Related Manuals for Motorola Handie-Talkie MTX Series
Summary of Contents for Motorola Handie-Talkie MTX Series
- Page 1 HT 1000 , MT 2000 MTS 2000 , and MTX Series Handie-Talkie ® Portable Radios Theory/Troubleshooting Manual...
-
Page 2: Table Of Contents
B. Digital Architecture ............................9 C. Audio Signalling Architecture........................9 , Motorola, Handie-Talkie, HT 1000, MT 2000, MTS 2000, MTX 838, MTX 8000, MTX 9000, Private-Line, Digital Private-Line, and Privacy Plus are trademarks of Motorola, Inc. © 1993 by Motorola, Inc., Radio Products Group Theory/Troubleshooting Manual 8000 W. - Page 3 CONTENTS (cont.) TITLE PAGE THEORY OF OPERATION (DETAILED FUNCTIONAL DESCRIPTION) INTRODUCTION ............................10 II. RADIO POWER .............................10 A. General..............................10 B. B+ Routing and DC Voltage Distribution (for a Closed Architecture Controller and a VHF or UHF Transceiver) .......................10 C. B+ Routing and DC Voltage Distribution (for an Open Architecture Controller and an 800 or 900MHz Transceiver)....................11 III.
- Page 4 LIST OF TABLES TABLE TITLE PAGE Option Select Definition......................18 Option Select Definition......................29 Universal Connector Mode......................29 LIST OF FIGURES FIGURE TITLE PAGE DC Power Distribution Block Diagram (Closed Architecture Controller and VHF or UHF Transceiver) ..........3 DC Power Distribution Block Diagram (Open Architecture Controller and 800 or 900MHz Transceiver)........3 VHF/UHF Frequency Generation Unit (FGU) Circuits...............4 VHF/UHF Receiver Block Diagram ...................5...
-
Page 5: Glossary Of Terms
FGU- Frequency Generation Unit FLASHport ™ - Is a Motorola term that describes the ability of a radio to change memory. Every FLASHport radio contains a FLASHport EEPROM memory chip that can be software written and rewritten to, again and again. -
Page 6: Introduction
INTRODUCTION PURPOSE Various switches, buttons, knobs, and indicators are ergonomically designed, making placement in strategic This manual will provide a theoretical explanation of locations on the different model radios. Refer to the spe- the HT 1000, MT 2000, MTS 2000, and MTX Series cific operating instructions on your radio for location and portable radio’s operation, troubleshooting, and addition- description of these controls. -
Page 7: Theory Of Operation (Basic Functional Description)
THEORY OF OPERATION (BASIC FUNCTIONAL DESCRIPTION) INTRODUCTION voltage sources required to operate various stages of the radio are distributed as shown in Figure1A. This publication covers a large family of portable radios: HT 1000, MT 2000, MTS 2000, and MTX series The power amplifier (PA) module (U105) and auto- units. - Page 8 U709 U706 Audio PA Regulator U705 U701 Controls Flex Micro C ASF IC Controller Board Front Cover Opt B+ Jumper Flex Universal Connector Flex Raw B+ Fuse 1 Amp Harmonic Filter U101 U105 Battery L105 7.5V PA Module CR109 CR108 L122 RF Amp L121...
