Issue 2 09/2003 Confidential Copyright 2003 Nokia
Page 2
Customer Care Solutions
Technical Documentation
Amendment Record Sheet
Amendment NoDateInserted ByComments
03/2003J FraserIssue 1
Issue 209/2003J FraserNew issue to reflect
change from Safari to
Taco. New parts lists,
new schematics, new
XY-grid information.
Issue 2 09/2003 Confidential Copyright 2003 Nokia
Page 3
Customer Care Solutions
Technical Documentation
RH-42 Series Cellular Phones
Service Manual – Overall Manual Contents
Service Manual comprising
RH-42 Series Transceiver booklet comprising
Foreword
General
Parts
Service Software Instructions
Service Tools
Disassembly/Assembly
Troubleshooting
System Module
Schematics
Issue 2 09/2003 Confidential Copyright 2003 Nokia
Page 4
This document is intended for use by qualified service personnel only.
Company Policy
Our policy is of continuous development; details of all technical modifications will be
included with service bulletins.
While every endeavour has been made to ensure the accuracy of this document, some
errors may exist. If any errors are found by the reader, Nokia Corporation should be notified in writing.
Please state:
Customer Care Solutions
Technical Documentation
IMPORTANT
Title of the Document + Issue Number/Date of publication
Latest Amendment Number (if applicable)
Page(s) and/or Figure(s) in error
Please send to: Nokia Corporation
CCS Technical Documentation
PO Box 86
FIN-24101 SALO
Finland
Issue 2 09/2003 Confidential Copyright 2003 Nokia
Page 5
Customer Care Solutions
Technical Documentation
Warnings and Cautions
Please refer to the phone's user guide for instructions relating to operation, care and
maintenance including important safety information. Note also the following:
Warnings:
1. CARE MUST BE TAKEN ON INSTALLATION IN VEHICLES FITTED WITH
ELECTRONIC ENGINE MANAGEMENT SYSTEMS AND ANTI-SKID BRAKING
SYSTEMS. UNDER CERTAIN FAULT CONDITIONS, EMITTED RF ENERGY CAN
AFFECT THEIR OPERATION. IF NECESSARY, CONSULT THE VEHICLE DEALER/
MANUFACTURER TO DETERMINE THE IMMUNITY OF VEHICLE ELECTRONIC
SYSTEMS TO RF ENERGY.
2. THE HANDPORTABLE TELEPHONE MUST NOT BE OPERATED IN AREAS LIKELY
TO CONTAIN POTENTIALLY EXPLOSIVE ATMOSPHERES EG PETROL STATIONS
(SERVICE STATIONS), BLASTING AREAS ETC.
3. OPERATION OF ANY RADIO TRANSMITTING EQUIPMENT, INCLUDING
Cautions:
1. Servicing and alignment must be undertaken by qualified personnel only.
2. Ensure all work is carried out at an anti-static workstation and that an
3. Ensure solder, wire, or foreign matter does not enter the telephone as
4. Use only approved components as specified in the parts list.
5. Ensure all components, modules screws and insulators are correctly
CELLULAR TELEPHONES, MAY INTERFERE WITH THE FUNCTIONALITY OF
INADEQUATELY PROTECTED MEDICAL DEVICES. CONSULT A PHYSICIAN OR
THE MANUFACTURER OF THE MEDICAL DEVICE IF YOU HAVE ANY
QUESTIONS. OTHER ELECTRONIC EQUIPMENT MAY ALSO BE SUBJECT TO
INTERFERENCE.
anti-static wrist strap is worn.
damage may result.
re-fitted after servicing and alignment. Ensure all cables and wires are
repositioned correctly.
Issue 2 09/2003 Confidential Copyright 2003 Nokia
Page 6
Customer Care Solutions
Technical Documentation
Issue 2 09/2003 Confidential Copyright 2003 Nokia
This section briefly describes how to install Phoenix and includes some basic information
on how to use the program. More detailed information can be found in the Phoenix Help
files. Each feature in Phoenix has its own Help file, which can be activated while running Phoenix. To activate a Help file while Phoenix is running, press the F1 key or the
specific feature’s Help button.
