Maintenance Manual DRC-200 DESKTOP REPEATER 450 - 470 MHz ERICSSONZ
AE/LZB 119 1882 R1B REVISION HISTORY REVISION DATE REASON FOR CHANGE R1A 9/96 Original R1B 11/96 Corrected item 10 on page 11. Change phone numbers. NOTICE! This manual covers Ericsson and General Electric products manufactured and sold by Ericsson Inc. NOTICE! Repairs to this equipment should be made only by an authorized service technician or facility designated by the supplier.
AE/LZB 119 1882 R1B TABLE OF CONTENTS DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . LOCATION CONSIDERATION . . . . . . . . . . . . . . CABLE CONNECTIONS . . . . . . . . . . . . . . . . . . HANDHELD MICROPHONE . . . . . . . . . . . . . . . OPERATING CONTROLS AND INDICATORS . . . . . . . . POWER ON/OFF Switch . . . . . . . . . . . . . . . . . . VOLUME Control . . . . . . . . . . . . . . . . . . . . . SQUELCH Control . . . . . .
AE/LZB 119 1882 R1B FIGURES Figure 1 - Front Panel Details . . . . . . . . . . . . . . . . . . . . Figure 2 - Rear Panel Details . . . . . . . . . . . . . . . . . . . . Figure 3 - DB15 Connector Pin Positions - Rear Panel View . . . Figure 5 - Microphone Matching Network . . . . . . . . . . . . . Figure 4 - Equipment Set-Up . . . . . . . . . . . . . . . . . . . . Figure 6 - Test Probe A . . . . . . . . . . . . . . . . . . . . . . . Figure 7 - Troubleshooting: Receiver Completely Dead . . . . . .
AE/LZB 119 1882 R1B SPECIFICATIONS - Continued (Subject to change without notice) Receiver - Cont.
AE/LZB 119 1882 R1B DESCRIPTION NOTE The DRC-200 is a state-of-the-art Desktop Repeater for operation in the Land Mobile UHF (450-470 MHz) frequency band. The repeater operates in the UHF band with a 25 watt (without duplexer connected) RF output. Low power operation of 2 Watts is also available (Dealer programmable). The built-in switching power supply automatically configures itself for operation on 120 VAC or 240 VAC, 50/60 Hz.
AE/LZB 119 1882 R1B INSTALLATION 3. If used, plug in the External Speaker. This disconnects the Unit’s internal speaker. 4. Install the microphone’s cable in the modular jack located on the front panel. There will be a click when the connector is fully seated. 5. Plug the AC cord into a suitable 120 or 240 VAC receptacle. NOTE It is recommended that the repeater and antenna installations be performed by a technician qualified in 2-way radio.
AE/LZB 119 1882 R1B POWER ON/OFF Switch Power ON/OFF is a rocker switch. Press in at the top end to turn the unit ON. Press in at the bottom end of it to turn the radio OFF. The indicator (LED) at the left end of the window (labeled POWER) should be lighted green when the unit is ON. REMOTE Button Not used. REM Indicator Not used. BZ Indicator VOLUME Control Use this knob to vary the receiver’s audio output level. This also varies the audio level to an external speaker.
AE/LZB 119 1882 R1B Continued Pin No. 9 Purpose/Specification Discriminator’s Audio Output; buffered unprocessed (not de-emphasized) audio. 10 Interconnect RX Audio Output; buffered de-emphasized receiver audio. 11 Data In; 4800 BAUD (2400 Hz) Maximum. 12 Remote Audio B. Not Applicable 13 External CG/DCG Input; modulates the VCO/Reference Oscillator; External Encoding must be selected for the Encode Tone. 14 Interconnect TX Audio Input; is pre-emphasized by the Unit.
AE/LZB 119 1882 R1B Although no repeater set-up would likely be configured to accept all 5 PTTs, it is quite possible that at least two of the five would be utilized. For example, the receiver’s PTT action and the front panel’s PTT would probably be used during the repeater’s initial installation and its checkout. What the effect of prioritizing the various PTTs means is that the TX audio of the PTT with the higher priority will always be transmitted.
AE/LZB 119 1882 R1B not be used for more than one user. However, the same encode code could be used for all 16 users if desired. 4. 5. 6. 7. External Encoder/Decoder – any one of the 16 user tones or codes can be programmed for using an external encoder. Courtesy Beep – each user can be programmed to provide a beep for 100 milliseconds after the originating transmission is stopped. This signals the receiving unit(s) that the originating unit has quit transmitting.