-
Page 9: Vhf/Uhf Transceiver Board
In the transceiver, SWB+ is routed directly to the 5v VCO buffer signal is applied to a comparator in the syn- regulator (U202). The regulated 5v supplies the IF IC thesizer. The synthesizer comparator also receives a (U3), the reference oscillator (U203), the Fractional-N reference frequency via a reference divider input from synthesizer IC (U204), the D/A IC (U102), and the R/T the 16.8 MHz temperature-compensated reference... -
Page 10: Receiver Back End (See Figure 3)
The filtered RF signal is then applied to the RF input is replaced by internal filters in the IF IC. The IF IC uses of a broadband mixer IC. An injection signal (FIRST a type of direct conversion process where the second LO), supplied by the FGU, is applied to the second input LO frequency is very close to the first IF frequency. -
Page 11: 800/900Mhz Transceiver Board
The RF PA module is a multi-stage amplifier, which Modulation of the carrier is achieved by using a 2- has the required gain to produce an output level of sev- port modulation technique. The deviation of the low eral watts. Some harmonic filtering is accomplished in frequency tone, such as DPL/TPL, is achieved by inject- the RF PA. -
Page 12: Receiver Back End (See Figure 6)
D. Receiver Back End (See Figure 6) E. Transmitter (See Figure 7) In the IF IC, the first IF frequency is down convert- The transmitter consists of the following stages: ed, amplified, filtered, and demodulated to produce the • Low-pass antenna matching circuit recovered audio. -
Page 13: Closed Architecture Controller
The digital portion con- the AUDIO PA IC. The IC’s output drives the radio’s sists of a special Motorola microcomputer. The audio internal speaker, or an external speaker connected via power amplifier (AUDIO PA) and audio/signalling/filter an option cable. -
Page 14: Digital Architecture
B. Digital Architecture C. Audio Signalling Architecture The Motorola microprocessor, in conjunction with The Motorola custom integrated circuit, ASF IC, per- the SLIC, performs the functions of controlling the inter- forms audio signal shaping and filtering. The ASF IC nal workings of the radio, as well as interfacing with the also encodes and decodes Private-Line (PL), Digital Pri- outside world. -
Page 15: Theory Of Operation (Detailed Functional Description)
The 5-volt regulator, U202, is schematic diagram(s) in the corresponding service man- applied this voltage through decoupling component ual (Motorola part number 68P81200C25), or previously C125 to produce a stable 5.0 volt output. Raw B+ (7.5V) 68P81200C20. -
Page 16: B+ Routing And Dc Voltage Distribution
800 or 900MHz Transceiver) zero, then Q702’s inverted output (pin 3) will be high, This radio differs from previous Motorola portable and the power switch (U712) will turn off, and SW B+ radios in that B+ from the battery is electrically switched will drop to zero. -
Page 17: Vhf/Uhf Transceiver
The open architecture controller board uses Flash III. VHF/UHF TRANSCEIVER memory (U715) in place of conventional EPROMs. A. Frequency Generation Unit (FGU) This allows the firmware to be reprogrammed The frequency generation unit (FGU) consists of through the side connector without opening the three major sections;... -
Page 18: Antenna Switch
diode CR203 sets the TX frequency while varactor transmit switching diode CR108, and sent to the anten- CR202 is the TX modulation varactor. The modulation of na. In the receive mode, RF is received from the the carrier is achieved by using a 2-port modulation antenna, routed through receive switching diode CR109, technique. -
Page 19: Receiver Back End
C80, C86, C87, C88, C97, C99, L3, L4, L5, and L30 J301 pin 11, where it is routed through the jumper flex (VHF); or C4 thru C7, C88 thru C94, C99, and L11 thru (P301 pin 11 to P704 pin 11) and applied to the con- L15 (UHF) to improve the spurious rejection. -
Page 20: 800/900Mhz Transceiver Board
3. ALC Circuits The 900MHz VCO is also a dual-range oscillator that covers the 896-902MHz and the 935-941MHz fre- Coupler module U104 samples the forward power quency bands. The low-band VCO (861-902MHz) and the reverse power of the PA output voltage. provides the first LO injection frequencies (861- Reverse power is present when there is other than 867MHz) that will be 73.35MHz below the carrier... -
Page 21: Antenna Switch
the SRL. The loop divider adds or subtracts phase to at the radios transmitter frequencies), and output match- the prescaler divider by changing the divide ratio via the ing components C141 and L30. Both pin diodes CR109 modulus control line. The output of the prescaler is then and CR108 must be back biased to properly route the applied to the loop divider. -
Page 22: Receiver Back End
The heart of the HT 1000 controller consists of a recovered signal strength indicator (RSSI) and squelch new generation Motorola microcomputer, U705. The output for use in other parts of the radio. microcomputer consists of 640 bytes of EEPROM, 760 E. - Page 23 2. Microcomputer Clock Synthesizer which consists of a transmit data line (U705 pin 1, PD3), a receive data line (U705 pin 84, PD2), and a Upon power-up, and assuming that the ASF IC clock line (U705 pin 2, PD4). In addition, each IC receives a proper 2.1MHz input at U701 pin 33 that can be accessed by the microcomputer, using (which comes from the transceiver board), the ASF...
