Page 3 - Board Layout
MAXONSP-300 HAND HELD Page -ii- May 2001 Board Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Exploded View. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Page 4 - GENERAL
Page -1- May 2001 MAXON SP-300 HAND HELD SPECIFICATIONS GENERAL Equipment Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hand portable Band . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UHF/ VHF Channel Spacings ...
Page 6 - MAXON; and suitable antenna; RECEIVER
Page -3- May 2001 MAXON SP-300 HAND HELD Transmitter Audio Distortion (Without CTCSS) . . . . . . . . . . . . < 5% @ 1 kHz Hum & Noise: 12.5 kHz Channel Spacing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . > 40 dB (with PSOPH) 25 kHz Channel Spacing . . . . . . . . . . . ....
Page 7 - RX TONE DEMODULATION CHARACTERISTICS; SUBAUDIO TONES - CTCSS
MAXONSP-300 HAND HELD Page -4- May 2001 RX TONE DEMODULATION CHARACTERISTICS SUBAUDIO TONES - CTCSS Tone Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Hz to 250.3 Hz Non-Standard Tones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
Page 8 - Main Features; INTRODUCTION
MAXON SP-300 Series HAND HELD Page -5- May 2001 SP-300 The SP-300 Series of portable radios from Maxon, utilizesthe latest technology in its design and manufacturing. Boththe VHF and UHF models are PLL (Phase Lock Loop Syn-thesizer) / microprocessor controlled, and offer 1 or 5 wattsof power with 4 ...
Page 9 - MUST; have a priority channel selected; Scan Delay Time
MAXONSP-300 HAND HELD Page -6- May 2001 A priority channel can be selected while programming theradio. A priority channel is a channel that can be period i- cally checked or looked back to while receiving on any chan-nel in the scan list, or in normal operation. It can also beselected for all transm...
Page 10 - VCO Lock Time
MAXON SP-300 Series HAND HELD Page -7- May 2001 VCO Lock Time The micro will allow more lock time for the VCO before theout-of-lock beep indication. Low Battery Indication Low Battery Indication will be changed so that it does notinhibit RX and will allow one transmission after low cell isindicated....
Page 11 - DESCRIPTION OF CONTROLS; maxon; Pin
MAXONSP-300 HAND HELD Page -8- May 2001 The controls, indicators and antenna connections on the VHF and UHF Scanning Handheld Series radios are all located on the top panel. The accessories socket is located on the radio chassis right hand side. The monitor and PTT buttons are located on the radio c...
Page 12 - DIGITAL CIRCUITS
MAXON SP-300 HAND HELD Page -9- May 2001 THEORY OF OPERATION The VHF and UHF scanning handheld series radios are com-prised of one main PCB. The main PCB contains the trans-mitter, receiver and control circuits. The control circuitscontain the micro controller and associated digital circuits. DIGITA...
Page 13 - RF CIRCUITS; The transmitter is comprised of:
MAXONSP-300 HAND HELD Page -10-May 2001 Mute (squelch) Circuit The mute circuit which is controlled by the output of IC409(micro) Pin 77 (386EN) is connected to Q34 via R122 whichmutes the LM386IC on the RF circuits. Pin 77 also controlsIC402B which mutes the audio path to the RF circuits. TX Audio ...
Page 14 - RF CIRCUITS PLL SYNTHESIZER
MAXON SP-300 HAND HELD Page -11-May 2001 RF CIRCUITS PLL SYNTHESIZER 12.8 MHz TCXO The TCXO contains the 3-stage thermistor network compen-sation and crystal oscillator and modulation ports. Compen-sation is +/-5 PPM or less from -30c to +60c. PLL IC Dual Modules Prescaler Input frequency of 12.8 MH...
Page 16 - Removing the belt clip:; Depress the metal release tab located on the top of; To replace the belt clip:; With the slides of the belt clip positioned in line with; maxon maxon; Figure 1-Belt Clip Removal
Page -13-May 2001 MAXON SP-300 HAND HELD MAINTENANCE AND REPAIR GENERAL Any repair or adjustment should only be made by or under thesupervision of a qualified radio service technician. When removing or fitting, use the Exploded View and PartsList (Page 51) in conjunction with the following procedure...
