Motorola Solutions 92FT3802 VRS750--Vehicular Repeater System User Manual Service Manual

Motorola Solutions, Inc. VRS750--Vehicular Repeater System Service Manual

Contents

Service Manual

1 VRS 750 Vehicular Repeater System Detailed Service Manual
2 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.” These FMRs provide complete information on changes, including pertinent parts list data. Computer Software Copyrights The Motorola products described in this manual may include copyrighted Motorola computer programs stored in semiconductor memories or other media. Laws in the United States and other countries preserve for Motorola certain exclusive rights for copyrighted computer programs, including, but not limited to, the exclusive right to copy or reproduce in any form the copyrighted computer program. Accordingly, any copyrighted Motorola computer programs contained in the Motorola products described in this manual may not be copied, reproduced, modified, reverse-engineered, or distributed in any manner without the express written permission of Motorola. Furthermore, the purchase of Motorola products shall not be deemed to grant either directly or by implication, estoppel, or otherwise, any license under the copyrights, patents or patent applications of Motorola, except for the normal non-exclusive license to use that arises by operation of law in the sale of a product.
i Table of Contents ➠ Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . inside front coverUser Safety, Training, and General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iiiSafe Handling of CMOS Integrated-Circuit Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viModel Chart for the VRS750 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viiVHF VRS750 Performance Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viiiUHF VRS750 Performance Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viiiGlossary of Terms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ixList of Abbreviations and Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .x1 - Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2VRS Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Mutually-Exclusive Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 - Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 VRS Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Installation of the Mounting Trunnion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6VRS Antenna Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7VRS750 Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3 - VRS Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Vehicle Interface Ports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20VRS Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20In-Car Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Mobile Audio Repeat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4 - Operation of VRS Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Base Repeater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Mobile Detector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23VRS Transmit PL Generator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23A , Private Line, and Motorola are registered trademarks of Motorola Inc.Systems 9000, ASTRO, Spectra, Call Alert, Private Conversation, Single Tone,Digital Private-Line, and Slimnet are trademarks of Motorola Inc.Torx is a trademark of Camcar Div. of Textron, Inc. © 2001, 2002 by Motorola Inc.Commercial, Government and Industrial Solutions Sector8000 W. Sunrise Blvd., Ft. Lauderdale, FL 33322Printed in U.S.A. 5/99. All Rights Reserved. 6881094C84Detailed Service Manual
ii ii VRS Mode Steering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Time-Out Timer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26VRS Single Tone. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26VRS Mobile-TX Acknowledgment Tones (Conventional Only) . . . . . . . . . . . . . . . . . . . . . . . . . . 27Flashing Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Repeater PPI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Quick-Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 5 - Detailed VRS Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Multi-VRS Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29Rptr PPI—Portable Priority Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34TX PL Self-Clearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36ICM Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37Acknowledgment Tones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38Non-Priority VRS Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40Emergency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 6 - Hardware Detailed Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Power Regulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43Bus Translation Circuitry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43Audio Routing Circuitry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44Single Tone Encoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45Single Tone Decoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45Boot Control Circuitry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45Program Sense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46Mode Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 7 - Maintenance and Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Troubleshooting Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49Disassembly and Reassembly Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51VRS Transceiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56VRS Tuning and Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 8 - Troubleshooting Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 List of Troubleshooting Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 9 - Diagrams and Parts Lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 List of Diagrams and Parts Lists. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
iii User Safety, Training, and General Information READ THIS IMPORTANT INFORMATION ON SAFE AND EFFICIENT OPERATION BEFORE INSTALL-ING 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. This radio complies with the IEEE (FCC) and ICNIRP exposure limits at duty cycles of up to 50% talk-50% listen and should be used for occupational use only. In terms of measuring RF energy for compliance with the FCC exposure guidelines, your radio radiates measurable RF energy only while it is transmitting (during talking), not when it is receiving (listening) or in standby mode.Your Motorola two-way radio complies with the following RF energy exposure standards and guidelines: • United States Federal Communications Commission, Code of Federal Regulations; 47CFR part 2 sub-part J • American National Standards Institute (ANSI) / Institute of Electrical and Electronic Engineers (IEEE) C95. 1-1992 • Institute of Electrical and Electronic Engineers (IEEE) C95.1-1999 Edition • International Commission on Non-Ionizing Radiation Protection (ICNIRP) 1998 • Ministry of Health (Canada) Safety Code 6. Limits of Human Exposure to Radiofrequency Electromagnetic Fields in the Frequency Range from 3 kHz to 300 GHz, 1999 • Australian Communications Authority Radiocommunications (Electromagnetic Radiation - Human Exposure) Standard 1999 (applicable to wireless phones only) Operational Instructions and Training Guidelines To ensure optimal performance and compliance with the RF energy exposure limits in the above standards and guidelines, users should transmit no more than 50% of the time and always adhere to the following procedures: Transmit and Receive • To transmit (talk), push the Push-To-Talk (PTT) button; to receive, release the PTT button. • Transmit only when people outside the vehicle are at least the minimum lateral distance away, as shown in Table 1, from a properly installed, externally-mounted antenna. Table 1 lists the minimum lateral distance for bystanders in an uncontrolled environment from the transmitting antenna at several different ranges of rated radio power for mobile radios installed in a vehicle.
iv iv 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. • The antenna installation must additionally be in accordance with: a. The requirements of the antenna manufacturer/supplierb. Instructions in the Radio Installation Manual • Use only Motorola approved supplied antenna or Motorola approved replacement antenna. Unauthorized antennas, modifications, or attachments could damage the radio and may violate FCC regulations. Approved Accessories For a list of Motorola approved antennas see the appendix of this user manual. Fixed Site Antennas If mobile radio equipment is installed at a fixed location and operated as a control station or as a fixed unit, the antenna installation must comply with the following requirements in order to ensure optimal performance and compliance with the RF energy exposure limits in the above standards and guidelines. • The antenna should be mounted outside the building on the roof or a tower if at all possible. • As with all fixed site antenna installations, it is the responsibility of the licensee to manage the site in accordance with applicable regulatory requirements and may require additional compliance actions such as site survey measurements, signage, and site access restrictions in order to insure that exposure limits are not exceeded. Electromagnetic Interference/Compatibility NOTE: Nearly every electronic device is susceptible to electromagnetic interference (EMI) if inadequately shielded, designed or otherwise configured for electromagnetic compatibility. It may be necessary to conduct compatibility testing to determine if any electronic equipment used in or around vehicles or near fixed antenna sites is sensitive to external RF energy and if any procedures need to be followed to eliminate or mitigate the potential for interaction between the radio transmitter and the equipment or device. Facilities To avoid electromagnetic interference and/or compatibility conflicts, turn off your radio in any facility where posted notices instruct you to do so . Hospitals or health care facilities may be using equipment that is sensitive to external RF energy. Table 1. Rated Power and Lateral Distance Rated Power of Vehicle-Installed Mobile Two-Way RadioMinimum 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)
v 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. Before installing the radio, determine the location of the electronic control modules and their harnesses in the vehicle.3. Route all radio wiring, including the antenna transmission line, as far away as possible from the electronic control units and associated wiring. Driver Safety Check the laws and regulations on the use of radios in the area where you drive. Always obey them.When using your radio while driving, please: • Give full attention to driving and to the road. • Pull off the road and park before making or answering a call if driving conditions so require. Operational Warnings For Vehicles With an Air Bag Do not place a portable or mobile radio in the area over an air bag or in the air bag deployment area. Air bags inflate with great force. If a radio is placed in the air bag deployment area and the air bag inflates, the radio may be propelled with great force and cause serious injury to occupants of the vehicle. Potentially Explosive Atmospheres Turn off your radio prior to entering any area with a potentially explosive atmosphere. Sparks in a potentially explosive atmosphere can cause an explosion or fire resulting in bodily injury or even death. The areas with potentially explosive atmospheres referred to above include fueling areas such as below decks on boats, fuel or chemical transfer or storage facilities, areas where the air contains chemicals or particles, such as grain, dust or metal powders, and any other area where you would normally be advised to turn off your vehicle engine. Areas with potentially explosive atmospheres are often but not always posted. Blasting Caps and Blasting Areas To avoid possible interference with blasting operations, turn off your radio when you are near electrical blasting caps, in a blasting area, or in areas posted: "Turn off two-way radio." Obey all signs and instructions.For radios installed in vehicles fuelled by liquefied petroleum gas, refer to the (U.S.) National Fire Protection Association standard, NFPA 58, for storage, handling, and/ or container information. For a copy of the LP-gas standard, NFPA 58, contact the National Fire Protection Association, One Battery Park, Quincy, MA.
vi vi 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.CMOS ICs do have internal protection, but it is effective only against overvoltages in the hundreds of volts, such as those that could occur during normal operations. Overvoltages from static discharge can be in the thousands of volts.When a CMOS IC is installed in a system, the circuit elements in the system distribute static charges and load the CMOS circuits. This decreases the vulnerability of the ICs to static discharge, but improper handling will probably cause static damage even when the ICs are so installed.To avoid damaging CMOS ICs, take the following precautions when handling, shipping, and servicing them.1. Before touching a circuit module, particularly after having moved around in the service area, touch both hands to a bare-metal, earth-grounded surface. This discharges any static charge you may have accumulated. NOTE: Wear a conductive wrist strap (Motorola part number RSX-4015A) to minimize the buildup ofstatic charges on your person while you are servicing CMOS equipment. When wearing a conductive wrist strap, be careful near sources of high voltage. By grounding you thoroughly, the wrist strap also increases the danger of lethal shock from accidental contact with such a source. 2. Whenever possible, avoid touching any electrically conductive parts of the circuit module with your hands.3. Check the INSTALLATION and MAINTENANCE sections of this manual and the notes on the schematic to find out whether or not you can insert or remove circuit modules with power applied to the unit, and act accordingly.4. When servicing a circuit module, avoid carpeted areas, dry environments, and the wearing of static-generating clothing.5. Be sure that all electrically powered test equipment is grounded. Attach the ground lead from the test equipment to the circuit module before connecting the test probe. Similarly, disconnect the test probe before removing the ground lead.6. When you remove a circuit module from the system, lay It on a sheet of aluminum foil or other conductive surface connected to ground through 100,000 ohms of resistance. If the aluminum foil is connected directly to ground, you may get a shock if you touch it and another electrical circuit at the same time. 7. When soldering, be sure the soldering iron is grounded.8. Before connecting jumpers, replacing circuit components, or touching CMOS pins (if this becomes necessary during the replacement of an integrated-circuit device), be sure to discharge any static buildup on your person (see step 1, above). Because you can have a voltage difference across your body, you should use only one hand if you must touch the board wiring or any of the pins on the CMOS device.9. When replacing a CMOS integrated-circuit device, leave the device in its metal rail container or conductive foam until you are ready to insert it into the pronged circuit module.10. Connect any low-impedance test equipment, such as a pulse generator, to CMOS device inputs after you have applied power to the CMOS circuitry. Similarly, disconnect such low-impedance equipment before turning off the power.11. Wrap CMOS modules in conductive material when transporting them from one area to another, even within the same room. Use wrapping material similar to that in which replacement modules are wrapped when they arrive from the factory. (You can also use aluminum foil.) Never use nonconductive material for packaging these modules.
vii Model Chart for the VRS750 MODEL NUMBER DESCRIPTIONP2080 VRS750 VHF (136-174 MHz)P2081 VRS750 UHF R1 (403-470 MHz)P2082 VRS750 UHF R2 (450-512 MHz)ITEM NUMBER DESCRIPTION X X X HHN4044* VRS750 Housing X X X HLN6855* VRS750 Mounting Assembly X X X PLN7780 † VRS750 Controller Board XX X HLN6856* XCVR Hardware X PMLD4196 VHF Transceiver X PMLE4242 UHF R1 Transceiver X PMLE4243 UHF R2 Transceiver XX X HKN6153 Cable, Mobile-to-VRS 1 1 1 HKN6154 Cable, Siren-to-VRS 2 2 2 6881094C84 VRS750 Detailed Service Manual XXX 2884606M01 Mini-UHF crimp connector XXX YLN4480 VRS Pushbutton XXX HBN5086 Packing Kit3085031D02 Cable, VRS Programming (accessory)NTN4056 Adapter, VRS Flash programming (accessory)NKN6460 y-cable kit for dual controlhead w/vrs (accessory)TLN5277 DC filter for excessive alternator whine (accessory)RLN5394 VRS750 Test Box (accessory)3080384N02 VRS750 ATE Cable (accessory) 1 = With option G334AC. Deletes HKN6153 cable. 2 = One item per 10 units.*For piece part information, refer to the Exploded View section. † For piece part information, refer to the Electrical Parts List section.
viii viii VHF Performance Specifications UHF Performance Specifications GENERAL TRANSMITTER RECEIVER Model P2080 (136-174 MHz) † Number of Channels: 1, T1 = R1 Frequency: Programmable, SynthesizedFrequency 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 Receive500 mA Transmit @ 275 mW1.10 A Transmit @ 2 W Squelch Operation: Private-Line required forrepeater access Duty Cycle: Intermittent per EIA at 275 mW PPI Sample Time: 16 ms Typical Singletone Encoder/Decoder: Nominal 847.5 Hz FCC Identifiers: AZ492FT3802 (P2080) Industry Canada:RF Power Out: 275 mW to 2 W tunable Spurious and Harmonic Emissions: -36 dBm < 1 GHz-30 dBm > 1 GHz Frequency Stability: ±2.5 ppm @ 25 kHz±2.5 ppm @ 12.5 kHz Modulation Limiting (Max): ±2.5 kHz @ 12.5 kHz±4.0 kHz @ 20 kHz±5.0 kHz @ 25 kHz Audio Response: (from 6 dB/octavepre-emphasis, 300 to 3000 Hz)+1, -3 dB Audio Distortion: 3% Typical @ 1 kHz,60% maximum deviation FM Hum and Noise: -40 dB TX Attack Time: 32 ms Typical Antenna Impedance: 50 ohms Antenna Connector: mini-uhfIntermodulation per EIA: 70 dBHum and Noise: -40dBm @ 25 kHz-35dBm @ 12.5 kHzReference Sensitivity (typical):0.28 µV (-118dBm) at 12 dB SINADConducted Spurious Rejection: 70 dBAdjacent Channel Selectivity:60 dB @ 12.5 kHz70 dB @ 25/30 kHzAudio Response (0.3-3 kHz): +1 to -3 dBAudio Distortion: 3% Typical @Mobile Rated Audio*Conducted Spurious Emissions:-57 dBm <1 GHz-47 dBm > 1 GHzRX Attack Time: 60 ms Typical*Typically 5 W in 8 ohms.†Consult the product catalog sheets (ECAT Price Pages) for a list of disallowed frequencies.GENERAL TRANSMITTER RECEIVERModel P2081 (403-470 MHz)P2082 (450-512 MHz)†Number of Channels: 1, T1 = R1Frequency: Programmable, SynthesizedFrequency ChannelChannel Spacing: 12.5/20/25 kHzOperation Temp. Range: -30°C to +60°CPrimary Power: 13.8 VDC ± 20%,Negative GroundDC Current Drain (max): 120 mA Receive700 mA Transmit @ 275 mW1.20 A Transmit @ 2 WSquelch Operation: Private-Line required forrepeater accessDuty Cycle: Intermittent per EIA at 275 mWPPI Sample Time: 16 ms TypicalSingletone Encoder/Decoder:Nominal 847.5 HzFCC Identifiers: AZ492FT4848 (P2081)AZ492FT4849 (P2082)Industry Canada:RF Power Out: 275 mW to 2 W tunableSpurious and Harmonic Emissions:-36 dBm < 1 GHz-30 dBm > 1 GHzFrequency Stability:±2.5 ppm @ 25 kHz±2.5 ppm @ 12.5 kHzModulation Limiting (Max):±2.5 kHz @ 12.5 kHz±4.0 kHz @ 20 kHz±5.0 kHz @ 25 kHzAudio Response: (from 6 dB/octavepre-emphasis, 300 to 3000 Hz)+1, -3 dBAudio Distortion: 3% Typical @ 1 kHz,60% maximum deviationFM Hum and Noise: -40 dBTX Attack Time: 14 ms TypicalAntenna Impedance: 50 ohmsAntenna Connector: mini-uhfIntermodulation per EIA: 70 dBHum and Noise: -40dBm @ 25 kHz-35dBm @ 12.5 kHzReference Sensitivity (typical):0.28 µV (-118 dBm) at 12 dB SINADConducted Spurious Rejection: 70 dBAdjacent Channel Selectivity:60 dB @ 12.5 kHz70 dB @ 25/30 kHzAudio Response (0.3-3 kHz): +1 to -3 dBAudio Distortion: 3% Typical @Mobile Rated Audio*Conducted Spurious Emissions:-57 dBm <1 GHz-47 dBm > 1 GHzRX Attack Time: 60 ms Typical*Typically 5 W in 8 ohms.†Consult the product catalog sheets (ECAT Price Pages) for a list of disallowed frequencies.
