PRELIMINARY USERS MANUAL Model Chart for the Vehicular Repeater System Model 750 Model Number P2080A P2081A P2082A X X X X X X X X X X X X X X Note 1 Note 2 Note 3 X X X X X X Note 1 Note 2 Note 3 X X X X X X X Note 1 Note 2 Note 3 X X X X X X Item Number HHN4044A HLN6855A PLN7780A HLN6856A PUD1001A PUE1036A PUE1037A HKN6153A HKN6154A 6881094C84 6881087C79 2884606M01 3305873U04 3085031D02 NTN4056A NKN6460A TLN5277B Note 1 Note 2 Note 3 With option xxxxA With option xxxxB One item per 10 units Desc
VRS750 SPECIFICATIONS- VHF GENERAL TRANSMITTER RECEIVER Model: P2080A (136 – 174 MHz) RF Power Out: Intermodulation per EIA: 275 mW to 2 W tunable 70 dB Frequency: Programmable, Synthesized Frequency Channel Spurious and Harmonic Emissions: Hum and Noise: Channel Spacing: -36 dBm < 1 GHz -30 dBm > 1 GHz -40dBm @ 25 kHz -35dBm @ 12.5 kHz Frequency Stability: Reference Sensitivity(typical): ±2.5 ppm @ 25 kHz ±2.5 ppm @ 12.5 kHz 0.
VRS750 SPECIFICATIONS-UHF GENERAL TRANSMITTER RECEIVER Model: P2081A (403 – 470 MHz) P2082A (450 – 512 MHz) RF Power Out: Intermodulation per EIA: 275 mW to 2 W tunable 70 dB Frequency: Programmable, Synthesized Frequency Channel Spurious and Harmonic Emissions: Hum and Noise: Channel Spacing: -36 dBm < 1 GHz -30 dBm > 1 GHz -40dBm @ 25 kHz -35dBm @ 12.5 kHz Frequency Stability: Reference Sensitivity(typical): ±2.5 ppm @ 25 kHz ±2.5 ppm @ 12.5 kHz 0.
List of Abbreviations and Acronyms B-P Base to Portable CPS Customer Programming Software DPL Digital Private Line HT750 Transceiver internal to VRS750 HUB Hang Up Box ICM In Car Monitor ms Millisecond PAC Portable Area Coverage PL Private Line PPI Portable Priority Interrupt P-B Portable to Base RF Radio Frequency RX Receive SB Serial Bus SBEP Serial Bus Expanded Protocol Slm-net Transceiver internal to VRS-EP TOT Time Out Timer TX Transmit VIP Vehicle Interface Port V
1. Introduction Description The ASTRO Spectra compatible Vehicular Repeater System - Model 750 (VRS750) is a mobile radio system component that provides on-site repeater capability between a portable radio and a base station. 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.
A separate antenna (not included) is necessary for use with the repeater. Typically, a onequarter (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 3dB gain antenna should be used. See "Installation," Chapter 4, for details. A filter for the battery lines (TLN5277B)is available for use with ASTRO Spectra mobiles.
Mutually-Exclusive Features The VRS IS NOT compatible with the following mobile radio features: o W3 Control Head is not supported with VRS o VSELP signaling type o 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.
indicator button positions. Field programming determines the exact position. The VRS requires an ASTRO radio with a remote-mount control head. Figure 1 Typical ASTRO Control Head with VRS 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.
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. ICM Transmissions VRS BASE: Press the mobile's PTT to transmit on the frequency corresponding to the mode shown on the control head’s display.
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. 3. Operation of VRS Options 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.
VRS. 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.
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.
The VRS will command the ASTRO mobile to send out an 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.
every 6 seconds is determined by the "temporary message display timer" value. This value (from 250 to 6250 ms [default = 1000 ms]) can be programmed by the CPS. It is in the RADIO WIDE DISPLAY OPTIONS screen (D, C, F from the main CPS 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.
a properly installed, externally-mounted antenna. Table ? lists the minimum lateral distance for the VRS 750: Rated Power of Vehicle-installed Mobile Two-way Radio Less than 7 Watts Minimum Lateral Distance from Transmitting Antenna 8 Inches (20 Centimeters) VRS Antenna Installation Recommended mobile antenna installations are limited to metal body vehicles at the center of the roof and center of the trunk deck locations.
