E.F. Johnson 7243 LTR-NET Service Manual Download Page 12

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2-1

November 2001

Part No. 001-7240-001

OPERATION

SECTION 2 OPERATION

Figure 2-1 Top Panel Controls

2.1 FEATURES

2.1.1 GENERAL FEATURES

The following features are available in all oper-

ating modes (LTR-Net/LTR/conventional).

•

Up to 16-100 systems programmable depending on
type (LTR-Net/LTR/conv) and number of groups in
each.

•

Up to 99 groups programmable per system

•

LTR-Net

™

, LTR

, and conventional operating

modes

•

Unique 8-character system and group identification
tags

•

System and group scanning

•

User programmable system and group scan lists

•

Menu mode to select functions

•

Telephone mode for convenient number dialing

•

Three programmable option switches

•

Keypad lock (with and without password)

•

Call indicator

•

Time-out timer

•

Receive-only groups

•

Companding

2.1.2 LTR-NET FEATURES

The following features are available when an

LTR-Net system is selected.

•

Roaming (automatic locality search)

•

Special calls including telephone, unique ID, and
directed group

•

Busy queuing of special calls by radio system

•

Transmit inhibit

•

Receive priority calls

•

Standard group calls (mobile-to-mobile)

•

Automatic registration/de-registration

2.1.3 LTR FEATURES

The following features are available when an

LTR system is selected.

•

Standard group and telephone calls

•

Transmit inhibit

•

Receive priority calls

2.1.4 CONVENTIONAL FEATURES

•

Busy indicator

•

Talk-around

•

User-adjustable squelch level

•

Monitor mode

•

Call Guard

squelch control

•

Transmit disable on busy

NOTE: Programming determines the availability of
many of the preceding features.

Antenna Jack

On-Off/Volume

Microphone

Speaker

Option

Switch 1

Accessory
Connector

Summary of Contents for 7243 LTR-NET

Page 1: ...TRUNKED PORTABLE RADIO SERVICE MANUAL First Issue November 2001 LTR NET 7243 UHF PORTABLE 7 5VDC 1 and 4 Watts Part No 242 7243 xxx ...

Page 2: ...manufactures and markets conventional and trunked radio systems mobile and portable subscriber radios repeaters and Project 25 digital radio products Viking Head EFJohnson logo LTR LTR Net and Call Guard are trademarks of the E F Johnson Company SMARTNET and SmartZone are trademarks of Motorola Inc All other company and or product names used in this manual are trademarks and or registered trademar...

Page 3: ...ompanding 2 10 Emergency Switch 2 10 Encryption 2 11 Home System Group Select 2 11 Option Select 2 11 Power Select 2 11 Proceed Clear To Talk Tone 2 11 Receive Only Groups 2 11 Time Out Timer 2 11 Tone Select 2 12 2 5 OPTION SWITCHES AND MENU MODE 2 12 Option Switches 2 12 Menu Mode 2 12 2 6 SYSTEM AND GROUP SCANNING 2 13 General 2 13 Scan On Off 2 13 Scan Types 2 14 LTR Net Mode Scanning 2 14 LTR...

Page 4: ...Edit Banks Screen 3 11 Edit Unique ID Screen 3 11 3 7 TRANSFER MENU 3 11 3 8 VIEW MENU 3 12 3 9 COMPORTS MENU 3 13 3 10 HELP MENU 3 13 3 11 ADDITIONAL PROGRAMMING INFORMATION 3 13 Program Key 3 13 Multiple Home Repeaters 3 13 Channel Number Programming 3 13 Repeater Numbering 3 13 Specifying RIC Equipped Repeaters 3 14 Test Locality 3 14 3 12 UPDATING RADIO SOFTWARE 3 14 Introduction 3 14 Data Fil...

Page 5: ...t Modes 5 11 6 LTR NET OVERVIEW 6 1 INTRODUCTION 6 1 General 6 1 Compatibility With LTR 6 1 LTR Net Features 6 2 Definitions 6 3 6 2 SYSTEM ARCHITECTURE 6 3 Introduction 6 3 Subscriber Units 6 3 Repeaters 6 4 3000 Series Switch 6 4 Call Processor 6 5 System and Subscriber Manager 6 5 6 3 STANDARD GROUP CALLS 6 5 6 4 WIDE AREA GROUP CALLS 6 5 6 5 SPECIAL CALLS 6 6 General 6 6 Auxiliary Calls 6 6 Te...

Page 6: ...ion 3 16 3 4 Group Programming Screen Description 3 17 3 5 Bank Programming Screen Description 3 19 3 6 Call Guard Codes and Tones 3 20 4 1 Microprocessor U208 Pin Descriptions 4 5 5 1 Test Channels 5 10 LIST OF FIGURES 1 1 Battery Charger 1 4 2 1 Top Panel Controls 2 1 2 2 Display 2 2 2 3 Front Panel Keys 2 3 2 4 Programmer Error Code Screen 2 32 3 1 Programming Setup 3 1 3 2 Main Window 3 5 3 3 ...

Page 7: ...ed in Table 1 1 A brief description of some of these accessories follows Extension Test Cable This cable is required to operate the transceiver when it has been opened to access internal components It reconnects the keypad display board to the audio logic board Programming Hardware The RPI provides the interface between the programming computer and 242 72 x 3 x x 3 Band Freq Range Signaling Type 3...

Page 8: ...ctory repair facilities Regular Customer Service hours are 7 30 a m 5 30 p m Central Time Monday Friday The Customer Service Department can be reached using the following telephone numbers Toll Free 800 328 3911 FAX 507 835 6969 E Mail customerservice efjohnson com You can also e mail a person directly if you know their first initial last name example jsmith efjohnson com NOTE Emergency 24 hour te...

Page 9: ...air efjohnson com 1 9 REPLACEMENT PARTS Replacement parts can be ordered directly from the Service Parts Department To order parts by phone dial the toll free number as described in Section 1 7 When ordering please supply the part number and quantity of each part ordered E F Johnson dealers also need to give their account number If there is uncertainty about the part number include the desig nator...