ixGlossary of TermsThe 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. Delay state zero has the least time delay (0 milliseconds); delay state seven has the greatest delay (approximately 3.5 seconds for conventional modes, and 10.5 seconds for trunked modes). A unit that is in delay state zero is the priority unit.Disable The deactivation of the repeater. Press the VRS button on the control head or switch the VIP input off.Enable The activation of the repeater. Press the VRS button on the control head or switch the VIP input on.Inhibit A condition that occurs when the countdown sequence of the logic circuitry of the repeater ends, or anytime the repeater stops transmitting.Non-Priority RepeaterA repeater in any delay state other than delay state zero. This unit is inactive and does not repeat until the unit steps down to delay state zero.PTT The Push-To-Talk button on a portable radio or mobile microphone.Priority Repeater A repeater with its counter in delay state zero. This unit repeats any signal with the proper carrier frequency and PL code.Quick-Key A short press of the portable’s PTT—one that is long enough for the VRS to key the mobile and access the trunking system, but less than 1 second in duration.Single Tone Burst When a repeater enables, it transmits a 700-millisecond audible tone. This tone burst increases the delay counter in all other repeaters within range of the transmitting vehicle by one delay increment.
xxList of Abbreviations and AcronymsB-P Base to PortableCPS Customer Programming SoftwareDPL Digital Private LineHUB Hang Up BoxICM In Car Monitorms MillisecondPAC Portable Area CoveragePL Private LinePPI Portable Priority InterruptP-B Portable to BaseRF Radio FrequencyRX ReceiveSB Serial BusSBEP Serial Bus Expanded ProtocolTOT Time Out TimerTX TransmitVIP Vehicle Interface PortVRS Vehicular Repeater SystemVRS-EP Vehicular Repeater System—Expanded ProtocolVRS750 Vehicular Repeater System—Model 750
1Introduction 1Description 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.The VRS receives transmissions on the portable radio’s transmit frequency with the proper access PL, and passes these portable signals to the mobile radio. The mobile radio re-transmits the signals to the base station on the mobile radio’s transmit frequency.NOTE: These transmissions have the mobile’s ID, not the portable’s.Similarly, base station signals received by the mobile radio are sent to the VRS and re-transmitted to the portable radio. The VRS does not provide local repeater capability (received portable signals are not repeated on the portable receive frequency).The VRS-to-portable and portable-to-VRS communications are limited to clear analog only. This is a simplex-only interface; the VRS cannot receive and transmit simultaneously. The base station-to-mobile and mobile-to-base communications protocol is not limited to analog only. Rather, this interface is limited by the features and functions of the ASTRO Spectra and the base.Figure 1. VRS750 Vehicular Repeater SystemSPEAKER CONTROL HEADASTRO MOBILEVRS750HKN6153AMOBILEMICROPHONE
2Ordering InformationThe 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. The VRS receives its programming information from the ASTRO Spectra mobile at power-up. The ASTRO Spectra mobile supports the VRS programming fields via ASTRO Customer Programming Software (CPS). For more information, refer to “VRS750 Programming,” in Chapter 2, “Installation.”The VRS is not compatible with ASTRO Spectra mobiles with the VSELP signaling type.When integrating a VRS with an ASTRO mobile with a Siren/PA, an alternate interface cable is needed (HKN6154A). This cable allows the VRS to be connected to the Siren/PA. For more information, refer to “Installation,” Chapter 2.When integrating a VRS with an ASTRO mobile with Dual Control heads, an alternate interface cable is needed (NKN6460A). This y-cable allows the VRS to be connected to the ASTRO mobile with two control heads.A separate antenna (not included) is necessary for use with the repeater. Typically, a one-quarter (1/4) wave length antenna maximizes radiation efficiency when installed at the center of the vehicle roof. If it is necessary to mount the antenna on the vehicle’s trunk lid, an appropriate 3 dB gain antenna should be used. See “VRS Antenna Installation,” in Chapter 2, for details.A filter for the battery lines (TLN5277B)is available for use with ASTRO Spectra mobiles. This filter can be used to prevent excessive alternator whine noise from being heard on the mobile speaker during VRS operation.The VRS ships from the factory with the low output power setting at 275 mW and a high output power setting of 2 W. The low output power setting is the default setting. We recommend the LOW Transmit Power setting of 275 mW for optimal performance. This output power provides the VRS with a similar range as the portable when attached to a mobile antenna. Any deviation from this setting could result in a loss of communication from the portable to the base.The Global Tuning Tool (not included) can be used to tune the VRS output power in the field. For more information refer to “VRS750 Global Tuner,” in Chapter 2.Contact Customer Resources for information on how to obtain this Global Tuning Tool.
3VRS 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.•Mobile radio transmitter steering of up to eight modes via Private-Line® (PL) code transmission from the portable radio.•TX PL generator.•Base repeater operation for two-frequency, simplex, fixed-repeater systems.•Mobile audio repeat.•Compatible with the VRS-EP.All VRS features can be programmed in the field using ASTRO Spectra mobile CPS. For more information, refer to “VRS750 Programming,” in Chapter 2.IMPORTANT NOTE: All ASTRO Spectra VRS systems with the same VRS RF transmit/receive frequency need to be CPS programmed identically to ensure proper operation. Failure to do so could result in erratic system operation.The VRS does not have to be installed in the system for programming—only the mobile radio is programmed. If the VRS is not connected after programming the mobile system, an error message “ERR 12/10” will be displayed on the control head.Mutually-Exclusive FeaturesThe VRS IS NOT compatible with the following mobile radio features:•W3 Control Head is not supported with VRS•Flush-mounted control heads•VSELP signaling type•Data—VRS and data are not compatible on the same channel and cannot be used simultaneously. VRS should never be activated on a channel that has packet data enabled, and VRS mode steering channels should not have packet data enabled.•Scan•Over-the-Air Rekeying (OTAR) Rekey Request
4•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.NOTE: When an Emergency Alarm is received, the dispatcher may elevate that talkgroup to Emergency status.•Reprogram Request—Trunking•Repeater Access Control—Conventional•Mobile Single Tone—Conventional•Seven-Tone Modat—Conventional•Motorcycle•Consolette (Digital Remote and Tone Remote)The following mobile radio features may be received but may not be initiated or responded to while VRS is enabled.•Private Conversation™—Trunking•Call Alert™—Trunking or Conventional•Telephone Interconnect—Trunking or Conventional•Voice Selective Call—Conventional
5Installation 2When 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).If an external Siren/PA is to be used, the G334AC option must be ordered which replaces the HKN6153A cable with a HKN6154A cable, or a separate HKN6154A cable must be ordered. To install, plug the “T” side of the HKN6154A cable to the Siren/PA. Replace the mounting screw on the HKN4363B cable with the double length screw. Plug this side into the “T” cable. Plug the DB-25 end of the HKN6154A into the VRS (see Figure 3).Figure 2. Installing the VRS to an ASTRO MobileFigure 3. Installing the VRS750 with an External Siren/PAControl HeadASTRO MobileVRS750HKN6153AControl HeadASTRO MobileSiren/PAVRS750HKN4363B HKN6154A
6Installation of the Mounting Trunnion, HLN68551. 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).5. Connect the VRS-to-Mobile cable to the 25 pin connector on the bottom of the VRS750.6. Position the VRS750 in the trunnion.7. Secure the VRS750 with the two wing screws, and the split and flat washers provided.Figure 4. Securing the Trunnion Mounting Bracket
7VRS Antenna InstallationRecommended 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 trunk-mounted VRS antenna.2. Run the coaxial cable to the VRS750 mounting location. If necessary, cut off the excess cable and install the cable connector.3. Connect the antenna cable mini-UHF connector to the antenna jack on the rear of the VRS750 (see Figure 5). A mini-UHF crimp connector is provided with each VRS750 unit for easier installation with a pre-existing antenna. Ensure that the antenna’s cable connector is fully tightened. An adapter should NOT be used between the antenna cable mini-UHF connector and the VRS750.VRS750 ProgrammingThe user selectable operating parameters for the VRS750 reside in the ASTRO mobile EEPROM during normal operation. The EEPROM located in the VRS750 holds the tuning parameters. The VRS750 programming windows reside in ASTRO Spectra CPS and are accessible when the “VRS-EP Option” is enabled in CPS under the Radio Configuration --> Radio Wide --> Advanced Window (see Figure 6).The VRS750 does not function without CPS programming and is not pre-programmed at the factory. To ensure operational compatibility from one unit to the next within the fleet, all of the ASTRO Mobile and VRS750/VRS-EP systems should be programmed the same way.Figure 5. Connecting the Antenna CableMini-UHF Connector to the Antenna JackANTENNACONNECTOR
8Special Programming NotesThe 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. Then use the Radio Configuration --> Radio Wide --> Radio VIP window (see Figure 7) to select the VIP to be used. However, the VRS button must still be added to the control unit if it is desired to have the indicator light when the VRS750 is enabled. See the ASTRO Spectra CPS user’s manual for details concerning programming the VIP.NOTE: The ASTRO Spectra CPS user’s manual does not indicate that the VRS button is required in order to have the indicator light when the VIP is enabled.Figure 6. Advanced Window(Radio Configuration --> Radio Wide --> Advanced)
9ASTRO VRS Programming WindowsThere 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). In this window Base Repeater, Mobile Detector, Flashing Display, VIP control of VRS, and Trunking Access Tones can be enabled or disabled by clicking in the box to the left of the option. This window is also where the ICM mode can be selected using a pull down menu. Enabling Base Repeater will add 300 ms of delay to the prioritization routine to account for fixed repeater attack time.The second window is the VRS Private Line subsection (see Figure 9). This window allows the user to select a Mode Steering type, if one is being used. If Mode Steering is set to Disabled, the Access PL Freq. and Access PL Code fields will become user selectable. These fields specify the one PL frequency transmitted by the portable that will be used to access the VRS750. The VRS750 will treat that access PL in the same manner as a “select mode” mode steering PL. To edit these fields click in the Access PL Freq. or Access PL Code box and use the pull down menu to select the desired frequency or code.Also located on the second window is the VRS Tx Squelch Type. To edit this field click in the box to the right and use the pull down menu to choose between TPL and CSQ. If TPL is selected, meaning that the VRS should transmit to the portable with PL, the VRS Tx PL Freq. and VRS Tx PL Code fields will become user selectable. To edit these fields, click in the VRS Tx PL Freq. or VRS Tx PL Code box and use the pull down menu to select the desired frequency or code.Figure 7. Radio VIP Window(Radio Configuration --> Radio Wide --> Radio VIP)
10Figure 8. VRS Window(Radio Configuration --> Radio Wide --> VRS)Figure 9. VRS Private Line Window(Radio Configuration --> Radio Wide --> VRS Private Line)
11The 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-Out-Timer 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. It should be noted that the Repeater PPI feature must be enabled to allow the multi-unit priority algorithm to function correctly when there will be multiple VRS units on scene. The time between interrupts may be set to Fast (500 ms) or Slow (2 seconds) for conventional modes and Fast (500 ms) or Slow (1 second) for trunked modes.NOTE: When using Rptr PPI, the receiver squelch setting of the portable must be programmed for CSQ (carrier squelch).The fourth window is the VRS Personality subsection (see Figure 11). The VRS Personality sets the VRS Frequency Band, Simplex Frequency, Channel Spacing, and TX Output Power for the VRS750. The VRS750 can be programmed for 12.5, 20, or 25 kHz Channel Spacing with a High or Low output power (factory power settings are 2 W for High and 275 mW for Low). Note that the VRS Personality will allow the Frequency Band to be set to VHF, UHF R1, or UHF R2 regardless of which model VRS750 is being used, but upon power up the error message “VRS 001” will be displayed if the frequency band is incorrect.Figure 10. VRS Advanced Window(Radio Configuration --> Radio Wide --> VRS Advanced)
12NOTE: 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.The VRS Personality can be programmed directly into the VRS750 EEPROM using Professional Radio CPS and a new dip switch configuration, Professional CPS Mode. All other operating parameters will still be programmed using the ASTRO Spectra CPS. For more information, refer to “Mode Configuration,” Chapter 6.The fifth window, Radio Configuration --> Radio Wide VRS-EP Mode Steering --> VRS-EP Mode Steering List --> VRS-EP Mode Steering - 1 (see Figure 12) is a table containing PL and mode steering information that can be edited. Mode Steering must first be enabled in the VRS Private Line window before the mode steering PLs in the table can be edited. To enter the PL codes used in mode steering and their corresponding destinations, enter the desired PL code or frequency by using the pull down menu in each PL Freq. or PL Code box. Then select the corresponding Steering Destination in the same manner.If the VRS Tx Squelch Type was set to TPL in the VRS Private Line window, none of the mode steering PLs may be the same as the VRS Tx PL Frequency.Figure 11. VRS Personality Window(Radio Configuration --> Radio Wide --> VRS Personality)
13NOTE: 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.Due to Host memory considerations, the maximum number of Zones allowed to be accessed by the VRS Mode Steering window is 20. Any Zone number greater than 20 will not be allowed in this window but is allowed for normal radio operation.VRS750 Global Tuner The Tuner for Professional Radios (Global Tuner) can be used to adjust the VRS750’s Transmitter Output Power and Receiver Squelch Settings while in Normal Mode (see Table 6 in Chapter 6). In order to program the VRS750 using the Global Tuner it should be connected to the mobile and to a PC via its COM port as indicated in Figure 13.Figure 12. VRS-EP Mode Steering WindowFigure 13. VRS Connection to the PCVRS750 SRIBASTRO MOBILEVRS750 TO MOBILE CABLE CONNECT TO THE PCsCOM PORT
14Once 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). We recommend setting and using a Low transmit power setting of 275 mW for optimal performance. This output power provides the VRS750 with a similar range as the portable when attached to a mobile antenna. Any deviation from this setting could result in a loss of communication from the portable to the base.NOTE: Please also note that some countries may have different restrictions on the power level. If you are not sure on the power to tune, please check with your regulatory body. The maximum available power level given in the table below must not be exceeded.NOTE: When checking the RF power output of the VRS750, always use an attenuator pad of at least 30 dB attached to the radio end of the RF cable. This will avoid an RF mismatch and ensure a stable RF reading that will not change with varying lengths of connecting cable.NOTE: The VRS750 will be programmed from the factory with a high power setting of ~2 W and a low power setting of ~275 mW.To perform Transmit High Power Tuning, do the following:1. Under the Tx Align menu, select Transmit Power, then select High (see Figure 14).2. Press PTT Toggle. This will key the radio up at F1.3. Adjust the high power level by moving the slider/spin control or keying in values in the edit control (press ENTER to confirm selection after typing in the softpot value).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 after typing in the softpot value) or toggling the softpot value using the spin control.Table 2. Transmit High Power Level for VRS750sRF Band (MHz) High Power (W)VHF (136-174) 5.2-5.7UHF Band 1 (403-470) 4.2-4.6UHF Band 2 (450-527) 4.2-4.5
155. 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.To perform Transmit Low Power Tuning, do the following:1. Under the Tx Align menu, select Transmit Power, then select Low.2. Press PTT Toggle. This will key the radio up at F1.3. Adjust the power level by moving the slider/spin control or keying in values in the edit control (press ENTER to confirm selection after typing in the softpot value).Figure 14. Transmit High Power Window in the Global TunerTable 3. Transmit Low Power Level for VRS750sRF Band (MHz) Low Power (mW)VHF (136-174) 240-310UHF Band 1 (403-470) 240-310UHF Band 2 (450-527) 240-310
164. 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.Squelch Tuning Under Rx Align, select Squelch Attn. Select either Squelch Attn. 12.5 kHz, Squelch Attn. 20 kHz, or Squelch Attn. 25 kHz Channel Spacing variations (see Figure 15).1. Apply an RF signal modulated with 1 kHz tone at 60% rated deviation (see Table 10 in Chapter 7) for current frequency point (F1 being the first) of -110 dBm. Make sure that the mobile mic is off HUB and the VRS is programmed for ICM BOTH mode so that the audio will be routed to the mobile speaker.NOTE: The -110 dBm squelch level was chosen so that each VRS750 would have the same squelch performance as other VRS750 units as well as VRS-EP units. This prevents one unit from receiving a signal that the other cannot.2. Set softpot to its maximum value to mute the radio. If the VRS750 remains totally unmute at this setting, leave it at the maximum setting and continue to step 4.3. Adjust the softpot value by using the slider, keying in the edit box (press ENTER to confirm selection), or using the spin controls. Figure 15. Squelch Attenuation Window in the Global Tuner