-
Page 24: Controller Board Circuit Operation
(PL/DPL), DTMF data for telephone the controller board via connector plug P701 communication, and MDC data for use in Motorola pin7. On the controller, from connector jack proprietary MDC systems. The deviation levels of... - Page 25 a. Sub-audible Data (PL/DPL) c. MDC Data Sub-audible data is composed of low-frequency The MDC signal follows exactly the same path PL and DPL waveforms for conventional opera- as the DTMF high group tone. MDC data uti- tion. Although it is referred to as “sub-audible lizes MSK modulation, in which a logic zero is data,”...
-
Page 26: Open Architecture Controller
The nominal voltage for rated audio is The open architecture controller consists of: 3.74Vrms, and the nominal audio input to U706 is 88.7mVrms, when rated audio output is • U705, a new generation Motorola microprocessor; obtained. • U710, a custom gate array; •... -
Page 27: Microprocessor (U705) And Associated Circuits
the external memory devices, U705 has 1k of RAM and fore, soon after the controller is powered up, serial 512 bytes of EEPROM on chip. Miscellaneous logic and data is being sent to the ASF IC on signal lines switching functions are provided by U703, U709, and U701-E3 and U701-F1. - Page 28 common symptom is the RESET line goes low peri- ports: U705 input PA1, and U710 output PL6. The odically, with the period being on the order of msec. BUSY signal is a bidirectional active-high signal that is normally pulled down by 10K resistor R739. It is 5.
-
Page 29: Controller Board Circuit Operation
FET electric type and, thus, require a dc bias- encryption algorithms) connected to connector jack ing voltage provided by R703 and R706, J702. A standard Motorola key-variable loader can respectively. Note that there are two distinct micro- be used to transfer key to the secure board. The... - Page 30 MDC data for use in uators, which are tuned in the factory or the Motorola proprietary MDC systems. The deviation field to set the proper amount of FM deviation. levels of the latter three types are tuned by a 5-bit The TX audio emerges from the ASF IC at digital attenuator inside the ASF IC.
- Page 31 Although it is referred to as “sub-audible data,” low-group and high-group tones are summed the actual frequency spectrum of these wave- (with the amplitude of the high group tone being forms may be as high as 250Hz, which is approximately 2dB greater than that of the low- audible to the human ear.
- Page 32 noise bursts in the recovered audio due primari- d. Differential Speaker Audio Amplification ly to multi-path fades. The IC monitors the noise The final stage in the receive path is the audio content of the discriminator as well as the amplifiers that drive either the internal or exter- received signal strength indicator (RSSI) line nal speakers.
-
Page 33: Universal Connector (See Tables 2 And 3)
secure board it is decrypted and converted attenuator. (Note that the expander is bypassed back to analog format, and then fed back to the even if U601 is present.) The tone exits at U701-J4, ASF IC from the AUX RX line (J702 pin 9). It is then is routed to the audio PA the same as receive then routed to the ASF IC pin U701-J6;... - Page 34 Pin 10, the Vpp/CTS pin, also serves several func- Table 2. Option Select Definition tions. When reprogramming the Flash memory device, MODE# MODE COMMENT this pin carries the programming voltage, Vpp. The pin is SEL 1 SEL 2 also used to identify that a key-variable loader is External PTT attached.
