems.
With features like digital signal processing, peak-reading
level meters and optional call signal interfacing, the
SSA-424 Dual Digital Hybrid assures ease of setup and
maximum transparency between intercom systems.
1.2 GENERAL FEATURES
Two Independent Hybrids: Interface two separate
2-wire lines to two separate 4-wire lines.
Automatic Nulling: Digital hybrids eliminate all nulling
and ducking adjustments. Quick, trouble-free setup. Puts
an end to concerns about echo and feedback when inter-
facing 2-wire lines.
Peak Reading Level Meters: Quick and accurate visual
audio level adjustment. No extra setup equipment or
guesswork is required.
Direct ADAM / Zeus Audio Connection: Accepts stan-
dard ADAM / Zeus DB9 or RJ11 keypanel cables.
Transformer Isolated: All audio inputs and outputs are
transformer isolated to prevent ground loops and hum.
Call Signal Option: Detects call signals from any of the
compatible 2-wire intercom systems, and then provides a
+5VDC output to the 4-wire intercom system. Accepts a
contact closure input from the 4-wire system and converts
it to the call signal format required by the 2-wire system.
The SSA424 can be directly connected to an ADAM,
ADAM CS, or Zeus GPI (General Purpose Interface). GPI
inputs can be programmed to activate call signals and au-
dio paths to any of the available types of communication
within the 4-wire system, including intercom ports, cam-
era ISO circuits, IFB circuits, etc. GPI outputs can be set
up to place calls only from a specific keypanel within the
4-wire system, or from any keypanel within the 4-wire
system that wishes to call the 2-wire system.
Half-rack Wide, 1RU High: Two SSA-424’s fit into a
single rack space. Compatible with RTS TW rack mount
hardware. Can be mixed with other TW equipment.
Universal Power Pack: Ready for worldwide use. Auto-
matically accepts any mains voltage from 100-250 VAC,
50/60 Hz. Power pack equipped with locking DIN con-
nector for attachment to the SSA-424.
User Instructions, SSA-424 Dual Digital Hybrid 5
AUX
J4B
J3B J2B J1B J1A J2A J3A
J4A
AUX
4 WIRE SYSTEM 4 WIRE SYSTEM
2 WIRE SYSTEM
Telex Communications, Inc., Made in U.S.A.
-15 -12 -9 -6 0 +3 +6 +9 +12
LEVEL
SET SYSTEM B
-15 -12 -9 -6 -3 0+3 +6 +9 +12 4W
2W
TO
TO
SSA-424
4W LEVEL
REF SEL
12
BAL
2W CHAN SEL
LEVEL
SET SYSTEM A
-3 4W
2W
TO
TO
POWER 4W LEVEL
REF SEL
12
BAL
2W CHAN SEL 12BAL
OFF
OFF
TM
RTN
+5V RTN
+15V -15V
-15V 0.3A
+15V 1.6A
+5V 3A
J5 POWER
0dB +4dB+8dB
+12dB
-10dB
0dB +4dB+8dB
+12dB
-10dB 12BAL
OFF
OFF
Figure 1. SSA-424 Reference View

1.3 FRONT AND BACK PANEL DESCRIPTIONS
1.3.1 Front Panel
There is a power on/off and call indicator at the left of the
front panel. This indicator lights continuously when the
SSA-424 is turned on and flashes when an incoming call
signal is detected. The remainder of the front panel is di-
vided into controls and indicators for the two separate hy-
brids, labeled SYSTEM A and SYSTEM B. For each
hybrid, there is a 10-segment, peak reading level meter to
display the 4-wire output level (TO 4W). There is a re-
cessed level set control to the left of the 4-wire meter
(LEVEL SET) and there is also a recessed, 5-position
range select control for the 4-wire output (4W LEVEL
REF SEL). Under the 4-wire meter, is an identical meter
for the 2-wire output level, and there is a recessed level
set control for the 2-wire output to the left of the meter.
Under the 2-wire meter, there is a recessed, 5-position se-
lector. The selector has two OFF positions for when no
2-wire input is connected. The three remaining switch po-
sitions select the 2-wire system as follows: position 1 se-
lects RTS TW channel 1; position 2 selects RTW TW
channel 2 or a Clear-Com channel; the BAL position se-
lects an Audiocom balanced channel. There are 3 led indi-
cators to display the current selection (2W CHAN SEL).