17Do 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. The VRS transceiver ships from the factory with the softpot set for -110 dBm. In the event that this value needs to be re-set in the field, it is recommended that a communications analyzer or similar piece of test equipment be used to verify these settings.Other adjustments can be made using the Global Tuner in the event that the transceiver is replaced. For more information, refer to “Transceiver Board Tuning Procedure,” Chapter 7.When all adjustments have been made, select File --> Program All. This will program all off the softpot values into the VRS750’s EEPROM.VRS750 Upgrade Kit The VRS750 firmware can be reprogrammed/reflashed using the VRS750 Upgrade Kit. In order to use the VRS750 Upgrade Kit the VRS750 should be connected to a desktop or laptop PC via a COM port as indicated in Figure 13. The Flash adapter (NTN4056A) should be placed between the VRS750 programming cable (3085031D02) and the SRIB (see Figure 16). When connecting the VRS750 to the SRIB via the Flash adapter, make sure that the switch on the adapter is in the “B” position. With the ASTRO mobile powered on and “PROG VRS” displayed on the control head, the upgrade can be started. Open the VRS750 Upgrade Kit and click on the “PROGRAM” button. Follow the instructions through to the completion of the Flash process. Upon completion, place the switch on the Flash adapter back in the “B” position and disconnect the VRS750 from the programming cable. For more detailed information on the flashing process, consult the “read me” file for the Upgrade Kit.Table 4. Softpot RangesBand Channel Spacing (kHz)Approximate Softpot Range for -110 dBmVHF 25 56-63VHF 12.5 63UHF R1 25 44-52UHF R1 12.5 63UHF R2 25 43-46UHF R2 12.5 63
18NOTE: 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.Figure 16. Flashing Adapter
19VRS Operation 3General 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. This prevents interference problems associated with multiple VRS units in proximity to one another.Control Unit The VRS may be enabled/disabled from the ASTRO mobile radio’s remote-mounted W4, W5, W7, or W9 control head (see Figure 17). The VRS button may occupy any of the indicator button positions. Field programming determines the exact position. The VRS requires an ASTRO radio with a remote-mount control head.When the VRS is turned on, the indicator illuminates and, after transmitting the Single Tone burst, the words “VRS BOTH” (indicating the In-Car Monitor mode) will be displayed momentarily. The indicator remains on for as long as the VRS is on.When the VRS unit is activated, it transmits Single Tone on the portable frequency, and assumes the priority (active) repeater state. The Single Tone frequency is fixed at 847.5 Hz. For proper operation, all VRS units to be used in the same system must be programmed with Figure 17. Typical ASTRO Control Head with VRSDir MPL VRS SirenXMIT BUSYDIMWail YelpHi-LoMonExRadRcl SqlDelPriNonPriMode Vol Sel Home123456789*0#MODE ROCKER HOME BUTTONAstroPA
20the 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 PortsAnother method of enabling/disabling the VRS option is through the use of a vehicle interface port (VIP). Using ASTRO CPS, the user can select which VIP to use and whether the input control voltage is to be high/ground or ground/high.One use of VIP operation connects the VRS switch lead to a portable radio vehicular control charger, such as the AVA, SVA, MVA, MTVA, or ASTRO XTS. Remove the portable from its charger pocket to automatically enable the VRS option. Replace the portable unit in its charger to disable the VRS option. A toggle switch on the portable unit charger allows the portable unit to be removed without enabling the VRS option.NOTE: This requires the VIP hardware interface kit, 0180757T61, which is not included with the VRS.Turning the portable unit charger off, then on does not disable the VRS option. The VIP setting controls the on/off state of the VRS option. If the field programmer chooses the VIP option, pressing the VRS button on the control head will only cause the display to change momentarily to the In Car Monitor Mode (“VRS BOTH”). It will not enable or disable the VRS as previously described. It is still necessary, however, to select in CPS an indicator button for the VRS if it is desired to have the indicator light when the VRS is enabled.VRS Access With the VRS on, press the portable radio’s PTT button to begin transmissions. The VRS programming must include correct PL frequencies to allow the portable unit to access the option. The VRS option receives signals with the correct PL, then uses the mobile radio to re-transmit the signals. The control head’s XMIT indicator lights during the re-transmission.The VRS re-transmits received mobile signals as explained in the “Mobile Audio Repeat” paragraph on page 21. Note that the XMIT indicator does not light when the VRS is transmitting to the portable.To transmit directly to the other portable units, turn off the portable transmit PL. This allows you to talk around the VRS without transmitting on the mobile channels.In-Car Monitor The “In-Car Monitor” (ICM) feature is for use in a two-man operation where one user (user 1) is out of the vehicle while the other (user 2) remains in the vehicle. This allows user 2 limited access to both mobile and portable communications when the VRS is on, even when the repeater is the priority unit. ICM operation is set to BOTH.
21ICM 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.VRS BOTH:Press the mobile’s PTT to transmit simultaneously on the frequency corresponding to the mode shown on the control head’s display, and the portable frequency. Use the ASTRO CPS to enable the VRS TX PL generator option to transmit with the proper PL frequency. If you press the mobile’s PTT during portable-to-base VRS activity, a momentary talk-prohibit tone sounds and the microphone audio is disabled.When using VRS BASE or VRS BOTH mode, all mobile transmissions are on the mode that is shown on the control head’s display. If the VRS is currently steering to another mode, that steered mode will be displayed on the control head. Any mobile transmissions will be on that new mode until the portable steers the VRS back or the mode rocker switch is used to change modes. If the mode rocker switch is used to change modes, the portable user will not be made aware of this mode change. With Ack Tones are enabled, the portable user will hear a “bad” tone if the mode is changed during the transmission.VRS Reception The VRS option has no effect on mobile radio squelch control or normal mobile radio reception. The VRS portable unit’s squelch setting is not user adjustable. Portable audio is heard from the mobile speaker of the priority VRS unit as shown in Table 5.Repeated portable transmissions will always be heard from the mobile speakers.Portable transmissions without proper PL will only be heard from the mobile speaker if the microphone is off HUB.Mobile Audio RepeatThe VRS transmits to the portable when audio unmutes the mobile speaker. This allows the user to set the monitor button “on” to defeat the coded squelch requirements of the mobile radio on a base-to-portable transmission or “off” to prevent the VRS from repeating base-to-portable (HUB will also disable this), unless the coded squelch requirements of the mobile radio are met. Button presses (that is, Volume, Mode, etc.) on the priority mobile unit will also be transmitted by the VRS.Table 5. Portable Audio Heard from Mobile SpeakerMobile MicrophonePortable Audio Heard from Mobile SpeakerOn HUB PL*Off HUB CSQ* = any valid repeater access PL
22Notes
23 Operation of VRSOptions 4 The following sections describe the operation of CPS field-programmable 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. This allows non-priority mobiles to detect any priority mobile in the system through the base repeater. Mobile Detector The Mobile Detector feature allows the user to operate VRS units with two-frequency simplex dispatch systems without a base repeater. This feature allows the automatic multi-unit priority resolution algorithm to function in the above scenario. When this feature is activated by the CPS, a non-priority VRS will send a message to the mobile to enable a “Listen Around” feature when a proper portable PL is received.“Listen Around” switches the mobile radio’s receive frequency to match that of its transmit frequency of the steered mode. The non-priority VRS will count down in priority if its corresponding mobile does not detect the repeated transmission on the “Listen Around” frequency. When the portable is dekeyed, the non-priority VRS will send a second message to the mobile to disable “Listen Around” and return to normal operation. This feature does not use any additional user modes in the mobile. NOTE: The Mobile Detector feature only works on conventional modes. Trunked modes will be unaffected. VRS Transmit PL Generator The transmit PL generator, when enabled, causes the VRS to transmit (base-to-portable), with specific field programmable PL tones. The selected VRS transmit PL frequency cannot be the same as any of the VRS receive PL frequencies that the portable uses to access the vehicular repeater. VRS Mode Steering The VRS steering option gives the portable operator the ability to select the current mobile radio mode via PL tones. The total number of Mode-Steered modes can not exceed eight (including emergency, message, and status). The operator may program as many as eight such tones, along with corresponding mobile mode numbers, into the VRS.
24 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. NOTE: If mode steering is not selected during CPS programming, the programmer will need to enter the repeater access PL, which corresponds to a single access PL with select mode steering. Steering Types • <Transmitter Steering/Receiver Latching>—On portable-to-base repeating, the mobile radio is steered to the proper mode as determined by the received PL from the portable. When the portable dekeys, the condition to repeat ceases, and the mobile radio remains on this mode. Thus, all future base-to-portable repeating is heard via the mobile mode last steered by the portable.The mobile control head will display the steered/latched mode. If, sometime after this operation and while no repeat is occurring, the ICM user keys the mobile with the microphone’s PTT button, the mobile will now transmit on the latched mode that is displayed on the control head. If, however, the in-car-monitor (ICM) user changes the selected mode using the mobile’s mode rocker switch before pressing the mic PTT, the mobile will now transmit on the new selected mode. NOTE: For the above type of steering, the portable user will be able to steer back to the selected user mode on the control head by programming one PL destination for Sel-Mode. However, the selected mode can be changed by the rocker mode switch. • <Transmitter Steering/Receiver Steering>—On portable-to-base repeating, the mobile radio is steered to the proper mode as determined by the received PL from the portable. When the portable dekeys, the condition to repeat ceases, and the mobile radio remains on this mode for 6 seconds. During this 6 seconds, the VRS waits for a repeatable base-to-portable transmission to be received.• If a base-to-portable transmission is not received, the mobile will return to the last mode selected by the control head’s rocker switch (current user-selected mode).• If a base-to-portable transmission is received during the 6-second timer, the timer will be reset back to 6 seconds and start over at the end of the transmission.• If the portable is keyed during the 6 seconds, the VRS will handle the destination PL accordingly and reset the timer. If the 6-second timer has not expired, no repeat is occurring, and the ICM user keys the mobile with a microphone PTT, the mobile will transmit on the steered mode and the 6-second timer will start over at the end of the transmission.
25Steering Destination TypesThere 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. Once the mobile has steered, it will follow the conventions of the type of steering selected (for example, Transmitter Steering/Receiver Latching).Select Mode The VRS will command the ASTRO mobile to return to the last mode selected by the rocker switch on the control head. If the portable user has steered to another mode, and the selected mode is changed in the car, the steering will be canceled until the VRS receives another mode steering PL.Emergency Alarm The VRS will initiate an Emergency Alarm through the ASTRO mobile, if the mobile is programmed for this type of Emergency, in the same manner as if the Emergency button on the control head were pressed. The type of Emergency (trunked or conventional) depends on the currently selected mobile mode, (trunked or conventional, respectively).The VRS will only generate an Emergency, not perform a portable-to-base audio repeat, while the portable is transmitting on an “Emergency request” channel. This feature is typically implemented in the portable, using a one-touch button that has been programmed for Emergency-revert to a channel with the proper PL.Although the portable generates MDC tones, the VRS cannot decode MDC. Instead it responds to the PL of the portable mode on which the Emergency MDC tones are transmitted. All of this is transparent to the user.Message The VRS will command the ASTRO mobile to send out a CPS-programmed message on the mode currently displayed on the control head, in the same manner as if the request to send a message had been generated using the control head. The VRS will send out only one message per received portable signal. No mode steering will occur; the currently steered/latched mode and the selected mobile mode will remain as they were before the request to send a message was received.If the message selected is valid, the VRS will transmit to the portable the mobile tones indicating whether or not the valid message was acknowledged. If the message selected is invalid, (either incorrectly programmed in CPS or not a valid message for the currently displayed mode), the VRS will send a low-pitched alarm tone to the portable.To generate a message request, the portable user would:•select the channel on the portable programmed for the message request,
26•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.Status The VRS will command the ASTRO mobile to send out a CPS-programmed status on the mode currently displayed on the control head, in the same manner as if the request to send status had been generated using the control head. The VRS will send out only one status per received portable signal. No mode steering will occur; the currently steered/latched mode and the selected mobile mode will remain as they were before the request to send a status was received.If the status selected is valid, the VRS will transmit to the portable the mobile tones indicating whether or not the valid status was acknowledged. If the status selected is invalid, (either incorrectly programmed in CPS or not a valid status for the currently displayed mode), the VRS will send a low-pitched alarm tone to the portable.To generate a status request, the portable user would:•select the channel on the portable programmed for the status request,•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 “status request” channel.NOTE: A status cannot be generated from the control head while the VRS is activated.Time-Out Timer The Time-out Timer (TOT) duration value sets the maximum allowable time for a base-to-portable transmission. The VRS TOT may be set to 30, 60, 120 seconds, or disabled. When a unit times out, it counts up to delay state one. This removes it as the priority unit.VRS Single Tone When the VRS unit is enabled, it transmits an audible tone (Single Tone) for 700 mS which is used by other VRS units for the automatic prioritization routine. The Single Tone frequency is fixed at 847.5 Hz.
27VRS 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. If the portable user does not hear a tone after completing a transmission, the portable is either out of range of the repeater or there is no priority repeater in the area.See “VRS Mobile Trunking Tones (Trunking Only)” on page 38 for a description of trunking acknowledgment tones.Flashing Display The Flashing Display feature causes the display on the control head to alternate between the current mode and “VRS BOTH.” This feature is used primarily when the VRS enable/disable button does not have an indicator light or when VIP activation is used. This feature is normally disabled in CPS. The length of time “VRS BOTH” is displayed every 6 seconds is determined by the “temporary message display timer” value. This value (from 250 to 6250 ms [default = 1000 ms]) canbe programmed by the CPS. To configure, select Radio Configuration --> Display & Menu --> Advanced screen.Repeater PPI The Repeater Portable Priority Interrupt (PPI), when enabled, causes a base-to-portable transmission to be interrupted every 1 second in trunked mode or 2 seconds in conventional mode so that the repeater can search for a portable radio signal. (These times are programmable and may be changed to 500 ms for trunked or 500 ms for conventional modes). This interruption may be heard on the portable as a “clicking” noise, but PPI is necessary to give the portable user priority over base-to-portable transmissions, for the self-clearing function of the automatic priority resolution feature, and to allow portable users in trunked mode to break in during system hang time to prevent loss of voice channel. This feature may be disabled through CPS.Quick-Key This feature allows the portable user to determine the status of the mobile trunking system. The feature is initiated by a short press of the portable’s PTT that is long enough for the VRS to key the mobile and access the trunking system, for less than 1 second in duration.
