jotron Tron TR20 GMDSS, Tron TR20 PLUS Technical Handbook
JOTRON electronics a.s.
Tron TR20 GMDSS
Tron TR20 PLUS
Technical Handbook
Januar 2003
Tron TR20 1-1
AMENDMENT RECORD
AMDT INCORP. BY DATE PAGE(S) AMDT INCORP. BY DATE PAGE(S)
1
BA 15.10.01
BOM/KP/E-99936
21
FIT 04.02.03
BOM/E-99940
2
BA 23.10.01
EM3688
BOM/KP/E-99936
22
PA 10.03.03
EM3948
BOM/E-99940
3
AF 08.11.01
EM3699
BOM-99936
23
PA 10.03.03
EM3953
BOM/E-99940
4
AF 14.11.01
EM3727
BOM/KP/E-99940
24
PA 10.03.03
EM3954
BOM/E-99936
5
BA 14.11.01
EM3728
BOM/KP/E-99936
25
6
BA 14.12.01 2-1,5-2, 7-1, 8-1
26
7
AF 07.01.02
EM3762
BOM-99940
27
8
BA 10,01.02
EM3764
BOM/E-99936
28
9
BA 04.02.02
7-1 Draw updated,
Appendix A added
29
10
FIT 20.02.02
EM3804
BOM-99940
30
11
BA 22.02.02
EM3805
E/KP/BOM-99940
31
12
FIT 26.02.02
EM3806
New SW u.gr.
32
13
BA 05.03.02
EM3810
KP-99936
33
14
BA 10.04.02
EM3824
KP-99940
34
15
AF 10.04.02
EM3825
KP-99936
35
16
BA 11.04.02
EM3828
KP-99940
36
17
AF 25.07.02
EM3860
KP/BOM-99936
37
18
TOW 23.09.02
EM3879
BOM-99930
38
19
PA 10.10.02
EM3890
E/BOM-99940
39
20
PA 28.10.02
EM3897
BOM-99940
40
Tron TR20 1-2
The information in this book has been carefully checked and is believed to be
accurate. However, no responsibility is assumed for inaccuracies.
CAUTION!
This equipment contains CMOS integrated circuits. Observe handling precautions to
avoid static discharges which may damage these devices.
JOTRON electronics a.s reserves the right to make changes without further notice
to any products or modules described herein to improve reliability, function or design.
JOTRON electronic a.s does not assume any liability arising
out of the application or use of the described product.
Tron TR20 1-3
CONTENTS
-----------------------------------------------------------------------------------------------------------------
1. SYSTEM DESCRIPTION ..............................................................1-5
General information ..........................................................................................................................1-5
2. TECHNICAL SPECIFICATION .....................................................2-1
3. FUNCTIONAL DESCRIPTION......................................................3-1
Precautions and Warnings................................................................................................................ 3-1
Batteries .......................................................................................................................................................3-1
Connectors and cables.................................................................................................................................. 3-1
Display and front panel................................................................................................................................ 3-1
Storage and safe handling ............................................................................................................................ 3-1
4. OPERATING INSTRUCTIONS .....................................................4-1
Controls............................................................................................................................................. 4-1
Auxiliary connector............................................................................................................................ 4-1
5. TECHNICAL DESCRIPTION ........................................................5-1
Introduction ....................................................................................................................................... 5-1
Main board (99940)........................................................................................................................... 5-1
Audio Frequency section ............................................................................................................................. 5-1
Receiver Audio circuits................................................................................................................................ 5-2
Control Circuits............................................................................................................................................ 5-2
Power supply Circuits .................................................................................................................................. 5-2
Synth / IF board (99936a)................................................................................................................ 5-2
Synthesiser ................................................................................................................................................... 5-2
IF circuit....................................................................................................................................................... 5-3
RF board (99936b)............................................................................................................................ 5-3
Receiver front end........................................................................................................................................ 5-3
Transmitter section....................................................................................................................................... 5-3
6. MAINTENANCE ............................................................................6-1
Tuning of LO frequency .................................................................................................................... 6-1
Other adjustments............................................................................................................................. 6-1
7. DIAGRAMS ...................................................................................7-1
8. PARTS LISTS ...............................................................................8-1
Tron TR20 1-4
1. SYSTEM DESCRIPTION
General information
The JOTRON Tron TR20 is a VHF radiotelephone designed to operate in the maritime VHF band.