1.3.2 Back Panel
The power pack connector is located at the right end of
the back panel. This is a locking DIN connector. The re-
mainder of the back panel is divided into connectors for
the two separate hybrids. Connectors are labeled with “J”
numbers followed by “A” or “B” to indicate system A or
system B. For each hybrid, there is an AUX connector.
This is used to connect to / from the optional call signal
card. Below the AUX connector, there are both a DB9F
connector and an RJ11 connector for 4-wire intercom
connection. These are directly compatible with standard
ADAM / Zeus keypanel cables. Next to the 4-wire con-
nectors, there is a 3-pin female XLR audio connector for
connection to the 2-wire intercom system. The pin-out of
this connector is determined by the position of the TW
CHAN SEL control on the front panel.
1.4 SPECIFICATIONS
2-Wire Ports
Input / Output Impedance: 5,000 ohms, nominal
Operating Level: -10 dBu to 0 dBu, nominal
Level Adjustment Range: ±12 dB
4-Wire Ports
Input Impedance: 10 kohms, nominal
Output Impedance: 200 ohms
Operating Levels: -10 dBu, 0 dBu, +4 dBu, +8 dBu,
+12 dBu
System to System
Frequency Response: 200 Hz to 4.5 kHz, +1 / -6 dB
S/N Ratio (Ref 1 kHz, 0 dB @ 2-wire): TBD
Crosstalk: TBD
Environmental
Operating Temperature: -20°C to 50°C
Storage Temperature: -40°C to 85°C
Humidity: 0 to 95%, non-condensing
Mains Voltage
100 to 250 VAC, 50 / 60 Hz
Dimensions
1.72” (44mm) high x 8.19” (208mm) wide x 8.0”
(204mm) deep
Weight
5.0 lbs. (2.3 kg)
Finish
Thermoplastic front panel, aluminum case, light gray
finish
Approvals
UL, CSA, UDE, CE
6User Instructions, SSA-424 Dual Digital Hybrid
Specifications subject to change without notice.

2 INSTALLATION
2.1 UNPACKING AND INSPECTION
Immediately upon receipt of the equipment, carefully in-
spect the shipping container and the contents for any dis-
crepancies or damage. Should there be any, notify the
freight company and the dealer at once. The following
items are included:
Qty Description
1 SSA-424 Dual Digital Hybrid
1 Power Pack with cord, 100-250 VAC, 50/60 Hz
1 Warranty and registration card
1 User Instruction Manual
Fill out and return the registration card.
2.2 MOUNTING
Place the SSA-424 on a desktop, or install it in an equip-
ment rack using an RTS MCP Rack Mount Kit. Several
rack mount options are available (Figure 2, page 8). There
are no special ventilation requirements for the SSA-424,
but allow ventilation around the power pack.
☞If the SSA-424 has the call signal option, the power
indicator flashes whenever a call signal is received
from either 2-wire line, and activity on the level dis-
play helps to indicate which line is calling. If the
SSA-424 is positioned near the 4-wire operator, this
can be used as an incoming call indication for the
4-wire system if desired (although other methods are
also available as described in paragraph 2.5).
☞You may wish to read about the internal mode DIP
switches before mounting the SSA-424. For further
information, see Mode Switch Settings, page 16.
2.3 4-WIRE AUDIO CONNECTIONS
2.3.1 ADAM, ADAM CS or Zeus Audio Connection
1. Use standard 9-pin or RJ11 keypanel cables. Connect
from one port of your intercom system to J2A or J3A
(System A connection) on the back of the SSA-424.
Connect from another port to J2B or J3B (System B
connection).
2. On the SSA-424 front panel, set the 4W LEVEL REF
SEL switches to the +8dB position.