Page 17 - REMOVING & REPLACING THE BATTERY; To remove the battery:; Holding the radio chassis in one hand, press and; To replace the battery:; Position the battery on the battery guide rail at the; To remove the PTT assembly:; Remove the 2 screws located at the top and bottom; Figure 3-Battery Removal
Page -14-May 2001 MAXONSP-300 HAND HELD REMOVING & REPLACING THE BATTERY To remove the battery: 1. Holding the radio chassis in one hand, press and hold the battery release catch on the upper back ofthe radio with the other hand. 2. Pull the battery back and away from the radio. 3. Remove the ba...
Page 18 - Figure 5-PTT Installation; Figure 7-Control Knob Removal & Installation
Page -15-May 2001 MAXON SP-300 HAND HELD 2. By placing thumb under bottom of the PTT assembly and gently pulling outward, unplug PTT Assemblyfrom Main Board. To replace the PTT assembly: 1. Reverse the steps taken to remove the PTT assembly. 2. Insure that the PTT jack is aligned properly when inser...
Page 19 - Figure 9A-Back Cover Removal & Installation
Page -16-May 2001 MAXONSP-300 HAND HELD REMOVING & REPLACING THE BACK COVER To remove the Back Cover: 1. Remove battery. (Refer to Removing &Replacing the Battery) 2. Unscrew the four Back Cover mounting screws located on the Back Cover of the radio. 3. Remove the Back Cover by pulling the l...
Page 20 - To remove the Main Board:; Figure 9-Main Board Removal & Installation
Page -17-May 2001 MAXON SP-300 HAND HELD REMOVING & REPLACING THE MAIN BOARD To remove the Main Board: 1. Remove the Battery (Refer to Removing & Replac- ing the Battery). 2. Remove the PTT Assembly (Refer to Removing & Replacing the PTT Assembly). 3. Remove the Dust Cap (Refer to Removi...
Page 21 - To replace the Main Board; Reverse the steps taken to remove the Main Board.
Page -18-May 2001 MAXONSP-300 HAND HELD To replace the Main Board 1. Reverse the steps taken to remove the Main Board. 2. When installing the Main Board into the chassis insure that the LED light guide is aligned properly. 3. When installing the Main Board into the chassis, place 2 fingers over the ...
Page 22 - To Replace a Daughter Board:; COMPONENT REPLACEMENT; Surface Mount Components
MAXON SP-300 HAND HELD Page -19-May 2001 REMOVING & REPLACING THE DAUGH-TER BOARDS The Daughter Boards are soldered into the Main Board Assy. 1. Remove the Main Board (Refer to Removing & Replacing the Main Board). 2. Unsolder the appropriate Daughter Board from the Main Board Assembly. To R...
Page 23 - It may be necessary to remove excess solder using a; Surface Mount Component Replacement; “Tin” one terminal end of the new component and; Surface Mounted Integrated Circuit Replacement
MAXONSP-300 HAND HELD Page -20-May 2001 4. It may be necessary to remove excess solder using a vacuum de-soldering tool or Solder wick . Again,use great care when de-soldering or soldering onthe printed circuit boards. It may also be necessaryto remove the epoxy adhesive that was under thesurface mo...
Page 24 - Cloning; ALIGNMENT PROCEDURE; SQUELCH ADJUSTMENT
MAXON SP-300 HAND HELD Page -21-May 2001 PROGRAMMING The SP-300 Series portable radios require the ACC-2300programming cable. With the 25 pin “D” type connectorinstalled on the computer, take the other end of the program-ming cable and insert it in the receptacle located on theopposite side of the P...
Page 25 - Note: Use TP1 to measure the voltage
MAXONSP-300 HAND HELD Page -22-May 2001 15. Disconnect the test equipment. Should repairs be required, the following procedures shouldbe applied: RX VCO 1. Set the unit to the highest receive frequency, 470 MHz(UHF), 174MHz(VHF) and adjust the VCOL303 to 10 volts. 2. Set the unit to the lowest recei...
Page 27 - ALIGNMENT POINTS DIAGRAM; ALIGNMENT POINTS VHF & UHF
MAXONSP-300 HAND HELD Page -24-May 2001 ALIGNMENT POINTS DIAGRAM ALIGNMENT POINTS VHF & UHF WITH TCXO MODULE ALIGNMENT POINTS UHF WITH OUT TCXO MODULE RV2 RV4 T1 RV1 RV3 TCXO1 TC701 L203 L303 RV401 RV403 RV402 TP1 RV2 RV4 T1 RV1 RV3 L203 L303 RV401 RV403 RV402 TP1 RV5
Page 28 - SYMPTOMS
MAXON SP-300 HAND HELD Page -25-May 2001 TROUBLESHOOTING GUIDE SYMPTOMS CAUSES COUNTER MEASURES 1. Complete discharge of battery (7.5v+/-10%) 1. Replace battery Unit does not Work 2. Fuse blown up (4a) 2. Replace fuse 3. 5v voltage source 3. IC1 (5v+/-0.2v) 1. Low battery (lower than 5.6v) 1. Replac...
