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SM-2000
SERVICE MANUAL
MAXON AMERICA, Inc.
10828 N. W. Air World Drive
Kansas City, MO 64153
Phone 816-891-6320 Fax 816-891-8815
680-100-0045 Revision C ECO 98017
December 98
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MAXON SM-2000 MOBILE TABLE OF CONTENTS TABLE OF CONTENTS Table Of Contents....................................................i Specifications........................................................1 Transceiver Nominal Performance ......................................1 General ...........................................................1 Transmitter ........................................................2 Tx Tone Modulation Characteristics.....................................4 Sub Audible Tone
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MAXON SM-2000 MOBILE TABLE OF CONTENTS Schematics and Block Diagrams........................................59 SM-2150/VHF Front End Schematic ....................................59 SM-2450/UHF Front End Schematic ....................................59 SM-2000 TCXO Schematic ...........................................59 MA-4472 Microphone Schematic.......................................60 SM-2000 Control Head Schematic ......................................60 SM-2000 Block Diagram ..............
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MAXON SM-2000 MOBILE SPECIFICATIONS SPECIFICATIONS TRANSCEIVER NOMINAL PERFORMANCE Performance Specifications .............................. FTZ 17TR2049 July 88 TIA/EIA-603 IEC 68 Series EC 529 IP54 MIL STD 810 C,D,E RF Output Power ...................................... 25 W Modulation Type....................................... G3E/F3E (PM/FM) Audio power .......................................... 4W Intermediate frequencies ................................ 45 MHz 455 kHz Number of Channels..
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MAXON SM-2000 MOBILE SPECIFICATIONS Switching range TX and RX (without re-tuning) Operational Bandwidth BAND TX RX MIN MAX MIN MAX VHF Band 1 136 162 136 162 VHF Band 2 148 174 148 174 UHF Band 1 400 430 400 430 UHF Band 2 420 450 420 450 UHF Band 3 440 470 440 470 UHF Band 4 470 490 470 490 UHF Band 5 490 512 490 512 Channel spacing ....................................... 25 kHz / 20 kHz / 12.5 kHz programmable (25 kHz - 12.5kHz switchable by CPU control) Dimensions (in/mm).....................
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MAXON SM-2000 MOBILE SPECFICATIONS Without sub audible tone With sub audible tone modulation Channel Spacing modulation @ 10% peak deviation (kHz) MAX DEV 25 + 5.0 kHz + 5.0 kHz 12.5 + 2.5 kHz + 2.5 kHz Audio characteristic .................................... (Method as FTZ 17 TR 2049 July 1988) MOD Type G3......................................... Within +1/-3 dB of 6 dB/octave pre-emphasis curve: 300 Hz 2.55 kHz for 12.5 kHz Channel Spacing 300 Hz 3 kHz for 20 , 25 kHz Channel Spacing MOD
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MAXON SM-2000 MOBILE SPECIFICATIONS TX TONE MODULATION CHARACTERISTICS Sub audible tones - CTCSS Tone range............................................ 67 250 Hz @ 0.3 % accuracy Tone standard......................................... RS-220A EIA Standard Non-standard tones..................................... 50 260 Hz @ 0.3 % accuracy Nominal tone deviation.................................. 10 % peak system deviation SUB AUDIBLE TONES - DCS Tone standard.....................................
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MAXON SM-2000 MOBILE SPECIFICATIONS AF power............................................. 5 W maximum @10% Distortion into a 4 ohm load. 4 Watts nominal. AF frequency response.................................. Method as FTZ 17 TR 2049 July 1988 MOD Type G3......................................... Within +1/-3 dB of 6 dB/octave de-emphasis curve 300 Hz 2.55 kHz for 12.5 kHz Channel Spacing 300 Hz 3 kHz for 25 kHz Channel Spacing MOD Type F3 ......................................... Within +1/
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MAXON SM-2000 MOBILE INTRODUCTION INTRODUCTION Advanced state-of-the-art technology is used in the design and manufacturing of the SM-2000 Mobile. The Phase Lock Loop (PLL) synthesizer provides more flexibility and capability in the SM-2000 Mobile. This scanning mobile has 4 channel capability. It offers CTCSS, DCS, scanning, priority channel, and many other functions. All these functions are controlled by the micro controller. The micro controller reads specific channel information from an Elec
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MAXON SM-2000 MOBILE UNPACKING INFORMATION UNPACKING INFORMATION Check the carton carefully for the following items: 1 Transceiver Unit 2 Microphone 3 DC Power Cord 4 Mobile Mounting Bracket 5 Assembly Hardware 6 Operating Guide Page-7- December 98
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MAXON SM-2000 MOBILE GENERAL DESCRIPTION GENERAL DESCRIPTION The Maxon SM-2000 is a rugged two way FM mobile radio which operates from 136-174 MHz (VHF) in two bands & 400-512 MHz (UHF) in five bands. The SM-2000 is a synthesized radio utilizing microcomputer technology to provide reliable high quality simplex two-way mobile communications. The SM-2000 transmitter output power level is 25 watts over a wide bandwidth, with a receiver operational bandwidth that covers the specified frequency band.