2.3.2 Audio Connections for Other 4-Wire
Communication Systems
1. Construct 9-pin or RJ11 cables to connect from your
4-wire system to the SSA-424. To connect to the Sys-
tem A hybrid use either J2A or J3A; for the System B
hybrid, use either J2B or J3B. Pin connections are as
follows:
9-Pin Connection
Connector Type (on SSA-424 end of cable): 9-pin
male D-subminiature
Pin 1: No connection
Pin 2: No connection
Pin 3: No connection
Pin 4: Balanced Audio + output (to 4-wire system)
Pin 5: Balanced Audio - output (to 4-wire system)
Pin 6: No connection
Pin 7: Balanced Audio - input (from 4-wire system)
Pin 8: Balanced Audio + input (from 4-wire system)
Pin 9: No connection
RJ11 Connection
Connector Type (on SSA-424 end of cable): RJ11
plug
Pin 1: No connection
Pin 2: Balanced Audio + input (from 4-wire system)
Pin 3: Balanced Audio + output (to 4-wire system)
Pin 4: Balanced Audio - output (to 4-wire system)
Pin 5: Balanced Audio - input (from 4-wire system)
Pin 6: No connection
2. On the SSA-424 front panel, set the 4W LEVEL REF
SEL switches to the position which most closely
matches the audio input and output levels of you
4-wire system. If you don't know the levels, select
+4dB for now.
User Instructions, SSA-424 Dual Digital Hybrid 7

8User Instructions, SSA-424 Dual Digital Hybrid
Side-By-Side Rack Mount Configuration Using an MCP1 Rack Mount Kit
Single-unit Rack Mount Configuration Using an MCP2 Rack Mount Kit
Tandem Configuration Using an MCP4Tandem Mount Kit
Console Mount Configuration Using an MCP3 Console Mount Kit
Figure 2. Rack mount configurations

2.4 2-WIRE AUDIO CONNECTIONS
2.4.1 RTS TW Audio Connections
1. Use standard TW intercom cables. Note that standard
TW system cables can carry either one or two chan-
nels, while each hybrid in the SSA-424 can only inter-
face one TW channel to one 4-wire channel (which
channel is determined by the front panel 2W CHAN
SEL switch). If your TW system cable is only carrying
one channel, or if you only need to connect one of two
channels, connect directly to J1A (System A) or J1B
(System B). If your TW system cable is carrying two
channels, and you want to connect both, use a TW-5W
or similar device as shown in Figure 3.
☞The SSA-424 features internal DC isolation. You can
therefore connect the SSA-424 to powered TW ca-
bles, and it will not draw any power from the TW
system.
2. On the SSA-424 front panel: For each hybrid (Sys-
tem A and System B) set the 2W CHAN SEL switch
to the appropriate position. To interface to TW chan-
nel 1, select position 1; for TW channel 2, select po-
sition 2.
☞If the System A or System B hybrid will not be used,
set its 2W CHAN SEL switch to either OFF position.
2.4.2 Audiocom Audio Connection
1. You can directly connect standard Audiocom
1-channel cables. Connect one Audiocom channel to
the J1A connector on the back of the SSA-424 (Sys-
tem A). Connect a second Audiocom channel to the
J1B connector (System B). If your Audiocom system
uses 2-channel cables, use a JB-2 Junction Box to
split the channels (Figure 4).
☞The SSA-424 features internal DC isolation. You can
therefore connect the SSA-424 to powered Audiocom
cables, and it will not draw any power from the
Audiocom system.
2. On the SSA-424 front panel, set the 2W CHAN SEL
switches for System A and System B to the BAL po-
sition.
☞If the System A or System B hybrid will not be used,
set its 2W CHAN SEL switch to either OFF position.
User Instructions, SSA-424 Dual Digital Hybrid 9
PUSH
AUX
J4B
J3B J2B J1B J1A J2A J3A
J4A
AUX
4 WIRE SYSTEM 4 WIRE SYSTEM
2 WIRE SYSTEM
TelexCommunications, Inc., Made in U.S.A.
RTN
+5V RTN
+15V -15V
-15V 0.3A
+15V 1.6A
+5V 3A
J5 POWER
TW-5W
SSA-424
FROM RTS TW
INTERCOM SYSTEM
TW CABLE PIN-OUT
PIN 1 COMMON
PIN 2 CH 1
PIN 3 CH 2
Figure 3. Using a TW-5W to connect twoTW channels
to the SSA424.