-
Page 35: Troubleshooting
By using the dia- than that recommended should be cleared through your grams, troubleshooting charts, and deductive Motorola Area Representative to ensure that it is of processes, the suspected circuit may be readily found. equivalent quality. To determine if analyzation of the radio is required,... -
Page 36: Check Overall Receiver Operation
To perform this measurement, connect the leads from a SINAD meter to the audio output of the test IV. TROUBLESHOOTING CHARTS box. Set the Motorola service monitor or rf signal generator to output a 1-millivolt signal. Modulate the The troubleshooting charts on the following pages... -
Page 37: (Vhf/Uhf Transceiver/Closed Architecture Controller)
TROUBLESHOOTING FLOW CHART (VHF/UHF Transceiver/Closed Architecture Controller) Start Note: Assumes Power Beep is Enabled Radio Drawing Check Fuse, Good Power Stand-by Current Up Beep? Volume Switch About 60mA? Go to Controller Chart #8A Is There Go to Transmitter TX Power? Chart #1A Go to No Transmit Is TX... -
Page 38: (800/900Mhz Transceiver/Open Architecture Controller)
TROUBLESHOOTING FLOW CHART (800/900MHz Transceiver/Open Architecture Controller) Start Note: Assumes Power Beep is Enabled Radio Drawing Check Fuse, Good Power Stand-by Current Up Beep? Volume Switch About 60mA? Go to Controller Chart #8B Is There Go to Transmitter TX Power? Chart #1B Is TX Go to No Receiver... -
Page 39: (Vhf/Uhf Transmitter Rf)
TROUBLESHOOTING FLOW CHART #1A (VHF/UHF Transmitter RF) No/Low Power Go to DC Switch TX Current Is T5 On Routine Chart #3A > 500 mA? at C153? B+ at Check B+, E101 (VHF) RF at RF U105, Pin 5 E101 and E104 (UHF) Replace RF Jack, Jack, S101 (VHF) -
Page 40: (800/900Mhz Transmitter Rf)
TROUBLESHOOTING FLOW CHART #1B (800/900MHz Transmitter RF) Replace No/Low Power Ant Contact TECHNICAL PUB DESCRIPTION DWG. NO. Check JEDI Check GOOD GOOD Check Continuity Input Drive Troubleshooting Chart Continuity at Current S101 across U105-1 Ant. Cont. >500 mA ILLUSTRATOR DATE ENGINEER DATE PROGRAM... -
Page 41: (Vhf/Uhf Receiver Rf)
TROUBLESHOOTING FLOW CHART #2A (VHF/UHF Receiver RF) Bad SINAD Bad 20Db Quieting No Recovered Audio NOTE: INJECT MODULATED ON CARRIER FREQUENCY SIGNAL AS REQUIRED Check Audio at Controller C306? Spray or Inject 1st IF into XTAL Filter IF FREQS: 44.85 VHF 73.35 UHF Audio Inject RF... -
Page 42: (800/900Mhz Receiver Rf)
TROUBLESHOOTING FLOW CHART #2B (800/900MHz Receiver RF) No-High SINAD Inject Check Comp. 73.350MHz VDC at Check Q1, CR5, C54, at Pin 1 FL1 Pin 18 U3 Freq. C55, L24, C56 -110 = 12dB 0 or 5V Pin 14-U3 & C57 SINAD Check U3 &... -
Page 43: (Vhf/Uhf Dc Switch)
TROUBLESHOOTING FLOW CHART #3A (VHF/UHF DC Switch) No R5 Q105 Pin 2 Voltage at Q105 Pin 3? Voltage Replace Less than Replace at U103, 4.8V at Q105 U103 Q105 Pin 3? Pin 1? Check L131, L121 and CR109 Voltage and L122 For at Q107, Open Connections Pin 2? -
Page 44: (800/900Mhz Dc Switch)
TROUBLESHOOTING FLOW CHART #3B (800/900MHz DC Switch) No R5/No T5 Voltage at Q108, Pin 4? Voltage Check Continuity at Q108: at U202 Between U202-1 Pin 5 - RX Pin 1? & Q108-4 Pin 3 - TX Check U102 Replace U202 U202-8 Check J301-2... -
Page 45: (Vhf/Uhf Frequency Generation Unit - Fgu)
TROUBLESHOOTING FLOW CHART #4A (VHF/UHF Frequency Generation Unit - FGU) FGU No Lo Injection/TX Unlock VDC at Replace VCTRL (TP5), U204 <0.7V? 5V at VDC at U204 U202 Pin 1, Pin 20, 23, 2 & 8 OK? 25, 41? Check Continuity between J1-17 &... -
