VRS 750 Vehicular Repeater System Detailed Service Manual 1
Foreword The information contained in this manual relates to the VRS750 Vehicular Repeater System, unless otherwise specified. This manual provides sufficient information to enable service shop personnel to troubleshoot and repair the VRS750 to the component level. Safety Information Before operating the VRS750, please read the “User Safety, Training, and General Information” section in the front of this manual. Manual Revisions Changes which occur after this manual is printed are described in “FMRs.
➠ Table of Contents Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . inside front cover User Safety, Training, and General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii Safe Handling of CMOS Integrated-Circuit Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi Model Chart for the VRS750 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VRS Mode Steering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Time-Out Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VRS Single Tone. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VRS Mobile-TX Acknowledgment Tones (Conventional Only) . . . . . . . . . . . . . . . . . . .
User Safety, Training, and General Information READ THIS IMPORTANT INFORMATION ON SAFE AND EFFICIENT OPERATION BEFORE INSTALLING AND USING YOUR MOTOROLA MOBILE TWO-WAY RADIO IN A VEHICLE OR AS A CONTROL STATION. Compliance with RF Energy Exposure Standards Your Motorola two-way radio is designed and tested to comply with a number of national and international standards and guidelines (listed below) regarding human exposure to radio frequency electromagnetic energy.
Table 1. Rated Power and Lateral Distance Rated Power of Vehicle-Installed Mobile Two-Way Radio Minimum Lateral Distance from Transmitting Antenna Less than 7 watts 8 inches (20 centimeters) 7 to 15 watts 1 foot (30 centimeters) 16 to 50 watts 2 feet (60 centimeters) 51 to 110 watts 3 feet (90 centimeters) Mobile Antennas • Install antennas at the center of the roof or the center of the trunk deck. These mobile antenna installation guidelines are limited to metal body vehicles.
Vehicles To avoid possible interaction between the radio transmitter and any vehicle electronic control modules, for example, ABS, engine, or transmission controls, we recommend that the radio be installed by an experienced installer and that the following precautions be used when installing the radio: 1. Refer to any manufacturers instructions or other technical bulletins or recommendations on radio installation. 2.
Safe Handling of CMOS Integrated-Circuit Devices Many of the integrated-circuit (IC) devices used in communications equipment are of the CMOS (Complementary Metal Oxide Semiconductor) type. Because of their high open-circuit impedance, CMOS ICs are vulnerable to damage from static charges. Everyone involved in handling, shipping, and servicing them must be extremely careful not to expose them to such damage.
Model Chart for the VRS750 MODEL NUMBER P2080 P2081 P2082 ITEM NUMBER X X X HHN4044* X X X HLN6855* X X X PLN7780† X X X X X X X 1 2 X X X X 1 2 X X X X 1 2 X X X HLN6856* PMLD4196 PMLE4242 PMLE4243 HKN6153 HKN6154 6881094C84 2884606M01 YLN4480 HBN5086 3085031D02 NTN4056 NKN6460 TLN5277 RLN5394 3080384N02 DESCRIPTION VRS750 VHF (136-174 MHz) VRS750 UHF R1 (403-470 MHz) VRS750 UHF R2 (450-512 MHz) DESCRIPTION VRS750 Housing VRS750 Mounting Assembly VRS750 Controller Board XCVR Hardware VHF Transceiver
VHF Performance Specifications GENERAL Model TRANSMITTER P2080 (136-174 MHz)† Number of Channels: Frequency: 1, T1 = R1 Programmable, Synthesized Frequency Channel Channel Spacing: 12.5/20/25 kHz Operation Temp. Range: -30°C to +60°C Primary Power: 13.8 VDC ± 20%, Negative Ground DC Current Drain (max): 120 mA Receive 500 mA Transmit @ 275 mW RF Power Out: Duty Cycle: Private-Line required for repeater access 275 mW to 2 W tunable 16 ms Typical Singletone Encoder/Decoder: Nominal 847.
Glossary of Terms The following glossary of terms and definitions help you to understand the VRS theory of operation. Countdown A term that describes the incremental step-down function of the counter in the repeater. Approximately 500 milliseconds of time delay for conventional modes and 1500 milliseconds for trunked modes separate each successive delay state. Delay State The specific condition of the counter. A series of eight delay states prioritize the repeaters within a common geographical area.
List of Abbreviations and Acronyms B-P Base to Portable CPS Customer Programming Software DPL Digital Private Line HUB Hang Up Box ICM In Car Monitor ms Millisecond PAC Portable Area Coverage PL Private Line PPI Portable Priority Interrupt P-B Portable to Base RF Radio Frequency RX Receive SB Serial Bus SBEP Serial Bus Expanded Protocol TOT Time Out Timer TX Transmit VIP Vehicle Interface Port VRS Vehicular Repeater System VRS-EP Vehicular Repeater System—Expanded Protoc
1 Introduction Description The VRS750 Vehicular Repeater System is a mobile radio system component that provides on-site repeater capability between a portable radio and a base station (see Figure 1). The VRS gives the portable user the equivalent range of a mobile radio with the flexibility of a portable. The VRS is not an ASTRO-capable radio; instead, it is designed to interface with an ASTRO Spectra® mobile radio. It can only transmit and receive clear analog transmissions.
