jotron TA-7650C Operating instructions

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85894_M&R_TA7650C_A 2
EC Declaration of Conformity available at: www.jotron.com
Abbreviations and definitions
ALARM
Message by which the unit signals the occurrence of an event. The alarm is indicated by an audible tone and/or a
message (or icon) on the display.
APM
Audio and PTT Modem. The APM is designed for use in applications, which requires long distance control of
radios through a 4 or 2 wire leased lines. The modems use in-band signaling for transfer of PTT and Squelch,
and FSK data for transfer of alarms and Main/Standby selection.
ARC
With Audio Remote Control it is possible to extend the audio and PTT signals for a transmitter/receiver
combination consisting of one main and one standby transceiver.
One or two line pair is used for each transceiver and contains both PTT and audio in both directions.
BAUD
Transmission rate unit of measurement for binary coded data (bit per second).
BIT
Short form of Binary Digit. The smallest element of data in a binary-coded value.
BITE
Built In Test Equipment
bps
Bits Per Second.
DRC
Data Remote Control. With the DRC unit functions like frequency settings, BITE etc. are extended to a remote
panel. The DRC unit requires 1 separate line pair that is connected to the serial interface of the radio. Several
DRC units may share the same line. All functions in the transmitter can be controlled from the DRC.
DSP
Digital Signal Processor
FbA, FbB, FbC
Functional buttons to maneuver in the menus, located at the front of the equipment.
FSK
Frequency Shift Keying
ICAO
International Civil Aviation Organization
IEC
International Electro-technical Commission.
INTERFACE
Electronic circuits that permit the passage of data between different types of devices.
ITU
International Telecommunication Union.

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LAN
Local Area Network
I.ED
Light Emitting Diode.
ORC
Operators Remote Control. With the ORC it is possible to select frequencies, which are stored in the channel
memory of the radio. To ease the operation, channel names can be used for each frequency. The ORC requires a
separate line pair that is connected to the serial interface of the radio. Several ORC units may share the same
line.
PA
Power Amplifier
PSU
Power Supply Unit. Separate unit to power the equipment.
PTT
Push To Talk
RESET
To return stored values to either the default value or zero in memory.
RF
Radio Frequency
R/O
Read only
R/W
Read and Write
SIGNAL- TO-NOISE RATIO (S/N)
Quantitative relationship between the useful and non-useful part of the received signal. A high S/N indicates a
good receiving condition.
S/N
See SIGNAL- TO-NOISE RATIO
SNMP
Simple Network Management Protocol
This equipment is defined as an AGENT in an SNMP system.
SOFTWARE
Values programmed and preloaded into memory. The values represent a permanent set of instructions for
running the automatic functions (computations) of the unit.
UHF
Ultra High Frequency; A set of frequencies in the upper MHz region.
VHF
Very High Frequency; A set of frequencies in the lower MHz region.
VSWR
Voltage Standing Wave Ratio.

85894_M&R_TA7650C_A 4
Amendment Record
AMENDMENT
NO. INCORP. BY DATE PAGE(S) VERSION REASON FOR CHANGE
1 ES 21.05.10 26 PA New release
2 ES 26.05.10 26 A Inserted stock no
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85894_M&R_TA7650C_A 5
The information in this book has been carefully checked and is believed to be accurate. However, no
responsibility is assumed for inaccuracies.
Jotron AS reserves the right to make changes without further notice to any products or modules
described herein to improve reliability, function or design. Jotron AS does not assume any liability
arising out of the application or use of the described product.
SAFETY INSTRUCTIONS
CAUTION!
This equipment contains CMOS integrated circuits. Observe handling precautions to avoid static
discharges which may damage these devices.
WARNING!
Some RF semiconductor devices used in this equipment may contain Beryllium Oxide. If inhaled, dust
from this oxide can be toxic. No danger will arise from normal handling but no attempt should be
made to tamper with these devices. On no account must these transistors be destroyed or discarded
with industrial or domestic waste, but should be returned to the manufacturers for subsequent disposal.
1. Do not place liquid-filled containers on top of the equipment.
2. Immediately turn off the power if water or other liquid leaks into the equipment.
Continued use of the equipment can cause fire or electrical shock.
Contact Jotron AS for service.
3. Immediately turn off the power if the equipment is emitting smoke or fire.
4. Do not operate the equipment with wet hands.