Page 10: ...to sense that the battery is nearly fully charged and that switching to the trickle mode should occur This method detects when the battery temperature begins increasing at a faster rate which normally provides the first indication that the battery is fully charged To provide fail safe operation the trickle rate is also selected if the battery temperature rises above 50 C 122 F or charge time in th...

Page 11: ...z 410 g Power Source 7 5 VDC nickel metal hydride NiMH battery pack 1450 mAH Typical Battery Life 5 5 90 7 3 hours high power 9 9 hours low power Compliance FCC parts 15 and 90 Circuit Protection 3 ampere fuse RECEIVER Sensitivity 0 35 µV 12 dB SINAD Selectivity 65 dB at 25 kHz 60 dB at 12 5 kHz Spurious and Image Rejection 65 dB Intermodulation 65 dB Audio Output Power Internal Speaker 0 5 watt 1...

Page 12: ...l indicator Time out timer Receive only groups Companding 2 1 2 LTR NET FEATURES The following features are available when an LTR Net system is selected Roaming automatic locality search Special calls including telephone unique ID and directed group Busy queuing of special calls by radio system Transmit inhibit Receive priority calls Standard group calls mobile to mobile Automatic registration de ...

Page 13: ...nsceiver Battery Release Button Not shown This button is located on the bottom end of the transceiver and it is pressed to release the battery so that it can slide down ward and be removed from the radio NOTE Turn off transceiver power before removing the battery This ensures that current settings are prop erly saved and the de registration message is sent 2 2 2 SIDE CONTROLS Option Switch 2 This ...

Page 14: ...rs when the push to talk switch is pressed or a register de register message is sent see Section 2 9 4 2 2 4 FRONT PANEL KEYS The front panel keys are shown in Figure 2 3 above Most keys control two or more functions The Figure 2 3 Front Panel Keys function labeled on the key is usually selected by simply pressing the key and the function labeled under the key is usually selected by first pressing...

Page 15: ...Mode FCN DIAL Selects the dial mode without changing the currently selected group 3 Pressing this key with the PTT switch pressed transmits the 3 digit Dial Mode 3 Dials the 3 digit FCN DIAL Exits the dial mode without sending the call termination characters 4 PAGE Standard Mode FCN PAGE The page function is currently not available 4 Pressing this key with the PTT switch pressed transmits the 4 di...

Page 16: ... GRP Selects the next higher group see preceding GRP key description FCN Selects the keypad standard lock feature Dial Mode Dials the digit FCN Displays the overflow digits FCN RCL Recalls the last number sent by FCN SND 2 3 BASIC OPERATION 2 3 1 POWER UP SEQUENCE When power is turned on using the top panel on off volume control a beep sounds the backlight turns on all segments and icons in the di...

Page 17: ...epeat and after the lowest system or group is selected wrap around occurs To directly select a system or group number press SYS or GRP and then the number of the desired system or group For example to select Group 9 press GRP 0 9 A leading 0 must be entered to select systems and groups 1 9 2 3 6 KEYPAD DISABLE STANDARD Occasionally the front panel keys may be acci dentally pressed for example if t...

Page 18: ...peration that is programmed is determined by the type of repeater equipment being accessed The differ ences in operation are described in the following infor mation and also noted elsewhere as required LTR Net and LTR Operation The LTR Net mode provides the most operating features Some features available only in the LTR Net mode include roaming automatic locality search unique ID calls and directe...

Page 19: ...anks systems and groups increases Systems Systems are a collection of groups and other information unique to that system see next para graph Each system is linked to one of the programmed localities and up to 99 systems can be programmed Each system is programmed with a unique alpha tag and can have a different display number in each bank see Section 2 4 1 LTR Net and LTR systems are programmed wi...

Page 20: ...pressed the system is accessed as soon as it is free If the radio system could not be accessed because of an out of range condition or some other reason the intercept tone sounds see Section 2 12 and NO ACCES is indicated in the display The PTT switch must then be released and pressed again to make another access attempt When responding busy or no access conditions may also occur the same as when ...

Page 21: ...ndividual groups can be programmed for this feature and it then turns on when a call is received on one of those groups This indicator is turned off by pressing any button or cycling power If scanning and the Last Received configuration is programmed see Section 2 6 10 the system and group of the last call are displayed Other wise the currently selected system group is displayed Each selectable gr...

Page 22: ...the same screen The proceed tone normally sounds almost imme diately when the PTT switch is pressed However with some calls such as wide area the user should wait a short time after pressing the PTT switch before speaking The proceed tone delay of 0 2 5 seconds can be programmed in the Timing Parameters screen This delay can then be enabled on each group by checking the Delayed Proceed Tone box If...

Page 23: ...Otherwise the tones that sound are fixed by programming The following choices are available Refer to Section 2 5 2 for more information on using the menu mode Silent All tones are disabled Keys Only the key press tones are enabled Alerts All tones except the preceding key press tones are enabled All Both the key press and alert tones are enabled 2 5 OPTION SWITCHES AND MENU MODE 2 5 1 OPTION SWITC...

Page 24: ...ture monitors in sequence the systems and or groups in the scan list When a message is detected that the transceiver is programmed to receive scanning stops and the message is received Shortly after the message is complete scanning resumes unless it has been disabled System and group scanning or group scanning only may be selected and they operate as follows Refer to Section 2 3 12 for more inform...

Page 25: ... systems the transceiver moves to it However searching continues for a programmed LTR Net locality and when one is detected registration on that site occurs and only LTR Net systems are again scanned This operation can provide uninterrupted operation when traveling through areas which have not yet been converted to LTR Net operation Other scan operation in this mode is as follows If Roaming Off an...

Page 26: ...tion in Section 2 6 2 Deleting a system only temporarily deletes the groups associated with that system because when a system is added back into the scan list the original group scan list is again active Scan lists can be programmed even when scanning is disabled and while listening to a message If a system or group is deleted while listening to a message scanning resumes after the receive delay t...

