This manual is intended for use by experienced technicians familiar with similar t ypes of communication equipment. It
contains all service information required for the equipment and is current as of the publication date.
Safety and General Information
Safety Standards
z This equipment should be serviced by qualified technicians only.
z Do not modify the radio for any reason.
z Use only HYT supplied or approved antenna.
z Install the mobile antenna at least 82cm (32 inches) away from your body, in accordance with the requirements
of the antenna manufacturer/supplier.
z Transmit only when people inside and outside the vehicle are at least 82cm (32 inches) away from a properly installed,
externally mounted antenna.
z Turn off your radio prior to entering any area with a potentially explosive atmosphere.
z To avoid electromagnetic interference and/or compatibility conflicts, turn off your radio in any facility where posted
notices instruct you to do so.
z To avoid possible interference with blasting operations, turn off your radio when you are near electrical blasting caps,
in a blasting area, or in areas posted: “Turn off two-way radio.” Obey all signs and instructions.
z For vehicles with an air bag, do not place a radio in the area over an air bag or in the air bag dep lo yment area.
z Do not expose the radio to direct sunlight over a long time, nor place it close to heating source.
z Do not place the radio in excessively dusty, humid areas, or on unstable surfaces.
Operation Safety Guidelines
z For vehicles equipped with electronic anti-skid braking systems, electronic ignition systems or electronic fuel injection
systems, interferences may occur during the radio transmission. If the foregoing electronic equipments are installed
on your vehicle, please contact your dealer for further assistance to make sure that the radio transmission will not
interfere with these equipments.
z For radio installation in vehicles fueled by LP gas with LP gas container within interior of the vehicles, the following
precautions are recommended for personal safety.
① Any space containing radio equipment shall be isolated by a seal from the space in which the LP gas container
and its fittings are located.
② Remote (outside) fitting connections shall be used.
③ Good ventilation is required for the container space.
Installation Safety Guidelines
z Do not mount the mobile radio overhead or on a sidewall unless you take special precautions.
z If the mobile radio is not properly installed, road shock could bump the radio loose, and the falling radio could, in
some circumstances, cause serious injury to the driver or a passenger. In case of vehicle accidents, even when
properly installed, the radio could break loose and become a dangerous pr ojectile.
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Radio Overview
Front Panel View
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① Volume Control Knob
Rotate the knob clockwise to increase the volume and counter-clockwise to decrease the volume.
② LCD
Please refer to section LCD Display.
③ Programmable Function Keys ▲ / ▼
Your local dealer can program these keys with various auxiliary functions.
Please refer to section Programmable Function Keys.
④ LED Indicator
⑤ Speaker
⑥ Power Switch
⑦ Programmable Function Keys P1 / P2 / P3 / P4
Your local dealer can programmed these keys with various auxiliary functions.
Please refer to section Programmable Function Keys.
⑧ Microphone Jack
Plug the microphone into the jack.
Rear Panel View
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① 15 Pin Connector (for external expansion)
② External Speaker Jack
Used to connect an external speaker with a 3.5 mm plug. Refer to Test Cable for Speaker Output in Tuning Description for
details.
③ Power Inlet
Use HYT-authorized DC power cord to inlet 13.6 V DC power.
④ Antenna Connector
Used to connect an external antenna.
Microphone
LED Indicator
Light greenReceiving
Flash orangeReceiving 5-Tone call
Light orangeTransmitting call
LCD Display
IndicatorDescription
Light redTransmitting
Figure 1 LCD Panel
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IndicatorDescription
1.Display zone / channel number.
2.Display channel label
3.Display DTMF digit
4.Display channel Frequency
5.Display menu, setting items, etc.
LoDisplay when the transmitting power is low.
The iconappears if any of the following conditions occurs:
1. Monitor status activated by pressing the Monitor key, and the channel
is initialized to Monitor Squelch.
2. Monitor status activated by a call or decoding, i.e., auto reset mode.
3. Monitor status activated by Force Monitor.
4. Carrier squelch mode under Rx Squelch.
5. Monitor status with authorization request.
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The iconappears when speaker is unmated.
Appears when scan mode is active.
Appears during the auto reset time.
Appears when DTMF Keypad mode is enabled.
Appears when scrambler function is enabled.
Appears when compander function is enabled.
Appears when the selected channel is busy.
Appears when scan pauses on a priority channel. P•standards for
Priority Channel 1, P. standards for Priority Channel 2, and P: standards
for Priority Channels 1& 2.