85894_M&R_TA7650C_A 6
TABLE OF CONTENTS
1MAINTENANCE AND TROUBLESHOOTING.................................................................................... 1-1
1.1 ENVIRONMENTAL CHECK...................................................................................................................... 1-1
1.2 ALARM READING .................................................................................................................................. 1-1
1.3 TX BITE MENU...................................................................................................................................... 1-2
1.3.1 BITE alarm condition................................................................................................................... 1-3
2TECHNICAL DESCRIPTION TA-7650C ..............................................................................................2-1
2.1 INTRODUCTION ..................................................................................................................................... 2-1
2.2 MAIN MODULE...................................................................................................................................... 2-2
2.2.1 Main board................................................................................................................................... 2-2
2.2.1.1 DSP .......................................................................................................................................... 2-2
2.2.1.2 Audio........................................................................................................................................ 2-2
2.2.1.3 Baseband DACs ....................................................................................................................... 2-2
2.2.1.4 PA Feedback ADC................................................................................................................... 2-2
2.2.1.5 BITE interface.......................................................................................................................... 2-3
2.2.1.6 I/O interface.............................................................................................................................. 2-3
2.2.1.7 Ethernet controller.................................................................................................................... 2-3
2.2.1.8 Memory.................................................................................................................................... 2-3
2.3 FRONT MODULE .................................................................................................................................... 2-3
2.3.1 Front board.................................................................................................................................. 2-3
2.4 PA MODULE .......................................................................................................................................... 2-3
2.4.1 PA board ...................................................................................................................................... 2-3
2.4.2 Regulator board ........................................................................................................................... 2-5
2.5 MODULATOR MODULE .......................................................................................................................... 2-5
2.5.1 Modulator board.......................................................................................................................... 2-5
2.6 SOFTWARE MODULE.............................................................................................................................. 2-6
2.7 PSU-7002 POWER SUPPLY UNIT ........................................................................................................... 2-6
2.8 REMOTE DATA INTERFACE ................................................................................................................... 2-6
3DIAGRAMS................................................................................................................................................ 3-1
3.1 TA-7650C TRANSMITTER UNIT............................................................................................................. 3-1
4PARTS LIST...............................................................................................................................................4-1
5APPENDIX.................................................................................................................................................5-1
5.1 PSU-7002 BILL OF MATERIALS ............................................................................................................. 5-1
5.2 PSU-7002 DIAGRAM 1OF 2................................................................................................................... 5-7
5.2.1 PSU-7002 diagram 2of 2.............................................................................................................. 5-8

85894_M&R_TA7650C_A 1-1
1MAINTENANCE AND TROUBLESHOOTING
1.1 Environmental check
Once a year:
1. Turn OFF the unit.
2. Disconnect all plugs.
3. Clean all metal surfaces using a humid rag to remove dirt and dust.
4. Clean the knobs and connectors.
5. Clean the loudspeaker cover.
6. Connect all plugs.
7. Turn ON the unit.
1.2 Alarm reading
If for some reason the “AL” light lit red and the display show one of these conditions, please
check TX BITE menu chapter 1.3 for abnormal readings.
Display text: Possible reason: Module or Board
Alarm Failure on the PA module PA module
Mod Failure on the Modulation module Modulation module
Front Failure on the Front Module Front module
Main Failure on the Main Module Main module
Ethernet Failure communicating with the ethernet_PHY Main board
Codec Failure communicating with the codec Main board
Spi Failure on the spi bus Main board
Front Failure communicating with the front module Main board
Remexp Failure communicating with the rem expander Main board
Biteadc Failure communicating with the bite adc Main board
Dsp Internal DSP failure Main board
txSpare Spare Spare

85894_M&R_TA7650C_A 1-2
1.3 TX Bite menu
To check the BITE alarm conditions, please see chapter 1.3.1 .
PA Module:Forward power in 1/10 dBm (472 =47dBm)
PA Module:Reflected power in 1/10 dBm (12 =1dBm)
PA Module:Calculated SWR in 1/10 (15 =1:1)
PA Module:Current consumption in milliAmps (mA)
PA Module:Temperature in degrees Celcius (°C)
PA Module:+28V DC voltage in milliVolts (mV)
PA Module:+12V DC voltage in milliVolts (mV)
FbA FbB
FbA FbB
PA Module:+5V DC voltage in milliVolts (mV)
PA Module:+3V3 DC voltage in milliVolts (mV)
PA Module:AM depth (modulation) in %
PA Module:FM deviation in kHz*10 (50=+/-5.0 kHz)
FbA FbB
Modulation Module:LO level in 1/10 dBm (100 =10dBm)
Modulation Module:LO Locked (1) or unlocked (2) - Locked is normal
Modulation Module:+6V voltage in milliVolts (mV)
Main Module:Line level output in 1/10 dBm (-100 =-10dBm)
FbA FbB
Push FbC
to enter
RX Alarm.