General Setup Procedure
Initial installation of Phoenix requires the complete Phoenix installation package. This
package, currently around 30 Megabytes in size, is provided on a CD-ROM disk. Because
of this large size, it is not recommended to download the file nor is it practical to provide
it on 3.5-inch floppy disks.
Install Phoenix by following the steps outlined on the material that comes with the disk.
It should be noted that installation of a Nokia dongle on the computer being loaded is
REQUIRED prior to beginning the installation of the software.
The software is packaged into an Installshield executable bundle. When the user doubleclicks on this file, the installation program provides on-screen instructions on how to
proceed. Standard installation, provided by selecting all default choices, is highly recommended. You may do a custom installation and place Phoenix into a special location on
your hard drive, but this is only recommended for experienced users.
It is necessary to reboot the computer after installing the software. The program will not
be usable until a reboot is performed. After reboot, the Phoenix icon is displayed on the
computer desktop. Double-clicking on this icon launches the program.
Service Software InstructionsCCS Technical Documentation
Hardware Requirements for using Phoenix
Minimum Hardware Requirements
Processor233 MHz
RAM64 MB
Disk Space Needed50-100 MB
Supported Operating SystemsNotes
Windows 95Limited, no USB support
Windows 98
Windows NT 4.0no USB support
Windows 2000Professional version
Installing Phoenix
Before installing the software, verify:
• The dongle is attached to the parallel port for PKD version dongles, or an FLS-4 version
dongle is attached on either the parallel port or the USB port (if the computer supports
USB).
• Ensure that if the computer supports administrator rights (typically on Windows NT
and Windows 2000 installations) that access is enabled for the user performing the
Phoenix installation.
• If a previous version of Phoenix has been installed, it may be necessary to first properly
remove that program prior to installing the new version. If installation is performed, be
sure to reboot the computer prior to continuing. See the section Uninstalling Phoenix
for instructions on how to uninstall.
Installation Directions
• Insert the CD-ROM disk into the computer drive
• Access the drive and double-click on the Phoenix software package found on the CD.
• Follow the on-screen prompts to conclusion.
Note that rebooting the computer may be necessary when completed.
Software Support Bundles:
The Phoenix installation is auto-executable. You must obtain Software Support Bundles
to load software upgrade files to customer-specific phone models.
These bundles are created by PAMS and made available by AMS on the Partners Web
Page http://americas.partners.nokia.com. This web page is password-controlled; if you
have not registered as a user, contact Nokia Central Service in Melbourne, Florida.
Similar to the Phoenix installation, these Software Support Bundles are InstallShield executable packages. Just double-click on the package and it will auto-install.
No rebooting of the computer is required.
Starting a Phoenix Session
Concepts
When referring to Phoenix, Product is the cellular phone attached to the computer.
More specifically, it is the particular type of phone.
Connection is the type of cable used to attach the phone and the port on the computer
where it is attached. Refer to Chapter 7-Service Tools for additional information.
The first time Phoenix is used, certain connection configurations must be made. Subsequent uses will rely on these selections and they will not need to be made again.
Initial Session with Phoenix
It is necessary to create the connection the first time Phoenix is used. Follow these simple steps:
Service Software InstructionsCCS Technical Documentation
Select Manage Connections… from the “File” drop-down menu.
Next click the Add… button to create a new connection.
When the Select Mode dialog box appears, you may then select either Wizard, which will
auto-detect your connection configuration, or Manual, which allows you to manually
select options to create the connection.
Once a connection is defined, make sure that the one to be used is moved to the top of
the list (use the up down arrows on the Manage Connections dialog box. Then click on
the Apply button. Close the window when finished.
You can now proceed with the normal initiation of a session by selecting a product or
scanning for a product.
Scanning for a Product
Many features of this program are product-specific. Therefore it is necessary to configure Phoenix for the product on which you will be working at the beginning of the session.
