ASCOM H952T User manual

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
Contents
1 General ............................................................................................................................ 1
1.1 Regulatory Compliance Statements (EU/EFTA only) ...................................................... 2
1.2 Regulatory Compliance Statements (USA only) .............................................................. 2
2 Board Description ..........................................................................................................3
3 Installation...................................................................................................................... 5
3.1 Mounting .................................................................................................................................... 6
3.2 Opening the Housing............................................................................................................... 7
3.3 Installation Together with Other Units............................................................................... 7
3.4 Wiring Runs ............................................................................................................................... 8
3.5 Connection of Buses and Control Equipment.................................................................... 9
3.6 Connection of Supply Voltage............................................................................................ 10
3.7 Addressing the Terminal Transmitter.............................................................................. 10
3.8 Coax Connection to Antenna.............................................................................................. 11
4 Parameter Settings ...................................................................................................... 12
5 Installation Test Procedure ......................................................................................... 13
5.1 Field Adjustment ................................................................................................................... 13
6 Circuit Board Replacement .......................................................................................... 14
7 Document History ........................................................................................................ 15
Appendix A: Installation of T952SM/FL Speech and Frequency Lock Module ........... 16
Appendix B: Coaxial Connectors..................................................................................... 18

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
1
1 General
Terminal Transmitter H/U952T is used in the Ascom Paging System. The Terminal
Transmitter operates in both UHF and HF frequency bands.
Figure 1. H/U952T Terminal Transmitter.
U952T is approved for On-board installations. See IMPORTANT: ON-BOARD INSTALLATIONS
on page 5 for more information regarding output power.
H952T U952T
Supply voltage: 12.5 V DC ± 10% 12.5 V DC ± 10%
Max. current consumption: 2.0 A 2.5 A
Max. current consumption during transmission: 1.6 A 1.6 A
Max. current consumption in standby: 0.2 A 0.4 A
IMPORTANT: Protect the unit against current exceeding 20 A. Use power cables with 
cross-section 3 mm2.
The Terminal Transmitter is available in two versions:
U952T: 425-475 MHz
H952T: 25-29 MHz, 29-32 MHz, 32-37 MHz, 37-42 MHz, 42-47 MHz, 47-50 MHz
Delivery includes:
• H/U952T Terminal Transmitter
•CoaxconnectorTNC
• Modular bus cabling
Tools etc., required:
•Screwdriver
•Screwsformounting
• Multimeter
As a complement to this Installation Guide, see the System Installation document.

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
2
1.1 Regulatory Compliance Statements (EU/EFTA only)
Hereby, Ascom (Sweden) AB, declares that this equipment is in compliance with the
essential requirements and other relevant provisions of R&TTE Directive 1999/5/EC.
The declaration of conformity may be consulted at:
https://www.ascom-ws.com/doc/
This equipment uses frequencies referring to different rules in the various EU&EFTA
countries.
A radio communications licence is in most cases necessary for the use of the equipment. The
frequencies required for operation of the radio equipment must be notified and assigned
prior to usage of the equipment.
1.2 Regulatory Compliance Statements (USA only)
FCC Compliance Statements
This equipment has been tested and found to comply with the limits for a Class B digital
device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable
protection against harmful interference in a residential installation. This equipment
generates, uses and can radiate radio frequency energy and, if not installed and used in
accordance with the instructions, may cause harmful interference to radio communications.
However, there is no guarantee that interference will not occur in a particular installation. If
this equipment does cause harmful interference to radio or television reception, which can
be determined by turning the equipment off and on, the user is encouraged to try to correct
the interference by one or more of the following measures:
• Reorient or relocate the transmitting antenna.
•Increase the separation between the equipment and Receiver.
• Connect the equipment into an outlet on a circuit different from that to which the
transmitter is connected.
• Consult the dealer or an experienced radio/TV technician for help.
Information to User
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two
conditions:
(1) this device may not cause harmful interference, and
(2) this device must accept any interference received, including interference that may cause
undesired operation.
Modifications
Changes or modifications to the equipment not expressly approved by the party responsible
for compliance could void the user's authority to operate the equipment.