Figure 4 Advanced window (Radio Configuration->Radio Wide->Advanced) 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. Special Programming Notes The VRS button can be located in any of the indicator button positions normally used for option buttons.
window (see Figure 5) 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 to have the indicator light when the VIP is enabled.
ASTRO VRS Programming Windows There are five windows for editing the VRS Option. Four of these windows are in the Radio Wide section of Radio Configuration while the fifth window is a table for the VRS mode steering PLs. The first window is the VRS subsection of the Radio Wide options (see Figure 6). 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.
The second window is the VRS Private Line subsection (see Figure 7). 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.
The third window is the VRS Advanced subsection (see Figure 8). 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.
The fourth window is the VRS Personality subsection (see Figure 9). 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 2W for High and 300mW for Low).
The “VRS Personality” can be programmed directly into the VRS750 EEPROM using Professional Radio CPS and a new dip switch configuration (see Figure 10). All other operating parameters will still be programmed using the ASTRO Spectra CPS.
Figure 11 VRS-EP Mode Steering window 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. 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 12.
Note: We recommend the LOW Transmit Power setting of 300mW 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.
To adjust the Receiver Squelch select RX Align->Squelch Attn.->(Select the Squelch Attn. for the channel spacing selected in the VRS Personality) (see Figure 14). The Receiver Squelch should be set at the factory to a tight setting. To obtain better performance from the VRS750 the Squelch softpot setting can be reduced, but if it is reduced too much the VRS750 will enter a monitor state and will not activate. Most settings should be above 30.
The following table shows the softpot ranges to achieve approximately -110dBm. The actual value varies from radio to radio. The VRS transceiver ships from the factory with the softpot set for -110dBm. 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. Band Channel Spacing VHF VHF UHF R1 UHF R1 UHF R2 UHF R2 25kHz 12.5kHz 25kHz 12.5kHz 25kHz 12.
transmit or cause a mobile PTT. The procedures for determining priority levels in multiVRS operation are discussed next. Determining Priority Levels Whenever 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.
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.
If unit B activates its VRS during portable transmissions, unit B does NOT transmit Single Tone or enable in delay state zero. Unit B must wait until it cannot detect the portable signal before transmitting Singletone and taking over as the priority unit as described above. 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 21.
If a portable's signal without PL tone is present when the repeater is interrupted, the repeater transmitter remains inhibited for the duration of the incoming signal. If the portable's signal is modulated with a PL signal, the priority unit repeats the message back to the base station on top of the incoming signal. In addition to giving the portable user priority over all incoming signals, the Portable Priority Interrupt is used for three basic functions: 1.
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.
In 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.
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. o 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.
o Portable Priority Interrupt is disabled o VRS TOT disabled o TX PL is disabled. To exit the test mode, the system needs to be reset after removing the test mode jumper. Non-Priority VRS Rules A priority VRS is placed into non-priority mode when one of the following occurs: 1. It receives a Single Tone burst at the fixed frequency of 847.5 Hz. 2. During a base-to-portable repeat, it receives a VRS/portable frequency RF signal without proper PL during the PPI.
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 Operation The ICM feature will continue to operate as described in the "ICM Functions" section except for the following: 1.
For silent Alarm, any of the following will cause the mobile to exit Emergency: o Extended keypress of the Emer button on the mobile's control head. o 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.
The HT750 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. Audio Routing Circuitry: There are four paths which are used to route audio between the mobile and the HT750 transceiver: AUX_RX_AUD, TX_AUDIO, MOB_MIC_HI and FIL_AUD.
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 HT750’s transmitter input (EXT_MIC, J30-19).