Scan Product – Choose Scan Product from the drop-down menu list and Phoenix will
automatically scan for product and select the necessary configurations. The status bar
at the bottom will indicate if the product was found and its type.
Using Components
When working with Phoenix, tasks are generally managed by specific software components. From the menu, select the desired component or task to be performed.
“Opening a component” is defined as opening a tool window within Phoenix. When this
window is opened, Phoenix also opens a toolbar for it and adds component-specific
menu items in the Window menu.
Using Profiles
Phoenix’s Profile feature allows product, connection and currently open components to
be stored into permanent storage by creating a profile file with a name of your choice
followed by an .nmp file extension for later retrieval.
Saved profiles makes it easy to configure Phoenix into a desired configuration with
favorite windows already opened and ready to go.
Service Software InstructionsCCS Technical Documentation
Opening and saving profiles is done via menu commands found in the File drop-down
menu: Open Profile and Save Profile.
Profiles are stored into a disk file with user-defined names. As a result, there can be
multiple profiles for different repeated tasks or user preferences.
Uninstalling Phoenix
As mentioned in the Installing Phoenix section, it may be necessary or desirable to
remove Phoenix. Care must be taken to follow this procedure. Failure to remove the
program properly will cause misconfiguration of the computer’s registry.
Uninstalling Phoenix version:
• Access the computer’s “Control Panel” section, selectable from the Start button or the
“My Computer” desktop icon
• Select the “Add/Remove Programs” icon
• Select the Phoenix version to be removed, and click the Add/Remove button
• Click on the OK button to begin the process of removal
has a modular connector,
and is used with the service Audio Box JBA-4 or a
modular T-adapter.
DDC-1Power Pack0670405The Power Pack provides
the phone with power via
FLA-39. The phone’s own
battery can be used in
DDC-1.
Note: DDC-1 allows battery charging. When it is
used as a charger, the
power pack need to be
disconnected.
Note: When DDC-1 is used
as a Power Pack, battery
charging is not allowed!
FPS-8CHeavy Flash Prommer0080396The FPS-8C is used for
heavy flashing.
GAC-1Galvanic Connector0770301The GAC-1 adapter is
needed for the RF connection. The GAC-1
adapter makes galvanic
connections to assembled handset RF-switches
possible. Via this adapter,
the handset is connected
to the RF measuring and
test equipment.
JBA-8Audio Box0770320The Audio Box is needed
for audio connections.
The box must support
DCT4 Janette audios.
The Service Audio box
provides an interconnection between the phone’s
system connector (XEAR,
XMIC) through a fixed
audio cable and Audio
tester with a BNC-BNC
coax. The connection to a
PC can be made with the
service battery, through a
DAU-9 cable. The Service
Audio Box JBA-8 is used
for service purposes.
JBV-1Docking Station0770298The Docking Station and
the Docking Station
Adapter (MJF-23) are
needed for Mbus, Fbus,
RF, and audio connections.
This setup allows connection between flash prommers. When the audio box
is connected, it has to be
connected to the phone’s
audio connector. The
Docking Station can be
powered by FPS-8 or
external power supply.
MJF-23Docking Station Adapter0770489The Docking Station
Adapter, together with
the Docking Station
(JBV-1), are needed for
Mbus, Fbus, RF, and audio
connections.
This setup allows connection between flash prommers. When the audio box
is connected, it has to be
connected to the phone’s
audio connector. The
Docking Station can be
powered by FPS-8 or
external power supply.
MJS-18Module Jig0770299This jig allow phone
PWB-level service and
troubleshooting.
Electric circuits have to
be protected against
over-voltage and overcurrent.
MJS-27Soldering Jig0775287This jig allows phone
PWB level service and
troubleshooting for
authorized service centers.
PCS-1Power Cable0730012The Power Cable PCS-1 is
used to connect the service tools (JBV-1, MJS-57)
to an external power supply.
is hardware device that,
when connected to the
parallel (LPT) port of the
PC, enables the use of the
service software. Without the dongle present, it
is not possible to use the
service software. Printers
or other peripheral
devices can be connected
to the PC through the
dongle, if needed.