It comes in two versions, Tron TR20 GMDSS and Tron TR20 PLUS.
Tron TR20 GMDSS is specially designed for GMDSS applications and fulfills the ETS 300 225
spesification and is waterproof to IP67. The housing is made of glass-reinforced polycarbonate in a
highly visible orange colour.
The Tron TR20 PLUS is designed for commercial and leisure use and fulfils the EN 301 178 standard.
This version is equipped with connectors for use of external headset and/or microphone. IP rating on
this version is IP54. The housing is made in the same material as the Tron TR20 GMDSS, but the
colour is grey as opposed to the orange GMDSS version
Tron TR20 1-5
2. TECHNICAL SPECIFICATION
General
Frequency range: 156 – 163 MHz
Channel spacing: 25kHz (12.5kHz optional)
Operating temperature range: –20 to +55°C.
Battery life: > 8 hours (Lithium battery,
2W power output, 10-10-80)
> 7 hours (1500mAh NiMH battery,
5W power output, 5-5-90)
Antenna connector: SMA
Microphone connector: 2.5mm jack (Tron TR20 PLUS)
Headset connector: 3.5mm jack (Tron TR20 PLUS)
AF output power internal: 200mW.
AF output power external: 100mW.
Housing material: Glass-reinforced polycarbonate
Display: Polycarbonate
Gasket: PTS Thermoflex
Keyboard: Silicon
Battery lock: POM
Size: 62mm wide x 160mm height x 41mm depth
Weight: Approx. 420g with NiMH battery
Approx. 350g with Lithium battery
Receiver
Maximum usable sensitivity: < 1µV for 20dB SINAD
Adjacent channel rejection: > 70dB
Blocking: > 90dB
Spurious response: > 70dB
Harmonic distortion: < 5%
Intermodulation rejection: > 68dB
Transmitter
RF output power, Hi 5 W TR20 PLUS
2 W TR20 GMDSS
RF output power, Lo 1 W TR20 PLUS
1 W TR20 GMDSS
Harmonics and spurious: < 0.25µW
Frequency error: < +1.5kHz
Adjacent channel power: < -70dBc
Tron TR20
2-1
3. FUNCTIONAL DESCRIPTION
Precautions and Warnings
Batteries
Two types of batteries are used:
Rechargeable batteries for normal use (type 80059),
and Lithium batteries for emergency use (type 80060).
The rechargeable battery is of NiMH type with a capacity of 7.2V/1500mAh. The following
should be noticed:
• Do not short-circuit, solder, crush, disassemble or incinerate the battery pack. This may
result in fire, explosion and severe burn hazard.
• Avoid charging batteries below 0 °C or above 40 °C.
The lithium battery has a capacity of 2000mAh. The following should be noticed:
• The Lithium battery is not rechargeable, and must never be charged.
• Do not short-circuit, solder, crush, disassemble or incinerate the battery pack. This may
result in fire, explosion and severe burn hazard.
Connectors and cables
When handling connectors and cables, notice the following warnings:
• Do not force plugs in place, as this may damage the pins in the plugs.
• Do not pull the cables when removing connectors from the Tron TR20, take instead a firm
grip around the connector and pull.
Display and front panel
Avoid touching the display with sharp objects. Scratches can reduce the visibility.
Storage and safe handling
Storage temperature range is from –30°C to +70°C and operating temperature is from -20 °C
to +55 °C.
Cleaning of the equipment can be done with a cloth soaked in a mixture of ordinary dishdetergent and water.
Tron TR20
3-1
4. OPERATING INSTRUCTIONS
Controls
Fig. 2.1 shows the location of different
controls and facilities of the Tron TR20:
1 - PTT (Push To Talk)
2 - Up
3 - Menu
4 - Channel
5 - High / Low power
6 - Channel 16
7 - Battery release
8 - ON / OFF
9 - Down
10 - Squelch
11 - Enter DW/TW
12 - Auxiliary connector
(Tron TR20 Plus only)
13 - Antenna
Auxiliary connector
The auxiliary connector on the Tron TR20 Plus enables the user to connect an external
microphone or headset.