To place the HT750 into bootstrap mode, it must be reset while the BOOT-CNTRL (J3028) pin is grounded. This pin is grounded when the programming cable is connected and the flash adaptor switch is turned on. Refer to Figure ?. 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 SW7.5V from 7.5V. At this point there is no supply voltage to the HT750. Meanwhile, 9.
sales representative for details about this mode. All other combinations of the dipswitch are not supported and will default to the Normal mode. 7. Maintenance and Troubleshooting The following paragraphs contain information to help you maintain and troubleshoot the VRS. A list of recommended test equipment is found in the "Recommended Test Equipment, Service Aids, and Tools" section of the ASTRO Spectra Basic Service Manual, Motorola publication 68P81076C20.
Common Power-Up Problems 1. "ERR 12/10" message is displayed on power-up. o The VRS mobile interface cable is disconnected or bad. o 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. o Check all regulators for proper voltages. The 9.6-volt regulator is accessible at C199. Do not probe U118 pin1 when the unit is powered.
Removing and Reinstalling the HT750 Transceiver 1. Remove the nuts and washers holding on the Flex retainer bracket (X). 2. Remove the Flex retainer bracket (X). 3. Unplug both the HT750 flex cable (X) from the 20 and 40 pin latch connectors and the VRS coax cable (X), from the pc board (X). 4. Loosen the 4 screws (X) that hold the HT750 retaining rails (X) to the pc board. 5. Slide the HT750 retaining rails apart so that the HT750 transceiver can be lifted away from the pc board. 6.
Tuning Procedure Board-Level Tuning Procedure 1. 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. f. Figure 15 illustrates the relative placement of the tuning potentiometers.
b. 7. Turn on the mobile control head and re-enable the VRS. Tuning is complete. 8. Troubleshooting Charts Introduction to this Section This section contains detailed troubleshooting flowcharts. These charts should be used as a guide in determining problem areas. They are not a substitute for knowledge of circuit operation and astute troubleshooting techniques. It is advisable to refer to the related circuit descriptions in the "Hardware Detailed Theory of Operation" section prior to troubleshooting.
Exploded View and Exploded View Parts List 59 Chart 15 - Programming/Tuning Failure Chart 5 - Error 12/84, Configuration Register Corruption Chart 6 - Error 12/88, HC11 RAM Failure Chart 7 - VRS 001, VRS Synthesizer Lock Failure Chart 8 - Single Tone Encode Failure Chart 9 - Single Tone Failure Chart 2 - Error 12/10 Chart 3 - Error 12/81 Chart 4 - Error 12/82, Codeplug Checksum Error Chart 10 - Base-to-Portable Repeat Failure Chart 11 - Portable-to-Base Repeat Failure Chart 13 - Serial Bus Failure Chart 1
C137 C149,C151,C153,C155,C182 C156,C162 C190 D100,D101 J30 L101 P101 P102 Q100,Q101,Q103,Q106,Q109,Q110,Q111,Q112,Q1 14 Q102,Q104 Q113 R101,R108,R172 2380090M40 2311049a19 2380090m25 2113741f21 4805129m05 0985173d01 2505462s03 0905904V02 2805429W03 cap_polar,2200uF cap_polar,10uF cap_polar,100uF CAP,680pF diode13 connector,30 pin flex inductor,1000uH CONN_J CONN_P 4880141l02 4813824A17 4813821a21 0662057a93 NPN PNP nchan_tmosfet_gsd RES,68K R102,R120,R121,R124,R127,R136,R137,R155,R16 2,R163,R164,R175,R
S1 T1,T2 U100,U107 U101,U102,U105 U103 U104,U124 U111 U118 U129 4080564c02 2584422t02 5113818a03 5184704m60 5113806a37 5113819a04 5113816a03 5105109z13 5105469E18 VR103,VR104,VR105,VR106,VR107,VR108,VR10 9,VR113,VR121,VR112,VR118,VR102 4805129m35 VR110,VR115 4813830a28 W101 W102 ASTRO Spectra Vehicular Repeater System Model 750 Printed Circuit Board Electrical Parts List 0984345R02 0905901V10 8485176D01 o200835638 o300114832 switch_dip xfmr_6pin mc33072-1 mc14053b mc14106 mc3303 MC78L05A LT1129 LM317T