Ordering Information The VRS is a crossband repeater that operates on either UHF or VHF frequencies. The repeater cannot be operated with a mobile radio operating in the same band as the VRS unit. The VRS RF platform is based on a synthesized transceiver. The VRS supports one channel whose frequency and channel spacing can be programmed in the field. The VRS remains a simplex repeater and as a result, the transmit frequency must be set equal to the receive frequency.
VRS Features The VRS operates with the ASTRO mobile radio and contains the following integrated features: • Automatic, multiple-unit, priority-resolution algorithm. • Portable priority interrupt (PPI) function. • Conventional/trunked operation. • Remote switch enable/disable capability for control charger interface. • Remote activation of emergency alarm feature. • In-car monitor operation. • VRS mobile access tones.
• Message (from the Control Head)—Trunking or Conventional • Status (from the Control Head)—Trunking or Conventional • Emergency Call—Trunking or Conventional—Emergency Call and VRS are mutually exclusive. Even if the mobile is programmed for Alarm and Call, when the Alarm case is exited, the mobile will not transition into Emergency Call while the VRS is activated. Likewise, if the mobile is in Emergency Call, the VRS cannot be activated.
2 Installation When selecting the location for the VRS, make certain that there is sufficient clearance for routing the antenna cable to the rear of the unit. VRS Installation The VRS750 is installed using the HKN6153A interface cable. The molded DB-25 end connects to the ASTRO mobile front connector. The DB-25 end with the plastic housing connects to the VRS (see Figure 2). Control Head VRS750 ASTRO Mobile HKN6153A Figure 2.
Installation of the Mounting Trunnion, HLN6855 1. Select the location to mount your VRS750. The VRS750 must be mounted within six feet of the mobile radio. Allow sufficient space around the VRS750 for free air flow for cooling. 2. Using the trunnion mounting bracket as a template, mark the positions of the holes on the mounting surface. 3. Center-punch the spots you have marked and drill a 4 mm (0.16 inch) hole at each. 4. Secure the trunnion mounting bracket with the four screws provided (see Figure 4).
VRS Antenna Installation Recommended mobile antenna installations are limited to metal body vehicles at the center of the roof and center of the trunk deck locations. 1. Mount the antenna using the instructions provided with the antenna kit by the manufacturer (an antenna is not included with the VRS models). Mount the antenna as far from the mobile radio antenna as possible, never less than three feet. An ideal configuration would be a roof-mounted mobile radio antenna and a trunkmounted VRS antenna. 2.
Figure 6. Advanced Window (Radio Configuration --> Radio Wide --> Advanced) Special Programming Notes The VRS button can be located in any of the indicator button positions normally used for option buttons. The VRS750 option can be enabled/disabled by a vehicle interface port (VIP). Use the VIP Control of VRS box in the Radio Configuration --> Radio Wide --> VRS window (see Figure 8) to enable VIP control and to select whether the input control is active open or active closed.
Figure 7. Radio VIP Window (Radio Configuration --> Radio Wide --> Radio VIP) ASTRO VRS Programming Windows There are five windows for editing the VRS Option. Four of these windows are in the Radio Wide section of Radio Configuration while the fifth window is a table for the VRS mode steering PLs. The first window is the VRS subsection of the Radio Wide options (see Figure 8).
Figure 8. VRS Window (Radio Configuration --> Radio Wide --> VRS) Figure 9.
The third window is the VRS Advanced subsection (see Figure 10). This window is used to enable/disable the Access Acknowledgment and Time-Out-Timer Tones and Repeater Portable Priority Interrupt (PPI) as well as selecting the Time-Out-Timer duration. The Time-OutTimer duration may be set to 30, 60, or 120 seconds, or infinite. The infinite setting should be used with caution, since damage to the transmitter could result from any extremely extended transmission.
NOTE: Older VRS units, such as the VRS-EP, do not support any of the fields in the VRS Personality window. However, these fields can be programmed without having any effect on the VRS-EP, so that the VRS-EP and VRS750 can be interchangeable without reprogramming the mobile. Figure 11.
NOTE: The Receive PL filter internal to the VRS is a low pass filter with a -3 dB point of approximately 170 Hz. As a result, the PLs greater than 170 Hz will be attenuated to allow for a decreased decode sensitivity. The higher the PL frequency the greater the attenuation. The Emergency, Message, and Status features of the VRS are best suited for use with these higher PL frequencies. Figure 12.
Once the setup is complete and the mobile is turned on the current tuning parameters can be read from the VRS750 by selecting File --> Read Radio Information and Softpots on the Global Tuner. NOTE: Radio Serial Number and Radio Model Number shown at the bottom of the screen will not match the model number and serial number of its associating VRS. Transmit Power Tuning The VRS750 supports 2 different power levels (High and Low). There are separate alignments for High and Low power (see Tables 2 and 3).
Figure 14. Transmit High Power Window in the Global Tuner 5. Press PTT Toggle again to key up the radio at the selected frequency point. 6. Repeat steps 3-5 for (F2-F7). 7. Press Program to store the softpot values into the radio’s codeplug. 8. Exit the Transmit High Power function. The mobile will reset upon exiting If low power channels are used, perform Transmit Low Power Tuning as shown in Table 3. Table 3.