Page 27: ...P keys Before scanning resumes exit the scan mode by pressing FCN SCAN The system group of the call then becomes the selected system group and it is not necessary to change it manually Last Received The selected system group changes to the system group of a call Therefore you can always respond to a call without having to manually change the system group To return to the previously selected system...

Page 28: ...FCN To erase the last digit press the CLR key To erase the entire number press FCN CLR To enter a pause press FCN each pause equals one character 2 7 4 SENDING THE NUMBER Access the radio system by briefly pressing the PTT switch Then when a dial tone is heard send the number in the display by pressing FCN SND The keypad remains active while in a conversation to allow additional numbers to be dial...

Page 29: ...th the ID code being transmitted must be selected or scanned Calls with a higher priority than the selected group are always received as described in Section 2 8 2 The procedure used to place and receive standard group calls is described in Section 2 3 13 2 8 2 CALLS ON PRIORITY ID CODES LTR Net transceivers use a different receive priority scheme than has been used with other E F Johnson transcei...

Page 30: ...ot programmed with the priority ID is being monitored 2 8 3 BLOCK ID CODES AND ACCESS PRIORITY This transceiver does not use blocks of ID codes However with up to 99 groups programmable per system and group scanning it is usually possible to program the transceiver to receive all desired calls Access priority to control which transceivers can access the system during busy periods is not available ...

Page 31: ...h Therefore a group programmed with the ID specified by the originating mobile must be selected or scanned or be assigned to a higher priority group To receive landside originated telephone calls the transceiver must be programmed for telephone calls even though the unique ID of the mobile may be speci fied when placing the call see Landside Originated Calls which follows With all special calls th...

Page 32: ...indicate that the number was accepted by the system If this beep does not sound an unauthorized number may have been dialed or a dialing mistake may have been made If a system resource busy condition exists the call is placed in a queue by the system see Section 2 9 3 6 The various types of calls then proceed as follows Telephone Call The normal landside ringing or busy tone is heard When the part...

Page 33: ...vided at the system level for LTR Net telephone unique ID and directed group calls but not standard group calls If this feature is enabled by the System and Subscriber Manager and resources are not available when one of these calls are placed a voice message informs the user that the call has been placed in a queue This message occurs when the PTT switch is released after dialing the digits If res...

Page 34: ...ccurs LCL SRCH is no longer displayed and the system of the new LTR Net locality is displayed The new system is the next higher system with a different locality that could be accessed For example if System 3 was selected and System 5 is the next higher system with a different locality number that becomes the selected system if it can be accessed wrap around occurs after the highest system is check...

Page 35: ...ermanently disables itself It is then totally inoperative and CALL SVC is displayed continuously It must then be brought back in for reprogramming to make it operational again 2 9 7 HOME CHANNEL ALIASING Introduction The home channel aliasing feature increases the number of standard group calls programmable on a locality by allowing calls to be programmed on non existent home repeaters Therefore i...

Page 36: ...a telephone group is selected to make a call the transceiver enters the telephone operating mode To place an LTR telephone call a telephone group must be selected and to receive an LTR tele phone call the telephone ID must be selected or scanned or have a higher priority Since this transceiver operates half duplex the PTT switch must be pressed to talk and released to listen the same time as with ...

Page 37: ...ort tone sounds to indicate that the number of the mobile being called should be dialed This number is usually five digits long and must be dialed using a tone type telephone The first two digits are the home repeater number of the mobile and the last three digits are the telephone ID code of the mobile With LTR interconnect equipment the first digit must be dialed within 5 seconds of hearing the ...

Page 38: ...lls is preset and cannot be changed If conven tional systems are programmed adjust the squelch as follows 1 Select a conventional system and group that is not busy 2 Press FCN SQL to select the squelch adjust mode The monitor mode is automatically selected in this mode The currently selected level is indicated by SQ xxx in the display 3 Press the key until receiver noise is heard and then press un...

Page 39: ...o bit or word synchronization information is used When the push to talk switch is released a turn off code is transmitted which eliminates the squelch tail similar to the reverse burst Although there are thousands of possible code combinations with 23 bits only 83 are unique with the data scheme used The number specified when the code is programmed is actually a seed for a special algorithm used t...

Page 40: ...e Section 2 3 5 Error Tone A 1050 Hz 80 ms tone followed by a 700 Hz 80 ms tone which indicates that an error condition occurred 2 12 2 LTR NET SPECIAL CALL TONES NOTE The following tones are produced by the LTR Net switch and are heard only when placing special calls Confirmation Tone A short tone which sounds when the number just dialed is accepted by the system Call Proceed Tone With LTR Net Di...

Page 41: ...ted by the FCN switch see Section 2 2 4 HSQ SRCH Indicates the transceiver is currently on the first pass while searching for a new locality on which to register see Section 2 9 4 LCL SRCH Indicates the transceiver is currently on the second or later pass while searching for a new locality on which to register see Section 2 9 4 NO ACESS Indicates that the repeater system could not be accessed perh...

Page 42: ...orary conventional channels When the test operating code is loaded several test functions are available Refer to Section 5 for more information To display the software version number turn power on with PTT switch pressed The version number is displayed as VER x xx see Section 2 3 10 If any error codes are present see next section the most recent error code is displayed instead of the software vers...

Page 43: ...tware described in Section 3 7 Connect the programming setup and then select Transfer Read Codes or click the icon in the toolbar see Section 3 7 The screen shown in Figure 2 4 is then displayed which indicates various information about each stored error code Contact the Customer Service Department as described in Section 1 7 for additional information on the displayed error codes To permanently e...

Page 44: ...meets the following minimum requirements Windows 95 98 or NT 4 0 operating system CD ROM drive One unused serial port The programming software requires a Windows 32 bit operating system such as Windows 95 98 2000 or NT 4 0 to run A 16 bit operating system such as Windows 3 1 cannot be used Since the program is relatively small approxi mately 600K it will run properly with the amount of RAM recomme...