LINES 1&2LINE 1 LINE 2
JB-2
SSA-424
CH 1 AND 2
FROM AUDIOCOM
INTERCOM SYSTEM
CH 1
CH 2
AUX
J4B
J3B J2B J1B J1A J2A J3A
J4A
AUX
4 WIRE SYSTEM 4 WIRE SYSTEM
2 WIRE SYSTEM
TelexCommunications, Inc., Made in U.S.A.
RTN
+5V RTN
+15V -15V
-15V 0.3A
+15V 1.6A
+5V 3A
J5 POWER
Figure 4. Using a JB-2 Junction Box to split a
2-channel Audiocom cable into two 1-channel cables.

2.4.3 Clear-Com Audio Connection
1. Use standard Clear-Com 3-pin cables. Connect one
Clear-Com party line to the J1A connector on the
back of the SSA-424 (System A). Connect a separate
Clear-Com party line to the J1B connector (System
B).
☞The SSA-424 features internal DC isolation. You can
therefore connect the SSA-424 to powered
Clear-Com cables, and it will not draw any power
from the Clear-Com system.
2. On the SSA-424 front panel, set the System A and
System B 2W CHAN SEL switches to position 2.
☞If the System A or System B hybrid will not be used,
set its 2W CHAN SEL switch to either OFF position.
2.4.4 Other 2-wire Audio Connection
1. Use the J1A connector on the back of the SSA-424 to
connect one 2-wire line to the System A hybrid. Use
the J1B connector to connect a second 2-wire line to
the System B hybrid. The pin configuration for the
J1A and J1B connectors depends on whether you are
connecting a balanced or unbalanced 2-wire line:
Balanced Configuration
Pin 1: No connection
Pin 2: Balanced Audio + Input/Output
Pin 3: Balanced Audio - Input/Output
There are two possible configurations for unbalanced con-
nection:
Unbalanced Configuration 1
Pin 1: Audio Common
Pin 2: Audio + Input/Output
Pin 3: No connection
Unbalanced Configuration 2
Pin 1: Audio Common
Pin 2: No connection
Pin 3: Audio + Input/Output
2. On the SSA-424 front panel, set the CHAN SEL
switches as follows:
•Balanced Configuration: set the CHAN SEL
switches to the BAL position.
•Unbalanced Configuration 1: set the CHAN
SEL switches to position 1.
•Unbalanced Configuration 2: set the CHAN
SEL switches to position 2.
☞If the System A or System B hybrid will not be used,
set its 2W CHAN SEL switch to either OFF position.
10 User Instructions, SSA-424 Dual Digital Hybrid

2.5 4-WIRE CALL SIGNAL CONNECTIONS
☞These connections require the call signal option.
2.5.1 Call Signal Connections for ADAM,
ADAM CS, and Zeus
You can use the General Purpose Interface (GPI) connec-
tor to interface call signals. The pin-out of the connector
is the same for all of these intercom systems (Table 1).
ADAM GPI Connector: XCP-ADAM-MC, J11
ADAM CS GPI Connector: J903
Zeus GPI Connector: J27
If your intercom system is equipped with a UIO-256 Uni-
versal Input/Output Frame, you can also use that for con-
nections (Tables 2and 3, page 12).
As an alternative to using the GPI, you can use external
components to send and receive call signals as described
in paragraph 2.5.2.
Typical GPI connections are shown in Figure 5. Note that
the example uses GPI outputs #1 and #2 and GPI input
#1. You may substitute other GPI inputs and outputs.
Important Note for ADAMedit users: ADAMedit ver-
sion 1.06 includes a feature which lets you invert the ac-
tion of the GPI outputs. By default, these outputs are set
to duplicate the action of the RTS FR9528 Relay Frame
accessory. This is the correct setting for use with the
SSA424. To check the ADAMedit setting, select Intercom
Configuration in the Options menu. Click on the Options
tab, and make sure that there is a check mark next to Con-
figure onboard GPI outputs in FR9528 mode.