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MAXON SM-2000 MOBILE DESCRIPTION OF CONTROLS DESCRIPTION OF CONTROLS Figure 1 SM-2000 Front Panel DESCRIPTION OF CONTROLS The controls, indicators and microphone/programming connector are located on the front panel. The Monitor and Auxiliary buttons are located on the radios front panel. The following table details the Mobile controls, indicators, and connections. TABLE 2 Controls, Indicators, And Connections ITEM FUNCTION Rotary switch, used to select one of 4 channels (max.) and to engage 1.
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MAXON SM-2000 MOBILE DESCRIPTION OF CONTROLS Rear Panel Connections ITEM FUNCTION 1. Antenna Connector ( S0-239 ) 50 ohm connector Used to connect the mobile to the power supply 13.2 VDC or 13.8 VDC 2. DC Power Connector U.S.A. Multipurpose socket used to connect to a remote speaker or for test 3. External Speaker Connector connection Figure 2 SM-2000 Rear Panel Page-10- December 98
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MAXON SM-2000 MOBILE THEORY OF OPERATION THEORY OF OPERATION Each of the Scanning Mobile radios, UHF & VHF, include a unique main P.C.B. consisting of RF, Digital and Analog circuitry. DIGITAL CIRCUITRY IC 411 and IC412 are digitally-controlled analog switches which internally consist of three single pole, double throw switches. By placing a high (5V) or low (0V) on the control lines which consists of A,B, and C. A controls the X ports B controls the Y ports and C controls the Z ports. Exa
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MAXON SM-2000 MOBILE THEORY OF OPERATION EEPROM RX/TX channels, CTCSS/DCS as well as other data from the programmer are stored in the EEPROM. The data stored is retained without power supplied. This is a non-volatile memory. The EEPROM may have information re-programmed or erased. IC408 is an EEPROM with 2048 (256x 8) bit capacity and data is written and read serially, with the Programming cable through the front panel microphone connector. High Pass Filter The high pass filter is an 8-pole .1dB
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MAXON SM-2000 MOBILE THEORY OF OPERATION PLL IC101 (MC1459IF) is a PLL frequency synthesizer with an on-board 1.1 GHZ divide by 64/65 dual modulus prescaler. In addition to the prescaler and frequency counters, the synthesizer IC has a a phase detector and a C register (Configuration register) that allows certain functions to be configured as desired. The synthesizer is serially controlled by three wire input to the IC. Serial data is fed to pin 19 of the IC. Serial data CLK (pin 18) and active
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MAXON SM-2000 MOBILE THEORY OF OPERATION RF SECTION (SM-2150/VHF) VHF Transmitter The Transmitter is comprised of: 1. Microphone Audio Circuit 2. Transmitter Stage and Harmonic Filter 3. Automatic Power Control 4. Frequency Synthesizer Circuit Microphone Audio Circuit Microphone audio from the digital circuitry is amplified, pre-emphasized, limited, and mixed with Sub-Audible and applied to the VCO at Pin 1, through RV101, to balance VCO and TCXO modulation. Transmitter Stage and Harmonic Filter
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MAXON SM-2000 MOBILE THEORY OF OPERATION RX VCO The RX VCO comprises JFET Q351, coil L356 and varactor D353 and is configured as a Colpits oscillator. D353 produces a change in frequency with a change in DC voltage and is controlled by the phase detector signal present at the anode. The local oscillator signal at the drain of Q351 is applied to RF out of the module when diode D103 is reverse biased and D104 is forward biased. L356 is used for PLL alignment. TX VCO The TX VCO comprises JFET Q352
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MAXON SM-2000 MOBILE THEORY OF OPERATION Out of Lock Detector The out-of-lock detector produces a high logic level when Fr and Fv are in the same phase and frequency, low logic level pulses when the loop is out-of-lock at Pin 2 of IC101. The signals at Pin 2 of IC101 are buffered by Q106 and then integrating by R114 and C122. The product of the integrating circuit is fed to L/D port. Prescaler The internal Prescaler of IC101 divides the incoming signal frequency from the VCO via input pin 1 by 6