Page 45: ...store data indefi nitely without the need for a constant power supply The battery can be removed from the transceiver indef initely without affecting programming If the operating program needs to be updated reprogramming is performed using special program ming software and the same setup used for personality programming Refer to Sections 3 12 and 5 2 for more information 3 1 6 HARDWARE HOOKUP The ...

Page 46: ...he title bar is located at the top of the window see Figure 3 2 and indicates the following Clicking this control icon displays the screen on the right which can be used to perform the indicated window control functions Name of the current data file Johnson_rad mbl in Figure 3 2 Program name LTR Net Programmer Window Minimize Maximize and Close buttons 3 3 2 MENU BAR The menu bar see Figure 3 2 di...

Page 47: ...ious screens Personality Displays a running total of the amount of space remaining in EEPROM memory of micropro cessor U208 if the transceiver was programmed with the current information If this number reaches zero before all data is entered fewer localities systems groups banks must be programmed see Section 2 3 12 Saved Info LTR Net Locality Functions like the Flash memory display just described...

Page 48: ...5 Portable Key Select this screen by clicking the tab at the top and then choose the function for each key from the drop down menu Section 3 6 6 Telephone Numbers Select this screen by clicking the tab at the top and then enter the preprogrammed telephone numbers Section 3 6 7 3 When all parameters in the Radio Parameters Screens are programmed click the OK button to save all changes or the Cancel...

Page 49: ...Click the Add button if adding a new group the Change button if editing a group or the Delete button if deleting a group To exit without saving the current changes click only the Done button 6 Repeat until the system has been programmed with the desired groups Then click the Done button to exit Repeat to program other systems if applicable 3 4 7 BANK PROGRAMMING At least one locality system and gr...

Page 50: ...er or toolbar icon saves the current programming data file to disk If it is the first time it is being saved a screen is displayed which allows a file name to be entered similar to the Save As function which follows The Save function should be used periodically while editing a file to prevent the loss of data if a power failure occurs or program execution is interrupted for some other reason Files...

Page 51: ... sounds with conventional calls in addition to LTR Net LTR standard calls Conversation Enabled When selected the proceed tone also sounds with LTR Net LTR telephone and auxiliary calls initial access only Scan Revert Mode Selects the system group on which transmissions occur in the scan mode Section 2 6 10 Last Selected Always on the selected Last Received Always on the last received Temporary On ...

Page 52: ... always sound If a menu item is selectable by the menu mode or an option switch the default condition exists only until the first time that function is changed manually or automatically The last selected and not the default condition is selected when power is turned on Refer to Section 2 5 2 for more menu mode information and to Table 3 1 for brief descriptions of items programmed in the Menu Item...

Page 53: ...s are not used Table 3 1 Menu and Option Switch Parameter Descriptions Parameter Menu Item Option Switch 1 Description Backlight X On Turns on briefly when a key is pressed Off Always disabled Bank Select X Selects banks when two or more are programmed Section 2 4 1 Display Mode Select X X Selects the alpha or numeric display mode The display mode can also be tog gled by FCN STR or STR option swit...

Page 54: ...n is displayed to select the system in which groups are to be added or edited After the desired system is selected click the OK button and the group editing screen in Table 3 4 is displayed Up to 99 groups can be assigned to each system or to any one locality 3 6 11 EDIT BANKS SCREEN The Edit Banks menu parameter see Figure 3 3 or equivalent buttons in the toolbar are used to select the screen tha...

Page 55: ...is occurring TYPE ERR Indicates that the programming data is incompatible with the transceiver A possible reason for this is using a version of the programming software that is not compatible with the transceiver software PROG ERR Indicates that an error was detected when verifying the data programmed into the transceiver Read Codes This menu item or toolbar button reads the error code log stored ...

Page 56: ...racters Then program the transceiver with the data file If the key is lost contact Customer Service as described in Section 1 7 for information on how this feature can be overridden 3 11 2 MULTIPLE HOME REPEATERS Systems linked to the same locality should not be programmed with different home repeaters as missed calls may result With LTR Net and LTR operation each home repeater transmits incoming ...

Page 57: ...12 1 INTRODUCTION The transceiver operating software firmware can be updated in the field without replacing the microcontroller or a memory device such as an EPROM For example the radio software may be updated to correct software bugs or add feature enhancements This is possible because a reprogram mable Flash memory device is used for program storage The same basic hardware setup used to program ...

Page 58: ...two LTR or LTR Net localities are close enough to interfere with each other One locality is then programmed 0 and the other 1 Rx Tx Base Frequency This is a non editable field shown for reference only It indicates the base receive and transmit frequency used to derive the frequency of each channel Power Programs the power output that is selected when the transceiver accesses that locality High 4 w...

Page 59: ...non RIC repeaters to make telephone calls Section 3 11 5 Table 3 3 System Programming Screen Description This screen is used to create a new system or edit a current system It is displayed by selecting the Edit Systems menu see Section 3 6 9 or clicking one of the buttons in the toolbar Groups are added using the Edit Groups function For a system to be selected or scanned it must be linked to a ba...

Page 60: ...mbers of 1 8 are selectable with LTR Net and LTR groups Section 2 8 2 Encode ID With dispatch group calls selects the ID code that is transmitted Codes 1 239 can be programmed with LTR Net systems and 1 250 can be programmed with LTR systems Section 2 8 1 When Disabled is selected transmitting is disabled so the group is receive only Decode ID Similar to Encode ID except selects the receive code t...

Page 61: ...Table 3 6 Rx Call Guard Type Selects the type of receive Call Guard squelch control as Tone CTCSS digital DCS inverted digital or none carrier See Section 2 11 6 Rx Call Guard Code If tone or digital decode Call Guard squelch was selected above selects the tone frequency or digital code that must be decoded to receive a call These tones and codes are also listed in Table 3 6 Add to Grp Scan List S...

Page 62: ...t is used only to identify it during programming Emergency System Grp The emergency switch is not available with this transceiver Home System Grp Selects the home system group selected by the Home select function on the bank Section 2 4 6 Bank Scan Enable Programs the default scan status on or off when the bank is selected Section 2 4 1 System Display No Systems can be assigned unique display numb...