4. Press PTT Toggle to dekey the radio, go to the next frequency point by selecting the slider, typing in the edit control box (press ENTER to confirm selection) or toggling the softpot value using the spin control. 5. Press PTT Toggle again to key up the radio at the selected frequency point. 6. Repeat steps 3-5 for (F2-F7). 7. Press Program to store the softpot values into the radio’s codeplug. 8. Exit the Transmit Low Power function. The mobile will reset upon exiting.
Do this until the radio is totally unmuted. Verify the squelch closing by inputting a signal level of 4 dB lower (than that of the -110 dBm level). 4. Repeat steps 1-3 for F2-F7. 5. Press Program to commit the softpot values into the codeplug. 6. Exit the Squelch Attn. function. The mobile will reset upon exiting. NOTE: The Auto Tuning feature does not work for the VRS750. Table 4 shows the softpot ranges to achieve approximately -110 dBm. The actual value varies from radio to radio.
Figure 16. Flashing Adapter NOTE: The VRS750 Upgrade Kit will request which baud rate to use when flashing the first radio. For the VRS750 the baud rate should not exceed 38,400 bps. Contact Customer Resources for information on how to obtain this VRS750 Upgrade Kit.
3 VRS Operation General The VRS is a crossband repeater that repeats either UHF or VHF portable transmissions though a VHF, UHF, or 800 MHz ASTRO mobile. The repeater cannot be operated with a mobile radio operating in the same band as the VRS unit. In multiple-VRS sites, the VRS uses a priority algorithm to prevent other VRS units from repeating. In this mode, only the highest priority VRS will serve multiple portable users.
the same Single Tone frequency, as well as other VRS and ASTRO mobile features. Press the VRS button to disable the VRS option. When the system is turned off and then back on from the control head, the VRS option returns to the state it was in immediately before the control head was turned off. Vehicle Interface Ports Another method of enabling/disabling the VRS option is through the use of a vehicle interface port (VIP).
ICM Transmissions VRS BASE: Press the mobile’s PTT to transmit on the frequency corresponding to the mode shown on the control head’s display. If this mobile’s VRS is the priority unit (in delay state zero), the VRS unit will then become non-priority upon the mobile PTT. If you press the mobile’s PTT during portable-to-base VRS activity, a talk-prohibit tone sounds and the mic audio is disabled.
Notes 22
Operation of VRS Options 4 The following sections describe the operation of CPS fieldprogrammable options of the VRS. This includes information about when to use an option and compatibility between options. Base Repeater For two-frequency simplex systems using a fixed-site repeater, you can enable the base repeater option. This adds 300 ms of delay to the prioritization routine to account for the fixed repeater attack time.
The portable operator sets the channel or mode select switch to the position corresponding to the desired mobile mode and keys up the portable. The VRS unit decodes the PL tone and steers the mobile radio to the desired mode. There are two types of steering supported: Transmitter Steering/Receiver Latching, and Transmitter Steering/ Receiver Steering.
Steering Destination Types There are five types of actions, or “steering destination types,” that the VRS can be programmed to perform as a result of receiving a portable transmission with the specified PL: NOTE: Each receive PL can only be used once and can only be programmed with one type of steering destination (for example, a single PL cannot be programmed to both change the mobile mode and send a message.) Zone/Chan The VRS will command the ASTRO mobile to change to the mode programmed by the CPS.
• momentarily press the PTT button, • wait for the confirmation tone, and • return the channel selector to a voice channel. The VRS will not perform a portable-to-base audio repeat while the portable is transmitting on a “message request” channel. NOTE: A message cannot be generated from the control head while the VRS is activated.
VRS Mobile-TX Acknowledgment Tones (Conventional Only) When this option is enabled, the VRS transmits a 750 Hz feedback tone after it has received a repeatable message on the portable frequency. This signals the portable operator that the transmission was received. If the repeated message was cut short due to the mobile TOT being exceeded or the mobile channel being changed during the repeat, a lower-pitched tone (304 Hz) sounds.
Notes 28
Detailed VRS Operation 5 Multi-VRS Operation The VRS is designed to accommodate multiple VRS units in the same area. This is accomplished by each VRS maintaining a priority level or delay state. During either portable-to-base or base-to-portable transmissions, only the highest priority VRS will transmit or cause a mobile PTT. The procedures for determining priority levels in multiVRS operation are discussed next.
On conventional modes if the VRS option is enabled via CPS, then an additional 300 ms time delay is added to the delay states. This allows time for the mobile radios to transmit to and receive from a repeater site. Base-to-Portable Transmissions When a base transmits, only the priority VRS unit will transmit to the portable. The other VRS units monitor activity on the portable channel.
SINGLE TONE BURST UNIT A “DELAY STATE ZERO” PRIORITY UNIT MAEPF-26079-O Figure 18. Single VRS Unit Operation Two-Unit Operation The arrival of another VRS-equipped vehicle (unit B) into the coverage area of unit A has no effect on unit A’s radio operation until unit B’s VRS is enabled. Unless there are portable transmissions occurring when unit B arrives, unit B’s repeater transmits a Single Tone burst when its VRS option is turned on.