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Programmable Function Keys
[P1]-[P4], [▲ ]/ [▼ ] can be programmed with the following auxiliary functions:
1.None
2.CH Up
3.CH Down
4.Zone Up
5.Zone Down
6.Monitor/ Cancel Call
7.Cancel Call
8.Display Channel Alias
9.Display Freqency
10. Display Mode Switch
11. User Selectable Tone
12. Adjust Power Level
13. Scan
14. Nuisance Temporary Delete
15. Reverse
16. Talk Around
17. Adjust Squelch Level
18. Home Channel
19. Public Adress
20. Scrambler
21. Compander
22. AUX A
23. AUX B
24. Emergency
25. Call Forward
26. Wisper
27. Lone-Worker
28. Contact List
29. Status List
30. Channel Shortcut Button
31. Missed Calls
32. Received Calls
33. Keypad Mode
34. Menu
35. Call 1
36. Call 2
37. Call 3
38. Call 4
39. Call 5
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Software Specifications
Radio Modes
1. Frame of Radio Modes
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2. Keypad Entry for Mode Startup
MODEMain MenuDisplay/Sub MenuOperationRemarks
USER
MODE
ADJUST MODE----------------------------
Model Set Mode----------------------------
Firmware Version Display
Mode
Wired Clone Mode----------------------------
Conventional
Mode
Turn on the radio to enter
---------------------------Conventional Mode
Press and hold [P1] to turn the
radio on.
Press and hold [P2] to turn the
radio on.
While holding down [P4] key,
---------------------------turn on the radio
While holding down [P3] key,
turn on the radio
PC Programming Mode----------------------------Receive commands from PC
Note: When power-on password is enabled, you must input the correct password before you can enter User Mode.
You can input password through the keypad and press [#] to clear.
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3.Error Information and Measures in User Mode
The radio self-checks when power on. If no error is detected, the radio enters conventional mode. While the radio will
sound alert once any error is checked.
Error information and measures:
No.Error InformationLCD DisplayMeasures
1Stun statusStunRe-program.
Re-program with programming software of right
2Data and Firmware Version mismatchNo Data
version.
4.Firmware Version Display Mode
Turn the radio on while holding down [P4] to enter Firmware Version Display Mode, the firmware version will be displayed
on the LCD.
Release [P4] to enter User Mode.
5.PC Programming Mode
Connect the radio with a PC by programming cable. If data is written to the radio from PC, it can be programmed into the
EEPROM. Data programming is accessible by programming software.
When data is written to the radio from PC, “PROGRAM”appears on the LCD. LED glows green when data is written to the
radio and red when data is read from the radio. Radio will restart automatically when programming is completed.
6.Wired Clone Mode
Data can be transmitted from radio to radio by wired cloning.
(1)Turn on the source radio while holding down [P3] simultaneously, the radio enters Clone Mode with “CLONE”on
the LCD, or enters User Mode if Clone Mode is disabled by your dealer.
(2)Press [P3] to toggle between Dealer Clone and Factory Clone Mode. “DEACLONE”or “FACCLONE”appears on
the display when the corresponding mode is selected. The radio restores the original display after 5 seconds.
Unlike Factory Clone Mode, adjustment settings and embedded messages are not covered in Dealer Clone Mode.
Dealer Clone Mode is the default mode.
(3)Connect the two radios by cloning cable, then turn on the target radio.
(4)Press [P4] to start cloning, the LED of source radio glows red and that of target radio glows green during cloning.
“PROGRAM”is also displayed on the target radio. “END”appears on the source radio when cloning is completed
and the target radio enters user mode.
(5)Press [P4] to return to Clone Mode. “CLONE”appears on the source radio. Repeat the above steps to continue
wired cloning.
Note: Cloning is available only when both radios are in the same mode.
7.Panel Tuning Mode
The radio is tuned in this mode. Operations are as follows:
(1)Press [P1] to turn on the radio and enter tuning mode.
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(2)Select the item with [Up]/[Down] keys. Press [P4] to enter the selected sub-item.
(3)Press [P4] to enter the sub-item and tune the data with [Up]/[Down] keys. Then press [P4] to save the data and
enter the next sub-item. Press [P1] to go back to the previous item without saving the data.
8.Model Set Mode
(1)Press [P2] to turn the radio on. The radio enters Model Set Mode. The frequency band appears on the LCD.
(2)Press [Up]/[Down] to choose right frequency band.
(3)Press [P4] to confirm. LED glows orange and ”WAIT”appears on the LCD; then the radio enters User Mode after
reset.
Notes:
1. Once [P4] key is pressed to set the new model, the previously stored channel data (frequency, CTCSS/CDCSS,
channel function settings) will be cleared, and part of functions also change. Therefore, do not make this operation unless
it’s necessary.