AE/LZB 119 1882 R1B Digital Channel Guard Codes 104 codes CDCSS codes are specified by a code number in the PC programmer. The following is the relationship between the PC programming code number and the resulting TIA/EIA CDCSS code and its inverted equivalent. Code DCS Inv. DCS Code DCS Inv. DCS Code DCS Inv. DCS Code DCS Inv. DCS Code DCS Inv.
AE/LZB 119 1882 R1B THEORY OF OPERATION GENERAL INFORMATION The Repeater circuitry is distributed on five PC boards as follows: a. Main PC Board containing the receiver section and transmitter/audio control section b. Microprocessor/Display PC Board. c. Control PC Board which contains the audio and squelch controls, d. PA PC Board. e. Power Supply module. MAIN BOARD RECEIVER SECTION The receiver section uses 13.8 V DC from the Power Supply module for the audio power amplifier U404.
AE/LZB 119 1882 R1B modulation of the transmit TCXO. For good broadband transmit frequency response, both the TCXO and the VCO are modulated. Two analog switches, U504A and U504C, control whether external CTCSS tones are to be transmitted or whether internal DCS or CTCSS signals are to be transmitted. These analog switches are controlled by Q516. An optional DTMF code can be generated by the microprocessor.
AE/LZB 119 1882 R1B TRANSMIT RECEIVE SWITCH When the transmit 13.6 Volt line (Pin 3 of J301) becomes active, current passes through L316, R308, L311, CR301, L315, CR302 and CR303 to ground. L316, C340, C339, L311 and C338 isolate and bypass the RF. CR301 conducts RF from Q303 to the low pass filter. CR302 and CR303 short to ground preventing RF from entering the receiver input P303. L315 along with the distributed capacitance form a high impedance path to ground, thus preventing loss of transmit power.
AE/LZB 119 1882 R1B Type: Digital Input Description: Unless superseded by a higher priority PTT input (see Table 1), when the REM LED on the front panel is illuminated, an active level at this input will cause the transmitter to transmit a carrier modulated by the audio signal on the REMOTE TX AUD input (pin 7). Level: This input is active with input voltages less than 0.8 volts and inactive with input voltages greater than 3.5 volts or when left unconnected. Voltages between 0.8 and 3.
AE/LZB 119 1882 R1B Pin Number: 7 Name: REMOTE TX AUD Type: Analog Input Description: This pre-emphasized audio input modulates the transmit carrier when the REM LED is illuminated, when the REMOTE PTT is taken to its active state and when no higher priority PTT has been enabled. Impedance: 600 ohms nominal, unbalanced. Level: Depending upon the setting of R553 (REMOTE AUDIO ADJ.) on the main board, between 25 mv and 250 mv RMS nominal at 1 kHz will produce ± 3 kHz deviation.
AE/LZB 119 1882 R1B series with analog inputs is required to block the 1.8 volts DC present at this pin. Frequency Response: Flat within +1/-3 dB, 5 Hz to 2.4 kHz. Note: The input is DC coupled to allow for proper switching of both TTL/CMOS and RS-232 logic signals, but capacitive coupling is used later in the audio chain limiting the frequency response to 5 Hz on the low end.
AE/LZB 119 1882 R1B Table 1 - PTT Priorities and TX Audio Details vs. MUX Logic Levels PTT PRIORITY SOURCE PTT INPUT 1 Local Microphone 2 Remote Audio DB-15 Connector Pin 2 3 Data Input 4 Interconnect 5 Receiver AUDIO INPUT Mic. Connector Mic.
AE/LZB 119 1882 R1B panel VOLUME control to the mid-range position. Connect an audio RMS voltmeter, SINAD meter, and distortion meter, if available, to the speaker terminals. MAINTENANCE RECEIVER For optimum performance, the unit should be realigned before being put into service. For base station units, set the unit to a receive frequency nearest the middle of the frequency list. NOTE Preliminary 1. 2. Program unit for the desired frequency(ies) and tones.
AE/LZB 119 1882 R1B generator output level to keep the signal on the oscilloscope at 0.1 volt p-p. VCO Tuning 3. 4. Adjust C435 for a DC voltage of 2.75 ± 0.05 volts at TP402. On base station units, check the maximum and minimum receive frequencies and insure that the voltage at TP402 is between 1.6 and 4.4 volts. Connect a frequency counter to the output of TEST PROBE A. See Figure below.