TRANSMITS TO ALL REPEATERS AND PORTABLE RADIOS IN THE AREA TRANSMITS TO BASE STATION AND MOBILE RADIOS IN AREA UNIT B “DELAY STATE ZERO” PRIORITY UNIT UNIT A “DELAY STATE ONE” MAEPF-26081-O Figure 20. Two-Unit VRS Transmissions If unit B activates its VRS during portable transmissions, unit B does NOT transmit Single Tone or enable in delay state zero. Unit B must wait until it cannot detect the portable signal before transmitting Singletone and taking over as the priority unit as described above.
TRANSMITS TO ALL REPEATERS AND PORTABLE RADIOS IN THE AREA TRANSMITS TO BASE STATION AND MOBILE RADIOS IN AREA UNIT C “DELAY STATE ZERO” PRIORITY UNIT UNIT B “DELAY STATE ONE” UNIT A “DELAY STATE TWO” MAEPF-26082 -O Figure 21. Three VRS Unit Transmission Sequence Departure of a VRS Unit The priority unit may change, depending upon the order in which they leave, as vehicles leave the coverage area.
~ 2 sec ~ 6 msec VRS REPEATER TRANSMITTER ON OFF PORTABLE TRANSMITTER WITHOUT “PL” ON OFF PORTABLE TRANSMITTER WITH “PL” ON OFF MOBILE TRANSMITTER ON OFF MAEPF-26083-O Figure 22. Priority Unit Reassignment Rptr PPI—Portable Priority Interrupt NOTE: When using Rptr PPI, the receiver squelch setting of the portable must be programmed for CSQ (carrier squelch). is CPS programmable. The main function of is to allow the portable to interrupt base-to-portable transmissions.
If a portable’s signal without PL tone is present when the repeater is interrupted, the repeater transmitter remains inhibited for the duration of the incoming signal. If the portable’s signal is modulated with a PL signal, the priority unit repeats the message back to the base station on top of the incoming signal. In addition to giving the portable user priority over all incoming signals, the Portable Priority Interrupt is used for three basic functions: 1.
NOTE: If Repeater PPI is disabled on an analog trunking system with transmission trunking enabled, the Quick Key feature becomes useless, since the user will be unable to break-in during the repeater hangtime after the channel is acquired. For this reason, repeater PPI should always be ENABLED on an analog trunking system. 3. Emergency—This allows the portable to have priority over dispatch.
ICM Functions The in-car-monitor (ICM) allows limited use of the mobile while the VRS is enabled. Mode In this mode pressing the mobile’s PTT will cause the mobile to transmit on the mode shown on the control head display. The VRS will not transmit the mic audio to the portable. During portable-to-base repeat operations pressing the mobile’s PTT will result in the talk prohibit tone sounding momentarily and the mic audio will not be transmitted to the portable.
• The mobile will key up and transmit mic audio to the base. 2. During a portable-to-base repeat operation, the mobile user initiates a mic PTT. • A momentary talk prohibit tone will be heard and the mic audio will be disabled. 3. During a base-to-portable repeat operation, the mobile user initiates a mic PTT. • The base-to-portable repeat will be interrupted. • Mic-Hi line audio is routed to the VRS and transmitted to the portable. • The mobile will key up and transmit mic audio to the base.
• The “talk prohibit” tone (a long, low tone) indicates to the portable user that the mobile cannot access the trunking system. For portable transmissions lasting longer than one second (as opposed to a “quick-key,” which must be less than one second), the VRS will respond with one of the following tones. If the “Trunking Access Tones” option is disabled in the “VRS Options” screen of the ASTRO mobile CPS, the “trunking access good tone” and the “trunking access bad tone” will not be generated.
Non-Priority VRS Rules A priority VRS is placed into non-priority mode when one of the following occurs: 1. It receives a Single Tone burst at the fixed frequency of 847.5 Hz. 2. During a base-to-portable repeat, it receives a VRS/portable frequency RF signal without proper PL during the PPI. When a VRS goes from priority to non-priority, the internal delay state changes from 0 to 1.
3. Upon reaching delay state 0, the non-priority VRS will become the priority VRS and start repeating. The maximum delay for a non-priority VRS to countdown into priority is 3.4 seconds for conventional and 5.8 seconds for trunking. 4. If the VRS does detect another VRS system repeating within the delay state, it will stop the countdown process and stay nonpriority. 5.
Emergency Feature Operation Whether the mobile is programmed for silent or non-silent alarm is transparent to the VRS. However, the Emergency Alarm sequence changes slightly between the silent and non-silent case. The main differences are listed below: 1. The alarm exit sequence For non-silent alarm, any of the following will cause the mobile to exit Emergency: • Extended keypress of the Emer button on the mobile’s control head. • Mobile microphone PTT or a portable-to-base repeat.
Hardware Detailed Theory of Operation 6 The VRS750 contains two main modules: a transceiver and an interface board. Transceiver This module is an Analog synthesized FM device that contains the receiver, transmitter, and controller section. A flex cable connects the transceiver’s two accessory connectors to a single connector, J30, on the interface board. The RF jack is connected to W101 on the interface board via the 50 ohm coaxial cable.
Audio Routing Circuitry There are four paths which are used to route audio between the mobile and the transceiver: AUX_RX_AUD, TX_AUDIO, MOB_MIC_HI and FIL_AUD. During the three types of communications of the VRS (Portable-to-Base, Base-to-Portable, and In-Car-Monitor), the routing is as follows: Portable-to-Base On channel RF signals are received by the transceiver through the connector, W101. The transceiver provides demodulated audio to the interface board at EXT_SPKR+ (J30-17) and URX_SND (J30-11).