2. Initialization Data Table and frequency range (FL: lowest frequency- FH: highest frequency -FC: center frequency) of
different models are shown in the following table.
The receiver utilizes double conversion superheterodyne. The first IF is 49.95MHz and the second is 450KHz. The first
local oscillator signal is supplied by the PLL circuit; and the second (50.4MHz) is generated from the frequency tripling of
TCXO (16.8MHz). The PLL circuit generates the frequencies required for transmission. (See figure 1).
Frequency Range VHF: 136MHz - 174MHz
2.1 High Frequency Bandpass Amplifier Circuit
It consists of BPF, RF amplifier (Q111) and BPF (D110 and D111). The range of bandpass frequency is the frequency
range of the radio itself. The signal is filtered by the BPF to eliminate unwanted signals before going to the first mixer.
2.2 First Mixer
The signal from BPF is mixed with the first local oscillator signal from PLL circuit at the first mixer (D112) to become a
49.95MHz first IF signal. The first IF signal is then fed through the crystal filter (IF200) to further remove spurious signals.
2.3 IF Amplifier
The first IF signal is amplified by Q113 and then enters IC102 (TA31136FN), where the signal is mixed again with the
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second local oscillator signal (50.4MHz) to become a 450KHz second IF signal. The second IF signal is then fed through a
ceramic filter (N: CF202; W: CF203) to eliminate unwanted signals. The resulting signal then is detected by IC102 and
output from Pin 9 as audio signals.
2.4 Audio Amplifier
The audio signal obtained from IC102 is amplified and filtered by IC402 before being amplified by IC401 (the received
signalling is separated and input into CPU for decoding). The processed signalling passes through Q406 (AF MUTE) and
is amplified by IC405. The amplified signal is fed to K301 controlling the volume and Q511 controlling SP MUTE on the
front panel before entering audio amplifier (IC511). The output audio signal drives the speaker.
2.5 Squelch Open
Part of the audio signals output from IC102 passes through IC102 Pin8 and is amplified by IC102 again, then is filtered
and rectified to produce an SQL level. The SQL level is compared with the existing reference level in CPU (IC502) to
generate a level to control AF MUTE and SP MUTE, which determines whether to output sounds from the speaker by
controlling Q406 and Q511.
3. Transmitter Circuit
The transmitter circuit is composed of the MIC circuit, modulation circuit, RF driver, final-stage power amplification circuit
and APC circuit.
Figure 2 Transmitter Circuit
3.1 MIC and Modulation Circuit
The audio signal from MIC is amplified by IC405 before being pre-emphasized and encoded by IC401. The output audio
signal is added into signalling and then is fed through VCO for modulation.
3.2 RF Driver and Final-Stage Power Amplification Circuit
The Tx-RF signal output from Q703 in the VCO circuit is amplified by Q101, drivers Q110 and Q109. The amplified signal
is then fed to IC101 (final-stage amplifier) and passes through LPF before reaching the antenna.
3.3 APC
The APC circuit stabilizes the output power at a predetermined level. D101 and D102 transform the signal from the
detector to DC voltage, which is then compared with the reference voltage from CPU in IC104 to output a DC voltage. The
DC voltage controls the output power by controlling the grid of IC101.
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4. PLL Circuit
The frequencies of receiving the first local oscillator signal and transmitting signal are generated by the PLL circuit. The
PLL circuit consists of Tx frequency oscillator (Q701), Rx frequency oscillator (Q702), buffer amplifier (Q703), RF amplifier
(Q102), PLL IC (IC801), LPF and Tx/Rx VCO control switch (Q704, Q706).
In transmit mode, IC120 transmits the frequency data to PLL IC. Q704 is turned on to activate Tx VCO. The output signal
is amplified by Q703 and Q102, and then divided by PLL IC into 2.5KHz, 5KHz or 6.25KHz signals. The divided signal is
compared with the 2.5KHz, 5KHz or 6.25KHz reference signal from a 16.8MHz crystal oscillator (2.5 PPM frequency
stability) in the phase comparator. The frequency control voltage output from the phase comparator issent to Tx VCO after
passing through LPF (Q802, Q803). In the meantime, the modulation signal (Tx) is passed to Tx VCO for frequency
modulation.
The working principle in receive mode is similar to that in transmit mode.
Figure 3
5. Control Circuit
The control circuit is composed of CPU, reset IC and power supply control circuit.
5.1 CPU
IC502 (CPU) operates at 9.8304MHz. CPU controls the data transmission among E2PROM (IC501), Rx circuit, Tx circuit,
control circuit, display circuit and peripheral circuits.