Page 29 - VOLTAGE CHARTS; NOTE: Q402 and Q409 are not fitted on this model series.; CONTROL CIRCUIT; TX; MAIN CIRCUIT; RX
MAXONSP-300 HAND HELD Page -26-May 2001 VOLTAGE CHARTS z NOTE: Q402 and Q409 are not fitted on this model series. z NOTE: Q9, 10, 15, 19, 20, 23 and 28 - 32 are not fitted on this model series. z NOTE: ~ indicates approximate voltage. Actual voltage may vary. CONTROL CIRCUIT RX TX REF # B C E B C E ...
Page 30 - RECEIVE STATE
Page -27-May 2001 MAXON SP-300 HAND HELD z NOTE: IC4, 403 and 405 are not fitted on this model series. RECEIVE STATE PIN # IC1 IC2 IC3 IC5 IC6 IC401 IC402 1 GND 1.6 - 4.0 1.4 0.0 0.0 2 GND 5.0 - 3.5 GND 1.0 0.0 3 GND 5.0 - 4.0 0.0 1.3 AUDIO 4 5.0 5.0 - 4.1 GND 0.0 0.0 5 GND 5.0 - 3.8 AUDIO 0.0 5.0 6...
Page 31 - TRANSMIT STATE
MAXONSP-300 HAND HELD Page -28-May 2001 TRANSMIT STATE PIN # IC1 IC2 IC3 IC5 IC6 IC401 IC402 1 GND 1.6M 0.0 - 1.3 1.9 0.0 2 GND 5.0 0.0 - GND 1.9 0.0 3 GND 5.0 0.0 - 0.0 1.9 0.0 4 5.0 5.0 GND - GND 1.9 0.0 5 GND 5.0 - - 1.5 0.0 0.0 6 7.5 0.0 - - 7.5 0.0 0.0 7 0.0 - - 7.5 0.0 GND 8 0.0 5.0 - 1.5 1.9 ...
Page 37 - SP-300 SERIES UHF RF SECTION PARTS LIST
MAXONSP-300 HAND HELD Page -34-May 2001 SP-300 SERIES UHF RF SECTION PARTS LIST REF # DESCRIPTION PART # REPLACEMENT MODULES FRONT ENDASSY, UHF (SEE NOTE 1) 650-110-0013 VCOTX/RX ASSY, UHF (SEE NOTE 1) 650-030-0020 POWERAMPASSY, UHF (SEE NOTE 1) 650-230-0013 COMPONENTS C1 CAP,CER,470PF,10%,50V,X7R,0...
Page 41 - COMPONENT PINOUT
MAXONSP-300 HAND HELD Page -38-May 2001 COMPONENT PINOUT BASE DIAGRAM MANUFACTURER'S PART NUMBER REFERENCE NO. SCHEMATIC Q202,203,302,303,601 2SC5084 MMBR951 Q16,17,501,601 BFR92A Q12,16,25 KTC3875S (BL) Q6,11,13,14,21,26,27 Q7,8,33 KTA1504SY KRC104S (ND) Q18,23,24,28,31,32,34,403,Q404,405,411,413 K...
Page 44 - SCHEMATICS & BLOCK DIAGRAM; VHF POWER AMP
PAGE -41- May 2001 SCHEMATICS & BLOCK DIAGRAM VHF FRONT-END (148-174MHz Band Shown) Schematic P/N: 770-110-0012 Rev. CPCB Assy. P/N: 650-110-0012 Rev C Notes: 1. ALL VALUES ARE IN OHMS,MICROHENRIES OR MICROFAR-ADS UNLESS OTHERWISE SPECI-FIED. 2. ALL RESISTORS ARE 1/10W 5%UNLESS OTHERWISE SPECIFI...
Page 45 - VCO R X; VCO TX
PAGE -42-May 2001 VHF V.C.O. (148-174MHz Band Shown) Schematic P/N: 770-030-0021 Rev. B PCB Assy. P/N: 650-030-0021Rev. B UHF V.C.O. (440-470MHz Band Shown) Schematic P/N: 770-030-0018 Rev. D PCB Assy. P/N: 650-030-0020 Rev. A Notes: 1. ALL VALUES ARE IN OHMS,MICROHENRIES OR MICROFAR-ADS UNLESS OTHE...