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
3
2 Board Description
J101
J100
SW100
J103
IC101
SW200
J200
J102
L301
LED100
P400
LED302
LED301
LED300
LED201
LED302
LED301
LED300
LED201
C444 (U952T)
L401 (H952T)
15
Figure 2. H/U952T circuit board.

Connectors
J100, J101 For connecting D-, and SP-bus via modular bus cabling.
J102 Supply voltage.
J103 For connecting D-bus (if modular bus cabling is not used) and Control
Equipment.
J200 For connecting the Speech and Frequency (T952SM/FL) Lock module.
Switches
SW100 Address selector switch.
SW200 Test switch, set to OFF during normal operation.
LEDs
LED100 Function indicator for green, red, or orange indication.
LED201 LED, TX ON, indicates carrier.
LED300 LED, TX DATA ON, indicates paging.
LED301 Indicates DSP running (blinks).
LED302 Indicates speech on.
Flash PROM
IC101 Program memory
Adjustable
Components
P400 Potentiometer, for calibration of output power.
L301 Inductance coil, for fine adjustment of reference frequency.
C444 Capacitor, for adjustment of VCO frequency (only U952T).
L401 Inductance coil, for adjustment of VCO frequency (only H952T).
TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
4

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
5
3 Installation
The unit should be placed in a dry environment. A temperature between 0 and +40°C is
preferred. The unit will operate in the temp range -15 up to +55°C. The unit can be installed
alone or together with other system units using the modular bus cabling or twisted-pair
wiring.
To prevent dust or moisture from damaging the electronics it is important to have the cover
mounted after installation and during use.
IMPORTANT: ON-BOARD INSTALLATIONS
The U952T Terminal Transmitter is shipped with standard output power. Full compliance
with RECOMMENDATION ITU-R M.1174-2 (Technical characteristics of equipment used for
on-board vessel communications in the bands between 450 and 470 MHz) and EN 300 720
(Electromagnetic compatibility and Radio Spectrum Matters (ERM); Ultra-High Frequency
(UHF) on-board communications systems and equipment, Part 1 and 2) regarding radiated
output power and frequency of operation is the responsibility of the installer.
In short:
ITU-R M.1174-2 recommends, in addition to frequencies of operation, “The effective
radiated power should be limited to the maximum required for satisfactory operations, but
should in no case exceed 2 W.”
EN 300 720 specifies frequencies of operation and a maximum output power of 4 W. Please
refer to the original documents for full details.

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
6
3.1 Mounting
IMPORTANT: The unit must be mounted to a vertical wall with the bottom facing the
floor.
Bottom
Top
The illustration below shows the dimensions in mm for mounting the unit.
9 9
275
56.5
188.5
65 130
112
Dimensions (H x W x D)
275 x 130 x 60 mm
Figure 3. Mounting dimensions in mm.
NOTE: To facilitate service after the unit is installed, we recommend a free space of about
150 mm above and 50 mm below the unit.

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
7
3.2 Opening the Housing
Use a screwdriver or similar to release the cover by applying a light pressure to the two snap
catches (1) and remove the cover (2).
1
1
2
Figure 4. Releasing the cover.
NOTE: The internal metal shield should not be opened.
3.3 Installation Together with Other Units
1
1
1 Remove upper and lower covers. Fasten together the lower rectangular covers of
adjacent units (1).
2 Fasten each unit to the wall with three screws, see figure 3 on page 6.

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
8
3.4 Wiring Runs
Wiring can be run three ways from the unit:
• Remove the rectangular covers and run the cabling out through the side (1).
•Run the cabling through the round holes at the bottom of the case (2).
• Remove the circular covers at the top of the side case (3).
1
2
1
2
3
3
IMPORTANT: Do not make any openings at the bottom of the front cover since this does
not comply with the fire enclosure requirements.
The plastic partition (shaded in the illustration) is scored to facilitate breaking at convenient
intervals.
1 Use pliers to break off a suitable section.
2 Run the wiring out through the cable duct at the bottom.
1 2 3 4 5
slots
3 Use the slots at the opening to secure the wiring with cable straps.