User Instructions, SSA-424 Dual Digital Hybrid 11
Pin No. Function
1 GPI Input #1 High (5-18 VDC)
2 GPI Input #2 High (5-18 VDC)
3 GPI Input #3 High (5-18 VDC)
4 GPI Input #4 High (5-18 VDC)
5 GPI Input #5 High (5-18 VDC)
6 GPI Input #6 High (5-18 VDC)
7 GPI Input #7 High (5-18 VDC)
8 GPI Input #8 High (5-18 VDC)
9 Common*
10 Common*
11 Common*
12 Common*
13 Common*
14 GPI Out #1
15 GPI Out #2
16 GPI Out #3
17 GPI Out #4
18 GPI Out #5
19 GPI Out #6
20 GPI Out #7
21 GPI Out #8
22 Common*
23 Common*
24 Common*
25 Common*
* Use any available common pin with any GPI input or
output.
Table 1. GPI Connector Pin-out (ADAM,
ADAM CS, and Zeus)
DB9F CABLE
(View from solder or crimp side)
CONNECTOR PIN NUMBERS
15432
67 89
TO SSA-424
AUX CONNECTOR
(SYSTEM A OR B)
FROM GPI OUT #1 (4-WIRE CALL SEND OUTPUT)
UIO-256 APPLICATION NOTE: GPI OUT - AT THE UIO-256 END, USETHE NORMAL OPEN (NO) CONTACT
FOR GPI OUT CONNECTION, AND USE THE RELAY COMMON CONTACT FORTHE COMMON CONNECTION.
- USE THE INPUT HIGH PIN FOR THE GPI IN CONNECTION, AND USE THE COMMON PIN FORTHE
COMMON CONNECTION.
GPI IN
CLEAR-COM APPLICATION NOTE: IF A
CALL ENABLE/INHIBIT SWITCH IS NOT
USED, A JUMPER MUST BE
INSTALLED TO ENABLE CALL SIGNALING.
THE JUMPER IS NOT REQUIRED FOR ANY
OTHER APPLICATION. FROM GPI OUT #2 (OPTIONAL CALL ENABLE/INHIBIT CONTROL)
GPI OUT COMMON (SEE UIO-256 APPLICATION NOTE)
TO GPI IN #1 (4-WIRE CALL RECEIVE INPUT)
TO GPI IN COMMON
Figure 5. Call signal connections for ADAM, ADAM CS, or Zeus Intercom Systems. This example uses GPI outputs #1
and #2 and GPI input #1; however, you may use any other available GPI inputs and outputs. The Call Enable/Inhibit connec-
tion is optional. It gives you the ability to disable call signaling using a GPI output. However, when connecting to a Clear-Com
intercom system, if an enable/inhibit switch is not connected, a jumper must be installed as shown to enable call signaling. The
jumper should not be installed for any other application. Note: You do not have to use GPI outputs for call signaling or call en-
able/inhibit: you can use simple switches instead as shown in Figure 6.

12 User Instructions, SSA-424 Dual Digital Hybrid
GPI Input Numbers* GPI Input Pin Numbers
UIO-256
Frame #1 UIO-256 Frame #2 UIO-256 Frame #3 UIO-256 Frame #4 Common Input High (5-18 VDC)
1173349934
2 18 345010 35
3 19 355111 36
4 20 365212 37
5 21 375313 38
6 22 385414 39
7 23 395515 40
8 24 405616 41
9254157126
10 26 42 58 2 27
11 27 43 59 3 28
12 28 44 60 4 29
13 29 45 61 5 30
14 30 46 62 6 31
15 31 47 63 7 32
16 32 48 64 8 33
*Dependent on UIO-256 DIP Switch SW1 Settings for Input/Output Range as summarized in the UIO-256 manual.
Table 2. UIO-256 GPI Inputs Connector (J7)
Relay Output Numbers* Relay Contact Pin Numbers**
UIO-256 #1 UIO-256 #2 UIO-256 #3 UIO-256 #4 Normal Closed
(NC) Contact Common Contact Normal Open (NO) Contact
1173349381340
2183450391415
3193551411643
4203652421718
5213753441946
6223854452021
7233955472249
8244056482324
925415726128
10 26 42 58 27 2 3
11 27 43 59 29 4 31
12 28 44 60 30 5 6
13 29 45 61 32 7 34
14 30 46 62 33 8 9
15 31 47 63 35 10 37
16 32 48 64 36 11 12
*Dependent on UIO-256 DIP Switch SW1 Settings for Input/Output Range as summarized in the UIO-256 manual.