Single Tone Encoder The VRS750 Single Tone Encoder (U100-1, U124-3, U124-2, and U1244) is used to produce a tone which is transmitted by the transceiver when the VRS750 is activated. Other VRS750 repeaters that are on in the operating area receive this Single Tone transmission. The other repeaters will then increment their priority counters by one while the transmitting VRS750 goes to delay state zero and becomes the priority repeater.
On. SW7.5V is connected back to 7.5 V again. At this point the microprocessor on the transceiver has been reset and is now in bootstrap mode. To prevent mobile bus messages from corrupting the flash programming of the transceiver, the control signals to U102-3, U105-2 and U105-3 are applied with 9.6V to disconnect the Bus+ (P102-5), Bus- (P102-14) and Busy (P102-23)lines from the mobile when the BOOT-CNTRL line is grounded.
To exit Test Mode, power down the VRS750 and reconfigure S1 for Normal mode. The ATE Test Mode configuration is used by Motorola for testing purposes. Professional CPS Mode is available for when the user requires the transmit and receive frequencies to differ. Operation during this mode is not advised and if required please contact your Motorola sales representative for details about this mode. All other combinations of the dipswitch are not supported and will default to the Normal mode.
Notes 48
7 Maintenance and Troubleshooting The following paragraphs contain information to help you maintain and troubleshoot the VRS. A list of recommended test equipment is found in the “Recommended Test Equipment, Service Aids, and Tools” section of the ASTRO Spectra Basic Service Manual, Motorola publication 68P81076C20. Additional information may be found in the Troubleshooting Chart in this manual. Troubleshooting Procedures VRS Activation 1. Turn on the mobile radio control head.
• ERR 12/84—CONFIG register corruption. The unit should be flashed with the correct version software. If this fails to correct the problem, the transceiver should be replaced. • ERR 12/88—HC11 RAM failure. Replace the Transceiver. • VRS 001—VRS Synthesizer out of lock error. See “Common Power-Up Problems” section on page 50 for possible solutions. If the solutions in the “Common Power-Up Problems” section do not fix the error then the transceiver should be replaced.
Common Operational Problems • Check the VRS750’s codeplug for incorrect programming. • Re-flash the VRS750 with new firmware using the VRS750 Upgrade Kit. 1. Common Portable-to-Base Repeat Problems. • Check portable for correct transmit frequency and PL. • Check portable for low battery. • Check VRS internal RF cable for loose connection. 2. Common Base-to-Portable Repeat Problems Disassembly & Reassembly Procedures • Check portable for correct receive frequency and PL.
Front Housing Main Chassis See Detail "A" Depress Snap Here Detail "A" Figure 25. Removing the Front Housing Remove the Top Cover 1. Insert a wide flat-blade screwdriver or like instrument in the recess area on the side of the main chassis near the RF connector end (see Figure 26). 2. Pry the cover off the chassis by pushing the handle of the screwdriver in and toward the chassis. This will disengage the snap between the cover and chassis. 3. Repeat Step 1 and Step 2 for the opposite side of the radio.
Front Pry Clip Off Here Figure 27. Removing the Antenna Connector Retaining Clip 4. Retain the heat conductive insulator from under the regulator. 2) Pull board forward out of chassis 1) Push up on board through accessory connector opening Figure 28. Removing the Interface Board Transceiver Disassembly 1. Detach the RF cable assembly from the right-angle SMB connector on the interface board. 2. Turn over the interface board. Remove the flex connector retainer, 4285168D01. 3.
VRS750 Reassembly Transceiver Reassembly NOTE: Replace all gaskets at each servicing to ensure proper sealing of unit. 1. Screw the RF adapter plug into the transceiver. Tighten until the stop on the adapter is fully seated in the RF jack. 2. Connect the RF coax cable to the RF adapter. 3. Place the transceiver in between the two retainers, sliding one sideways if needed. 4. Adjust the retainers so that they align with the groove between the transceiver board and its chassis.
4 5 2 1 3 7 6 8 Figure 29. VRS750 Torque Sequence Table 8. VRS750 Torque Sequence Step No. Screw P/N Bit Torque 1 6 0310907A20 Torx T10 — Start Only — — — Place Antenna Conn. 2 3 4-8 0310907A20 Torx T10 8 in-lb 4 1-3 0310907A20 Torx T10 8 in-lb Notes Number 6 Inclusive Twist o-ring Cover gasket Figure 30. Cover Gasket Location Assembly of Front Cover to Main Chassis Refer to exploded views on page 88 for parts referenced in this procedure. 1.
3. Install the remote front housing over the 18 position connector onto the front of the chassis ensuring that both snaps are engaged. 4. Place the gasket within the recessed area for the 18-pin programming connector. 5. Connect the Programming Connector Cover to the main chassis. VRS Transceiver Field repair of the transceiver is not recommended. Contact your local service representative for a replacement transceiver.