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
9
3.5 Connection of Buses and Control Equipment
Buses are connected either via modular bus cabling or twisted-pairs.
NOTE: Data buses are polarized! Use only twisted-pairs for separate wiring!
Bus Connections via Modular Bus Cabling
Pin 1
234567
Pin 8
Pin
1
2
3
4
5
6
7
8
Signal
A1 data bus
A2 data bus
B1 data bus
B1 data bus
D1 data bus
D2 data bus
SP1 speech bus
SP2 speech bus
J100 + J101
Figure 5. Modular bus cable pins.
Note that only D- and SP-bus are used by the Terminal Transmitter. When the modular bus
cable is used, no further connection of the SP-bus to T952SM/FL Speech and Frequency Lock
Module is required.
• Connect the modular bus cabling to connectors J100 and J101, see figure 2 on page 3.
Bus Connections via Twisted-Pairs
J103
1 D1
2 D2
3 Booster control
4 Monitor input
5 GND
H/U952T
D-bus, connection
to a Central Unit
Control of
Power Amplifier
H/U950SC
• Connect the D bus to connector J103, screw 1 and 2.
• If speech is used, see Connection of SP/FL Bus via Twisted-Pairs on page 17.
Connection of Control Equipment
• Connect H/U950SC Output Power Surveillance Module to J103, screw 4 and 5.
See also the Installation Guidefor the respective units.

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
10
3.6 Connection of Supply Voltage
Power Supply
Unit
+
-
• Connect supply voltage to connector J102 screw 1 and 2. See the System Installation
document, chapter Power Supply.
J102
3 +12V
4 GND
1 +12V
2 GND
Supply voltage-in
H/U952T
• An external fuse must be placed between supply voltage connector and power supply.
The recommended fuse is 3.15A, use a quick acting, fast or very fast. It is recommended
to use an output power of 5W or less. Elevated power levels can lead to various
problems, as well as blow the fuse.
NOTE: If a HF transmitter with an indoor antenna (for example, Sat-1) is connected to a
switched-mode power supply (for example, type 3020) using a coax cable of the
minimum specified length of 2.71m, random fluctuations in the electrical signal may
be sufficient to disturb the power supply and cause intermittent restarts of the
transmitter. The problem usually occurs when the installation is housed in a small
room. To reduce the risk of such disturbances, the use of a ferrite core between the
power supply and transmitter is recommended.
3.7 Addressing the Terminal Transmitter
Select the address by setting the address selector switch SW100. See the System
Installation document, chapter Addressing.
The address for H/U952T must not be 00, nor the same as any other Ascom Paging unit 
D-bus address. In case the system includes speech, the Terminal Transmitter must be in the
address range for speech transmitters (hex address 80-FF).

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
11
3.8 Coax Connection to Antenna
• Connect the antenna coax to the antenna output connector located at the upper right of
the Terminal Transmitter.
• To prevent water from running along the antenna cable and entering the Terminal
Transmitter, let the cable form a loop downwards.
Transmitter
For assembly of the coax connector to the cable, see Appendix B.
When an outdoor antenna is used the screen of the antenna cable may be connected to
protective earth. If there is more than one ground connection in the system it will generate a
ground loop. To avoid a ground loop, the antenna cable must be isolated from other
grounding points.
The following options are possible:
For HF: Use Antenna Transformer MAT-50 between the antenna and the Terminal
Transmitter.
For UHF: Insert isolation on the D-bus between the Central Unit and the Terminal
Transmitter. The speech and FL bus is already isolated by transformers. There are two
options:
1 T938D Data Modem. These are used in pairs and cause delay.
For more information see the System Installation document, chapter With Modem to
Transmitters. See also Installation Guide, Data Modem T938D, TD 90907GB.
2 T938BC2 Bus Converter. Isolation by an opto coupler. T938BC2 has two channels.
Only one is used.
See Installation Guide, Bus Converter T938BC2, TD 90925GB.
IMPORTANT: The T938BC2 may be placed either at the Terminal Transmitter or at the
Central Unit position. The Central Unit position is recommended, since than
one channel may be used for one transmitter and the other channel for
another transmitter.