Table 3. UIO-256 GPI Outputs Connector (J5)

2.5.2 Call Signal Connections for Other 4-Wire
Communication Systems
2.5.2.1 4-Wire Call Send and Call Enable/Inhibit
The SSA-424 accepts a switch-contact input from the
4-wire system and then generates a call signal output to
the 2-wire system. The SSA-424 also accepts an optional
switch contact input to enable or inhibit call signalling be-
tween the 4-wire and 2-wire systems. Figure 6shows the
typical connections.
2.5.2.2 4-Wire Call Receive
The SSA-424 receives call signals from the 2-wire sys-
tem, then converts this to relay contact closure for use as a
4-wire call receive indication. The SSA-424 also provides
+5VDC which can be connected to the relay contacts to
generate a DC output signal instead of a contact closure.
Connections for simple contact closure and DC output
signal are shown in Figure 7.
☞The SSA-424 power indicator flashes whenever a call
signal is received from either 2-wire line. This can be
used as an incoming call indication for the 4-wire
system if desired, and the level display should pro-
vide an indication of which line is calling.
User Instructions, SSA-424 Dual Digital Hybrid 13
COMMON
4-WIRE CALL SEND
CALL ENABLE/INHIBIT
15432
6789
DB9F
(View from solder or crimp side)
CONNECTOR PIN NUMBERS
CLEAR-COM APPLICATION NOTE:
IF A CALL ENABLE/INHIBIT
SWITCH IS NOT USED, A JUMPER
MUST BE INSTALLED TO ENABLE
CALL SIGNALING.THE JUMPER IS
NOT REQUIRED FOR ANY OTHER
APPLICATION.
Figure 6. Typical call send and call enable/inhibit con-
nections for a 4-wire intercom system.
10 Ohm
PIN 4
AUX
CONNECTOR
(SYSTEM A OR B)
PIN 8
PIN 5
PIN 3
PIN 9
5VDC
DC COMMON
15432
6789
TO SSA-424 AUX CONNECTOR
DB9F CABLE
(View from solder or crimp side)
CONNECTOR PIN NUMBERS
TO 4-WIRE SYSTEM
DB9F CABLE
(View from solder or crimp side)
CONNECTOR PIN NUMBERS
15432
67 89 TO 4-WIRE + INPUT
TO 4-WIRE COMMON
TO SSA-424
AUX CONNECTOR
(SYSTEM A OR B)
SSA-424 INTERNAL CIRCUIT FOR CALL SIGNAL
OUTPUT TO 4-WIRE INTERCOM SYSTEM
+5VDC SIGNAL TO 4-WIRE
SYSTEM WHEN 2-WIRE SYSTEM CALLS
OUTPUT SHORTSTO COMMON FOR NO CALL
SIMPLE SWITCH CONTACT CLOSURE TO 4-WIRE
SYSTEM WHEN 2-WIRE SYSTEM CALLS
OPEN CIRCUIT FOR NO CALL
Figure 7. Call signal connections for 4-wire intercom
systems other than ADAM, ADAM CS, and Zeus.

2.6 2-WIRE CALL SIGNAL CONNECTIONS
2.6.1 Call Signal Connections for Audiocom,
RTS TW and Clear-Com
The call signals are superimposed on the audio signal, so
no separate call signal connections are required. However,
make sure that a call enable switch or jumper is installed
for Clear-Com applications as shown in Figures 5and 6.
2.6.2 Call Signal Connections for Other 2-wire
Communication System
Any other 2-wire device must be able to generate and re-
ceive a 20 kHz signal superimposed on the audio as fol-
lows:
Balanced Audio Configuration
Pin 1: No connection
Pin 2: Balanced 20 kHz + Input/Output
Pin 3: Balanced 20 kHz - Input/Output
SSA-424 Signal Specifications for balanced configuration:
SSA-424 Receive: 20 kHz ±100 Hz, 100mV p-p
SSA-424 Send: 20 kHz ±800 Hz, 1V p-p
Unbalanced Configuration 1
Pin 1: 20 kHz Common
Pin 2: 20 kHz Input/Output
Pin 3: No connection
Unbalanced Configuration 2
Pin 1: 20 kHz Common
Pin 2: No connection
Pin 3: 20 kHz Input/Output
SSA-424 Signal Specifications for unbalanced configu-
rations:
SSA-424 Receive: 20 kHz ±100 Hz, 0.3 Vrms
SSA-424 Send: 20 kHz ±200 Hz, 100 mVrms
14 User Instructions, SSA-424 Dual Digital Hybrid

3 OPERATION
3.1 GENERAL INSTRUCTIONS
1. Attach the power pack to the SSA-424, and apply
power to all components. Confirm that the power in-
dicator is lit on the SSA-424 front panel.