Page 63: ...req Code Freq Code Freq Code Freq Code Freq 01 67 0 10 94 8 19 127 3 28 173 8 37 241 8 02 71 9 11 97 4 20 131 8 29 179 9 38 250 3 03 74 4 12 100 0 21 136 5 30 186 2 39 69 3 04 77 0 13 103 5 22 141 3 31 192 8 40 206 5 05 79 7 14 107 2 23 146 2 32 203 5 41 229 1 06 82 5 15 110 9 24 151 4 33 210 7 42 254 1 07 85 4 16 114 8 25 156 7 34 218 1 08 88 5 17 118 8 26 162 2 35 225 7 09 91 5 18 123 0 27 167 9...

Page 64: ...wn the 7 5V battery supply to produce the signal that is applied to pin 95 of the microprocessor Regulator U601 on the RF board provides the C5V supply and regulator U602 provides the T5V and R5V supply The T5V supply is enabled when the DPTT delayed PTT signal goes low and the R5V supply is enabled when it goes high The DPTT signal is from pin 85 of the microprocessor and it also controls R5V sup...

Page 65: ...hip U202 contains a prescaler A N and reference counters and a phase detector and charge pump Channels are selected by programming the A N and reference counters to divide by a certain number This programming is performed by the micro processor via the serial data bus which consists of the Clock Data and Latch Enable lines pins 11 14 of U202 The divide numbers are chosen so that when the VCO is op...

Page 66: ...th the first injection frequency to produce a first IF of 45 3 MHz low side injection is used The injection frequency is from the synthesizer and it is fed through a low pass filter C520 C521 L506 which attenuates harmonic frequencies present in the injection signal Impedance matching on the input of Q302 is provided by C328 L307 and L308 Likewise imped ance matching on the output is provided by C...

Page 67: ...voltage to the first stage Vbb Control is from the power control circuit and the supply voltage to the last stages Vcc is the unswitched battery supply 4 4 2 ANTENNA SWITCH AND LOW PASS FILTER The antenna is switched between the receiver and transmitter by an antenna switch consisting of D101 D102 and several other components In the transmit mode the T5V supply is enabled and current flows through...

Page 68: ... out of the trans ceiver on pins 3 and 4 of the accessory connector UDC connector Data is transferred to DTMF encoder U201 by another serial bus formed by TxD0 and RxD0 pins 53 and 57 Descriptions of the U208 pins are located in Table 4 1 4 5 2 DISPLAY ASSEMBLY DESCRIPTION U501 on the display board is an intelligent LCD display controller driver It communicates with the microprocessor on the logic...

Page 69: ...ply voltage control High 38 Vss Ground 39 40 41 42 43 DISST Output LCD driver chip enable signal 44 PT Output Compander control signal Low 45 W_N Output Wide narrow band switching High 46 PLLSK Output PLL clock 47 Vss Ground 48 PLLSO Output PLL data 49 PLLST Output PLL strobe 50 51 ULOCK Input PLL unlocked signal High 52 Vcc L5V 53 DTMFSO Output DTMF data 54 TXD Output Programming data out 55 56 R...

Page 70: ... Output R5V supply control signal High 86 87 88 NPSPAC Output Controls NPSPAC channel audio level High 89 MSO Output Serial data output 90 MSI Input Serial data input 91 SER_CLOCK Output Serial data clock 92 93 Avcc L5V 94 Vref L5V 95 BATT VCC Input Low battery voltage detection 96 RSSI Input RSSI Receive Signal Strength Indicator 97 L5V L5V 98 Ground Ground 99 External pull up 100 External pull u...

Page 71: ...er also provides de emphasis of the audio signal On the input of U101A Q102 provides wide and narrow band compensation The base of Q102 is high in the wideband mode and low in the narrow band mode Therefore R103 is grounded in the wideband mode which lowers the input level to U101A This maintains a constant audio output level since the higher deviation in the wideband mode results in a higher inpu...

Page 72: ...103A The cut off frequency of the filter is then approximately 150 Hz Then when a high frequency Call Guard tone is received Q103A turns off and the cut off frequency is approximately 190 Hz This switches additional capacitance into the circuit which lowers the filter cut off frequency From the filter the data signal is applied to a DC restoration circuit formed by U103B and U103A This circuit con...

Page 73: ...dio signal When the PT input of U204 is high companding is disabled and the signal is fed through U204 without compression The transmit audio DTMF signal is fed out of U204 on pin 2 and applied to a high pass filter formed by U151B This filter has a 3dB cutoff frequency of approximately 300 Hz to attenuate frequencies that could cause interference with the Call Guard signals 4 8 2 LIMITER U151A Pr...

Page 74: ...4A B and U143B is similar in function to the receive data circuit described in Section 4 7 1 It converts the data signal from AC floating at half supply to DC levels of 0 and 5 volts that can be detected by the micropro cessor Diodes D141 and D142 charge and discharge C148 and C150 to establish a DC reference on pin 6 of comparator U143B that is the average of the positive and negative going alter...

Page 75: ...ffect the factory alignment In addition before a transceiver is initially placed in service the perfor mance tests in Sections 5 14 and 5 15 should be performed To perform the alignment described in this section special PCTune and PCFlash software is required see Table 1 1 The setup is basically the same as that used for programming This equipment is shown above and also described in Section 3 1 O...

Page 76: ...ent because this is the only RPI that has Flash programming capa bility and microphone and speaker audio jacks that are required for alignment Connect the test setup as shown in Figure 5 1 Refer to Section 3 1 for more information Starting PCFlash and PCTune Select Start Programs EFJohnson and then click the PCFlash 72xx or PCTune icon as applicable 5 2 2 SAVING PERSONALITY INFORMATION When tempor...

Page 77: ...ied when the program was installed 6 Make sure that the correct serial port is selected and then click the Program Radio button to program the transceiver with test software When down loading is complete PCTune can be used to tune the transceiver as described in Section 5 4 NOTE The test operating code also provides several transceiver test functions that are described in Section 5 16 7 When align...