85894_M&R_TA7650C_A 1-3
1.3.1 BITE alarm condition
PARAMETER:
Alarm criteria Condition: Module:
Min Max Unit
PA_3V3 2.9 3.6 V PA
PA_5V 4.5 5.5 V PA
PA_12V 11 12.8 V PA
PA_28V 20 29 V PA
PA_CUR 0 10 A PA current drain PA
MOD_6V 5.0 7.0 V Modulator
MOD_LD_L01 Digital 3v3 - 3.3V Logic – alarm if unlocked Modulator
PA_TEMP -25 +85 °C PA temperature PA
MOD_LEVEL_L01 -20 8 dBm Modulator
PA_5VN -6.2 -4.0 V PA
PA_SWR NA NA - Calculated SWR Main

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2TECHNICAL DESCRIPTION TA-7650C
The transmitter TA-7650C is described in this manual.
2.1 Introduction
84555
TA-7650C
TRANSMITTER UNIT w/PSU
82417
PSU-7002
UNIT
84830
SW7000
BOOTLOADER
84552
SW
MODULE
84554
PA
MODULE
82419
FRONT
MODULE
84001
FRONT
BOARD
84557
MODULATOR
MODULE
84553
PA
BOARD
8245884006
MAIN
BOARD
84556
MODULATOR
BOARD
REG
BOARD
84558
MAIN
MODULE
84549
OPTION
POWER FILTER
The TA-7650C transmitter unit consists of five modules and five boards:
•Main module
•Main board
•Front module
•Front board
•PA module
•PA board
•Reg. board
•Modulator module
•Modulator board
•Software module

85894_M&R_TA7650C_A 2-2
2.2 Main module
The main module consists of the main board and the modulator module.
The modulator module is plugged into the main module.
2.2.1 Main board
The main board consists of DSP section, Audio section, DAC/ADC interface, BITE interface,
I/O interface, Ethernet controller and memory section.
2.2.1.1 DSP
The heart of the board is a digital signal processor (DSP-IC42) running firmware for all
interactions with it’s peripherals. The DSP has implemented functionality to:
•Modulate a given input signal with AM and D8PSK, and generate I/Q baseband data.
•Interface with the Audio Codec responsible for converting audio signals and BITE
measurements.
•Interface with the D/A converters converting baseband signals to RF/IF
•Interface with the A/D converters converting the demodulated output signal from
analog to digital.
•Implement an adaptive linearization loop for improving Power Amplifier (PA)
performance
•Interact with the ethernet controller for external control and data exchange
•Implement a user interface, interact with user actions and provide visual feedback
through display and LED’s.
2.2.1.2 Audio
The audio codec(IC 13) will receive and transmit digital audio data from/to the DSP. The
audio codec itself will be responsible for:
•Amplifying, mixing and converting microphone signals to digital codes
•Amplifying, mixing and converting analogue input line(s) to digital codes
•Conduct analogue BITE measurements and convert these to digital values
The audio from the audio codec is routed to an audio amplifier (IC 38 –Monitor, IC11-
Headphone)
2.2.1.3 Baseband DACs
A dual DAC(IC 17) will interface with the DSP. This DAC will :
•Perform high-quality DA conversion of the digital signal to analog I/Q-signal
•Provide a good match between the I/Q channels.
2.2.1.4 PA Feedback ADC
Two ADC’s will demodulated output signal. The output of this will be fed into the DSP,
which in turn will use this data for adaptive pre-distortion of the PA and output signal for
monitoring purposes.