Figure 4 Control Circuit
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5.2 Power Supply
+B supplies power for the radio. D135 and D137 are over-voltage protection diodes. Power-on/off can be controlled via
the software.
Figure 5 Power Supply Circuit
Vout provides power for IC601, IC602 and IC803, which produces 8V, 5V, 3.3V voltage for the circuit.
6. Display Circuit
The display circuit is comprised of CPU (IC502), LCD, LED and other components. The radio can be manually operated
through P1 / P2 / P3 / P4 and ▲ / ▼ keys. Relevant channel information is displayed on the 15-segment LCD in
alphanumeric form.
Figure 6 Display Circuit
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Semiconductor Data
1.Positive Voltage Regulator: TA7805F (POWER unit IC602) and TA7808S (POWER unit 601).
2.EEPROM: AT24C256N10SI2.7 (CPU unit IC501)
2.1 Pin Function
Pin No.NameI/OFunction
1~3A0~A2IAddress input
4GNDGND
5SDAI/OSerial data
6SCLSerial clock input
7TESTTest
8VCC+5V.
3.Audio Processor: AK2346 (AFPwr Unit IC404)
3.1 Pin Function
Pin No.NameI/OFunction
1AGNDINIAnalog ground input
2AGNDOAnalog ground output
3TxINITx audio signal input
4TxINOOTxA1 feedback output
5LIMLVILimit level tuning
6EXTLIMINIExternal signal input pin for pre-limiter circuit.
7MODOModulated Tx signal output
8VSSGND.
9TCLKOClock output pin for MSK transmission data.
10TDATAIMSK transmission data input
Delay data is latched with the TCLK rising edge.
11DI/OI/OSerial data input and output
Memory setting data during inputting; MSK receiving signal during outputting
12RDF/FCOMSK signal output of receiving flag and frame detection signal
13SCLKII/O clock input of serial data
14DIRISerial data I/O control
15XOUTICrystal oscillator input
16XINI/OCrystal oscillator input and output
17VDDPositive power supply
18EXPOUTOOutput signal after audio processing
19RxAFINIRx audio signal input
20RxAFORx audio signal output
21RxLPFOORx LPF output
22RxINOORxA1 feedback output
23RxINIDemodulated Rx signal input
24TESTITest register control input
4.Audio Power Amplifier: TDA7297D (AFPwr unit IC511)
Pin Function
3P92/ TB2in2TN/5TNI2-Tone/5-Tone decode pulse input
4P91AFDIOI/OAK2346 DATA I/O(SDAT)
5P90AFSCLKOAK2346 serial clock (SCLK)
6BYTEBYTEI+5V(5C)
7CNVSSCNVSSIGND (ground via 0 resistance)
8P87PAOMIC PAswitch control,PA: H
9P86HMBLOMicrophone backlight control
10RESETRESETIReset
11XOUTXOUTOClock output
12VSSVSSIGND
13XINXINIClock input
14VCCVCCI+5V
15P85/NMINMIINMI (usually not used)
16P84/INT2AFRDFIBaseband chip MSK receive detect (RDF/FD)
17P83/INT1DTMFSTDINot used (left open)
18P82/INT0AUX1I/OOptional circuit board port 1(input)(renamed AUX1)
19P81/TA4inSBCSB Power switch control,H: off,L: on
20P80/TA4outCTC_OUTOCDCSS Balance
21P77/TA3inSPMUTEOSP Mute,Mute: H
22P76/TA3outCTC_PLLOCTCSS/CDCSS modulation output
23P75/TA2inEMICCOExternal Mic control,External Mic: H (now NC)
24P74/TA2outAFTDATAOBaseband chip MSK serial data (TDATA)
25P73/TA1inAFTCLKIBaseband chip MSK serial clock (TCLK)
26P72/TA1outAFDIROBaseband chip I/O control pin (DIR)
27P71/RxD2RxD2INot used
28P70/TxD2TxD2INot used
29P67/TxD1TxD1OSerial data output,PTT ON: L
30P66/RxD1RxD1IMicrophone HOOK input/serial data input,ON: L
31P65AUX4I/OAUX4— — optional circuit board port 5 (output)
32P64AUX5I/OAUX5— — optional circuit board port 6 (output)
33P63TxD2OAcc comm0 (serial data output)
34P62RxD2IAcc comm0 (serial data input)
35P61MICDATI/OMicrophone key code data input/output
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36P60AUX2I/OAUX2— — optional circuit board port 2 (input)
37P57RDYIPull Up
38P56NCNot used (left open)
39P55HOLDNot used (left open)(for recording)
40P54NCNot used (left open)
41P53NCNot used (left open)
42P52RDOExternal expansion, read(Not used)
43P51NCNot used (left open)