Page 78: ... 3 and 1 4 Help Displays the PCTune version number Display Factory Info Screen 5 3 2 RADIO TUNE SCREEN CAUTION Clicking any of the top six buttons on the Radio Tune screen in Figure 5 2 selects that test and immediately keys the transmitter Therefore make sure that no test equipment is connected to the antenna jack that could be damaged Click the Disable Transmit button to turn the transmitter off...

Page 79: ...by ordering Part No 515 3102 060 Test Cable An extension test cable see Table 1 1 is required to operate the transceiver when it is opened This cable reconnects the keypad display board to the audio logic board RF Signal Generator When connecting the gener ator to the antenna jack use at least a 6 dB pad between the generator and transceiver This protects the generator if the transmitter is accide...

Page 80: ... at all data points by clicking the Down Down Fast or Up Up Fast buttons on the screen 5 7 LOW RF POWER ADJUST 1 If manually selecting each test click the Low Power button in the screen shown in Figure 5 2 Otherwise this function is selected automatically after completing the preceding High Power adjustment 2 Set the low power output for 1 0 watt at all data points 5 8 MODULATION BALANCE 1 If manu...

Page 81: ...justment 2 Connect a SINAD meter to the speaker output jack of the RPI see Section 5 4 1 and inject the channel frequency and signal level indicated on the screen 3 Follow the instructions on the screen to sample the RSSI level at several data points 4 When all the data points have been set click the Exit button The squelch adjust screen is then displayed If the squelch sensitivity must be adjuste...

Page 82: ...r automatically mutes when a load of approximately 1k ohm or less is con nected to this output 1 Connect a SINAD meter to the speaker output of the RPI see Section 5 4 1 2 Decrease the signal generator output to obtain a 12 dB reading on the SINAD meter The signal gener ator output should be 0 35 µV maximum 3 Check both wide and narrow band channels if appli cable and also check the channels on ea...

Page 83: ...rature the frequency should be within 400 Hz This also checks the receive frequency 5 15 3 TRANSMIT MODULATION 1 Select a channel not programmed for Call Guard CTCSS DCS squelch and monitor the transmit signal with a communication monitor Speak into the microphone with a normal voice and modulation should be approximately 3 4 kHz wideband or 1 4 kHz narrow band 2 Select a channel programmed for Ca...

Page 84: ...he selected modulation signal is indicated by the group number displayed as the right most digit in the display Press the key to increase the group number and the key to decrease the group number The last selected group is saved at power down and the DCS CTCSS schemes of Groups 4 7 are also active in the receive mode The modulation signals selected by Groups 1 7 are as follows Group Modulation Sig...

Page 85: ...etting and exits the Parameter Edit mode FCN GRP Changes the edit value to 0 Selecting Parameters The parameters that can be selected and the key sequence used to select each are as follows FCN 5 Receive RF Bandpass Filter Changing the number changes the center frequency FCN 6 Receiver Squelch Increasing the number selects a tighter squelch setting for the currently selected channel bandwidth FCN ...

Page 86: ...ced operating features while maintaining compatibility with most current LTR equipment Some new LTR Net features include roaming unique ID calls and over the air reprogramming Equipment changes include the addition of an LTR Net 3000 Series switch and System and Subscriber Manager to provide system control A diagram of an LTR Net system is shown in Figure 6 1 6 1 2 COMPATIBILITY WITH LTR LTR Subsc...

Page 87: ...smitted to specific location selected by unique ID code not currently available System Control When new channels are added to a locality subscriber units can be updated with those channels over the air This eliminates the need to bring them back in for reprogramming Over the air subscriber unit programming allows the ID codes of up to 99 systems and 99 groups to be changed The system group current...

Page 88: ... See Locality Status Repeater The repeater at a locality designated to provide home channel backup It transmits call information for all subscriber units on that locality Refer to Section 6 6 for more information System Radio This refers to the radio equipment and other infrastructure that is accessed when a call is placed System Selectable A subscriber unit has selectable systems and groups Each ...

Page 89: ...e same or a different audio path than the voice A locality refers to repeaters at the same loca tion that are interconnected by a common high speed data bus Up to 20 repeaters can be interconnected so a locality can include up to 20 repeaters Although more than 20 repeaters could be co located they would be considered separate localities because they are not interconnected by the same data bus A s...

Page 90: ... subscriber unit system usage in a standard database format This information can then be exported and used by billing software to generate customer billing 6 3 STANDARD GROUP CALLS Standard group calls are between subscriber units at the same locality and use ID codes 1 239 that are assignable on each home repeater A group ID can be assigned to one subscriber unit or a group of subscriber units as...

Page 91: ...roup calls to be selectively placed to any group in any locality Refer to Section 2 9 2 for more information on these calls 6 5 3 TELEPHONE CALLS Telephone calls allow calls to be placed over the public switched telephone network After the system is accessed a dial tone sounds and the telephone number being called is entered using the DTMF keypad Since most subscriber units are half duplex do not ...

Page 92: ...t or falls below a minimum threshold the subscriber unit auto matically begins monitoring the locality status repeater If a usable signal is detected from the status repeater it continues to monitor that repeater If a message is detected that has its home repeater as the channel in use or free repeater the subscriber unit then returns to monitoring its home repeater A roaming subscriber unit also ...

Page 93: ...ice it automatically responds with an acknowl edge message and this will be indicated on the system manager s screen 6 7 5 KILL AND SLEEP If a subscriber unit has been lost or stolen or is being used to interfere with communications it can be permanently disabled by the kill command or tempo rarily disabled by the Sleep command If the Kill command is sent the unit responds indicating that it has r...

Page 94: ...a subscriber unit is no longer in service power is turned off a de registration message is automatically sent if possible This prevents the system from wasting resources trying to reach out of service units Power is automatically held on until this message is sent De registration is not available with 8170 portable transceivers 6 7 7 NEW CHANNEL UPDATES New subscriber units are initially programme...