Page 46 - TCXO; Shown for reference only; FUSE
PAGE -43- May 2001 Notes: 1. ALL VALUES ARE IN OHMS,MICROHENRIES OR MICROFAR-ADS UNLESS OTHERWISE SPECI-FIED. 2. ALL RESISTORS ARE 1/10W 5%UNLESS OTHERWISE SPECIFIED. TCXO Schematic P/N: 770-100-0002 Rev. D PCB Assy. P/N: 650-100-0002 Rev. D ACC-200 BATTERY Schematic P/N: 770-210-0010 Shown for refe...
Page 47 - Digital Schematic; Digital Schematic Diagram
PAGE -44-May 2001 Digital Schematic 1 23 4 567 89 10 11 12 VOLUME P/S 5V 386 EN N/S SW SPK CHARGE PWR H/L ALERT AUDIO PLL EN LOCK D/T RX EN TX EN BUSY CLOCK DATA TCXO MOD TX 5V 1.DATA2.CLOCK 4.+7.5V 7.GND8.MIC+ 10.INT_SPK_MIC_DSBL11.SPKR+ X0 12 X1 13 Y0 2 Y1 1 Z0 5 Z1 3 INH 6 A 11 B 10 C 9 X 14 Y 15...
Page 48 - VHF RF Schematic; VHF RF SCHEMATIC
PAGE -45- May 2001 VHF RF Schematic MOD 1 2 3 4 5 6 7 8 MIXER PWR H/L GA1 1 -IN 2 +IN 3 GND 4 OUT 5 VCC 6 B.P 7 GA2 8 AUDIO AMP OSO 1 LD 2 *R 3 *V 4 VPD 5 PD 6 GND 7 RX 8 FIN 10 FIN 11 VCC 12 VDD 14 EN 17 CK 18 DT 19 OSI 20 TST1 9 TST2 13 O/B 15 O/A 16 MC145191F PLL EN DATA CLOCK 4 3 TCXO 1 2 2 1 MI...
Page 49 - UHF RF Schematic; UHF RF SCHEMATIC
PAGE -46-May 2001 UHF RF Schematic 6 TX 5V 1 D20 KDS160 R43 10K MOD C57 470P MOD 2 4 3 5 7 4 PWR H/L STREENG 5 6 1 2 G A 1 - I N + I N G N D O U T V C C B . P G A 2 LM386N-3 AUDIO AMP OSO 1 LD 2 *R 3 *V 4 VPD 5 PD 6 GND 7 RX 8 FIN 10 FIN 11 VCC 12 VDD 14 EN 17 CK 18 DT 19 OSI 20 TST1 9 TST2 13 O/B 1...
Page 50 - Block Diagram
PAGE -47- May 2001 Block Diagram REVISIONS CHG BY DATE DESCRIPTION DESCRIPTION RELEASED TO MANUFACTURING REV A DGC 03/01 TITLE SCALE SHEET OF SIZE DOCUMENTNUMBER B 1 1 NA SP-300 Series SYSTEM ELECTRICALBLOCK DIAGRAM 060-***-**** LEVEL SHFTER Q6,7,8,11 TCXO1 FRONT END R V C21,C22 REF L.P.F. Q202/203 ...
Page 51 - PCB LAYOUTS
PAGE -48-May 2001 PCB LAYOUTS Board Layout (Top) Main Board Assembly 416121B Board Layout (Bottom) Main Board Assembly 416121B Board Layout J3 VR3 CH404 FON1 TCXO1 D5 L13 C132 L11 C75 R70 L16 L17 C701 LED1 C136 RV2 RV4 R93 T1 C74 L8 C73 L7 C76 VR1 RV3 Q22 R54 R53 C65 L15 C93 R65 T2 C87 L14 LK100 XF1...
Page 52 - Exploded View
PAGE -49- May 2001 max on 2 11 21 24 23 7 14 13 40 41 39 36 42 54 26 25 27 VHF UHF 1 550-021-0025 UPPER COVER ASS'Y PART NAME PART NO. NO. 2 490-070-0035 NAME PLATE 3 5 6 7 8 8-1 9 10 11-1 13 14 15 16 17 18 19 20 21 33 39 38 37 36 35 34 32 31 11 1 4 3 22 16 18 19 20 X2 32 33 X2 X2 29 15 45 46 47 49 ...