1- Mic ground
2- Mic
3- Speaker
4- Speaker ground
For further instructions on use, please consult the Users Manual.
Tron TR20
4-1
5. TECHNICAL DESCRIPTION
Introduction
The transceiver consists of 3 printed circuit boards.
• Main board (99940)
This board contains the power supply and power control circuits. In addition the board contains the
microcontroller and display.
• Synth/IF board (99936a)
The synthesiser unit includes the VCO, buffer amplifier and synthesiser for the transceiver. It also
contains the IF and detector circuits for the receiver.
• RF board (99936b).
This board contains the transmitter power amplifier chain, RF switch, the RF front end and first
mixer.
Most components used are of surface mount type except some high-power devices.
Main board (99940)
The Main board can be divided into three main sections:
• Audio frequency section.
• Power supply section.
• Control circuits.
Audio Frequency section
Microphone amplifier, bandpass filter and modulation adjustment
The microphone is connected via the switch (101) to the VOGAD (Voice-Operated Gain-Adjusting
Device) amplifier (IC103).
The gain of this amplifier is automatically adjusted and different acoustic levels will be corrected to
give nominal modulation.
When an external microphone is connected, IC101 is used to turn of the internal microphone.
This function is performed by IC104A. It is sensing the presence of an external microphone by sensing
the current flowing through the external microphone supply.
The next amplifier stage is operates as gain stage and limiter (IC102A). To prevent the deviation
passing ±5kHz, the limiter is clipping signals with a peak level of more than +
2.5V.
C109 and R108/R110 perform the pre-emphasis of the modulation signal.
The signal then enters the band pass filter (IC102B).
Output from the band pass is fed to IC108. IC108 is a quad D/A converter. The modulation signal is
scaled by the D/A converter to give the correct modulation. The microcontroller controls the D/A
converter. The signal is then fed to the modulator on the VCO.
Tron TR20
5-1
Receiver Audio circuits
The audio signal from the IF section enters through J103 # 19, and is feed to the de-emphasis network
(R128, C122), and then to the low pass filter (IC105B). The signal is then feed to the audio output
amplifier (IC107). The microcontroller adjusts the volume by varying the voltage on pin 4 with the D/A
converter (IC108).
The squelch level is also adjusted with the D/A converter. The level set by the microcontroller is
compared with the RSSI signal from the demodulator by IC104B. R135 provides hysteresis to the
circuit.
Control Circuits
The microcontroller (IC109) sets up the synthesiser and controls all functions in the transceiver.
It has a built in ADC with multiplexer which is used to measure the most important parameters in the
transceiver. During transmitt the output power is measured to check that the transmitter is actually
transmitting, and the lock status of the synthesiser is also checked. Any fault will be indicated on the
display. (E1 = Synthesiser out of lock, E2 = No output power).
Configuration data, such as channel settings, volume and squelch settings are stored in an external
EEPROM (IC111). Both the graphical display and the synthesiser are controlled via the SPI bus.
Q110 and D106 act as an infrared port used for factory testing.
The microcontroller contains one software module. To read out the software version, enter the main
menu and select ”info”. The software version is then shown on the display. The controller is made with
flash technology, so firmware upgrade is possible without changing the controller. J104 is the
programming port.
Power supply Circuits
IC113 is the main power switch in the radio. Power off is controlled from the microcontroller.
IC112 is a low drop voltage regulator, and supplies 5V to most of the radio’s circuits.
Synth / IF board (99936a).
Synthesiser
The synthesiser is located on the Synth/IF board. M1 is the oscillator transistor in the VCO. The
oscillator frequency is controlled by the varicaps D2 - D6.
The signal is tapped on the lower side of the tank coil to ensure as high Q as possible. The signal is
buffered by the emitter follower Q4, and then feed to the synthesiser (IC2). The synthesiser has a built
in dual modulus prescaler. The microcontroller controls the synthesiser via the SPI bus.
The output from the phase comparator (#2) is filtered in a passive loop filter to minimise noise in the
output signal.
The modulation signal is applied to D11.
Q6 and surrounding components act as a low noise voltage regulator, filtering the supply voltage for
the VCO.
The output signal is feed to the first mixer on the RF board.