Mobile Communication Analyzer DC Supply + VRS Communication Analyzer ASTRO Spectra Mobile Speaker VRS750 HKN6153A Mobile Microphone W7 Control Head Figure 31. General Cabling Diagram 4 5 2 1 3 7 6 R148 R146 R150 8 Figure 32.
b. Set the Mobile Communications Analyzer frequency to the current mobile mode. c. Switch on the Mobile Communications Analyzer RF. d. Adjust R150 on the VRS board until 3.0 kHz deviation is obtained on the VRS Communications Analyzer. e. Switch off the Mobile Communications Analyzer RF. 3. Adjust the Mobile Microphone Deviation Level: a. Inject a 1 kHz tone at 80 mVrms into the mobile microphone. b. Key the mobile microphone.
d. Switch off the VRS Communications Analyzer RF. 6. Take the VRS out of test mode: a. Turn off mobile control head and set the dipswitch S1 pins 1, 2, 3, and 4 to ON. b. Turn on the mobile control head and re-enable the VRS. 7. Tuning is complete. Transceiver Board Tuning Procedure The transceiver board can be tuned using the Global Tuner when the VRS750 is in ATE Test Mode.
Table 9. Default Softpot Values for VHF and UHF Softpot Value (Decimal) Frequency Point VHF UHF F1 36 38 F2 57 48 F3 84 79 F4 124 110 F5 166 135 F6 195 161 F7 225 186 Under Rx Align, select the Front End Filter option. 1. Inject a -70 dBm RF Signal with Frequency F1 (for UHF)/F3 (for VHF) modulated with 1 kHz tone at 60% rated deviation (see Table 10) into the VRS750. A 1 kHz tone must be detected at the RX Audio connector on the test box to verify that the radio is receiving. 2.
Table 10. VRS750 Deviation Levels Rated Volume Tuning Channel Spacing (kHz) Rated System Deviation (kHz) Signal Generator Deviation (kHz) 12.5 2.5 1.5 20 4.0 2.4 20 5.0 3.0 25 5.0 3.0 30 5.0 3.0 Under Rx Align, select Rated Volume. NOTE: The received audio output is taken from the positive terminal of C189. 1. Inject a -47 dBm RF Signal modulated with 1 kHz tone at the 60% rated deviation (see Table 10) into the VRS750. 2.
7. Program the warp value into the radio by pressing the Program button. 8. Exit the Reference Oscillator Warp function. VCO Attenuation VCO Attn. 25 kHz NOTE: The Transmit Deviation Limit softpot sets the maximum deviation of the carrier. Tuning is performed for 12.5 kHz, 20 kHz, and 25 kHz channel spacing. Tuning for 25 kHz channel must be done first for all frequency points. Tuning for 12.
8. Exit the VCO Attn. 20 kHz function. VCO Attn. 12.5 kHz NOTE: Tuning of VCO Attn. for 25 kHz channel spacing must be done first. 1. Under the Tx Align menu, select VCO Attn. 12.5 kHz. 2. Press PTT Toggle to key up the radio at the last non 0 transmit frequency point (normally F7). 3. Inject a 1 kHz at 80 mVrms signal into the external mic connector on the test box (VRS750 input). 4. Note down the deviation obtained. 5.
8. Press Toggle Bias 1 in order to enable the PA Bias softpot. 9. Increase the softpot value to obtain Z until Z-Y is within the range for Bias Current as indicated in Table 13. 10. Press Toggle Bias 1 again to disable the PA Bias softpot. 11. Program the Bias softpot into the radio’s codeplug via pressing Program. 12. Exit the PA Bias High Power function. 13. Under Tx Align, select PA Bias, Low Power. (If UHF, skip to step 15 and continue to Procedure 2.) 14. Repeat steps 3-11. 15.
****** If a failure occurs, go to STEP 3 otherwise proceed 9. Press Toggle Bias again to disable the PA Bias softpot. 10. Program the Bias softpot into the radio’s codeplug via pressing Program. 11. Exit the PA Bias Low Power function. STEP 2 1. Increase Y until Y-X is within the range given for PA current in Table 14 (STEP 2). 2. Press Toggle Voltage again to disable the PA control voltage edit box/spin control. 3. Press Toggle Bias in order to enable the PA Bias softpot. 4.
10. Press Toggle Bias again to disable the PA Bias softpot. 11. Program the Bias softpot into the radio’s codeplug via pressing Program. 12. Exit the PA Bias Low Power function. NOTE: After tuning a transceiver, go back and tune the interface board (details in this chapter) and then adjust the output power and squelch settings (see Chapter 2).
8 Troubleshooting Charts Introduction to this Section List of Troubleshooting Charts This section contains detailed troubleshooting flowcharts. These charts should be used as a guide in determining problem areas. They are not a substitute for knowledge of circuit operation and astute troubleshooting techniques. It is advisable to refer to the related circuit descriptions in the “Hardware Detailed Theory of Operation,” Chapter 6.
VRS ENABLE FAILURE START Is VRS button enabled in the mobile codeplug? No Yes Is the mobile codeplug programmed for VRS VIP? No Program mobile codeplug for VRS VIP. Yes Is the mobile codeplug programmed for VRS VIP active state? No Program mobile codeplug for proper VRS VIP active state. Yes Is switch in correct VIP? No Move switch or reprogram mobile codeplug. Yes Check VRS VIP switch input. Is mobile codeplug programmed for VRS VIP? Yes Program mobile codeplug for VRS button operation.