Caution: Make sure that
you have switched off the
PC and the printer before
making connections!
Caution: Do not connect
the PKD-1 to the serial
port. You may damage
your PKD-1!
SCB-3DC Cable 0730114The DC Cable SCB-3 is
used to connect the
docking station to the
charger connection (Vin)
of the phone to conduct
the charger calibration
service procedure.
XCS-4Mbus/Fbus Cable0730178The XCS-4 Service Cable
is a modular cable for
flashing DCT4 products.
XRF-1RF Cable0730085RF Cable XRF-1 is used to
connect the service tools
to RF measuring equipment.
Flashing, testing, and tuning with covers on (Setups 2a, 2b, 2c, 2d)
Tightened performance specifications require more precise equipment and methods for
testing and alignment. Manual tuning can’t provide accurate results for RH-42 products,
which means that this task has to be automated.
These setups are intended to be used with either Phoenix or Darium SW. With the Phoenix SW, it is possible to do manual testing and automated tuning. With Darium, it is possible to do automated testing and tuning.
Note: Make sure that the antenna springs do not
get damaged or touched during assembly.
No fingerprints should get on the springs.
Step 1. Assemble the metal deck from the
back cover side by pressing it with your
fingers.
All six tabs should snap into the slots in the
D-cover.
Step 2. Place the IR window onto the
D-cover before assembling the
antenna.
3.
The battery connector will be assembled onto the D-cover
with interference fixing.
Step 7. Place connector onto D-cover with tweezers.
Step 8. Push the connector into the D-cover slot with your fingers.
4.
Step 5. Place one end of the battery latch into
the D-cover slot.
Step 6. Bend the latch and move the other
end into the D-cover slot.
Note: Make sure that the
battery connector is
below the D-cover edges after assembly. If the
buzzer or vibra assembly is in place, make
sure that the buzzer springs stay intact. They
may be damaged, if touched.
Step 9. Place the vibra assembly into its slot. Use
6.
Note: If the battery connector or the buzzer assembly is in
place, make sure that the battery connector springs
and the buzzer springs stay intact. The springs may be
damaged, if touched.
tweezers.
The vibra is assembled into the D-cover with
interference fixing.
Step 10. Place the buzzer assembly into its place.
Use tweezers.
The buzzer is assembled into the D-cover with
interference fixing.
Step 11. Place the release spring into the
8.
9.
D-cover slot.
The release spring is attached onto the
D-cover with screws that are used for
attaching the C- and D-covers. No heat
staking is needed.
Assemble the C-cover.
Step 1. Check the condition of the screw holes
If they are worn out, change the cover.
Step 2. Place the C-cover into a jig. Make sure
that the speaker with the speaker
gasket is in place.
7.
Note: Make sure that the speaker springs stay intact. They may be damaged, if touched.
is required, in order to prevent
fingerprints from appearing on the
LCD. Make sure that the elastomer
connector and domes stay intact
during assembly. Use compressed air
or a vacuum before assembling
the D-cover, in order to prevent
dust from getting onto the engine
layout.
Page 65
RH-42
CCS Technical DocumentationAssembly
Note: The use of gloves is mandatory in
order to prevent fingerprints from
11.
Place the engine module on top of the
LCD module.
appearing on the engine layout. Use
ionized air or a vacuum, before
assembling the D-cover, to remove
dust and other foreign particles
from the PWB assy.
Place the system connector on top of the
engine module.
12.
Note: The use of gloves is mandatory in order to
prevent fingerprints from appearing on
the engine layout and system connector
pads (charging pads). Make sure that the
system connector springs stay intact. The
springs may be damaged, if touched.
Assemble the D-cover assembly.
Step 1. Place the assembled D-cover on top of the
C-cover.
Step 2. Press the D-cover to snap the side locks.
14.
Assemble the keymat onto the front cover.