28Notes
29Detailed VRS Operation 5Multi-VRS OperationThe 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 multi-VRS operation are discussed next.Determining Priority LevelsWhenever a VRS is enabled, it transmits a Single Tone burst (except if portable activity is already present). The Single Tone burst frequency is fixed at 847.5 Hz. By default, when a VRS (VRS number 1) unit is enabled, it becomes the priority unit with a delay state of zero. When a second VRS unit (VRS number 2) is enabled in the area, it will transmit a Single Tone burst as described. Upon receiving this signal, VRS number 1 will know that another VRS is active and change its priority to delay state one from delay state zero. If a third VRS were to be enabled, VRS number 1 would change to delay state two and VRS number 2 would change to delay state one. This process could continue up until delay state seven is reached by VRS number 1, meaning that eight VRS units have been enabled. After eight VRS units are activated, they begin to stack up at delay state seven.Portable-to-Base TransmissionsIf a portable begins to transmit, only the highest priority VRS will PTT its corresponding mobile for transmission to the base. The other VRS units, however, will be able to hear the portable transmission and monitor for mobile channel activity. Channel activity is verified by a squelch detect of the mobile. For non-priority units, the portable’s audio will be sent to the mobile’s speaker (unmuted) from the VRS, not from the mobile. This allows the mobile to monitor the correct transmit frequency. If mode steering options are enabled then the non-priority VRS units monitor their mobile’s channel activity on the channel steered to by the portable’s PL and not on the mobile’s current user selected channel.The non-priority VRS units have a short delay in which they expect to see the squelch detect message. Conventional system units will wait at least 600 ms and trunking system units will wait at least 1500 ms. This time period is referred to as one delay state. If in the appropriate time frame a squelch detect message is not received, the priority VRS unit is assumed to have been disabled and all other VRS units will increase one priority level (for example, go from delay state 2 to delay state 1). The VRS units will continue to count down until a squelch detect message is received. In an extreme case, in which all but the lowest priority VRS units are disabled, it is possible that the remaining VRS unit which was the lowest priority (highest delay state) will have to wait up to 7 delay states before transmitting. This can lead to a transmission delay of up to 10.5 seconds for a trunking unit.
30On conventional modes if the VRS <Base Repeater> 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 TransmissionsWhen a base transmits, only the priority VRS unit will transmit to the portable. The other VRS units monitor activity on the portable channel. Similar to the previous case, if portable activity is not detected in the specified time frame after receiving mobile channel activity, the non-priority VRS units will decrease one delay state, until eventually one unit is in priority.During base-to-portable transmissions, the delay state timing is slightly different from that encountered during portable-to-base transmissions. On conventional modes, the first delay state is 1 second; on trunking modes, the first delay state is 3.4 seconds. All other delay states, on either trunking or conventional modes, are 400 mS. The worst-case delay for a unit to count into priority during a base-to-portable transmission in a trunking system would, therefore, be 5.8 seconds.See the description of the Portable Priority Interrupt feature on page 34 for information on the self-clearing feature used to re-establish a single priority unit when multiple units are mistakenly in priority. This condition may occur when a VRS unit is activated before arriving on a scene, or in the unlikely case where several units stack up at delay state seven and all higher priority units (those in delay states one through six) leave the scene first or are otherwise disabled.Single Unit Operation Normal radio communication between a VRS-equipped vehicle (unit A) and the base is via the mobile radio. When the operator decides to leave the vehicle and use the VRS option, simply press the VRS button or remove the portable from the charger if VIP operation is enabled to turn on the vehicle’s repeater. The repeater transmits the Single Tone burst on the associated portable radio frequency and sets the delay state to zero. When the delay state is zero, this unit is the priority unit. See Figure 18.IMPORTANT NOTE: The VRS is designed to be a stationary repeater system. The VRS unit should always be disabled when the vehicle is moving. FAILURE TO DO SO COULD RESULT IN ERRATIC SYSTEM OPERATION.
31Two-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. Unit B’s repeater priority counter initializes in delay state zero, making unit B the priority unit. Unit A’s repeater/portable receives unit B’s Single Tone transmission, which sets unit A’s repeater to delay state one. See Figure 19. Transmissions from portable units in the area now repeat through unit B. See Figure 20.A portable radio’s transmissions (solid arrows in Figure 20) go to all portable radios and VRSs in the area. Because unit B is the priority repeater, it repeats the portable’s signal (open arrows in Figure 20) to the base station and other mobile radios.Unit A cannot countdown and repeat until the delay state one time delay elapses. However, because unit A detects the mobile carrier of the priority unit (open arrow in Figure 20) before the delay expires, the priority counter does not begin the countdown. Unit A remains in delay state one and does not repeat portable transmissions.Figure 18. Single VRS Unit OperationSINGLE TONEBURSTUNIT A“DELAY STATE ZERO”PRIORITY UNITMAEPF-26079-OFigure 19. Two-Unit VRS OperationSINGLE TONEBURSTUNIT A“DELAY STATE ONE”UNIT B“DELAY STATE ZERO”PRIORITY UNITMAEPF-26080-O
32If 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.Three-Unit Operation Should another VRS-equipped vehicle (unit C) come into the area, the same sequence of events occurs as previously described in the “Two-Unit Operation” section on page 31. Unit C’s arrival has no effect on unit A’s or B’s radio operation until unit C’s VRS is enabled.Unless there are portable transmissions occurring when unit C arrives, unit C’s repeater transmits a Single Tone burst when its VRS option is turned on. Unit C’s repeater priority counter initializes in delay state zero, making unit C the priority unit. Unit A’s repeater/portable receives unit C’s transmission which sets unit A’s repeater to delay state two. Unit B’s repeater/portable receives unit C’s transmission which sets unit B’s repeater to delay state one. Transmissions from portable units in the area now repeat through unit C. All lower-priority units will receive incoming portable transmissions, but will not key up their mobiles because they are in a delay state. See Figure 21.Figure 20. Two-Unit VRS TransmissionsUNIT A“DELAY STATE ONE”UNIT B“DELAY STATE ZERO”PRIORITY UNIT MAEPF-26081-OTRANSMITS TOBASE STATION ANDMOBILE RADIOSIN AREATRANSMITS TOALL REPEATERS ANDPORTABLE RADIOSIN THE AREA
33Departure of a VRS Unit The priority unit may change, depending upon the order in which they leave, as vehicles leave the coverage area. For example, in Figure 21, when unit A turns the VRS option off, it has no effect on the priority unit (unit C). Unit C continues to be the priority unit and repeat transmissions.When the priority unit (unit C) turns the VRS option off and conditions for repeater transmissions occur, the unit in delay state one (unit B in Figure 21) counts down to delay state zero and becomes the priority unit. See Figure 22.IMPORTANT NOTE: Non-priority units (those in delay state 1 or higher) will not count down into priority if the portable user attempts to send a status or message. If there is no priority unit on scene, the request will be ignored.Figure 21. Three VRS Unit Transmission SequenceUNIT B“DELAY STATE ONE”UNIT A“DELAY STATE TWO”UNIT C“DELAY STATE ZERO”PRIORITY UNITMAEPF-26082 -OTRANSMITS TOBASE STATION ANDMOBILE RADIOSIN AREATRANSMITS TOALL REPEATERS ANDPORTABLE RADIOSIN THE AREA
34Rptr PPI—Portable Priority InterruptNOTE: When using Rptr PPI, the receiver squelch setting of the portable must be programmed for CSQ (carrier squelch).<Rptr PPI> is CPS programmable. The main function of <Rptr PPI> is to allow the portable to interrupt base-to-portable transmissions. During VRS to portable transmissions, an interrupt is sent to the transmitter every 2 seconds on conventional modes and 1 second on trunking modes. (These times are CPS programmable and may be changed to 500 ms for trunked modes or 500 ms for conventional modes.) There is also a random time factor added to the base interval to prevent two VRS units from interrupting at the same time. This interrupt allows the receiver to monitor portable or other VRS activity for approximately 6 ms. See the timing chart in Figure 23.Figure 22. Priority Unit ReassignmentMAEPF-26083-OVRS REPEATERTRANSMITTERPORTABLETRANSMITTERWITHOUT “PL”PORTABLETRANSMITTERWITH “PL”MOBILETRANSMITTERONOFFONOFFONOFFONOFF~ 2 sec ~ 6 msecFigure 23. Portable Priority InterruptUNIT BDELAY UNITS 1 0MAEPF-26084-OREPEATER WAITS ONE DELAY UNIT, COUNTS DOWN (1,0),AND BECOMES PRIORITY UNIT.THE PRIORITY STATE COUNTER IN OTHER REPEATERSALSO COUNTS DOWN BY ONE DELAY UNIT.
35If 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. Self-Clearing—This is used when two or more priority VRS units are on the same scene. On the first base-to-portable transmission, all priority VRS units will start to transmit. The first one to have an interrupt and detect carrier without proper portable PL (meaning another VRS is transmitting) will count up to priority state one, a condition which is referred to as self clearing. This will continue to happen until only one priority VRS is on scene.As an example, consider a case in which both units A and B are in the priority state (delay state zero). When conditions for repeater transmitting begin (i.e., the mobile receives a base signal), both VRS units begin transmitting. Figure 24 shows the unit B interrupt pulse occurring first (due to the random time factor added to the interrupt interval). When unit B is interrupted, it detects another VRS unit transmitting and so unit B’s transmitter remains inhibited. Unit B is set to delay state one and unit A remains the priority unit since by the time unit A’s transmitter is interrupted, unit B is no longer transmitting.2. Repeater Hangtime—This allows the user to get back into a conventional repeater or trunked system during hangtime. The timing is faster for trunked systems due to the added feature of talk permit tones being passed to the portable. If the portable keys up with proper PL, then the VRS will key up the mobile. If proper PL is not sent, the VRS will assume another VRS is in the area and count itself out of priority.Figure 24. Self-Clearing Timing DiagramTWO UNITS IN PRIORITY STATEMOBILE RADIOS A & BRECEIVE MESSAGEREPEATER ATRANSMITSREPEATER BTRANSMITSREPEATER A WAS NOT INTERRUPTED AND REMAINSTHE PRIORITY UNIT.REPEATER B WAS INTERRUPTED BY ANOTHER REPEATER,THEREFORE DELAY IS INCREMENTED BY ONE UNIT.MAEPF-26085-OINTERRUPTPULSE DELAY STATEDELAY STATE0 00 1
36NOTE: 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.A drawback of portable priority interrupt is that during all base-to-portable transmissions, the signal drops out for approximately 6-8 ms every: 2 seconds (conventional); or 1 second (trunking) if the “slow” PPI option is chosen; or every 500 ms (either trunking or conventional if the “fast” option is chosen in CPS).The repeater PPI function may be used by the portable user in the following manner:During a base-to-portable transmission, the portable user wants to interrupt and transmit to the base.• Portable must transmit with the VRS correct access or steering PL.• When the VRS transmitter is interrupted, the VRS will detect channel activity from the portable’s transmission and switch to receive mode.• The VRS will then transmit VRS TX Audio to the base.• The VRS RX Audio is routed to the mobile speaker.TX PL Self-Clearing As part of the multi-unit resolution prioritization algorithm, TX PL Self-Clearing operates by adding the VRS transmit PL to the list of PLs that the VRS monitors. If a VRS transmit PL is detected by a priority VRS (delay state 0), it will indicate that another VRS is transmitting. This feature will cause the original priority VRS to count up to delay state 1, 2, or 3, and allow the transmitting VRS to remain in priority. The delay state is randomized to prevent multiple units from stacking up in delay state 1. In order to prevent ICM transmissions from other VRS units affecting the priority states, the TX PL Self-Clearing feature only works when detecting TX PL from a VRS that is repeating a Base-To-Portable transmission. This function is not programmable, but has no effect unless TX PL is used. This feature will not operate properly unless all VRS units are programmed to transmit with the same frequency PL, and the receiver squelch of the VRS750 units is set to approximately -110 dBm.NOTE: The VRS750 ships from the factory with a receiver squelch setting of approximately -110 dBm. If the VRS750 is not going to be programmed with a TX PL, then the Global Tuner can be used to loosen the receiver squelch for better radio performance.
37ICM Functions The in-car-monitor (ICM) allows limited use of the mobile while the VRS is enabled.<ICM Base> ModeIn 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. When the mic is on HUB portable transmissions will not be heard at the mobile’s speaker. When the mic is off HUB only portable transmissions with the proper PL will unmute the speaker. The following paragraphs detail how the VRS should operate in <ICM Base> mode during different cases.1. No VRS repeat operations in progress and the mobile user initiates a PTT.• The mobile will key up and transmit mic audio to the base.• Mic-Hi line audio is not routed to the VRS transmitter.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 operation will be interrupted.• Mic-Hi line audio is not routed to the VRS transmitter.• The mobile will key up and transmit mic audio to the base.• When the mobile mic PTT is released, the base-to-portable repeat will continue if the mobile is still receiving a base transmission.<ICM Both> ModeIn this mode pressing the mobile’s PTT will cause the mobile to transmit on the mode shown on the control head display and cause the VRS to transmit to the portable. If the portable is using a PL frequency then the VRS can be programmed to transmit the proper PL. 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. When the mic is off HUB all portable transmissions are heard at the mobile’s speaker. When the mic is on HUB only portable transmissions with the proper PL will unmute the speaker. The following paragraphs detail how the VRS should operate in <ICM Both> mode during different cases.1. No VRS repeat operations in progress and the mobile user initiates a PTT.• Mic-Hi line audio is routed to the VRS and transmitted to the portable.
38• 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.• When the mobile mic PTT is released, the base-to-portable repeat will continue if the mobile is still receiving a base transmission.NOTE: If the VRS is in a non-priority state all portable transmissions will be heard on the mobile’s speaker. The above descriptions apply to a VRS unit in a priority state.Acknowledgment TonesVRS Mobile-TX Acknowledgment Tones (Conventional Only)When this option is enabled, the VRS transmits a 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 sounds. If the portable user does not hear a tone after completing a transmission, the portable is either out of range of the repeater or there is no priority repeater in the area.VRS Mobile Trunking Tones (Trunking Only)For trunked modes, the VRS regenerates the standard trunking access tones and transmits them to the portable. These tones, which are essentially the same as those heard at the mobile’s speaker, are accessed with the “quick-key” feature. For this operation, the portable user briefly (less than one second) presses the PTT button, and then listens for one of the following tones:•The “talk permit” tone (three short beeps) indicates to the portable user that the trunking system has granted a voice channel to the mobile and that keying the portable during the trunking system hangtime will result in acquiring this channel.•The “system busy” tone (a telephone-like busy tone) indicates that, at the time the portable user dekeyed, the trunking system had no voice channel available. If the user does not key the portable again after receiving a system busy signal, a “talk permit” tone will be transmitted to the portable as soon as a voice channel is available.
39•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.•The “trunking access good” tone (a single beep) indicates that a portable-to-base transmission has occurred and the mobile remained keyed for the entire transmission.•The “trunking access bad” tone (a single, low-pitched tone) indicates that all or part of the portable-to-base transmission was not repeated or was interrupted during the portable’s valid PL transmission. This would handle, for example, the case of the mobile’s TOT expiring or the case where a “system busy” is received first, and then a “talk permit,” so that only part of the transmission could be repeated. This tone can also indicate that the VRS has counted down in priority from a delay state of 2 or higher.•The “talk prohibit” tone (a long, low tone) indicates to the portable user that the mobile cannot access the trunking system.•The “system busy” tone (a telephone-like busy tone) indicates that, at the time the portable user dekeyed, the trunking system had no voice channel available. If the user does not key the portable again after receiving a system busy signal, a “talk permit” tone will be transmitted to the portable as soon as a voice channel is available.Message/Status Acknowledgment TonesThere are four different tones that the portable user can receive at the end of a message/status attempt:•Message/Status Acknowledged Good Tone—This tone is generated by the mobile when the message/status has been acknowledged by the base station. The VRS repeats the tone to the portable.•Message/Status Not Acknowledged Bad Tone—This tone is generated by the mobile when the message/status has been transmitted but was not acknowledged by the base station. The VRS repeats the tone to the portable.•Message/Status Not Supported Conventional Bad Tone—This tone is generated by the VRS when it receives a message from the mobile indicating that the message/status number selected is not a valid message or status while the mobile is on a conventional channel.•Message/Status Not Supported Trunking Bad Tone—This tone is generated by the VRS when it receives a message from the mobile indicating that the message/status number selected is not a valid message or status while the mobile is on a trunking channel.