85894_M&R_TA7650C_A 2-3
2.2.1.5 BITE interface
The BITE interface consists of a A/D converter (IC 8) with 12 analog channels, reading
analog measurements from all modules. It communicates with the DSP on a SPI bus.
2.2.1.6 I/O interface
The I/O expander (IC12) provides the board with sufficient digital I/O lines for external and
internal interfaces. It communicates with the DSP on a SPI bus. All external interfaces are
passed through either relays or optocouplers for good immunity.
As part of the external interface, an RS232 (IC 34) and an RS485 (IC33) bus is provided
2.2.1.7 Ethernet controller
To simplify external communication, an on-board ethernet controller is implemented. This is
responsible for:
•MAC/PHY layer interaction with LAN (IC 44).
•Communication with DSP through memory bus.
2.2.1.8 Memory
The DSP needs external memory banks to work. The board is equipped with 32Mbit Flash (IC
1) and 128Mbit SDRAM (IC 3).
2.3 Front module
The front module consists of the front board and the front panel.
2.3.1 Front board
The front board contains the Graphical OLED display and the push buttons visible on the
front panel. The display is controlled trough the SPI bus. The push buttons and LED’s are
interfaced to an I/O expander (IC 1). The expander communicates with the DSP through the
SPI bus.
The Front board is connected directly to the TX main board trough connector PL1.
2.4 PA module
The PA module consists of the PA board with cooling profile and fans. It also contains the
Regulator board and rear wall with connectors.
2.4.1 PA board
RF amplifier:
The signal from the Modulator module, located on the TX main board, enters trough PL1. The
signal is buffered by transistor Q15 to achieve a good matching of the output of the
modulator.

85894_M&R_TA7650C_A 2-4
The signal then the first amplifier, Q6. Q6 is autobiased by the circuit consisting of Q3 and
Q1. The gain in this stage is also adjustable by altering the bias of D1. This is part of the
overall gain control in the PA.
Then the signal is amplified further in the pre-driver, Q6. This is a MOSFET type transistor,
and it is auto-biased by Q2 and Q4. The output is taken trough a 4:1 impedance transformer
and fed to the input of the driver transistor Q8. Q108 is also of MOSFET type.
Q8 drives the output stage Q5 trough a single ended 4:1 impedance transformer, and a
9:1 balanced impedance transformer. Q111 is a “gemini” transistor set which operates as a
push-pull amplifier. The output is impedance transformed and converted to single ended by
transformer T2.
All RF stages are enclosed in a shielded box to avoid excessive RF interference on the
surrounding circuitry.
PIN switch
From the output of the power amplifier the signal is fed to the T/R switch which is realised by
using PIN diodes. In transmit mode D7 and D6 are forward biased, and the RF then passes
through D7 and trough the antenna filter. In receive mode both D6 and D7 are unbiased, and
the antenna signal flows through the directional coupler and antenna-filter, trough L6 and out
on the Rx port PL5.
Antenna filter and directional coupler
In transmit mode, after passing trough the T/R switch the output signal passes trough the
lowpass filter consisting of L7/L8/L9/L10/L11 and C67/C68/C69/C70/C71/C72. The low
pass filter ensures excellent attenuation of the harmonics from the output stage.
A directional coupler is the last element in the signal path. It plays a vital role in the
modulation process, and is a critical part for obtaining good modulation characteristics.
Both forward and reflected power is detected in the directional coupler. D9 rectifies the
reflected power and this voltage is used in the BITE and to detect poor impedance matching
of the output. The detected forward power is passed trough the attenuator consisting of R81,
R82 and R83 and passed to the modulator module through PL7, where it is demodulated by
the quadrature demodulator (se modulator module).
Voltage regulators and control circuits
IC1 is the fan control circuit. It reads the voltage from temperature sensor IC4. IC4 senses the
temperature of the cooling tunnel and the speed of the fan is regulated according to the
measured temperature. The fan starts at approx. 40°C.
The main supply for the RF amplifier is regulated with IC17B and Q9. Q9 is a very low

85894_M&R_TA7650C_A 2-5
on-resistance MOSFET and acts as a switch when the input voltage goes below the wanted
output voltage. IC6 supplies approx. 35V, (input voltage + 8.2V) to the main regulator circuit.
The relay RL1 is the main powerswitch and also acts as a reverse polarity protection because
of D4.
Current measurement is done with IC2. There is also a current limiter (IC5B), which reduces
supply voltage if current consumption is too high.
IC8 generates -5VDC for the TX main board.
2.4.2 Regulator board
This board accepts 21.6 - 31.2VDC input voltage.
The DC voltage is converted to +3.3VDC, +5VDC and +12VDC by switchmode regulators
IC1, IC2 and IC5. All regulator outputs are filtered to prevent noise from interfering on the
Modulator board and TX Main board.
The microcontroller IC4 controls the powerup of the regulators, and controls ON switching of
the equipment via the power relay on the PA board.. It also stores the current powerstate in
the internal EEprom, so that it remembers if the unit was switched on after a power failure.
2.5 Modulator module
The Modulator module consists of the RF frontend board and a shielding box
The Modulator module is plugged directly into the Main board.
2.5.1 Modulator board
The Modulator board can be divided into four main sections:
•I/Q modulator
•I/Q demodulator
•Synthesiser
I/Q modulator
IC4 is a I/Q modulator and the output signal is controlled by the I/Q input signals from the
Main board. The signals are filtered are filtered by LC filters on the inputs. The output signal
is filtered by a tracking filter to improve wideband noise.
IC5 is a powerdetector and measures the output level of the modulator. It is used to tune the
trackingfilter and is also a part of the BITE.
I/Q demodulator
IC2 is the demodulator and demodulates the signal from the directional coupler on the PA
board. It plays a vital part of the control loop of the transmitter. The demodulated signal is