AE/LZB 119 1882 R1B 2. Preset R528 (HI PWR Set) and R526 (LO PWR Set) on the Main PC board fully counter-clockwise. Deviation Adjustment 9. Preset R544 (MASTER DEVIATION) and R583 (BALANCE) to mid-range. VCO Tuning 3. Adjust C545 for a DC voltage of 2.45 ± 0.05 volts at TP501. On base station units, check the minimum and maximum transmitter frequencies to ensure that the DC voltage is between 1.0 and 4.0 volts. 4.
AE/LZB 119 1882 R1B 13. Repeat steps 11 and 12 several times checking deviation and the demodulated waveform since R544 and R583 interact. Internal DCS Adjustment 14. Preset R562 (INTERNAL DCS DEV. ADJ.) to mid-range, if not already done. 15. Remove the 1000 Hz tone. 16. Set the unit to a channel programmed for a DCS tone or on repeater units, program the unit for a DCS tone. 17. Adjust R562 (INTERNAL DCS DEV. ADJ.) for ± 700 Hz deviation. Internal CTCSS Adjustment 18.
AE/LZB 119 1882 R1B 29. Connect the audio generator to pin 14 of P502 on the rear of the unit. The generator should be set for a 1 kHz sine wave at the desired output level. 30. Ground pin 5 of P502. The unit should begin transmitting. 31. Adjust R548 (INTERCONNECT AUDIO ADJ.) on the Main PC board for ± 3.0 kHz deviation as shown on the FM demodulator. Remote Audio Adjustment NOTE This adjustment need only be made if the user wishes to use the remote audio input. 34. Ground pin 2 of P502.
AE/LZB 119 1882 R1B Figure 7 - Troubleshooting: Receiver Completely Dead (Page 1 of 2) 25
AE/LZB 119 1882 R1B Figure 7 - Troubleshooting: Receiver Completely Dead (Page 2 of 2) 26
AE/LZB 119 1882 R1B Figure 8 - Troubleshooting: Noise Present But No Signal Received (Page 1 of 2) 27
AE/LZB 119 1882 R1B Figure 8 - Troubleshooting: Noise Present But No Signal Received (Page 2 of 2) 28
AE/LZB 119 1882 R1B Figure 9 - Troubleshooting: No Transmit Power 29
AE/LZB 119 1882 R1B Figure 10 - Troubleshooting: Receive Synthesizer 30
AE/LZB 119 1882 R1B Figure 11 - Troubleshooting: Transmit Synthesizer 31
AE/LZB 119 1882 R1B DUPLEXER REMOVAL AND REPLACEMENT The following procedures should be followed to remove and replace the duplexer. 1. Turn off the Unit and unplug the AC Cord. 2. Disconnect the TX and RX coaxial cables from the rear panel. 3. Remove the 8 black Phillips head screws that fasten the wrap to the chassis. 4. Remove the wrap by sliding it off towards the rear of the Unit. 5. Remove the top cover, using a T9 TORX screwdriver for the 16 screws that hold the cover in place. 6.
AE/LZB 119 1882 R1B 25. Connect the antenna’s coax cable to the lower Ntype connector labelled ANTENNA. NOTE It may be easier to perform Steps 19 and 20 BEFORE the Main Board Assembly is fully lowered into place. 26. Plug in AC cord. The unit is now ready for use. DUPLEXER TUNING PROCEDURES 18. Fasten the Main Board Assembly in place, using the 6 TORX screws removed in Step 7. 19. Insert P401 (miniature coax) Into J401 located at the front right corner of the Main Board Assembly. 20.
AE/LZB 119 1882 R1B TUNING INSTRUCTIONS 1. 2. Turn off the DRC-200 with the front panel POWER ON/OFF switch and unplug AC power cord Remove the eight (8) black Phillips head screws that fasten the cover wrap to the chassis and slide the cover wrap off towards the rest of the unit. Disconnect the communications monitor and 50 ohm pad from the TX port and reconnect the cable to the TX port that was removed in step 4. 10.
AE/LZB 119 1882 R1B Figure 13 - Duplexer Connections and Tuning Adjustements REPLACEMENT PARTS LISTS Replacement Parts are arranged in Tables 2 through 7 as follows. Figure references to the relevant parts placement diagrams are also included. TABLE NO.