40Non-Priority VRS RulesA 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. Upon subsequent reception of Single Tone bursts (that is, other VRS units activate in the same coverage area), the non-priority unit will increase delay states up to a maximum of 7. While in non-priority, the following occur:Portable-to-Base Non-Priority Operation1. Upon reception of a portable frequency RF signal with proper PL, the VRS will determine if the mobile of another VRS system is repeating the signal.2. For the prioritization routine to function, all of the mobiles with a VRS must be able to receive other mobile transmissions, either directly (TX=RX), or on a trunked system (TX≠RX), or through a base repeater (TX≠RX) in conventional modes with the <Base Repeater> feature enabled. For conventional non-repeater dispatch systems (TX≠RX), the Mobile Detector must be enabled for the prioritization routine to function properly.3. The VRS will determine if the mobile of another VRS system is repeating the portable signal by steering the mobile to the mode corresponding to the received PL. If, within one delay state (at least 600 ms for conventional, at least 900 ms for <Base Repeater>, and at least 1.5 seconds for trunking), the mobile in the non-priority VRS system does not receive the repeated signal, it will countdown from the current delay state.4. 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 4.2 seconds for conventional, 6.3 seconds for <Base Repeater>, and 10.5 seconds for trunking.5. If the VRS does detect another VRS system repeating within the delay state, it will stop the countdown process and stay non-priority.Base-to-Portable Non-Priority Operation1. Upon reception of a repeatable base signal, the non-priority VRS will monitor for a VRS-to-portable transmission from another VRS system (that is, a signal on the portable frequency without proper VRS access PL).2. If, within one delay state, the VRS does not receive the repeated signal, it will countdown from the current delay state.
413. 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 non-priority.5. If the VRS detects a portable frequency signal with proper PL while receiving a repeatable base signal, it will handle it according to the portable-to-base case.ICM Non-Priority OperationThe ICM feature will continue to operate as described in the “ICM Functions” section except for the following:1. While receiving a portable transmission with correct repeat qualifiers, the unit will not repeat as long as the unit is non-priority.2. During a portable-to-base transmission with correct PL, the non-priority VRS will steer the mobile to the mode programmed for that PL frequency. This allows the mobile to monitor for priority repeater traffic.EmergencyEmergency Feature SummaryAn emergency alarm is initiated when the VRS receives a portable transmission which contains the Emergency Alarm PL, as programmed in the mode-steering screen of CPS. Upon decoding the Emergency Alarm PL, the VRS sends an “enter emergency” bus message to the mobile radio. The mobile radio will respond as if the Emer button had been pressed on the control head, and will proceed with the Emergency operation which is programmed by the CPS.In addition, an “emergency acknowledgment” tone is transmitted by the priority VRS as part of the automatic multi-unit priority resolution algorithm. The “Emergency ACK” tone generated by the VRS is a 1250 Hz tone lasting 500 ms in duration. Once in Emergency Alarm, the VRS ignores subsequent portable transmissions with the Emergency Alarm PL until the mobile exits Emergency. (The “Emergency ACK” tone, however, will always be generated in response to each portable transmission with the proper Emergency Alarm PL).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.
42Emergency Feature OperationWhether 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 sequenceFor 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.• Mobile exhausts its retries without receiving an “Emergency ACK” from the base.• The mobile receives an “Emergency ACK” from the base.For 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 mic PTT or a portable-to-base repeat.2. The mobile will not unmute due to base traffic during silent alarm, and therefore the priority VRS will not attempt a base-to-portable repeat. If there are other, non priority VRS units in the area, they will perform the base-to-portable repeat without counting into priority.IMPORTANT NOTE: While in Emergency, attempts to send a message or status from the portable will be ignored and WILL NOT cause the mobile to exit Emergency.
43Hardware DetailedTheory of Operation 6The 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.The VRS750 software is embedded in the digital portion of the transceiver’s controller which consists of a microcontroller and associated EEPROM, RAM, and ROM memories.NOTE: This transceiver cannot be used as a stand-alone portable.Interface Board This board provide power regulation, bus translation circuitry, audio routing circuitry, Single Tone Encoder and Decoder circuitry, programming circuitry, and mode configuration.Power Regulation The VRS750 is powered by the mobile’s Radio_SWB+ (13.8 VDC) at the connector P102-22. L101 and C137 are used to filter alternator whine from this signal before providing it as SWB+ to the interface board. The VRS750 utilizes the mobile’s analog (P102-2, 10, 11, 21) and digital grounds (P102-18).U111 regulates the SWB+ down to +5 VDC. This voltage provides power for several switching transistors and voltage dividers on the VRS750 board. U118 i a micropower low dropout regulator used to provide +9.6 V for all of the analog audio circuitry. R162 and R164 form a divider network from this 9.6 V to produce the 4.8 V (VAG) used to bias the audio circuits. Finally, U129 is a three-terminal regulator used to provide the regulated 7.5V to the transceiver via Q113 in the reset circuit. SW7.5 V is provided to the transceiver at pad P31.Bus Translation CircuitryThe devices U100-2, U103, Q100, Q101, Q102, Q103, and Q104 are used to separate messages from the bi-directional SB9600 serial bus Bus+, Bus-, and Busy into and from the single direction RXD, TXD, BUSY OUT, and BUSY IN signals at the transceiver.The transceiver’s microcontroller can be reset by an external device by generating an active high reset pulse at pin P102-19, RADIO_RESET. This will cause Q109 to drive J30-5 low.
44Audio Routing CircuitryThere 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).The receive audio at EXT_SPKR+ is volume controlled. The transceiver monitors the mobile’s volume setting and then updates its volume accordingly. The audio is filtered by a 2-pole low pass filter, U107-1, which has a corner frequency of 3.2 kHz. T1, a 600-ohm to 600-ohm audio transformer, is used to isolate any ground noise such as alternator whine from the receive audio before being routed to the mobile at AUX_RX_AUD (P102-7). During portable-to-base transmissions the mobile routes this audio to its speaker.The receive audio at URX_SND is at a fixed level of 260 mVrms. It is attenuated through op amp circuit U104-3 to a level of 60 mVrms which can be adjusted via potentiometer R146. T2, a 600-ohm to 600-ohm audio transformer, is used to isolate this audio from any ground noise such as alternator whine before being routed to the mobile at TX_AUDIO, P102-8. During portable-to-base transmissions, the mobile routes TX_AUDIO to its transmitter.Base to Portable The MIC_FIL_SEL (J30-15) and TONES-MOBILE_AUD (J30-8) control signals are generated by the microcontroller and are used to control audio routing circuits, U101-1 and U101-3, for “Base to portable” activities.FIL_AUD (P102-6)—This audio path contains receive audio from the mobile during Base-to-portable transmissions. The receive audio passes through op amp circuit U104-1 and can be level adjusted via potentiometer R150. When a base-to-portable repeat occurs, TONES_MOBILE_AUD is in a low state and MIC_FIL_SEL is in a high state so that FIL_AUD is routed to the transmitter input (EXT_MIC, J30-19).In-Car-Monitor The MIC_FIL_SEL (J30-15) and TONES-MOBILE_AUD (J30-8) control signals are generated by the microcontroller and are used to control audio routing circuits, U101-1 and U101-3, for “In-Car-Monitor” activities.MOBILE_MIC_HI (P102-12)—This audio path contains microphone audio from the mobile during In-Car-Monitor (ICM) transmissions. The microphone audio passes through op amp circuit U104-4 and can be level adjusted via potentiometer R148. During an ICM transmission, both MIC_FIL_SEL line and TONES-MOBILE_AUD line are set to a Low state to configure both mux U101-3 and mux U101-1 to route the mobile mic audio to the transmitter input (EXT_MIC, J30-19).
45Single Tone Encoder The VRS750 Single Tone Encoder (U100-1, U124-3, U124-2, and U124-4) 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.When the VRS750 is in transmit mode for Single Tone, the microcontroller generates a square wave at a set frequency of 847.5Hz to the SNGL_TX_DATA (J30-6) pin. The control signal, TONES-MOBILE_AUD, is set to a High state to allow the Single Tone signal to be routed to the input of the Single Tone Filter. The Single Tone Filter is a band pass filter that allows frequencies between 300Hz and 1.7 kHz. U124-4, R126 and R127 are for gain adjustment. The resulting sine wave is then sent to the transceiver to be transmitted on EXT_MIC (J30-19).This circuit is also used when the transceiver generates various VRS750 acknowledgment tones.Single Tone Decoder The VRS750 Single Tone Decoder (U100-1, U124-3, U124-2, and U124-1) detects other Single Tone transmissions, then increments the priority counter.VRS_TX*_RX from the microprocessor is set to a High state when the VRS750 is in the Single Tone Decode mode (receive mode). When this signal is high, U101-2 allows receive audio (URX_SND, J30-11) to pass to buffer U100-1. The output of the buffer drives the low-pass filter that is also used in the encoder circuit. U124-1 and the associated diodes, D100 and D101, produce a square wave which is divided down to 3.3V by R172 and R173. This signal, SNGL_DET(J30-12), is then sampled by the microprocessor to determine if Single Tone is present.Boot Control CircuitryThe firmware for the VRS750 is stored in the transceiver’s Flash memory. This firmware can be programmed using the VRS750 Upgrade Tool (refer to “VRS750 Upgrade Kit,” Chapter 2). Prior to programming the firmware, the microprocessor must be placed into bootstrap mode.To place the microprocessor into bootstrap mode, it must be reset while the BOOT-CNTRL (J30-28) pin is grounded. This pin is grounded when the programming cable is connected and the flash adapter switch is turned to the “A” position.When the BOOT-CNTRL line is grounded, Q100 which controls U102 and U105, is opened and 9.6V passes through U102-2 to the base of Q112. Q113 opens and disconnects SW7.5 V from 7.5 V. At this point there is no supply voltage to the transceiver.Meanwhile, 9.6V is also applied to the base of Q112 thus charging up capacitor C182. After approximately 1.5 seconds, C182 is charged to a voltage that saturates Q111, causing Q112 to open and Q113 to turn
46On. 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.Program Sense The PROG_SENSE signal(J30-10) is monitored by the VRS to detect when the programming cable is connected at connector P101. This line will be pulled to ground when the programming cable is connected or will be 3.3VDC when the programming cable is not connected.The programming cable is used when adjusting the VRS using the Tuning Tool (refer to “VRS750 Global Tuner,” Chapter 2) or when updating the VRS firmware using the VRS750 Upgrade Kit (refer to “VRS750 Upgrade Kit,” Chapter 2).To prevent mobile bus messages from corrupting the codeplug programming and/or tuning of the transceiver, the control signal to U105-1 pin 10 is driven to ground.Mode Configuration There are various operating modes of the VRS750. The mode is selected at power-up based on the settings of dipswitch S1 pins 1, 2 and 3. Pin 4 is unused. Table 6 shows the supported modes:Normal mode is the default and standard configuration for the VRS750. The Test Mode configuration is used when the transceiver requires tuning. The VRS750 can be put into Test Mode by placing S1 Pins 1, 2, and 3 to the OFF position before system power-up. When this setting is detected by the VRS µP at power up, the following will occur:•VRS TEST is displayed momentarily on the control head.•Portable Priority Interrupt is disabled.•VRS TOT disabled.•TX PL disabled.Table 6. VRS750 Supported ModesOperating Mode S1 Pin 1 S1 Pin 2 S1 Pin 3Normal On On OnTest Mode Off Off OffATE Test Mode On Off OffProfessional CPS Mode Off On On
47To 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.
48Notes
49Maintenance andTroubleshooting 7The 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 ProceduresVRS Activation 1. Turn on the mobile radio control head. The radio should go through self-check and then display the home mode of the mobile radio.2. Possible error messages on power up are:• ERR 12/10—No VRS detected. See “Common Power-Up Problems” section on page 50 for possible solutions.• ERR 12/81—Flash EPROM failure. If re-flashing the unit does not fix this problem the transceiver should be replaced.• ERR 12/82—Codeplug checksum error. After verifying that both mobile and VRS have the correct software version, checking the mobile-to-VRS connection, and moving the cable away from any interference, reprogram the VRS750’s codeplug using the correct version of the CPS. If the codeplug cannot be corrected using CPS then the unit will need to have a new default codeplug written to the unit. Contact Customer Service for the default codeplug that corresponds to your model (see Table 7).Table 7. Default CodeplugsBand VRS750Model No.VRS750Back Cover Kit No.Internal Codeplug No.VHF P2080 PMLD4196 PMUD1479UHF R1 P2081 PMLE4242 PMUE1433UHF R2 P2082 PMLE4243 PMUE1476
50• 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.• PROG VRS—The VRS750 is in programming configuration. This is only an error if the programming cable is not plugged into the front connector of the VRS750. Reset the ASTRO Mobile radio and if the problem is not corrected check P101 Pin 9 and the PROG_SENSE line for any shorts to ground.3. Enable the VRS unit by pressing the VRS button on the mobile control head.•“VRS BOTH” must be displayed momentarily on the control head and the indicator must light.• Verify a short single tone burst is transmitted upon activation at approximately 3 KHz deviation for a channel spacing of 25 kHz.NOTE: Because of the short burst, it may be necessary to verify the deviation on the modulation scope instead of the usual deviation meter. Activation may be repeated by pressing the VRS button once to disable the unit and again to reactivate it.Common Power-Up Problems1. “ERR 12/10” message is displayed on power-up.• The VRS mobile interface cable is disconnected or bad.• Verify the VRS Firmware is correct. Immediately after power up press the HOME button on the control head five (5) times and verify the correct firmware version is displayed.• Check all regulators for proper voltages. The 9.6-volt regulator is accessible at TP116.CAUTION: Do not probe U118 pin1 when the unit is powered. U118 will shut down without any recovery if pins 1 and 2 are accidentally shorted to each other.2. “VRS BOTH” message does not display momentarily on control head when VRS is enabled.• VRS is receiving a VRS frequency signal. (VRS will not display “VRS BOTH” or transmit Single Tone if there is RF activity on the VRS frequency.)• Check the VRS750’s squelch setting.3. “VRS 001” message is displayed on power-up.• VRS Frequency Band in the VRS Personality of the ASTRO Mobile codeplug is incorrect.
51• Check the VRS750’s codeplug for incorrect programming.• Re-flash the VRS750 with new firmware using the VRS750 Upgrade Kit.Common Operational Problems1. 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• Check portable for correct receive frequency and PL.• Check mobile for correct frequency.• Check that portable is set for the bandwidth corresponding to the VRS.• Check VRS internal RF cable for loose connection.Disassembly & Reassembly ProceduresThe disassembly/reassembly procedure covers all VRS750 models.CAUTION: Refer to the “Safe Handling of CMOS Integrated-Circuit Devices” section at the beginning of this manual prior to disassembling the radio.Disassembly to Interface Board LevelRemove Front Housing 1. Disconnect the Programming Connector Cover by squeezing the top and bottom of the connector together, disengaging the bottom snap then the top and pulling straight out.2. Remove the gasket within the recessed area for the 18-pin programming connector.3. Insert a small flat-blade screwdriver or like instrument in the side groove at the interface between the remote front housing and the main chassis (see Figure 25). Press while pulling the housing away from the chassis until the snap releases. Repeat the operation on the opposite side.4. Pull front housing off the chassis.5. Remove white retainer (p/n 4205395X01) from the header (or front housing).6. Remove the 18 pin connector (2805347X01) from the front of the chassis.7. Remove the front cover gasket.