Page 95: ...909 109 C206 ECS T1CY105 capacitor 022 3909 108 C207 ECS T1CY105 capacitor 022 3909 108 C501 GRM39X7R182K50PT capacitor 022 3909 233 C502 GRM39Y5V104Z25PT capacitor 022 3909 074 D303 17 21VGC TR8 backlight LED 022 3909 202 D304 17 21VGC TR8 backlight LED 022 3909 202 D305 17 21VGC TR8 backlight LED 022 3909 202 D306 17 21VGC TR8 backlight LED 022 3909 202 D307 17 21VGC TR8 backlight LED 022 3909 2...

Page 96: ...6W 104JV resistor 022 3909 007 R411 CR 1 16W 104JV resistor 022 3909 007 R412 CR 1 16W 104JV resistor 022 3909 007 R413 CR 1 16W 104JV resistor 022 3909 007 Ref No Description Part No R414 CR 1 16W 104JV resistor 022 3909 007 R415 CR 1 16W 104JV resistor 022 3909 007 R416 CR 1 16W 473JV resistor 022 3909 042 R501 CR 1 16W 104JV resistor 022 3909 007 R502 CR 1 16W 473JV resistor 022 3909 042 R503 C...

Page 97: ...pacitor 022 3909 077 C321 GRM39COG090D50PT capacitor 022 3909 069 Ref No Description Part No C322 GRM39COG050C50PT capacitor 022 3909 065 C323 GRM39COG050C50PT capacitor 022 3909 065 C324 GRM39COG090D50PT capacitor 022 3909 069 C325 GRM39COG040C50PT capacitor 022 3909 064 C326 GRM39COG060D50PT capacitor 022 3909 066 C327 GRM39COG120J50PT capacitor 022 3909 077 C328 GRM39COG030C50PT capacitor 022 3...

Page 98: ... 3909 074 C607 ECS T1CY475 capacitor 022 3909 111 C608 ECS T1CY475 capacitor 022 3909 111 C610 GRM39X7R103K50PT capacitor 022 3909 073 C611 GRM39X7R103K50PT capacitor 022 3909 073 C612 ECS T1CY105 capacitor 022 3909 108 Ref No Description Part No C613 GRM39X7R103K50PT capacitor 022 3909 073 C614 GRM39X7R103K50PT capacitor 022 3909 073 C615 ECS T1CY475 capacitor 022 3909 111 C616 GRM39Y5V104Z25PT c...

Page 99: ...9 031 R116 CR 1 16W 333JV resistor 022 3909 031 R117 CR 1 16W 124JV resistor 022 3909 011 R120 CR 1 16W 683JV resistor 022 3909 051 R121 CR 1 16W 153JV resistor 022 3909 014 R122 CR 1 16W 821JV resistor 022 3909 056 R125 CR 1 16W 182JV resistor 022 3909 017 R202 CR 1 16W 152JV resistor 022 3909 013 R203 CR 1 16W 823JV resistor 022 3909 058 R204 CR 1 16W 124JV resistor 022 3909 011 R205 CR 1 16W 24...

Page 100: ... 1 16W 154JV resistor 022 3909 015 R540 CR 1 16W 393JV resistor 022 3909 037 R543 CR 1 16W 000JV resistor 022 3909 001 R545 CR 1 16W 123JV resistor 022 3909 010 R546 CR 1 16W 221JV resistor 022 3909 020 R547 CR 1 16W 562JV resistor 022 3909 045 R548 CR 1 16W 182JV resistor 022 3909 017 R550 CR 1 16W 820JV resistor 022 3909 055 R551 CR 1 16W 124JV resistor 022 3909 011 Ref No Description Part No R5...

Page 101: ... GRM42 6Y5V105Z25PT capacitor 022 3909 076 Ref No Description Part No C165 GRM39X7R272K50PT capacitor 022 3909 235 C166 GRM39X7R681K50PT capacitor 022 3909 104 C167 GRM39X7R333K50PT capacitor 022 3909 236 C168 GRM39X7R392K50PT capacitor 022 3909 093 C170 GRM39COG680J50PT capacitor 022 3909 237 C171 GRM42 6Y5V105Z25PT capacitor 022 3909 076 C173 GRM42 6Y5V105Z25PT capacitor 022 3909 076 C174 GRM39C...

Page 102: ...09 191 D205 UDZ3 9B 3 9V zener SC76 022 3909 193 D206 UDZ16B 16V zener SC76 022 3909 192 D207 UDZ5 6B 5 6V zener SC76 022 3909 194 D208 UDZ5 6B 5 6V zener SC76 022 3909 194 D209 UDZ5 6B 5 6V zener SC76 022 3909 194 D211 UDZ5 6B 5 6V zener SC76 022 3909 194 D213 DA114 switching diode SC70 022 3909 191 F201 TR3216CP 3A fuse 19700005 022 3909 221 Ref No Description Part No J1 FLSH 110 01 F DH connect...

Page 103: ... R168 CR 1 16W 562JV resistor 022 3909 045 R170 CR 1 16W 563JV resistor 022 3909 046 Ref No Description Part No R171 CR 1 16W 333JV resistor 022 3909 031 R172 CR 1 16W 105JV resistor 022 3909 008 R173 CR 1 16W 102JV resistor 022 3909 005 R174 CR 1 16W 821JV resistor 022 3909 056 R175 CR 1 16W 474JV resistor 022 3909 043 R176 CR 1 16W 303JV resistor 022 3909 027 R177 CR 1 16W 823JV resistor 022 390...

Page 104: ...W 000JV resistor 022 3909 001 R305 CR 1 16W 000JV resistor 022 3909 001 R306 CR 1 16W 000JV resistor 022 3909 001 U101 TA75W01FU bandpass filter op amp SSOP8 022 3909 178 U102 LM2904 rx data LPF SO 8 022 3909 243 Ref No Description Part No U103 LM2904 rx DC restoration SO 8 022 3909 243 U141 C4053DT analog s w SOP 16 022 3909 186 U142 LM2904 rx tx data LPF SO 8 022 3909 243 U143 LM2904 data LPF SO...