ERROR 12/10 START START Is the VRS mobile interface cable connected? ERROR 12/84 Reflash the VRS750 with the correct version firmware. No Reconnect the cable. Reset the system. Yes Are the regulated voltages present? No Troubleshoot the regulator circuit. Is the 12/84 error still displayed? No Problem is corrected. Yes Yes Is the VRS750 firmware correct? No Flash the VRS750 with the correct firmware. Replace the transceiver board.
VRS 001 FAILURE START Does the Freq. Band field in ASTRO CPS match the freq. Band of the VRS750 attached to the mobile? No Correct the freq. band field for the VRS750 in the ASTRO mobile codeplug. Yes Replace the transceiver board.
SINGLE TONE ENCODE FAILURE START Is 3.3VDC square wave at R114 during Single Tone burst? No Yes Is there continuity between J30-6 and J40-21 on the flex cable? No Replace the flex cable. Yes Replace the transceiver. Is 80mVpp sinewave at TP104? Check and/or replace U100, U124. No Yes Is the sinewave present at TP101? Verify that pin 10 of U101 is 0VDC during the Single Toneburst. Check U101 and Q106.
SINGLE TONE FAILURE START Verify that the VRS750 dip switches are set to normal operation. Verify that J30-20 (boot control) is ~3.3VDC. Does TP105 pulse ~5VDC when the volume button is pressed? No Check the mobile to VRS cable. Yes Does J30-21 pulse to ~0VDC when the volume button is pressed? No Check and/or replace U103 and Q103. Yes Is there continuity between J30-21 and J20-9 on the flex cable? No Replace the flex cable. Yes Check and/or replace the transceiver.
BASE TO PORT. AUDIO ISSUES Verify that the VRS750 dip switches are set to normal operation. START Provide an on-channel RF signal to the mobile. Is audio present at C135? Activate the VRS750. Is "VRS BOTH" displayed briefly? Yes The VRS750 is not enabled and audio will not be heard. No Chekc mobile and its connection to the VRS. No Yes Is audio present @ U101 pin 5? Yes Is audio present @ U101 pin 4? No Check U104. Adjust R150 if necessary.
PORTABLE-TO-BASE AUDIO ISSUE Verify dip switches are set to normal operation. Activate the VRS750. Is "VRS BOTH" displayed briefly? No The VRS750 is not enabled and will not repeat. Yes Provide an on channel RF signal with an Access or Mode Steering PL to the VRS750. Is the 1kHz tone present @ J30-11? Is there continuity between J30-11 and J40-28 on the flex cable? No Yes Is the 1kHz tone present at TP102? Yes No Replace transceiver. Replace the transceiver.
IN-CAR-MONITOR AUDIO ISSUES Verify that the VRS750 dip switches are set for normal operation. Is "VRS BOTH" displayed briefly? Activate the VRS750. Yes PTT the mobile's local mic and talk into it. Is audio present at C134? During Base-to-Portable communications, is audio heard @ the portable? Yes Check the mobile and its mic connections. No Refer to the Base-to-Portable troubleshooting chart. No Check C185 and C166 to make sure they have not been shorted to ground.
SERIAL BUS FAILURE START Verify that the VRS750 dip switches are set to normal operation. Verify that J30-20 (boot control) is ~3.3VDC. Does TP105 pulse ~5VDC when the volume button is pressed? No Check the mobile to VRS cable. Yes Does J30-21 pulse to ~0VDC when the volume button is pressed? No Check and/or replace U103 and Q103. Yes Is there continuity between J30-21 and J20-9 on the flex cable? No Replace the flex cable. Yes Check and/or replace the transceiver.
PORTABLE AUDIO AT LOCAL SPEAKER ISSUE START Verify that the VRS750 dip switch settings are set to normal operation. Activate the VRS750. Is "VRS BOTH" displayed briefly? No The VRS750 is not enabled and audio will not be heard. Yes Provide an on-channel RF signal with the proper Access or Mode Steering PL to the VRS750. Is audio present @ EXT_SPKR+ J30-17? No Yes Is there continuity between J30-17 and J20-4 on the flex cable? No Replace the flex cable. Yes Replace the transceiver.
PROGRAMMING AND TUNING ISSUES ATE Test Is 13.8V supplied to the test box? No Start Is the VRS750 in ATE Test or Normal Mode? Supply 13.8V to the VRS750 test box. Normal Is the mobile radio powered on? Yes No Power on the mobile radio. Yes Is the VRS750 programming cable securely plugged into the VRS750 and an SRIB? No Is "PROG VRS" displayed on the mobile control head? Plug the 25 pin connector into the SRIB and the 18 pin connector into the VRS750. Verify that the mobile is powered on.
PROGRAMMING AND TUNING ISSUES (CONT.) A. Is the Flashing Adapter being used? No Is there a 18 pin extension in the connector, 2805347X01, on the front of the VRS750? No Replace the header block. Yes Yes Place the switch in the B position and reset the mobile. No Is the switch in the B position? Is the cathode of VR121 grounded when plugged into the SRIB? No Replace the programming cable. Yes Yes Remove the Flashing Adapter and reset the mobile. The Flashing adapter could be bad.
Notes 80
Diagrams and Parts Lists Introduction to this Section 9 This section contains schematics, a component layout diagram, an exploded view, and electrical and exploded view parts lists.