52Remove 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.Remove the Interface Board1. Remove the antenna connector retaining clip by inserting a small flat-blade screwdriver or like instrument between the clip and the top of the cavity wall as shown in Figure 27. Gently pry upwards.2. Remove the board screws with a T-10 Torx Driver.3. Carefully remove the interface board by rotating it out of the chassis. Slowly lift the board on the front edge while pushing up on the board through the accessory connector opening. Pull the board forward out of the chassis (see Figure 28).Figure 25. Removing the Front HousingDepress Snap HereSee Detail "A"Front HousingMain ChassisDetail "A"Figure 26. Removing the Top CoverDisengage Snap here and on other sideSee Detail ADisengage Snap hereDetail “A”
534. Retain the heat conductive insulator from under the regulator.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. Gently lift the clasps of the 20-pin and 40-pin flex connectors. Remove the 20-pin and 40-pin ends of the flex cable from the transceiver leaving the 30-pin end attached to the interface board.4. Loosen the screws for the two retainers holding the transceiver to the interface board. Slide one of the retainers away from the edge of the transceiver to free it.5. Remove the transceiver from within the two retainers.6. Detach the RF cable from the RF adapter plug. Unscrew the RF adapter plug from the transceiver.Figure 27. Removing the Antenna Connector Retaining ClipFigure 28. Removing the Interface BoardFrontPry Clip Off Here2) Pull board forward out of chassis1) Push up on board through accessory connector opening
54VRS750 Reassembly NOTE: Replace all gaskets at each servicing to ensure proper sealing of unit.Transceiver Reassembly 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. Tighten the four screws of the retainers. If needed, adjust the screws so that the transceiver lays flat against the interface board.5. Connect the 20-pin and 40-pin ends of the flex cable to the flex connector. Gently close the clasps on the connectors.6. Reattach the flex connector retainer, 4285168D01.7. Turn over the board.8. Connect the RF coax cable to the right-angle SMB connector on the interface board.Interface Board Reassembly1. Install a new gasket around the 25 pin connector and Antenna connector located on the board.2. Check that the foam seal is correctly positioned on the 25 pin connector on the bottom side of the board.3. Add the conductive insulator to the back of the regulator.4. Insert the main board carefully at an appropriate angle (approximately 30°) into the chassis. Start, but do not torque down, screw number 6 per Figure 29 and Table 8.5. Install the antenna retaining clip.6. Attach the nylon washer to the regulator at screw hole number 4 as indicated in Figure 29.7. Install the screws with 6-8 in-lbs of torque using a T-10 Torx driver per sequence shown in Figure 29 and Table 8.8. Place a new cover gasket around the chassis ensuring that it is placed under the locking tabs and ledge at the front of the chassis (see Figure 30). To ensure that the gasket remains seated along the groove, twist the gasket between fingers down and toward the chassis on both sides of the chassis.9. If chassis is being replaced, add the plastic insert and seal into the area at the back of the main chassis opposite the antenna connector.10. Install the top cover by engaging the hooks on front of the chassis and rotating the cover back. Ensure that the side snaps on the cover are engaged.11. Install the front cover gasket over the front of the chassis ensuring that the rectangular hole in the chassis aligns with the rectangular hole in the gasket. Press the gasket flush against the chassis to ensure proper sealing.
55Assembly of Front Cover to Main ChassisRefer to exploded views on page 88 for parts referenced in this procedure.1. Install the 18 pin connector into the female connector (mounted on the PC board) through the hole in the front of the chassis.2. Place white remote retainer (4205395X01) over the 18 pin connector.Figure 29. VRS750 Torque SequenceTable 8. VRS750 Torque SequenceStep No. Screw P/N Bit Torque Notes1 6 0310907A20 Torx T10 — Start Only2 — — — Place Antenna Conn.3 4-8 0310907A20 Torx T10 8 in-lb Number 6 Inclusive4 1-3 0310907A20 Torx T10 8 in-lbFigure 30. Cover Gasket Location42785316Cover gasketTwist o-ring
563. 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. If replacement of the transceiver is necessary, refer to the Disassembly & Reassembly section and the Tuning Procedure section.VRS Tuning and AlignmentThe VRS is tuned at the factory and should not need to be realigned. Refer to the proper manuals for programming and alignment for the associated portable radio and mobile unit before attempting to troubleshoot the VRS unit. If proper tuning of the associated radio fails to correct a problem, the following procedure may be used to align the VRS.SetupASTRO Spectra Station Cable SetupEnsure that the ASTRO Spectra B+ cable is disconnected from the power supply and the control head is off (WARNING: Never turn B+ power off with the control head still on.) Connect the VRS DB-25 cable (HKN6153A) into the accessory connector of the mobile. Connect the other end of the VRS cable to the VRS. Set the test station power supply to 13.8 Vdc and current limiter to 12 amps. Connect the mobile’s B+ cable to the power supply (see Figure 31).Tuning ProcedureInterface BoardTuning Procedure1. Place the VRS in the test mode:a. Turn off the mobile radio control head.b. Place the VRS into Test Mode by setting dipswitch S1 pins 1, 2, 3, and 4 to OFF.c. Turn on the mobile control head and re-enable the VRS.d. While in Test Mode, the VRS will not have portable priority interrupt and will not transmit PL with VRS-to-portable transmissions.e. Figure 32 illustrates the relative placement of the tuning potentiometers.2. Adjust the VRS Deviation Level:a. Set the Mobile Communications Analyzer RF output to-50 dBm, with a standard test modulation (1 kHz tone, 3 kHz deviation).
57Figure 31. General Cabling DiagramFigure 32. Tuning PotentiometersMobileCommunicationAnalyzer DC Supply+-ASTRO Spectra MobileW7 Control HeadSpeakerMobileMicrophoneHKN6153AVRS750VRSCommunicationAnalyzer42785316R150R148 R146
58b. 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. (Refer to the ASTRO Spectra Mobile service manual for specialized equipment.)c. Adjust the signal level of the 1 kHz tone until 3.0 kHz deviation is obtained on the Mobile Communications Analyzer.d. Adjust R148 on the VRS board until 3.0 kHz deviation is obtained on the VRS Communications Analyzer.e. Dekey the mobile microphone.4. Adjust the Mobile Deviation Level:NOTE: Set the VRS Communications Analyzer RF output to-50 dBm with a standard test modulation (1 kHz tone, 3 kHz deviation) and any receive PL for which the VRS is programmed (750 Hz deviation). If the receive PL for “select mode” is not used, the Mobile Communications Analyzer frequency may need to be adjusted.a. Set the Mobile Communications Analyzer frequency to the current mobile mode.b. Switch on the VRS Communications Analyzer RF.c. Adjust R146 on the VRS board until 3.00 kHz deviation is obtained on the Mobile Communications Analyzer.d. Switch off the VRS Communications Analyzer RF.5. Check the VRS RF Sensitivity:a. Set the VRS Communications Analyzer RF output to -115 dBm with a standard test modulation (1 kHz tone, 3 kHz deviation) and any receive PL for which the VRS is programmed (750 Hz deviation).NOTE: If the receive PL for “select mode” is not used, the Mobile Communications Analyzer frequency may need to be adjusted.b. Switch on the VRS Communications Analyzer RF. The unit should not retransmit this signal to the Mobile Communications Analyzer.c. Slowly increase the input signal. The unit should begin repeating to the Mobile Communications Analyzer at no more than -104 dBm.
59d. 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 ProcedureThe transceiver board can be tuned using the Global Tuner when the VRS750 is in ATE Test Mode. Connect the VRS750 to the test box (RLN6394A) instead of the ASTRO Spectra mobile using the VRS750 ATE Cable (3080384N02) as shown in Figure 33. Before applying power, set dipswitch S1 pin 1 to ON and pins 2, 3, and 4 to OFF. This configures the VRS750 for ATE Test Mode. Make the appropriate connections to the VRS750 test box for power and audio. Once this is complete the VRS750 can be tested and tuned using the Global Tuner.Front End Filter Tuning NOTE: Tuning is normally not required for VHF radios. It should only be performed if a radio has poor sensitivity. VHF radios are only tuned at one softpot frequency (F3: The values for the untuned frequencies are determined by adding the offset, calculated by subtracting the default softpot value for frequency F3 from the tuned softpot value for frequency F3. The default softpot values are listed in Table 9.)Figure 33. ATE Test Mode ConfigurationVRS750VRS750TEST BOX(RLN5394A)VRS750PROG. CABLERX AUDIOAND EXT MICCONNECTORSSRIBDC SUPPLYVRS750 ATE CABLE(3080384N02)CONNECT TO THE PCsCOM PORT
60Under 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. Measure the RSSI voltage with a DC voltmeter capable of 1 mV resolution at test point 111 on the VRS750. It is recommended that an RCA filter (1.5 K-47 uF) be added at the input of the voltmeter to reduce RSSI noise.3. Increment the softpot value by adjusting the slider, keying in the softpot values in the edit box (press ENTER to confirm selection) or using the spin control until the maximum RSSI voltage has been achieved.4. For UHF and VHF radios:a. UHF radios: Choose the next frequency and repeat steps 1 to 3 until all seven tuning points are done.b. VHF radios: Calculate the softpot offset by subtracting the default softpot value for F3 from the tuned softpot value for F3. Add the calculated offset to all default values and enter the results in the edit boxes for the appropriate softpot frequencies.5. Press Program to commit the softpot values into the codeplug.Table 9. Default Softpot Values for VHF and UHFFrequency PointSoftpot Value (Decimal)VHF UHFF1 36 38F2 57 48F3 84 79F4 124 110F5 166 135F6 195 161F7 225 186
61Rated Volume Tuning 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. Adjust the softpot value by using the slider, keying in the edit box (press ENTER to confirm selection/send a softpot value), or via the spin controls. Repeat this until a 1.58 Vrms ±200 mVrms signal can be obtained at the positive terminal of C189.3. Press Program to commit the softpot value into the codeplug.Reference Oscillator WarpNOTE: Perform this operation prior to all other transmit tuning operations in order to minimize heating and because of the impact of warp on signaling operations.1. Under Tx Align menu, select Reference Oscillator Warp.2. There is only 1 frequency point shown which is always the last non 0 transmit frequency point, which will normally be F7.3. Click on the slider thumb. Press PTT Toggle to key up the radio at the corresponding frequency point.4. Monitor the transmit frequency.5. Adjust the slider, spin or edit control (press ENTER to confirm selection/send a softpot value) until the frequency is as close as possible to the indicated transmit frequency (refer to Table 11).6. Dekey the radio by pressing PTT Toggle.Table 10. VRS750 Deviation LevelsChannel Spacing (kHz)Rated System Deviation (kHz)Signal Generator Deviation (kHz)12.5 2.5 1.520 4.0 2.420 5.0 3.025 5.0 3.030 5.0 3.0Table 11. Frequency Error SpecificationsRF Band Target (Hz)VHF (136-174) ±200UHF Band 1 (403-470) ±200UHF Band 2 (450-527) ±200
627. Program the warp value into the radio by pressing the Program button.8. Exit the Reference Oscillator Warp function.VCO Attenuation 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 12.5 kHz and 20 kHz channel spacing determines only the offset to the previously tuned deviation for 25 kHz tuning channel spacing. For (12.5, 20 kHz) channel spacing, only the last non 0 transmit frequency point (normally F7) will be used for tuning.VCO Attn. 25 kHz 1. Under the Tx Align menu, select VCO Attn. 25 kHz.2. Begin with the lowest frequency. Select the thumb of the slider at the lowest frequency point and then press the PTT Toggle button to key up the radio at the corresponding frequency point. The spin control can also be toggled via its up/down arrow buttons. The softpot value can also be typed into the edit control (press ENTER to confirm selection/send a softpot value).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. Adjust the slider, adjust the spin control or key in softpot values (press ENTER to confirm) for the frequency point until the deviation is within range as defined in Table 12.6. Dekey radio (press the PTT Toggle button). Choose the next frequency, key up and repeat steps 3 to 6 until all seven tuning points are done.7. Program the softpot value by pressing the Program button.8. Exit the VCO Attn. 25 kHz function.VCO Attn. 20 kHz NOTE: Tuning of Modulation Balance Attn. and VCO Attn. for 25 kHz channel spacing must be done first.1. Under the Tx Align menu, select VCO Attn. 20 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. Adjust the slider, adjust the spin control or key in softpot values (press ENTER to confirm) for the frequency point until the deviation is within range as defined in Table 12.6. Press PTT Toggle to dekey the radio.7. Program the softpot value by pressing the Program button.
638. 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. Adjust the slider, adjust the spin control or key in softpot values (press ENTER to confirm) for the frequency point until the deviation is within range as defined in Table 12.6. Press PTT Toggle to dekey the radio.7. Program the softpot value by pressing the Program button.8. Exit the VCO Attn. 12.5 kHz function.PA Bias Tuning UHF/VHF VRS750s (Procedure 1)IMPORTANT NOTE: Tuning must be performed for both High and Low power for UHF and VHF radios. Take note that Procedure 1 IS NOT TO BE PERFORMED for UHF low power level tuning. Please refer to Procedure 2.1. Ensure that the radio’s antenna output is terminated to a 50 Ohm load. This is to prevent self destruction of the PA.2. Under Tx Align, select PA Bias, select High Power.3. Measure/read the dc current drawn from radio (specifications will vary from radio to radio). Call this X. This value should typically range from 70-100 mA or 0.07-0.1 A.4. Press Toggle Voltage to enable the PA control voltage edit box/spin control.5. Increase the Voltage softpot value and measure/read from current meter. Call the new value Y.6. Increase Y until Y-X is within the range given for PA current in Table 13.7. Press Toggle Voltage again to disable the PA control voltage edit box/spin control.Table 12. Deviation Specifications for VRS750 UHF/VHF RadiosBand Channel Spacing (kHz) Deviation (kHz)UHF/VHF 12.5 2.20-2.30UHF/VHF 20 3.40-3.60UHF/VHF 25 4.40-4.60
648. 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. Exit the PA Bias Low Power function.PA Bias Tuning for UHF Low Power VRS750s (Procedure 2)NOTE: Failure in the instructions below means that you cannot get a reading which is within the range of the current window as specified in Table 14 for each individual step.Ensure that the radio’s antenna output is terminated to a 50 Ohm load. This is to prevent self destruction of the PA.STEP 1 1. Under Tx Align, select PA Bias, select Low Power.2. Measure/read the dc current drawn from radio (specifications will vary from radio to radio). Call this X. This value should typically range from 70-100 mA or 0.07-0.1 A.3. Press Toggle Voltage to enable the PA control voltage edit box/spin control.4. Increase the Voltage softpot value and measure/read from current meter. Call the new value Y.5. Increase Y until Y-X is within the range given for PA current in Table 14 (STEP 1) below.****** If a failure occurs, go to STEP 2 otherwise proceed6. Press Toggle Voltage again to disable the PA control voltage edit box/spin control.7. Press Toggle Bias in order to enable the PA Bias softpot.8. Increase the softpot value to obtain Z until Z-Y is within the range for Bias Current as indicated in Table 14 (STEP 1).Table 13. PA Bias High Power Specifications UHF/VHF VRS750sRF Band PA Current (mA) Bias Current (mA)VHF 90-110 90-110UHF Band 1 30-45 600-700UHF Band 2 30-55 400-480
65****** If a failure occurs, go to STEP 3 otherwise proceed9. 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. Increase the softpot value to obtain Z until Z-Y is within the range for Bias Current as indicated in Table 14 (STEP 2).****** If a failure occurs, go to STEP 3 otherwise proceed5. Press Toggle Bias again to disable the PA Bias softpot.6. Program the Bias softpot into the radio’s codeplug via pressing Program.7. Exit the PA Bias Low Power function.STEP 3 1. Press Toggle Bias twice to reset the softpot value.2. Press Toggle Bias again to disable the PA Bias softpot.3. Measure/read the dc current drawn from radio (specifications will vary from radio to radio). Call this X. This value should typically range from 70-100 mA or 0.07-0.1 A.4. Press Toggle Voltage to enable the PA control voltage edit box/spin control.5. Increase the Voltage softpot value and measure/read from current meter. Call the new value Y.6. Increase Y until Y-X is within the range given for PA current in Table 14 (STEP 3).7. Press Toggle Voltage again to disable the PA control voltage edit box/spin control.8. Press Toggle Bias 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 14 (STEP 3).Table 14. PA Bias Low Power Specification for VRS750s (UHF Only)Step PA Current (mA) Bias Current (mA)STEP 1 20-30 630-750STEP 2 30-45 750-900STEP 3 40-55 600-750
6610. 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).
67Troubleshooting Charts 8Introduction to this SectionThis 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.List of Troubleshooting ChartsChart Number DescriptionPage Number1 VRS Enable Failure 682 Error 12/10 693 Error 12/81 694 Error 12/82, Codeplug Checksum Error* 695 Error 12/84, Configuration Register Corruption* 696 Error 12/88, HC11 RAM Failure 697 VRS 001, VRS Synthesizer Lock Failure 708 Single Tone Encode Failure 719 Single Tone Failure 7210 Base-to-Portable Repeat Failure 7311 Portable-to-Base Repeat Failure 7412 VRS ICM Audio Failure 7513 Serial Bus Failure 7614 Portable Audio at Local Speaker Issue 7715 Programming/Tuning Failure 78*Older VRS-EP versions may show a 12/82 Error flashing every 5 seconds for Codeplug Checksum Error, and a 12/82 Error at power-up only for Configuration Register Corruption.