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
12
4 Parameter Settings
All parameters must be set in the U/H952 Flash PROM IC 101, before the tuning procedure.
The instruction for programming fixed equipment is described in General Description PCPAR,
TD 90799GB. Note that licence is required when FOM/SFO or FL is used.
1 Open PCPAR and select software S952T.
2 Set the Terminal Transmitter frequency in Hz.
3 Set the channel spacing.
4 If there is speech in the system check:
• Subtone frequency (default 127.3 Hz).
When FL (frequency locking) is used check:
• That frequency locking is enabled with the right reference frequency.
5 When FOM or SFO is used this has to be enabled with the right offset.
6 If the Terminal Transmitter is to be used withold central software that do not
support U/H952T (specified in the parameter list), set the Terminal Transmitter to
act as an U/H950T.
7 If FOM/SFO or FL is used, enter the required licence code.
8 When you have edited the parameter list, download the changes to flash prom
IC 101 and exit PCPAR.

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
13
5 Installation Test Procedure
1 Check that all sections of switch SW200 on the Terminal Transmitter are set to OFF.
2 Check that address switch SW100 has the right address. See the System Installation
document, chapter Addressing.
3 Energize all units in the Ascom Paging System. Function indicator LED100 on the
Terminal Transmitter should light red for about 1 second and then change to a
flashing green.
If it continues to indicate steady red, check that supply voltage is 12.5 Vdc ± 10%.
Flashing red indicates a program fault, parameter fault, or a faulty 125 MHz
oscillator.
4 If H/U952T is connected to another unit, the indicator should show a steady green
indication within 90 seconds.
If the indicator continues to blink green, check:
• Polarity of data bus(es)
• Connections on H/U952T
• That H/U952T is properly addressed
• That all sections of SW200 is set to OFF
If everything seems to be OK but the function indicator still blinks, the fault is
probably located outside H/U952T:
Check the other Ascom Paging units according to the System Installation document,
or contact your dealer.
5 If T952SM/FL module is used:
• Check that T938RM is connected as a Reference Module if the Terminal
Transmitter is included in a frequency locked system.
• When frequency locking is used it should be locked to a reference frequency
within 20 seconds, the indicator on the T952SM/FL Speech and Frequency Lock
Module is lit red.
• Perform a speech test.
6 Initiate a paging from a unit. The LEDs TX ON and DATA ON lights momentarily, about
2.5 sec. If not, contact your dealer.
7 Replace the cover.
When all other units are installed, perform the system test described in the System
Installation document.
5.1 Field Adjustment
Reference frequency, VCO frequency and output power are all factory-set. If adjustments are
to be done, see Repair Manual, H/U952T Transmitter, TD 92023GB, chapter Alignment and
Adjustment.

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
14
6 Circuit Board Replacement
1 Disconnect the power supply.
2 Remove the antenna coax.
3 Release the cover, see figure 4 on page 7.
4 Lift off the screw connectors from the circuit board.
1
1
3
2
1
1
5 Press the four holding clips (1) and release the circuit board as shown (2 and 3).
6 Install the new circuit board in the case, make sure it clicks into the position.
7 Remove the SM/FL module from the old circuit board (if any) and install it on the new
circuit board.
8 Set all switches and jumpers as they were on the old circuit board.
9Replace the connectors and the antenna coax.
10 Check installation according to the System Installation document.
11 Replace the cover.