AE/LZB 119 1882 R1B Table 2 - Replacement Parts, Microprocessor/Display Board ITEM REF. NUMBER DESCRIPTION ITEM REF.
AE/LZB 119 1882 R1B Table 4 - Replacement Parts, Main Board Table 4 - Replacement Parts, Main Board ITEM REF. NUMBER DESCRIPTION ITEM REF. NUMBER DESCRIPTION L402 L403 L404 L407, 408 L409 L410, 412, 501, 503 L411 L413, 504 L414, 415, 505 L416 L506 Coil, AW; 16 Ga. Coil, AW; 2.5T, Grn Filter, Helical; 4-Sec. Coil, IF; 21.4 MHz Coil, IF Choke, 390 nH; SMD Choke, 0.27 µHy; SMD Choke, 33 nH; SMD Choke, 100 nH; SMD Choke, 8.2 µH, 10%; SMD Choke, 6T Capacitor, E; 4.
AE/LZB 119 1882 R1B Table 5 - Replacement Parts, Control Board Table 4 - Replacement Parts, Main Board (Cont’d) ITEM REF.
AE/LZB 119 1882 R1B Table 6 - Replacement Parts, Power Supply Board ITEM REF. NUMBER DESCRIPTION ITEM REF. NUMBER DESCRIPTION T2 Transformer BD1 Diode Bridge; 4A, 800V U1 IC C1, 4 C2, 3 C5, 6 C7 C8 C9, 10, 12, 16 C11 C13 C15 C17 C18, 19 C20 C24, 25, 30, 31 C29 C32 C34, 35 C36, 37 Capacitor, CD; 0.1µF, 250V Capacitor, CD; 4700pF, 250V Capacitor, E; 330µF, 200V Capacitor, CD; 2.2µF, 250V Capacitor, CD; 1500pF, 1000V Capacitor, E; 1µF, 50V Capacitor, CD; 2200pF, 50V Capacitor, Mylar; 0.
AE/LZB 119 1882 R1B Table 7 - Replacement Parts, Miscellaneous ITEM REF. NUMBER DESCRIPTION F1 Fuse, 4 Amp; 3 AG, 250V J1 J2 J3, J4 Jack, 3.5MM Phone; w/Nut Cable Assembly, 15 Cond.; Multifunction Port Connector, BNC to N; Qty. 2 PS1 PCB Assembly, Power Supply SPKR1 Speaker, 8 Ohm SW1 Switch, Rocker; ON/OFF Bracket, Ground; Qty. 2 Bracket, Duplexer Retainer (DRU) Foot, Rubber; Qty. 4 Chassis Front Panel, Desktop Top Cover Keyboard (Button); Qty. 3 Fuse Holder; w/Nut and Washer Lug, Solder; Qty.
AE/LZB 119 1882 R1B You may use this form to record the Unit’s configuration.
AE/LZB 119 1882 R1B CONTROL BOARD (305-187, Rev. A) (305-684, Rev.
BLOCK DIAGRAM AE/LZB 119 1882 R1B BLOCK DIAGRAM (701-174, Rev.
AE/LZB 119 1882 R1B MAIN (COMPOSITE) BOARD (701-215, Sh. 1, Rev. A) (701-216, Sh. 1, Rev.
SCHEMATIC DIAGRAM AE/LZB 119 1882 R1B MAIN (COMPOSITE) BOARD (701-215, Sh. 2, Rev. A) (701-216, Sh. 2, Rev.
AE/LZB 119 1882 R1B MICROPROCESSO/DISPLAY BOARD (701-130, Rev. M) (701-203, Rev.
SCHEMATIC DIAGRAM AE/LZB 119 1882 R1B PA BOARD (602-752, Rev. A) (602-753, Rev.
AE/LZB 119 1882 R1B POWER SUPPLY BOARD (602-589, Rev.
SERVICE OUTLINE AE/LZB 119 1882 R1B MICROPROCESSOR/DISPLAY BOARD (305-536, Rev.
AE/LZB 119 1882 R1B PA BOARD (305-537, Rev.
SERVICE OUTLINE AE/LZB 119 1882 R1B MAIN BOARD (305-703, Rev.
Ericsson Inc. Private Radio Systems Mountain View Road Lynchburg, Virginia 1-800-592-7711 (Outside USA, 804-592-7711) AE/LZB 119 1882 R1B Printed in U.S.A.