68Chart 1—VRS Enable FeatureVRS ENABLE FAILUREYe sNoYe sNoYe sYe sNoYe sNoYe sNoNoSTARTIs VRSbutton enabled inthe mobilecodeplug?Is mobilecodeplug programmedfor VRS VIP?Is the mobilecodeplug programmedfor VRS VIP?Program mobile codeplug forVRS button operation.Is"VRS BOTH"message displayed onbutton press?VRS is now enabled.Reset system and start over. If CSQ is being detected theVRS will not enable.Isthe mobilecodeplug programmed forVRS VIP activestate?Program mobile codeplug forVRS VIP.Is switch incorrect VIP?Program mobile codeplug forproper VRS VIP active state.Check VRS VIP switchinput.Move switch or reprogrammobile codeplug.
69Chart 2—Error 12/10Ye sNoYe sNoYe sNoSTARTIs the VRSmobile interface cableconnected?Are theregulated voltagespresent?Reconnect thecable.Is theVRS750 firmwarecorrect?Troubleshoot theregulator circuit.Check thetransceiver board.Flash the VRS750with the correctfirmware.ERROR 12/10Chart 3—Error 12/81STARTReprogram theFlash Memory.ERROR 12/81Chart4—Error 12/82, Codeplug Checksum ErrorSTARTReprogram theVRS750 Codeplug.ERROR 12/82Chart 5—Error 12/84, Configuration Register CorruptionYe sNoSTARTReflash the VRS750with the correctversion firmware.Reset the system.Is the12/84 error stilldisplayed?Replace thetransceiver board.Problem iscorrected.ERROR 12/84Chart 6—Error 12/88, HC11RAM FailureReplacethe transceiver.Error12/88ERROR 12/88
70Chart 7—VRS 001, VRS Synthesizer Lock FailureVRS 001 FAILUREYe sNoDoes theFreq. Band field inASTRO CPS match the freq. Bandof the VRS750 attached tothe mobile?Replace thetransceiver board.Correct the freq. bandfield for the VRS750 inthe ASTRO mobilecodeplug.START
71Chart 8—Single Tone Encode FailureNoNoNoYe sNoYe sNoYe sNoIs therecontinuity betweenJ30-19 and J20-7 on theflex cable?Check and/orreplace C104.Replace thetransceiver.Replace the flexcable.Replace thetransceiver.Replace the flexcable.STARTSINGLE TONE ENCODE FAILUREYe sYe sYe sIs3.3VDC square waveat R114 during SingleTone burst?Is80mVpp sinewaveat TP104?Isthere continuitybetween J30-6 andJ40-21 on the flexcable?Is thesinewave present atTP101?Check and/orreplace U100,U124.Isthe sinewavepresent at the negativeterminal of C104?Verify that pin 10 of U101 is0VDC during the SingleToneburst. Check U101 andQ106.
72Chart 9—Single Tone FailureYe sNoYe sNoYe sNoSTARTVerify that the VRS750dip switches are set tonormal operation.DoesTP105 pulse ~5VDCwhen the volume buttonis pressed?Does J30-21pulse to ~0VDC whenthe volume button ispressed?Check the mobileto VRS cable.Is therecontinuity betweenJ30-21 and J20-9 on theflex cable?Check and/orreplace U103 andQ103.Check and/orreplace thetransceiver.Replace the flexcable.Verify that J30-20(boot control) is~3.3VDC.SINGLE TONE FAILURE
73Chart 10—Base-to-Portable Repeat FailureYe s NoYe sNoYe s NoYe sNoYe sNoYe sNoYe sNoYe sNoYe sNoYe sNoYe sNoSTARTVerify that the VRS750dip switches are set tonormal operation.Activate theVRS750.Is "VRSBOTH" displayedbriefly?Provide anon-channel RFsignal to the mobile.The VRS750 is notenabled and audiowill not be heard.Isaudio present atC135?Is audiopresent @ U101 pin5?Chekc mobile andits connection tothe VRS.Is audiopresent @ U101 pin4?Check U104.Adjust R150 ifnecessary.Isaudio present @TP101?Verify that thelocal mic is notpressed.Isaudio present@ J30-19?Is pin 10of U101 HIGH-9.6VDC?Isthere continuitybetween J30-19 andJ20-7 of the flexcable?Replace thetransceiver. Replace U101.Isthere continuitybetween J30-8 andJ40-23 on the flexcable?Is pin9 of U101 low(0VDC)?Repair/replaceU101.Isthere continuitybetween J30-15 andJ40-23 on the flexcable?Replace thetransceiver.Replace the flexcable.Check and/orreplace Q106.Replace the flexcable.Repair/replaceQ114.Replace the flexcable.BASE TO PORT. AUDIO ISSUES
74Chart 11—Portable-to-Base Repeat FailurePORTABLE-TO-BASE AUDIO ISSUEYe sYe sYe sNoYe sYe sYe sNoNoNoNoYe sNoNoVerify dip switchesare set to normaloperation.Is the1kHz tone present @J30-11?Is the1kHz tone present atTP102?Replacetransceiver.Isaudio present @TP125?Check U104 andreplace ifnecessary.Is mobiletransmit deviation3kHz?Check solder connextionsfor C132, C133, and T2.Replace if necessary.Complete.Adjust R146 to obtain3kHz deviation frommobile.Activate theVRS750.Is "VRSBOTH" displayedbriefly?Provide an on channel RFsignal with an Access orMode Steering PL to theVRS750.The VRS750 is notenabled and willnot repeat.Isaudio present @TP128?Isthere continuitybetween J30-11 andJ40-28 on the flexcable?Replace thetransceiver.Replace the flexcable.
75Chart 12—VRS ICM Audio FailureIN-CAR-MONITOR AUDIO ISSUESYe sYe sYe sYe sYe sYe sNoYe sNoYe sYe sNoNoNoNoNoNoYe s NoVerify that the VRS750dip switches are setfor normal operation.PTT the mobile's localmic and talk into it.Isaudio present atC134?Refer to theBase-to-Portabletroubleshooting chart.Is audiopresent @ pin 3 ofU101.?Check the mobileand its micconnections. Check U104 andadjust R148 ifnecessary.Check and/orreplace U101. Check and/orreplace Q114.Activate theVRS750.Is "VRSBOTH" displayedbriefly?DuringBase-to-Portablecommunications, is audio heard@ the portable?Check C185 and C166 tomake sure they have notbeen shorted to ground.Verify that theMOBILE_MIC_HI line inthe mobile to VRS is ok.Is audiopresent @ pin 1 ofU101?Is audiopresent @ pin 15 orU101?Is pin 9 ofU101 a logic HIGH -9.6VDC.?Is pin 10of U101 a logic HIGH -9.6VDC.?Check and/orreplace U101.Check and/orreplace Q106.Isaudio present @J30-19?Isthere continuitybetween J30-19 andJ20-7 of the flexcable?Check and/orreplace C104.Replace thetransceiver.Replace the flexcable.
76Chart 13—Serial Bus FailureYe sNoYe sNoYe sNoSTARTVerify that the VRS750dip switches are set tonormal operation.DoesTP105 pulse ~5VDCwhen the volume buttonis pressed?Does J30-21pulse to ~0VDC whenthe volume button ispressed?Check the mobileto VRS cable.Is therecontinuity betweenJ30-21 and J20-9 on theflex cable?Check and/orreplace U103 andQ103.Check and/orreplace thetransceiver.Replace the flexcable.Verify that J30-20(boot control) is~3.3VDC.SERIAL BUS FAILURE
77PORTABLE AUDIO AT LOCAL SPEAKER ISSUEYe sYe sYe sYe sNoNoNoNoYe sNoIsaudio present @EXT_SPKR+ J30-17?Isaudio present atC183?Isthere continuitybetween J30-17 andJ20-4 on the flexcable?Verify that the VRS750dip switch settings areset to normal operation.Isaudio present atTP108? Repair and/orreplace U107.Adjust mobile volumeon controlhead to level7.Check solderconnections for C183,C103, and T1.Activate theVRS750.Is "VRSBOTH" displayedbriefly?Provide an on-channel RFsignal with the properAccess or Mode SteeringPL to the VRS750.The VRS750 is notenabled and audiowill not be heard.STARTReplace thetransceiver.Replace the flexcable.Chart 14—Portable Audio at Local Speaker Issue
78Chart 15—Programming/Tuning FailureATE Test NormalYe sYe sYe sNoNoNoNoYe sYe sYe sYe sNoYe s NoNoNoNoYe sNoYe sStartIsthe VRS750 in ATETest or Normal Mode?Is 13.8Vsupplied to the testbox?Is the mobile radiopowered on?Is the SRIBconnected to the computerand powered on?Plug the 25 pin connectorinto the SRIB and the 18pin connector into theVRS750.Is theFlashing Adapter beingused?Connect the SRIB to theserial port of thecomputer using a nullmodem cable and makesure it is turned on.Verify that P101-7 isconnected to J30-24.Is the SRIBconnected to the computerand powered on?Disconnect theprogramming cable fromthe VRS750.Didthe mobile radioreset?Plug theprogramming cableback in to theVRS750 and tryagain.Reset the mobileradio.Plug the programmingcable back in to theVRS750.Is "PROGVRS" displayed on the mobilecontrol head?Tr yprogrammingagain.A.Connect the SRIB to theserial port of thecomputer using a nullmodem cable and makesure it is turned on.Verify that themobile ispowered on. Ifnot, power themobile on andstart over.A.Isthe VRS750programming cablesecurely plugged into theVRS750 and anSRIB?Supply 13.8V to theVRS750 test box.Is"PROG VRS"displayed on the mobilecontrol head?Power on themobile radio.Is theswitch in the Bposition?Remove the flashingadapter and cyclepower to the VRS750.Place the switch in the Bposition and cycle power tothe VRS750. The A positionis for flashing only.Cycle power to the VRS750and try again. If the problempersists, try a differentprogramming cable.PROGRAMMING ANDTUNING ISSUES
79Chart 15—Programming/Tuning Failure (Cont.)Ye sNoYe sNoYe sNoYe sNoIsthe switch in the Bposition?Is there a 18 pinextension in the connector,2805347X01, on the front of theVRS750?Remove the FlashingAdapter and reset themobile. The Flashingadapter could be bad.Place the switch in the Bposition and reset themobile.Is thecathode ofVR121 grounded whenplugged into theSRIB?Replace theheader block.Verify that P101-7 isconnected to J30-24.Replace theprogramming cable.Is theFlashing Adapterbeing used?A.PROGRAMMING ANDTUNING ISSUES (CONT.)
80Notes
81Diagrams and Parts Lists 9Introduction to this SectionThis section contains schematics, a component layout diagram, an exploded view, and electrical and exploded view parts lists.List of Diagrams and Parts Lists DescriptionPage NumberPrinted Circuit Board Electrical Parts List 83Printed Circuit Board Component Location Diagram 84-85Printed Circuit Board Schematic Diagram 86-87Exploded View and Exploded View Parts List 88VRS-to-Mobile Cable 89VRS-to-Siren Cable 89VRS750 Programming Cable 90VRS750 Programming Cable Schematic Diagram 90VRS750 Flashing Adapter Schematic Diagram 90
82Notes
83 VRS750 Vehicular Repeater SystemPrinted Circuit Board Electrical Parts List(PLN7780A) Notes: 1. For optimum performance, order replacement diodes, transistors, and circuit modules by Motorola part number only.2. When ordering crystals, specify carrier frequency, crystal frequency, crystal type number, and Motorola part number.3. Part value notations:p=10 -12 µ=10 -6 k=10 3 n=10 -9 m=10 -3 M=10 6 ITEM MOTOROLAPART NUMBER DESCRIPTIONCAPACITOR, Fixed; pF: unless otherwise statedC100 2113740F59 220C101 2113740F39 33C102 2113740F59 220C103, 104 2311049A08 Polar, 1 µFC105 2113741B69 0.1 µFC107 2113740F59 220C108 2113741B69 0.1 µFC109 2113740F59 220C111, 112 2113740F59 220C113 2113741F33 2200C114 thru 116 2113741A45 .01 µFC117 2113741A49 .015 µFC118 2113740A79 1000C119 2113743B21 0.22 µFC120 2113741B69 0.1 µFC121 2113740B49 100C122 thru 131 2113740F59 220C132, 133 2311049A08 Polar, 1 µFC134, 135 2113743E20 0.1 µFC136 2113740F59 220C137 2380090M40 Polar, 2200 µFC138, 139 2113740F59 220C140 2113743E20 0.1 µFC141 2113741A45 .01 µFC142 2113740F59 220C143 2113741B69 0.1 µFC145 2113740A79 1000C146, 147 2113740F59 220C148 2311049A08 Polar, 1 µFC149 2311049A19 Polar, 10 µFC150 2113740F59 220C151 2311049A19 Polar, 10 µFC152 2113740F59 220C153 2311049A19 Polar, 10 µFC154 2113740F59 220C155 2311049A19 Polar, 10 µFC156 2380090M25 Polar, 100 µFC157 thru 161 2113740F59 220C162 2380090M25 Polar, 100 µFC164 thru 167 2113740F59 220C168 2113743E20 0.1 µFC170 2113740F59 220C171 2113743E20 0.1 µFC172, 173 2113740F59 220C175 2113740F59 220C179 2113740F59 220C180 2113740A79 1000C182 2311049A19 Polar, 10 µFC183 2311049A08 Polar, 1 µFC184 2113740F59 220C185 2113743A13 0.047 µFC188 2113740F59 220C189 2311049A08 Polar, 1 µFC190 2113741F21 680C191 2113740F59 220C194 2113740A79 1000C195 2113740F59 220C196 2113743E20 0.1 µFC197 2113740F59 220C198 2113743E20 0.1 µFC199 2113740F59 220C200 2113743E20 0.1 µFC201 thru 208 2113740F59 220 DIODE: See Note 1D100, 101 4813825A08 MBD701D102 4813832C77 Transient supressor, 24 V FUSE: F100 6580542Z01 3 A JACK: J30 0985173D01 Connector, 30 pin flex COIL, RF: L101 2505462S03 Inductor, 1000 µH PLUG: P101 0905904V02 Connector, JP102 2805429W03 Connector, P TRANSISTOR: See Note 1Q100, 101 4880141L02 NPNQ102 4813824A17 PNPQ103 4880141L02 NPNQ104 4813824A17 PNPQ106 4880141L02 NPNQ109 thru 112 4880141L02 NPNQ113 4813821A21 nchan_tmosfet_gsdQ114, 115 4880141L02 NPN RESISTOR: Ohms ±5%; 1/8 W unless otherwise statedR101 0662057A93 68 kR102 0662057A73 10 kR104, 105 0662057A25 100R106 0662057A65 4.7 kR107 0662057A69 6.8 kR108 0662057A93 68 kR109 0662057A97 100 kR110 0662057A77 15 kR111 0662057A83 27 kR112, 113 0662057A97 100 kR114 0662057B10 330 kR115 0662057A94 75 kR116 0662057A84 30 