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
15
7 Document History
Version Date Description
A13 November 2002 First version
B6 July 2006 Information and requirement for On-board
installation have been added to the document.
C16 May 2007 Insert of regulatory text for EU & EFTA
D3 March 2011 Added text to section Regulatory Compliance
Statements.
3.4 Wiring Runs on page 8 Information about that is
not allowed to make an openings on the front cover
added.
3.8 Coax Connection to Antenna on page 11
Information about the antenna cable added.
Galvanic isolation added.
3.1 Mounting on page 6 Figure and text about
mounting vertically added.
3.6 Connection of Supply Voltage on page 10
external fuse added.
Minor changes
E11 May 2012 Added instruction to protect the unit against
current exceeding 20 A.
Added FCC Compliance Statements.
Changed references to system documents.
Renamed old systems to Ascom Paging System.
Removed section Connection to Slave Transmitter.
Removed H/U989M Monitor Receiver.
Removed H/U954 Power Amplifier.
Minor text changes.
F12 April 2013 Added note to 3.6 Connection of Supply Voltage on
page 10 about recommendation to avoid potential
power supply disturbances.
G3 July 2013 In Appendix B: Coaxial Connectors on page 18:
Added information about an additional brand of the
TNC coax connector.

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
16
Appendix A: Installation of T952SM/FL Speech and Frequency Lock Module
Board Description
2500 3125
R100
J100
R202
R211 R212
1
R203
952SM/FL
LED100
2
1
1
1
+
-
Figure 6. Circuit Board for 952SM/FL.
Connections, etc.
J100 Screw terminal, for speech bus (SP-bus) if system bus cabling is not
used.
LED100 Indicates frequency locking (red).
R100 Speech bus termination resistor.
R211, R212 The mounted resistor indicates the reference frequency used
(default 3125 Hz).
R202, R203 These resistors have to be exchanged when reference
frequency 2500 Hz is used.
Changing Reference Frequency to 2500 Hz
1 Move R212 to R211
2 Change R202 from 33 kto 39 k(tolerance 1%).
3 Change R203 from 34.8 kto 47 k(tolerance 1%).
Installation
• Plug the T952SM/FL Speech and Frequency Lock module onto the connector J200 on the
Terminal Transmitter board, see figure 2 on page 3.

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
17
Connection of SP/FL Bus via Twisted-Pairs
NOTE: Not needed if the buses are connected to the Terminal Transmitter via modular bus
cabling.
• Connect SP-bus to connector J100
J100
1 SP1
2 SP2
T952SM/FL
Connection to
speech bus
.
Figure 7. SP-bus connection via twisted-pairs.
Speech Termination
If more than one speech transmitter is used in a system, only one of the T952SM/FL
modules can have the speech bus termination resistor (R100) connected. R100 must be cut
off on all other T952SM/FL modules.

TD 92022EN
3 July 2013 / Ver. G
Installation Guide
H/U952T Terminal Transmitter
18
Appendix B: Coaxial Connectors
This appendix applies to the following two brands of the TNC coax connector:
• TESCH TNC-30C-TGN
• Telegärtner J01010A0023
Note: The TNC coax connector images below shows the Telegärtner J01010A0023.
When connecting the antenna cable to the Terminal Transmitter the TNC coax connector for
soldering is preferable to use, but an TNC-UHF adapter can be ordered from your supplier if
for example the antenna cable already is equipped with a PL259 (UHF)
TNC Angle connector TNC - UHF adapter
connector.
Figure 8. TNC connector and TNC-UHF adapter.
Assemble TNC Coax Connector as follows:
b
c
d
Washer
Braid
Housing
Shank cone
Cable sheat
Clamprings Nut
a
Telegärtner J01010A0023
Gasket
Screw
Soldering
5.5 13.5 16 19
TESCH TNC-30C-TGN 7.1 8.3 915.4
abcd
1
2
3
Figure 9. Assembly of TNC coax connector.
1 Cut and strip cable as shown in figure at (1) according to the used brand of the TNC
coax connector.