Notes 82
VRS750 Vehicular Repeater System Printed Circuit Board Electrical Parts List (PLN7780A) ITEM MOTOROLA PART NUMBER DESCRIPTION C100 C101 C102 C103, 104 C105 C107 C108 C109 C111, 112 C113 C114 thru 116 C117 C118 C119 C120 C121 C122 thru 131 C132, 133 C134, 135 C136 C137 C138, 139 C140 C141 C142 C143 C145 C146, 147 C148 C149 C150 C151 C152 C153 C154 C155 C156 C157 thru 161 C162 C164 thru 167 C168 C170 C171 C172, 173 C175 C179 C180 C182 C183 C184 C185 C188 C189 C190 C191 C194 C195 C196 C197 C198 C199 C200 C2
TP104 R110 C107 16 R111 R112 TP119 C171 R184 1 R161 U118 R163 D102 R148 C153 TP121 R145 TP122 R146 TP123 C127 C161 VR118 TP107 5 8 C124 C151 U104 7 F100 TP128 VR104 TP124 VR102 R159 C201 R147 TP118 C129 C185 C166 C134 VR106 D101 R171 D100 R122 C117 C182 C121 C205 R124 R121 8 R119 R125 7 TP113 C115 4 5 B E C197 C R200 Q110 C R213 R212 B 9 E C E Q112 C140 C198 8 R138 B R211 C202 R210 C122 C203 Q113 VR110 C188 C113 R221 8 U107 C19
C195 C196 C137 L101 C183 P102 4 3 T1 18 1 6 14 C103 C157 6 P101 C132 4 3 9 C159 10 T2 1 C156 8 U111 5 4 C133 P31 P32 P33 8485176D01 REV A 13 25 C162 W101 W102 VRS750 Vehicular Repeater System Printed Circuit Board Component Location Diagram (Sheet 2 of 2) 85
SW7.5V (J20-16) J30 28 BOOT-CNTRL C161 220pF VR112 23 220pF VR115 VR102 15V 5.6V J30 P102-3 C175 220pF (J20-11) 5V P102-1 P101-3 C164 5V DNP 5.6V R104 U100-2 R101 R118 100 7 C101 68K RXD 33pF 6 R105 4.7K TP110 PTT * P102-4 Q100 U103-2 4 R102 C100 10K C179 J30 20 220pF 3 100 4.7K 5V MC14106 220pF VR118 B MC33072 R117 MMBT3904 (J20-8) A 5 R106 5.6V P101-7 (J20-12) J30 (J20-4) J30 24 5 TXD R225 C189 17 C190 R220 680pF VR113 5.
5V 9.6V 9.6V 9.6V 9.6V 5V A MC14053B R180 4.7K U105-3 8 16 POWER U100 3 B C139 C140 220pF 0.1uF 4 4 6 7 C142 16 POWER U101-4 8 C195 C196 220pF 0.1uF 6 7 8 C197 C198 220pF 0.1uF 4 14 220pF POWER U102-4 C143 POWER U103-7 .1uF C171 C172 POWER U104-5 0.1uF 220pF 11 7 5V 5 C123 R142 9.6V MC14053B U103-1 P101 IS 18 PIN PROGRAMMING CONNECTOR 9 Q102 220pF 1K 1 P102 IS 25 PIN DB25 CONNECTOR BUS+ MMBT3906 13 R141 14 C126 P102-5 12 TP106 6 4.
VRS750 Vehicular Repeater System Exploded View Parts List ITEM NO.
VRS-to-Mobile Cable HKN6153A VRS-to-Siren Cable HKN6154A Pin Number VRS750 P102 ASTRO Spectra Mobile DB25 Female 1 Pin Number Signal Name VRS750 P102 Siren (HLN1439A) 39 pin J1 Signal Name N/C 1 FIL_Audio_GND 2 3 N/C 3 N/C 4 N/C 4 N/C 2 2 N/C 15 FIL_Audio_GND 5 5 Bus+ 5 17 Bus+ 6 6 FLT_Audio 6 9 FLT_Audio 7 7 Rx_Audio 7 33 Rx_Audio 8 8 Tx_Audio 8 3 Tx_Audio N/C 9 9 N/C 10 10 AGND 10 11 AGND 11 11 Mic_Lo 11 14 Mic_Lo 12 12 Mic_Hi 12 27 Mic
VRS750 Programming CableVRS750 3085031D01 VRS750 Programming Cable 3085031D01 Programming Cable 3085031D01 Pin Number Pin Number VRS750 P101 SRIB DB25 Female 1 1 Signal Name VRS750 P101 SRIB DB25 Female Ground 10 N/C N/C 11 N/C Boot_Cntl 12 N/C 4 N/C 13 N/C 5 N/C 14 N/C 6 N/C 15 N/C TXD 16 N/C N/C 17 N/C Prog_Sense 18 N/C 2 3 7 16 15 8 9 2 VRS750 Programming Cable Schematic (3085031D01) VRS750 Flashing Adapter Schematic (NTN4056A) 90 Signal Name
REPLACEMENT PARTS ORDERING ORDERING INFORMATION When ordering replacement parts or equipment information, the complete identification number should be included. This applies to all components, kits, and chassis. If the component part number is not known, the order should include the number of the chassis or kit of which it is a part, and sufficient description of the desired component to identify it.
6881094C84 72 Motorola 8000 West Sunrise Boulevard Fort Lauderdale, Florida 33322