2. The power indicator flashes when a call signal is re-
ceived from a 2-wire line. The SSA-424 level dis-
plays should help to confirm which line is calling.
3. Use the level adjust trimmers (Figure 8) to fine-adjust
the listen levels.
☞For 4-wire systems other than ADAM, ADAM CS,
and Zeus, you may have to change the setting of the
4W LEVEL REF SEL control to establish the correct
level. For 2-wire systems other than Audiocom, TW,
and Clear-Com, you may have to adjust the level at
the 2-wire system if you cannot establish the correct
level with the 2-wire listen level trimmers.
3.2 OPERATING NOTES FOR ADAM, ADAM CS,
AND ZEUS INTERCOM SYSTEMS
1. In ADAMedit (or ZEUSedit) use port alpha setup to
name each 4-wire intercom port that is connected to
the SSA-424. Choose names which help indicate
which 2-wire line is being interfaced.
2. Key assignment, party line assignment, etc. is the
same as for any other intercom port.
3. Optional call signal output using the GPI: You can
assign the GPI output to a talk or listen key, then acti-
vate that key to generate a call signal.
Another way to generate a call signal is by assigning
the GPI output as a level 2 talk key assignment for
any key that is assigned to talk to the SSA-424. How-
ever, this will cause the call lights to flash on the
2-wire line during the entire conversation.
Another solution is to assign a dedicated key as a
UPL resource key (which you could name CALL).
Then for each key that talks to an SSA-424 hybrid,
create a UPL statement that will activate (assert) the
appropriate GPI whenever the call key AND the talk
key are pressed. This lets you use the same call key
with more than one GPI. To use this, you simply acti-
vate the call key and the appropriate talk key. Then,
when a verbal response is received, release the call
key.
4. Optional call signal input using the GPI.
A. In ADAMedit (or ZEUSedit) access GPI input
setup. (Click the GPI In button on the toolbar.)
B. Whichever GPI input you are using for 4-wire
call receive, select that GPI input from the list
(double-click). This will open the Edit GPI Input
window.
C. In the Port Alpha list box, select the intercom
port that you named in step 1.
D. In the Key Number box, type 1. This selects key
1 at the intercom port that you selected in step C.
E. Select Talk Key.
F. Click Done.
G. Access keypanel setup, and select the same
intercom port that you selected in step C.
H. Make sure the setup page Main is selected.
I. Assign talk key number 1 to talk to the intercom
port that you setup in step 2. We also
recommend that you assign auto-listen (AL) to
the listen key above that talk key.
5. Optional call enable control. If you connected a GPI
output for use as a call enable control, you can assign
that GPI output to any intercom key in the 4-wire in-
tercom system. If System A is connected to an
Audiocom or TW intercom system, pressing the key
will disable call signaling. (However, the effect is the
opposite if a Clear-Com system is connected: press-
ing the key will disable call signaling.)
6. Send your changes to the intercom system. This com-
pletes any required programming for an ADAM,
ADAM CS, or Zeus intercom system.
User Instructions, SSA-424 Dual Digital Hybrid 15
-15 -12 -9 -6 0 +3 +6 +9 +12
LEVEL
SET SYSTEM B
-15 -12 -9 -6 -3 0+3 +6 +9 +12 4W
2W
TO
TO
SSA-424
4W LEVEL
REF SEL
12
BAL
2W CHAN SEL
LEVEL
SET SYSTEM A
-3 4W
2W
TO
TO
POWER 4W LEVEL
REF SEL
12
BAL
2W CHAN SEL 12BAL
OFF
OFF
TM
0dB +4dB+8dB
+12dB
-10dB
0dB +4dB+8dB
+12dB
-10dB 12BAL
OFF
OFF
4-WIRE LISTEN LEVEL ADJUSTMENT
2-WIRE LISTEN LEVEL ADJUSTMENT
Figure 8. Location of level adjust trimmers

4 APPENDIX
4.1 INTERNAL ACCESS
1. Remove six screws from the back cover.
2. Remove the top cover. This provides access to all in-
ternal adjustments.