15.
Step 1. Place the keypad onto the front
cover before the cover is assembled
to the basic transceiver.
Step 2. Press the keypad into its place.
16.
13.
Assemble the screws.
Step 1. Fasten the 6 screws. The assembly
order is shown in the disassembly
section. The torque is 20 - 21 Ncm
350/RPM.
Assemble the front cover onto the basic
transceiver.
Step 1. First push the basic transceiver to the
front cover’s IR window.
Step 2. Press the bottom part onto the front
part, so that it snaps onto the front
cover.
First, carry out a thorough visual check of the module. Make sure that:
• there is no mechanical damage
• the solder joints are OK
Note: Before changing anything, ALL SUPPLY VOLTAGES AND THE SYSTEM CLOCK / SLEEP
CLOCK should be checked.
Baseband Troubleshooting
General testing
The phone has three different modes for testing and/or repairing the phone. The modes
can be selected with suitable resistors connected to BSI- and BTEMP- lines as illustrated
in the following table:
ModeBSI-resistorBTEMP resistorRemarks
Local mode0 - 1k0 - 1k
Test mode>1k0 - 1k
Normal mode68k47kRecommended for baseband
testing. Same as local mode, but
making a phone call is possible.
If the corresponding resistors are connected, the MCU software automatically enters into
the local or test mode when the supply voltage is connected to the phone.
The power can be switched on by:
1Pressing the power key.
2Connecting the local/test mode resistors to the bsi/btemp lines and connecting
the battery voltage to the phone.
3Connecting a charger.
4Phone’s internal functions (Real time clock alarm)
In the local and test mode, the baseband can be controlled through MBUS or FBUS (FBUS
is recommended) connections using Phoenix service software.
Troubleshooting
Note: Most of the baseband repair actions require removing the baseband shield. The shield must not
be removed unless separately authorized by the program.
Note: The phone’s ESN has to re-written to the UEM, if the UEM is replaced. This can be done only in
Central Service.
• VCTCXO enabled by VR3 -> RFClk 19.44 MHz running.
2Purx released
• Purx released by UEM, UEMINT goes high for 100 ms, SleepX goes high and
UEM starts feeding SleepClk (32 KHz) to UPP.
Note: The sleepclock starts running in the crystal circuitry (B200) immediately when the battery voltage is supplied.
3Software running
• Default value for Vcore is 1.5 volts when the software is running.
• Cbus (1.08MHz) clock starts running.
Phone does not start up normally or does not stay on
Note: In case of power up faults, it is not possible to force the phone on by disabling the watchdog.
Instead, measurements should be taken immediately when the power key is pressed or when the battery voltage is connected to the phone (local/test mode).
The easiest way to check if the software is running when the phone takes an abnormal
amount of current is to measure the cbusclk and Vcore.
The Dbus clock (programmable 9.72 MHz) is not automatically visible in the test and
local modes.
1The phone communicates with the prommer via the production test pattern,
using the following signals:
• FBUSTX(serial data to phone)
• FBUSRX(serial data from phone)
• MBUS(serial clock for FBUSRX)
• VPP(External flashing voltage for speed up flashing)
The BSI line is also used when initializing flashing (battery connector).
2When the phone is powered (VBAT>3V), the MBUS and FBUSTX lines are pulled
up internally by the phone.
3The prommer sends a command to the UEM, using FBUSRX, to enter the Flash-
mode. During the sending of this command, the prommer keeps the BSI line high
and MBUS is used as a serial clock.
4When the Flash-mode command is acknowledged, UEM enters the Flash-mode
and releases reset (PURX) to MCU.
5After reset is released, UPP checks if there is a request for the Bootstrap code
(that resides in the UPP ROM).
6The request for Bootstrap is the MBUS pulled down by the prommer (if the boot-
strap is not requested, the bootstrap code jumps to FLASH SW).