Tron TR20
5-2
IF circuit
The 21.4 MHz signal from the 1. Mixer on the RF board is feed trough two sections of crystal filters
(Y1 and Y2).
The signal is then fed trough a matching network into the IF integrated circuit (IC1). It then enters the
second mixer, and is converted down to 450kHz, amplified and feed trough two sections of ceramic
band pass filters (FLT1 and FLT2). Then it passes through a limiter circuit and is fed to the
discriminator DXR1. This produces demodulated audio on #9, which is fed to the band pass filter on
the main board.
The second Local Oscillator, which is a part of the IF circuit, operates at 20.950MHz and also
functions as the reference for the synthesiser controlling the 1 LO. The oscillator is voltage
controllable, to make frequency adjustment and temperature compensation available for the
microcontroller. Frequency adjustment is available from the front panel of the transceiver.
RF board (99936b).
Receiver front end
The antenna signal enters first the low pass filter, and the first band pass filter. The signal is then
amplified by Q1, before entering the second band pass filter. It then enters the first mixer (Q2) were it
is mixed with the LO signal from the synthesiser down to 21.4 MHz. The signal is the feed to the
Synth/IF board through J1 #11.
Transmitter section
The LO signal is amplified by Q8 and feed to the mixer in Rx mode, and to the transmitter in Tx mode.
IC3 is an integrated output stage with up to 5W output power. The power output is adjusted with the
bias pin (#2), and is controlled by the “SET_PWR” signal from the micro controller. IC5 acts as a
buffer amplifier.
The output power is detected by D18, and the produced voltage is feed to one of the A/D inputs on the
microcontroller to check that the transmitter is actually transmitting.
The output from IC3 is taken through the RF switch (D9,D10), trough the low pass filter to the antenna.
Tron TR20
5-3
6. MAINTENANCE
No maintenance is necessary except to check / tune the LO frequency after 1 year and then every 3rd
year.
Tuning of LO frequency
The LO frequency is checked at the antenna output. Unscrew the antenna and connect the output to a
frequency counter or a radio testset. Note that the input impedance should be 50Ω, and the input must
be able to handle up to 5W of RF power. The connector is standard SMA.
1. Press the “Hi/Lo” key while powering up the Tron TR20 to enable service mode.
2. Set the radio to Low Power by pressing the “Hi/Lo” key.
3. Enter the main menu, and use the arrow keys to select “Ref” adjustment.
4. Press “PTT” and read the frequency on the frequency counter. The limit is +1.5kHz.
5. If adjustment is required, use the arrow keys to adjust the centre frequency.
6. Press enter to store the setting.
When refitting the antenna, apply a small amount of silicon grease on the mating surface oft the
antenna. Tighten with hand force only, make sure that the rubber housing on the antenna mates well
with the rubber sealing on the housing.
Other adjustments
The service mode enables access to a few more adjustments.
These are: Power output (High and Low) and modulation.
Note! These adjustments are meant for factory use only.
To adjust High Power:
1- Press the “Hi/Lo” key while powering up the Tron TR20 to enable service mode.
2- Set the radio to High Power by pressing the “Hi/Lo” key.
3- Enter the main menu, and use the arrow keys to select “Pwr” adjustment.
4- Press “PTT” and read the output power on a power meter. The output power should be
approx. 2W on Tron TR20 GMDSS and 4W – 5W on Tron TR20 PLUS.
5- If adjustment is required, use the arrow keys to adjust the output power.
6- Press enter to store the setting.
To adjust Low Power:
1- Press the “Hi/Lo” key while powering up the Tron TR20 to enable service mode.
2- Set the radio to Low Power by pressing the “Hi/Lo” key.
3- Enter the main menu, and use the arrow keys to select “Pwr” adjustment.
4- Press “PTT” and read the output power on a power meter. The output power should be
approx. 1W on Tron TR20 GMDSS and Tron TR20 PLUS.
5- If adjustment is required, use the arrow keys to adjust the output power.
6- Press enter to store the setting.
NOTE! On Tron TR20 GMDSS the power output must never be adjusted higher than 2.5W.
If a higher output power is selected, the radio may not operate properly due to the relative high internal
resistance of the Lithium battery.
Tron TR20
6-1
Loading...