Page 46: (800/900Mhz Frequency Generation Unit - Fgu)
TROUBLESHOOTING FLOW CHART #4B (800/900MHz Frequency Generation Unit - FGU) ILLUSTRATOR DATE ENGINEER DATE PROGRAM DISK CHECK FGU No Lo Injection/TX Illustrator 3/12/93 O.K. AS IS EDITOR DATE CHECKER DATE CORRECTED Unlock O.K. AS MARKED 3/22/93 MARKED ISS. REVISION RLSE. RLSE. -
Page 47: (Vhf/Uhf Voltage Controlled Oscillator - Vco)
TROUBLESHOOTING FLOW CHART #5A (VHF/UHF Voltage Controlled Oscillator - VCO) VCO TX/RX UNLOCK Check VDC at C246 (VCTRL) NOTE: If C240 is found NOTE: If C240 is found Replace 13V/0.7V/ ONLY ONLY defective, change to 2.7PF (VHF)/ defective, change to 2.7PF (VHF)/ U201 Drifting 2.4PF (UHF1)/2.4PF (UHF2) -
Page 48: (800/900Mhz Voltage Controlled Oscillator - Vco)
TROUBLESHOOTING FLOW CHART #5B (800/900MHz Voltage Controlled Oscillator - VCO) VCO TX/RX Unlock U205-9 U204-19 U204-20 U204-17 Check Continuity Refer to Check C253 if Between Chart #3B DC OK Change U204 U204-19 & U205-9 5VDC 5VDC U205-3 U205-8 Measure Measure 777-825MHz 850-870MHz Freq. -
Page 49: (Vhf/Uhf, Closed Architecture, No Receive Audio)
TROUBLESHOOTING FLOW CHART #6A (VHF/UHF, Closed Architecture, No Receive Audio) Audio at Audio at Check Rx (Go to Troubleshooting chart #2A) Audio R755? C306? Check Flex P301, R775, C710 Audio at Audio at Ext. Spk. Int. Spk. Check Spk. Flex, P701, L705, L706 Ext. -
Page 50: (800/900Mhz, Open Architecture, No Receive Audio)
TROUBLESHOOTING FLOW CHART #6B (800/900MHz, Open Architecture, No Receive Audio) No/Low Audio Inject on Freq. -47dBm Modulated Carrier Check Check U3 Audio J301 Pins 10 & 12 U3 Circuitry Check Replace Audio J704 Jumper Flex Pins 10 & 12 HearClear Radios Only Check Check... -
Page 51: (Vhf/Uhf, Closed Architecture, No Transmit Deviation)
TROUBLESHOOTING FLOW CHART #7A (VHF/UHF, Closed Architecture, No Transmit Deviation) -
Page 52: (800/900Mhz, Open Architecture, No Transmit Deviation)
TROUBLESHOOTING FLOW CHART #7B (800/900MHz, Open Architecture, No Transmit Deviation) No TX Dev. Ext. Setup - Inject 80mV-1k Signal into Ext. Mic. Path Check Check Continuity Check Continuity Audio between V Gnd between Pin 14-J701 at MK401 14-J701 & MK401 = 2k &... -
Page 53: (Closed Architecture Controller)
TROUBLESHOOTING FLOW CHART #8A (Closed Architecture Controller) Radio Button Closed Controller EMER MONITOR functions and Check Signalling Problems. Press PTT. Press MON. Enable and Not able to Red LED Button, Radio Before replacing press EMER. Power Up program RF does not does not Button. -
Page 54: (Open Architecture Controller)
TECHNICAL PUBLICATIONS DEPT. TROUBLESHOOTING FLOW CHART #8B JEDI DESCRIPTION DWG. NO. RADIO MBEPF-234 OPEN CONTROLLER POWER-UP (Open Architecture Controller) TROUBLESHOOTING CHART ILLUSTRATOR DATE ENGINEER DATE PROGRAM DISK 4/2/93 Illustrator O.K. AS IS EDITOR DATE CHECKER DATE CORRECTED O.K. AS MAR 4/5/93 MARKED POWER-... -
Page 55: (Vhf/Uhf Only, Vco Crossover Frequency Tune)
UHF1 UHF2 VCTRL (TP5) C240(RX) >3.0V? C223(TX) A complete part description and Motorola part number for ordering Program Radio to is located in the service manual. High Band Edge 178 MHz (VHF) 470 MHz (UHF1) 520 MHz (UHF2) Replace C240 or C223... - Page 56 *6881200C15* Motorola 8000 West Sunrise Boulevard Fort Lauderdale, Florida 33322 68P81200C15-O...