7If the Bootstrap code is requested, UPP enters the Flash-mode and sets FbusTX to
'0' as an acknowledgement to the prommer. This is an indication that UPP can
run, at least, the fixed Bootstrap code – although it is not able to run the FLASH
code. UPP then sends an UPP-ID to the prommer via the FBUSTX line.
8After the prommer has received the UPP-ID, it sends a corresponding Secondary
Boot Code to the phone via FBUSRX. The Secondary Boot Code, when run in UPP,
requests UPP to send information to the prommer about the flash type and other
HW-related parameters about the device to be flashed.
9Prommer then sends the Algorithm Code corresponding to the HW parameters,
and this algorithm, when run in UPP, takes over handling the MCUSW transfer to
Flash.
10 12 volts can be supplied to Vpp (by the prommer) to speed up flashing.
Note: The charging voltage and current can be checked by connecting the phone to the service software and reading the ad- converter values of the vchar and ichar.
"The Prommer has not received Phone
acknowledge to the message."
(C383-during algorithm download to target
phone)
(C583-during erasing)
(C683-during programming)
"The Phone has generated NAK signal during
data block transfer."
(C384-during algorithm download to target
phone)
(C584-during erasing)
(C684-during programming)
Data block handling timeout"
(C585-during erasing)
(C685-during programming)
"The status response from the Phone informs
about fail."
(C586-during erasing)
(C686-during programming)
Flash
UPP
Signals between UPP-Flash
Flash
UPP
Signals between UPP-Flash
Flash
UPP
Signals between UPP-Flash
Flash
If charging fails when the LCH-9 is used, and works with ACP-7 and ACP-8, check that
the charge control pin of the system connector is connected to the ground.
In case of audio failures, there are three possibilities to check the audio lines.
1Make a phone call against tester and check audios.
2In case the earpiece/XMIC fails: Feed a 1 Khz signal to the XMIC line and measure
In case the internal microphone/XEAR fails: Feed the tone to the microphone and measure the signal from the XEAR line. The Audio test box (JBA-8) is needed. The Audio loop
Change the UEM
Figure 3: Fault tree, charging
the signal from the earpiece line. The Audio test box (JBA-8) is needed. The Audio
loop (Audio test/Ext In Hp Out) must be switched on by the Phoenix service software. This loop will connect audios only through the UEM. In this case, the UPP is
not used.
(Audio test/Hp In Ext Out) must be switched on by the Phoenix service software. This loop
will connect audios only through the UEM. In this case, the UPP is not used.
3Run the audio-loop self-test with Phoenix (BB Self Tests/
ST_EAR_DATA_LOOP_TEST). This loop will test the ear-data/mic-data lines
between the UPP and the UEM.
Earpiece or external microphone line does not work
• No sound: Try using a known good buzzer instead. If there is still no sound, change the
UEM (D200)
• Weak sound: Use the Audio test in Phoenix to set the buzzer parameters (frequency,
strength). If it does not affect the sound level, change the buzzer.
Keyboard does not work
Check that there is no dirt between the dome sheet and the PWB. Check EMI/ESD filter
(Z301) that all lines come through. If not, change Z301. If the keyboard still does not
operate normally, try to use the Keyboard test in Phoenix to see if the pressed key is
identified. If it is not identified, change the UPP (D400).
Receiver Troubleshooting
General instructions for RX troubleshooting
Start the Phoenix software and use it to start the required RX mode of the mobile phone.
The troubleshooting flowchart is divided into three steps: (1) general checking, (2) local
checking, and (3) RX chain checking.
Note: Before changing ASICs or filters, all solderings and missing components must be checked visually. After any possible component changes, the phone must be tuned with the Phoenix autotune SW.
Path of the received signal
Block level description of the receiver:
(Antenna/ext RF) – Diplexer – Duplexer – Low Noise Amplifier (LNA) – RX band filter –
First mixer – 135.54 MHz RX IF filter – IF-amplifier – second mixer – 14 kHz low-pass filter – adjustable IQ amplifier – Baseband.