85894_M&R_TA7650C_A 2-6
prosessed in the DSP on the mainboard, and the I/Q signals to the modulator are modified
accordingly.
Synthesizer
The VCO is operating at 2 times the output frequency. Q4 is the oscillator transistor and the
frequency is controlled by varicaps D1and D2. The VCO have a separate regulated supply to
get as low noise as possible on the output signal. The signal is then split up in three parts. On
signal is going to the divider IC1 which supplies the modulator LO signal. The VCO signal is
also supplied directly to the demodulator which operates on the double frequency. A part of
the LO signal is also fed to the synthesizer IC3. The synthesizer is controlled from the main
board via the SPI bus.
Reference input is taken from the system clock located on the main board.
2.6 Software module
The Software module contains all necessary software to make the TA-7650C transmitter unit
functional.
2.7 PSU-7002 Power supply Unit
The PSU converts an AC input voltage between 105VAC and 250VAC to a 28V regulated
DC voltage to support the 7000 series transmitters.
The maximum load is 280VA.
If both the AC and DC power supply connection is made to the PSU, it will automatically
switch to the DC backup supply in case the main AC supply fails.
2.8 Remote Data Interface
The data on the RS-232/RS-485 bus is transferred both ways with a data rate of 1200 b/s,
using 9 bit data format, and 1 stop bit.
The data on the LAN connection uses SNMP protocol.

85894_M&R_TA7650C_A 3-1
3DIAGRAMS
3.1 TA-7650C transmitter unit
Block diagram TA-7650C BD-84555
Circuit diagram, Main board part 1 E-84006-1
Circuit diagram, Main board part 2 E-84006-2
Circuit diagram, Main board part 3 E-84006-3
Circuit diagram, Main board part 4 E-84006-4
Circuit diagram, Main board part 5 E-84006-5
Circuit diagram, Main board part 6 E-84006-6
Circuit diagram, Main board part 7 E-84006-7
Circuit diagram, Main board part 8 E-84006-8
Circuit diagram, Main board part 9 E-84006-9
Place plan, Main board part 1 KP-84006-1
Place plan, Main board part 2 KP-84006-2
Circuit diagram, PA board part 1 E-84553-1
Circuit diagram, PA board part 2 E-84553-2
Circuit diagram, PA board part 3 E-84553-3
Place plan, PA board, part 1 KP-84553-1
Place plan, PA board part 2 KP-84553-2
Circuit diagram,Reg board E-82458-1
Place plan, Reg board KP-82458-1
Circuit diagram, Front board part 1 E-84001-1
Place plan, Front board part 1 KP-84001-1
Place plan, Front board part 2 KP-84001-2
Circuit diagram, Modulator board part 1 E-84556-1
Circuit diagram, Modulator board part 2 E-84556-2
Circuit diagram, Modulator board part 3 E-84556-3
Place plan, Modulator board, part 1 KP-84556-1
Place plan, Modulator board part 2 KP-84556-2

85894_M&R_TA7650C_A 4-1
4PARTS LIST
Bill Of Material (BOM)
Transmitter Unit BOM-84555
Front module BOM-82419
Front board BOM-84001
PA module BOM-84554
PA board BOM-84553
Reg. Board BOM-82458
Main module BOM-84558
Main board BOM-84006
Modulator module BOM-84557
Modulator board BOM-84556

85894_M&R_TA7650C_A 5-1
5APPENDIX
5.1 PSU-7002 bill of materials
The PSU-7002 consists of a traded power supply, PBNO0311, from Powerbox A/S.
The PBNO0311 consists of LEP240F-36 from Cosel.

85894_M&R_TA7650C_A 5-2

85894_M&R_TA7650C_A 5-3