Page 105: ...hone 022 3909 204 20 MK3 Key Dsply Bd 21900145 3K2687 LCD bracket 022 3909 143 21 EH1 Key Dsply Bd 12000020 LCD 1710T4138001 022 3909 201 22 MK1 Key Dsply Bd 12200490 31 5 x 1 5 x 2 5 zebra 022 3909 120 23 MK2 Key Dsply Bd 21600024 3K 2684 reflector 022 3909 141 24 A001 Complete assy s 51300081 Keypad Display PC Board complete 022 3909 002 25 MK14 Front Panel 23300494 BH2 4L fastener t p screw 022...

Page 106: ...PARTS LIST 7 12 November 2001 Part No 001 7240 001 EXPLODED VIEW ...

Page 107: ... Key S4 NC MSO MICE Gnd Bat Out Keypad Int In 30 29 28 27 26 25 24 23 22 21 Audio VRIN In Reset Mic Audio Out Key S4 NC MSO PTT Flash Gnd Bat In Keypad Int Out KEYPAD DISPLAY BOARD J2 J801 Tx In Gnd Tx Out CLR CODE T5C NC NC NC NC Sw Bat Out AMUTE In Beep Out AMUTE Out Opt B Ext DC Rx Out PTT In Rx In PTT Out Gnd 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 J3 TO OPTIONAL ENCRYPTION MODULE _...

Page 108: ... C134 1000pF C140 1000pF C144 10 C142 4 7 BATT C106 5pF Q101 2SC3357 L102 22nH R103 3 6k R104 5 6k L101 18nH T5V C615 4 7 C616 0 1 C614 0 01 R5V Source C613 0 01 R116 33k C601 4 7 C602 0 1 C603 0 01 C610 0 01 C608 4 7 C605 4 7 C606 0 1 C604 0 01 C607 4 7 C5V Source Q601 KRA105 C612 4 7 C611 0 01 T5V Source L112 D102 C122 22pF C118 5pF L110 C116 8pF L108 C114 8pF C115 1 5pF L107 C113 5pF C120 22pF ...

Page 109: ... Part No 001 7240 001 8 3 1 8 1 10 C C C B B B E E E C E C B E 2 1 3 C B E B E C 11 20 9 16 RT401 1 2 3 4 2 19 20 1 4 5 6 Antenna Jack B E C E C E C B E C B C E C E B 11 23 00 RF BOARD TOP VIEW RF BOARD BOTTOM VIEW ...

Page 110: ... _WDTOVF FWE PF2 _LCASI_WAIT _BREQ0 P17 PO15 TIOCB2 TCLKD P15 PO13 TIOCB1 TCLKC GND6 GND15 GND24 PA4 A20 _IR04 PA6 A22 _IR06 P65 _IR01 P64 _IR00 GND38 GND47 GND59 GND79 AGND 03 GND104 P43 AN3 77 78 95 10 11 12 14 16 18 19 35 P40 AN0 R236 1M C244 27pF C243 27pF Y202 9 8304 MHz C245 3pF Q207 UMT3904 C246 0 1 R234 4 7k 28 Clock Shift R235 470 PC7 A7 PB0 A8 PB1 A9 PB3 A11 PB4 A12 PB6 A14 PB7 A15 PA7 A...

Page 111: ... 2001 Part No 001 7240 001 8 5 LOGIC BOARD TOP VIEW LOGIC BOARD BOTTOM VIEW 1 1 1 120 31 61 91 C C C B B B E E E C B E C B E C B E 10 5 00 10 5 00 J103 J104 J106 1 30 1 15 16 1 2 19 20 1 1 1 1 1 10 11 20 C E B ...

Page 112: ...w Batt KEYPAD R408 100k External Speaker Internal Speaker Internal Speaker Sw Batt Source 2 1 3 4 5 6 8 7 9 10 11 12 35 36 34 33 32 31 29 30 28 27 26 25 47 48 46 45 44 43 41 42 40 39 38 37 14 13 15 16 17 18 20 19 21 22 23 2 1 3 4 5 6 8 7 9 10 11 12 24 14 13 15 16 17 18 20 19 21 22 23 24 35 36 34 33 32 31 29 30 28 27 26 25 R501 100k C501 1800pF R502 47k R508 3 3k R505 3 3k R506 3 3k R503 3 3k R504 ...

Page 113: ... 4 5 6 U5 1 22 23 44 1 15 30 16 1 20 48 1 J802 J801 C E B C E B C B E C B E C B E C B E C B E C B E C B E C B E C B E C B E C C B E B E 10 5 00 7 9 10 8 6 5 3 4 2 1 S902 S901 S903 PTT Sw Lower Opt Sw Upper Opt Sw Top Panel Option Sw To Speaker To J802 Keypad Display Bd To Accessory Connector DISPLAY KEYPAD BOARD BOTTOM VIEW DISPLAY KEYPAD BOARD TOP VIEW FLEX CIRCUIT LAYOUT ...

Page 114: ...q Q101 Amplifier Power Control U102A B U103 TRANSMITTER RECEIVER SYNTHESIZER Low Pass Filter 7 5VDC Battery L107 L108 L110 DTMF Tones Speaker Audio RECEIVE AUDIO PROCESSING RECEIVE DATA PROCESSING Tx DATA PROCESSING Tx AUDIO PROCESSING POWER SUPPLIES SMARTNET Rx Tx DATA PROCESSING Rx Tx Data Sel U141B Low Pass Filter U145A B Test Norm Sel U141A Data Type Sel U141C Compressor High Pass Filter Limit...

Page 115: ...Part Number 001 7240 001NR 11 01hph Printed in U S A ...

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Summary of Contents for 7243 LTR-NET

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E.F. Johnson 7243 LTR-NET, Service Manual, Page: 12 / 115

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Summary of Contents for 7243 LTR-NET

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