kR117, 118 0662057A65 4.7 kR119 0662057A69 6.8 kR120, 121 0662057A73 10 kR122, 123 0662057A83 27 kR124 0662057A73 10 kR125 0662057A91 56 kR126 0662057A77 15 kR127 0662057A73 10 kR128 0662057P95 100 k, 1%R129 0662057P27 27.4 k, 1%R130 0662057P22 22.1 k, 1%R131 0662057P95 100 k, 1%R132, 133 0662057A65 4.7 kR136, 137 0662057A73 10 kR138 0662057A65 4.7 kR139 0662057A49 1 kR140, 141 0662057A65 4.7 kR142 0662057A49 1 kR143 0662057A65 4.7 kR145 0662057A89 47 kR146 1813905A11 Pot, 20 kR147 0662057A65 4.7 kR148 1813905A11 Pot, 20 kR149 0662057A91 56 kR150 1813905A11 Pot, 20 kR151 0662057A97 100 kR155 0662057A73 10 kR156 0662057A49 1 kR157 0662057A77 15 kR158 0662057A38 360R159 0662057A55 1.8 kR160 0662057A77 15 kR161 0662057A47 820R162 thru 164 0662057A73 10 k ITEM MOTOROLAPART NUMBER DESCRIPTION R165 0662057A56 2 kR166 0662057A65 4.7 kR171 0662057T64 47.5 k 1%R172, 173 0662057A73 10 kR174 0662057P27 27.4 k, 1%R175 0662057A73 10 kR180, 181 0662057A65 4.7 kR182 0662057A49 1 kR183 0662057A73 10 kR184 0662057A65 4.7 kR200 0662057A65 4.7 kR210 0662057A49 1 kR211, 212 0662057A73 10 kR213' 0662057A65 4.7 kR215 0662057A83 27 kR216 0662057B26 1.5 MR217 0662057A49 1 kR220 0662057B47 0R221 0662057A81 22 kR224 0662057A97 100 kR225 0662057A73 10 kR226, 227 0662057A65 4.7 kR228, 229 0662057A73 10 k SWITCH: S1 4080564C02 Dip TRANSFORMER: T1, T2 2584422T02 6-pin INTEGRATED CIRCUIT MODULE: See Note 1U100 5113818A03 MC33072-1U101, 102 5184704M60 MC14053BU103 5113806A37 MC14106U104 5113819A04 MC3303U105 5184704M60 MC14053BU107 5113818A03 MC33072-1U111 5113816A03 MC78L05AU118 5105109Z13 LT1129U124 5113819A04 MC3303U129 5105469E18 LM317T DIODE: See Note 1VR102 thru 109 4805129M35 Zener, 13, 5.6 VVR110 4813830A28 Zener, 13, 15 VVR112, 113 4805129M35 Zener, 13, 5.6 VVR115 4813830A28 Zener, 13, 15 VVR118 4805129M35 Zener, 13, 5.6 VVR121 4805129M35 Zener, 13, 5.6 VVR123 4805129M35 Zener, 13, 5.6 V CONNECTOR: W101 0984345R02 SMB Jack Rt. Ang PCBW102 0905901V10 J, Antenna Connector MISCELLANEOUS: 8485176D01 Board, PC0200835638 Nut0300114832 Screw ITEM MOTOROLAPART NUMBER DESCRIPTION VRS750 Vehicular Repeater SystemPrinted Circuit Board Electrical Parts List (PLN7780A)
84C100C101C102C104C105C107C108C109C111C112C113C114C115C116C117C118C119C120C121C122C123C124C125C126C127C128C129 C130C131C134C135C136C138C139C140C141C142C143C145C146C147C148C149 C150C151C152C153C154 C155C158C160C161C164C165C166C167C168C170C171C172C173C175C179C180C182C184C185C188C189C190C191C194C197C198C199C200C201C202C203C204C205C206C207C208D100 D101D102F10030J30BECQ100BECQ101BECQ102BECQ103BECQ104BECQ106BECQ109BECQ110BECQ111BECQ112Q113BECQ114BECQ115R101R102R104R105R106R107R108R109R110R111R112R113R114R115R116R117R118R119R120R121R122R123R124R125R126 R127R128R129R130 R131R132R133R136R137R138R139R140R141R142R143R145R146R147R148R149R150R151R155R156R157R158R159R160R161R162R163R164R165R166R171R172R173R174R175R180R181R182R183R184R200R210R211R212R213R215R216R217R220R221R224R225R226R227R228R229S1TP101TP102TP103TP104TP105TP106TP107TP108TP109TP110TP111TP112TP113TP114TP116TP117TP118TP119TP120TP121TP122TP123TP124TP125TP126TP127TP128458U1008916U1018916U1027814U1037814U1048916U105458U10715U1187814U124U129VR102VR103VR104VR105VR106VR107VR108VR109VR110VR112VR113VR115VR118VR121VR123 VRS750 Vehicular Repeater SystemPrinted Circuit Board Component Location Diagram (Sheet 1 of 2)
85W1028485176D01 REV AC103C132C133C137C156C157C159C162C183C195C196L101P31P32P3318109P10125 1413P1021346T11346T2458U111W101 VRS750 Vehicular Repeater SystemPrinted Circuit Board Component Location Diagram (Sheet 2 of 2)
86(J20-16)URX_SND(J20-1)*(J20-15)(J40-29)(J40-24)(J20-4)(J20-12)(J40-28)(J40-20)(J40-2)EXT_MIC(J40-22)(J20-10)(J20-13)(J20-19)(J20-20)(J20-9)(J20-14)(J20-8)(J40-21)(J20-7)(J40-1)(J40-25)(J20-11)(J40-13)(J40-23)DNP.015uFC11731U124-1MC33032J30 209.6VC1041uF27K5.6VVR112R122J30 5231C1190.22uF33pFU100-1MC330721000pFC145C101220pFC205C204220pF220pFC203220pFC202220pFC206U124-2MC33036571KR217J30 212J304.7KR16610KR102220pF VR1235.6VP102-17C207P102-16R1184.7KR1711%J30 1727KR11147.5KT113456P101-9R114330KJ30 1J30 6R175VAG10KC188220pFTP112R1174.7KR13710K25J30J30 45V5.6VVR12110KR225MMBT3904Q1035.6VVR1028R22001000pFU124-3MC330391016C118MMBT3904Q112J3081TP11028S1J30C146220pFQ111MMBT39041000pFC1801uFC189TP111C165220pFC111220pF220pFC109C113R1232200pF27KMC33072U107-1231R21210KJ30 24MMBT3904Q110TP113220pFC10215KR1105.6VVR113R113100K22KR22110uFC18227KR215R1076.8K5V100KR224C114.01uFDGS4.7KR213J30 7Q113R17427.4KVR1185.6VVAG1%J30 22J30 11R17210K5VC100220pFS16310022.1KR1301%220pF R104R12710KC161220pFC112R156J30 101KR12615KC175D100220pFR140100K4.7KSW7.5VR11210KR211P101-11KR2104.7KR200TP101J30 3C122220pFU103-5MC1410611101uFC103100KR1096.8KP102-3J30 26R119C116.01uFU107-2MC330726570.1uFQ104MMBT390610KC105C107R173220pF9.6VR216C1941.5MEG13MC14053BU102-394531000pFMC14053BU102-2111412220pFC1917.5VP102-15V0.1uFC12068KP101-7VR11515VR108R105R1064.7KU124-4131214100R1391KMC330310K68KR124R101U101-2MC14053B 11141213J30 12J30 305V9.6VJ30 8J30 9R128100K1%TP104R12010KR11630K4.7KR1385VQ100MMBT3904R12556KJ30 27C164220pFSW7.5V5V72MC14106U103-356J30 29S1R15510K10KR13610KJ30 23P101-3J30 19R121Q101MMBT3904C179P102-4220pFC121100pFD101TP103MC14106U103-2341%9.6V.1uFC108100KR13175KR115TP123 TP124TP121 TP12227.4KR1291%C125220pF5V5VC1831uFTP120U100-2MC33072657C190680pFTP102.01uF5VEXT_SPKR+C115TXDSNGL_DETTEST_MODE-INRSS TX_RX_AUDIOPTTVRS_TX*_RXBUSYOUTBOOT-CNTRLRXDSNGL_TX_DATATONES-MOBILE_AUDRESETBUSYINRX_FIL_AUDPROG_SENSEEXT_MICSNGL_OUTABCDEFGHIJ VRS750 Vehicular Repeater SystemPrinted Circuit Board Schematic Diagram (Sheet 1 of 2)
87MOB_ANA_GNDP102 IS 25 PIN DB25 CONNECTOR(J40-30)AUX_RX_AUDMOB_ANA_GNDP101 IS 18 PIN PROGRAMMING CONNECTORFIL_AUDCONNECTIONSTO TRANSCEIVERDGNDR2264.7K84MC14106U103-613 12U107SWB+C150220pFC170220pFC139220pFW102 1P102-57.5VD1024.7KR132220pFC201220pFC2000.1uF0.1uFC199C197220pFC198220pFC1279.6VQ106MMBT3904220pFC152220pFC16710KR163U101-3MC14053B9453R22910KR22810K220pFC2089.6VMMBT3904Q115R2274.7KF10012VAGU103-1MC14106C1950.1uFC1965V220pFTP1089108C124220pFU101-416678U104-3MC3303R1804.7K100uFC156C1372200uFTP1145.6VVR108Q109MMBT39041.8KR159P102-2C126220pFC166220pF10KR164C1321uFP102-181000uHL101P102-104.7KR1339453MC14053BU105-3P102-23P102-22220pFP102-12C128C157220pF360R158C15510uFR1421KC15110uFOUT 1SHDN*4TAB6U102-1MC14053B101521U118LT1129CQADJ 2GND3IN5SWB+R1414.7KC1734.7K220pFR147VAG1uFC148C133C130VAGP102-81uF411220pFU104-5220pFC160C162100uFTP10910uFC153TP116C123220pF5.6VU129ADJIN OUTP102-7VR105C136220pFW102 3U124-541115KR157U102-416678P102-21C129220pFU104-4MC33031312145V.1uFC143R16015K5VRADIO_SWB+TP117220pFC1472KR165VAGC158220pFC1400.1uFU104-1MC33032314569.6VT2135VSW7.5VR161220pFC159C14910uF820220pF.01uF5VC131C14156KR14947KR145U100POWER POWER POWER POWERPOWERPOWERPOWERPOWER84W10123451P102-1920KR150J30 13P102-6C1425.6VVR1079.6V220pFTP119220pF9.6VC138VR1045.6VVR1065.6V220pFC184R18310K9.6VR1821K0.1uFC1359.6VR14620K9.6VP102-115.6VVR103C185.047uF100K5.6VVR109R1512110KR162MC14053BU101-110150.1uFC171J30 15TP1069.6VC172220pFR14820KU105-416678TP118MMBT3906Q102147VR11015VU103-7P334.7KR143TP105NC 4NC158VIN VOUT 1U111GND 2GND1 3GND27GND360.1uFC134P320.1uFC168TP127 TP128TP125 TP1269.6V220pFC1549.6VMC14053BU105-1101521111412134.7KR181U105-2MC14053BR1844.7KW102 2MMBT3904Q114P31P102-14TP107RADIO_SWB+SWB+SWB+MIC_FIL_SELBUSYRX_FIL_AUDBUS+BUS-MOBILE_MIC_HIRADIO_RESETTX_AUDIOSNGL_OUTEXT_MICVRS_TX*_RXLM317ABCDEFGHIJ VRS750 Vehicular Repeater SystemPrinted Circuit Board Schematic Diagram (Sheet 2 of 2)
88VRS750 Vehicular Repeater SystemExploded View Parts List ITEMNO.MOTOROLAPART NUMBER DESCRIPTION1 1505764X01 COVER ASSEMBLY, Midpwr Top2 3205931V02 GASKET, Front Cover3 1505905V02 HOUSING, Remote Front4 2805347X01 CONNECTOR, 18 Position5 4205395X01 RETAINER, Programming Connector6 3205789X01 GASKET, Remote Cable7 3385950D01 LABEL, Front8 1505784W01 HOUSING, Programming Connector9 1505791W01 HOUSING, Programming Connector Terminal10 3285803D01 PLUG, Programming Connector11 PLN7780A VRS750 Controller Board12 0310907A20 SCREW, M3 x .5 x 10 (8 req’d)13 320545Z03 GASKET, Antenna Connector14 0410057A13 WASHER, Nylon (for Regulator)15 1483820M02 INSULATOR, Nylon, Heat Conductive(for Regulator)16 TRANSCEIVERPMLD4196A VHF TransceiverPMLE4242A UHF R1 TransceiverPMLE4243A UHF R2 Transceiver17 2885170D01 PLUG, RF Phone to SMB18 3085166D01 CABLE, RF Coax19 4285033D01 RETAINER, Internal Radio (2 req’d)20 0300139800 SCREW, 6-32 x .521 0200844628 NUT, 6-3222 4285168D01 RETAINER, Flex Connector23 1485171D01 INSULATOR, PC Board24 8485177D01 CABLE, Flex25 2785032D01 CHASSIS, Modified26 3205934V01 GASKET, Casting27 4205938V01 CLIP, Spring28 3885558D01 PLUG, Plastic DC29 3285169D01 SEAL, Power30 0785588D01 BRACKET, Sp. Mounting31 3205935V01 GASKET, 25-Pin Connector32 0305760W02 SCREW, M5 x 0.8 x 12 (2 req’d)33 0400135783 WASHER, Lk. Splt. (2 req’d)34 0490440S01 WASHER, Flat (2 req’d)35 0312002B14 SCREW, 10-16 x 1 (4 req’d) VRS750 Vehicular Repeater SystemExploded View and Exploded View Parts List
89VRS-to-Mobile Cable HKN6153APin NumberSignal NameVRS750P102ASTRO Spectra Mobile DB25 Female1 N/C2 2 FIL_Audio_GND3 N/C4 N/C5 5 Bus+6 6 FLT_Audio7 7 Rx_Audio8 8 Tx_Audio9 N/C10 10 AGND11 11 Mic_Lo12 12 Mic_Hi13 N/C14 14 Bus-15 N/C16 N/C17 N/C18 18 DGND19 19 Reset20 N/C21 21 Bus_GND22 22 SWB+23 23 Busy24 N/C25 N/CVRS-to-Siren Cable HKN6154APin NumberSignal NameVRS750 P102Siren (HLN1439A)39 pin J11 N/C2 15 FIL_Audio_GND3 N/C4 N/C5 17 Bus+6 9 FLT_Audio7 33 Rx_Audio8 3 Tx_Audio9 N/C10 11 AGND11 14 Mic_Lo12 27 Mic_Hi13 N/C14 25 Bus-15 N/C16 N/C17 N/C18 19 DGND19 4 Reset20 N/C21 18 Bus_GND22 6 SWB+23 5 Busy24 N/C25 N/C
90VRS750 Programming Cable 3085031D01Pin NumberSignal NameVRS750 P101SRIB DB25 Female1 1 Ground2 N/C3 16 Boot_Cntl4 N/C5 N/C6 N/C7 15 TXD8 N/C9 2 Prog_Sense10 N/C11 N/C12 N/C13 N/C14 N/C15 N/C16 N/C17 N/C18 N/CVRS750 Programming Cable 3085031D01Pin NumberSignal NameVRS750 P101SRIB DB25 FemaleVRS750 Programming Cable 3085031D01VRS750 Programming Cable Schematic (3085031D01)VRS750 Flashing Adapter Schematic (NTN4056A)
91REPLACEMENT PARTS ORDERINGORDERING INFORMATIONMAIL ORDERSSend written orders to the following addresses:TELEPHONE ORDERSUnited States and Canada Accessories and Aftermarket Division: Servicers Training (VHS Video Tapes):Call: 1-800-422-4210 Call: 847-576-28281-800-826-1913 (For Federal Government Orders)1-847-538-8023 (International Orders)FAX ORDERSUnited States and Canada Accessories and Aftermarket Division: Federal Government Orders:FAX: 847-538-8198 (Domestic) FAX: 410-712-4991847-576-3023 (International) International: 410-712-6200Parts ID: 847-538-8194PARTS CUSTOMER SERVICE PRODUCT CUSTOMER SERVICEWhen ordering replacement parts or equipmentinformation, the complete identification numbershould be included. This applies to all components,kits, and chassis. If the component part number isnot known, the order should include the number ofthe chassis or kit of which it is a part, and sufficientdescription of the desired component to identify it.Crystal and channel element orders should specifythe crystal type or channel element type number,crystal and carrier frequency, and the modelnumber in which the part is used.Replacement Parts/Test Equipment/Manuals/Crystal Service Items:Motorola Inc.United States and Canada Accessories and Aftermarket DivisionAttention: Order Processing1313 E. Algonquin RoadSchaumburg, IL 60196Federal Government Orders:Motorola Inc.United States and Canada Accessories and Aftermarket DivisionAttention: Order Processing7230 Parkway DriveLandover, MD 21076International Orders:Motorola Inc.United States and Canada Accessories and Aftermarket DivisionAttention: International Order Processing1313 E. Algonquin RoadSchaumburg, IL 60196United States and Canada Accessories and Aftermarket Division:Call: 1-800-422-4210Parts Identification:Call: 847-538-0021Customer Resource Product Support(Sales and Service Assistance):Call: 1-800-927-2744FAX: 1-954-723-4800
72Motorola8000 West Sunrise BoulevardFort Lauderdale, Florida 333226881094C84

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