3. For option card installation, slide the circuit board out
toward the back to remove it from the bottom cover.
4.2 MODE DIP SWITCH SETTINGS
S301 contols the operating mode for System B and S302
controls the operating mode for System A. Settings are
summarized in Table 4.
4.3 LEVEL DISPLAY CALIBRATION
☞This is a factory preset adjustment and should not re-
quire readjustment.
1. On the front panel, set the 4W LEVEL REF SEL
controls to -10dB.
2. Set the 2W CHAN SEL switches to 1.
3. Input a 1 kHz, -10dBu test signal at J1A (System A)
or J1B (System B). (Pin 1, signal common; pin 2, sig-
nal high).
4. Adjust RV101 (System A) or RV201 (System B)
while watching the top display (TO4W). All of the
green displays should be lit and no amber displays
should be lit.
5. Remove the test signal.
16 User Instructions, SSA-424 Dual Digital Hybrid
AUX
J4B
J3B J2B J1B J1A J2A J3A
J4A
AUX
4 WIRE SYSTEM 4 WIRE SYSTEM
2 WIRE SYSTEM
Telex Communications, Inc., Made in U.S.A.
RTN
+5V RTN
+15V -15V
-15V 0.3A
+15V 1.6A
+5V 3A
J5 POWER
Figure 9. Location of screws for disassembly
RV102
RV101
RV202 RV201
S301
S302
Figure 10. Locations of internal controls
Switch Settings Description
1234
Off Off Off Off Configuration 1, Half / Full Duplex
Mode: Automatically switches between
modes. Useful in situations where there
is high ambient noise. Also useful when
there is acoustic feedback.
On Off Off Off Configuration 2, Switched Full Duplex
Mode (Default Setting): Switches from
half duplex to full duplex 3-9 seconds
after conversation begins on the 4-wire
line. Stays in full duplex mode until
60-90 seconds after conversaton
ceases. This helps to keep the line
quiet during periods of no conversa-
tion, while permitting natural conversa-
tion when people are talking. This is
the preferred operating mode for many
situations, and particularly for fast,
close-coordination, team operations.
On Off Off On Configuration 3, Locked Full Duplex
Mode: Same as configuration 2, but
once a hybrid enters full-duplex mode, it
stays in that mode until power-down.
Off Off On Off Configuration 4, Half / Full Duplex
Mode: Similar to configuration 1, but
with higher sensitivity.
Table 4. Mode DIP Switch Settings
Half-duplex Definition: Only one side of the line can
talk at a time and the other side must wait until the
first side is done talking before responding.
Full-duplex Definition: Both sides of the line can
talk simultaneously.

6. Set the 2W CHAN SEL switches to either OFF
position.
7. Input a 1 kHz, -10dBu test signal at the 4-wire audio
input. Use either connector:
9-Pin Connector
Pin 7: Balanced Audio - input
Pin 8: Balanced Audio + input
RJ11 Connector
Pin 2: Balanced Audio + input
Pin 5: Balanced Audio - input
8. Adjust RV102 (System A) or RV202 (System B)
while watching the bottom display (TO2W). All of
the green displays should be lit and no amber dis-
plays should be lit.
9. Remove the test signal. This completes the adjust-
ment.
4.4 CALL SIGNAL OPTION CARD
INSTALLATION
Use these instructions to install a Call Signal Option Card
in an SSA-424 that was originally ordered without it.
1. Disassemble the SSA-424 as previously described.
2. Assemble the standoffs to the circuit board using the
supplied screws and lockwashers.
3. Connect the supplied power cable from J8 on the op-
tion card to J303 on the main board of the SSA-424.
4. Insert the connectors on the option card into the con-
nectors on the main board.
5. Use the remaining screws and lockwashers to secure
the standoffs to the main board.
6. Reassemble the SSA-424.
User Instructions, SSA-424 Dual Digital Hybrid 17
Figure 11. The Call Signal Option Card after installaton
in the SSA-424.