Since the same physical signal path is used for both analog and digital modes at the
lower band, there is no need for additional troubleshooting in the digital mode. So if the
digital mode at the lower band is not working properly, start the analog mode troubleshooting.
Transmitter Troubleshooting
General instructions for TX troubleshooting
Always use an RF cable connected from an external RF connector to the analyzer via (rfpower) attenuator. This is important to protect the analyzer against excessive RF power
and not to allow leakage of undesired RF power into the cellular frequencies.
1Start the Phoenix software and select the TX mode under Testing (AMPS,
DAMPS).
2It is useful to select the mid channel (383 for AMPS/DAMPS) and the power
level 2.
Note: After any component change, tune the phone with the Phoenix autotune SW.
Path of the transmitted signal
l
AMPS/DAMPS
UEM TX I/Q DA-converters -> I/Q modulator and Digital gain step amplifier (Taco) ->
IF-BPF -> Upconverter+driver (Taco) -> Balun->BPF -> PA -> Coupler (Power detector) >
Duplex-filter -> Diplexer -> EXT RF Connector Switch -> Antenna
Fault-finding charts for the transmitter
AMPS
1Start the Phoenix software and set the phone to the analog mode by using RF
Test UI.
2Set the channel to 383 and the power level to 2.
3Connect the RF cable to the Ext RF connector switch.
4Connect the cable to the Spectrum analyzer input.
5Measure the RF level.
Note: Insertion loss of the cable and attenuations.
Note: TXPWRDET is the difference between TX on burst and off burst.
2500
2000
1500
A800
1000
Voltage [mV]
500
0
2345 678 91
Power Level
D800
Synthesizer Troubleshooting
There are four oscillators generating the needed frequencies for RF section: 19.44 MHz
VCTCXO is used as a reference signal oscillator reference oscillator, 2 GHz UHF VCO with
loop filter circuit is used for RX and TX channel selection, TX VHF and RF VHF are for TX
modulator, and 2nd RX mixer locals generation.
The VHF synthesizers are integrated in Taco, but have external VCO coils and loop filters.
RX VHF frequency is fixed 271.08 MHz and TX VHF is fixed to 271.08 MHz . All locals are
locked to stable 19.44 MHz reference oscillator.
The frequency range for 2 GHz UHF VCO is: 2009.1 MHz … 2125.53 MHz. The output frequency range for the lower band is from 2009.16 MHz to 2059.02 MHz.
A practical way to check out synthesizer status is by measuring control voltage of the
VCO from the Integrator capacitor. If voltage is stable and reasonable, local oscillators
are running correctly.
19.44 MHz reference oscillator
The VCTCXO oscillator frequency (G790) is controlled by UEM. This output 19.44 MHz
signal is connected to Taco. It is used as a reference signal in Taco and also fed out as
buffered clock signal to UPP. All synthesizers use divided 19.44 MHz signal as a reference
signal for Phase locked loop to provide correct LO frequency.
The RX VHF signal is used to generate receiver Intermediate frequency. RX VHF has one
fixed frequency 271.08 MHz. Operating frequency is locked in Phase locked Loop.
RX VHF PLL output signal is integrated in Taco. There are only four external components:
VCO coil (L730), and loop filter components C740, C741, and R741.
The TX VHF signal is used to generate transmitter Intermediate frequency. TX VHF VCO
has one fixed frequency (361.08). Operating frequency is locked in Phase locked loop. TX
VHF VCO output signal is divided by 2 and fed to the modulator.
The UHF VCO signal is used for RF channel selection. This signal is fed as a local signal for
1st mixer of RX path and for upconverter of TX path. When operating on lower band the
VCO signal is divided by 2 before feeding. This synthesizer is used for channel selection in
all modes.
The UHF synthesizer consists of an external 2GHz VCO module with loop filter components and integrated PLL parts in Taco. Integrated charge pump circuit allows analog and
digital operation modes. The VCO Oscillation frequency is from 2009.1 MHz to
2125.53 MHz. The output frequency of the VCO module depends on the DC control voltage which is controlled by PLL circuit inside Taco.