Emcee TTU500FA, User Manual

Page 1: ...P O Box 68 White Haven PA 18661 Phone 570 443 9575 FAX 570 443 9257 MDS MMDS ITFS LPTV North America South America Europe Asia Australia Africa Since 1960 6 USERS MANUAL TTU500FA SOLID STATE LDMOS 500...

Page 2: ...TTU500FA SOLID STATE LDMOS 500W UHF TRANSMITTER 05 01...

Page 3: ...uptible power supplies to the more cost effective AC power line protectors As transients are most often caused by lightning induction and switching surges AC power line protectors are the most practic...

Page 4: ...UHF Exciter 2 3 500 Watt UHF Power Amplifier 2 4 Output Section 2 5 Control Metering Panel III MAINTENANCE 3 1 Periodic Maintenance Schedule 3 2 Recommended Test Equipment 3 3 Troubleshooting 3 4 Ali...

Page 5: ...i SECTION I THE TTU500FA TRANSMITTER 1 1 INTRODUCTION 161 1 2 SPECIFICATIONS 161 1 3 INSTALLATION 163 1 4 OPERATION 164 1 5 WARRANTY AND PARTS ORDERING 165...

Page 6: ...maintain with RF alignment practically nonexistent A number of controls and indicators furnished on the transmitter s Control Metering panel and the EMEX1 Exciter front panel provide convenient opera...

Page 7: ...k nominal Video Input Impedance 75 ohms unbalanced Aural Output Power 25 watts average Emissions 250KF3E Frequency Stability 200Hz re visual Audio Input Level 0dBm nominal Audio Input Impedance 600 oh...

Page 8: ...oming ac line breaker to the OFF position Ac breakers can be found on the transmitter s AC Distribution Panel at the rear of the amplifier and Exciter drawers and on the front AC Power panel Place an...

Page 9: ...position Also switch the Exciter and amplifier drawer rear panel breakers to on 3 Move the AC POWER circuit breaker located on the bottom front panel of the transmitter to the ON position 4 If applic...

Page 10: ...e 10 Place the Control Metering panel s meter switch to FWD for constant monitoring of the transmitter s final output power The transmitter is now in operation Check its coverage area for clean sharp...

Page 11: ...c Shipping and billing addresses Spare and Replacement Parts The Spare Modules and Components section of this manual provides a detailed listing of the modules and some discrete components contained w...

Page 12: ...167 For EMERGENCY technical assistance EMCEE offers a toll free 24 hour 7 day a week customer service hot line 1 800 233 6193...

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Page 16: ...etector 269 2 2i Control Interface Board 269 2 2j Display Monitor Board 2620 2 2k 28V 15V 5V Power Supply 2624 2 3 500 WATT UHF POWER AMPLIFIER DRAWER 2624 2 3a Power Splitter 2625 2 3b 300W UHF Power...

Page 17: ...e VDS detects the presence of composite video connected to its A INPUT directly from the VIDEO connector mounted on the Video Audio Remote Panel A8J2 If a loss of video is detected then the unit switc...

Page 18: ...ier stages providing approximately 12dB of gain per device A phase correction network is centered around amplifiers U2 through U5 while the circuitry surrounding U7 and U8 corrects for differential ga...

Page 19: ...tion of the visual IF carrier is reduced during this period causing the waveform to stretch Slope control R41 is typically used to correct differential gain while R57 primarily adjusts sync amplitude...

Page 20: ...AGC CONTROL line which is connected to pin 6 IN of switch S1 This low supplied by the OPERATE SWEEP switch PC4S1 on the Control Interface board will disconnect the input AGC voltage at S1 8 from S1 1...

Page 21: ...voltage is then sent through pins 8 and 1 of switch S2 and divider R56 R61 to amplifier U18A which controls the attenuation value of PIN diodes CR9 CR10 and subsequently the output power of the trans...

Page 22: ...al is sent to pin 1 of U1 Fin from U2 4 OUT and with the aid of the A and N counters within U1 the prescaled signal is also divided down to 50kHz using a divide by ratio selected through the switch se...

Page 23: ...irst three sections of the filter composed of variable capacitors C1 C2 C3 and their associated tuned stubs are terminated at the input of U1 a 14dB amplifier Variable capacitors C1 C2 C3 and C4 C5 C6...

Page 24: ...cting as signal coupling capacitors positioned at the input and output of 3dB matching attenuator R13 R14 R15 At the input of 8 pin DIP power FET Q2 is a microstrip network with matching capacitors C1...

Page 25: ...esistive attenuator R1 R2 R3 and coupling capacitor C1 to integrated circuit U1 an RMS detector At pin 7 U1 outputs the video component of the UHF visual carrier while C3 rolls off the aural energy co...

Page 26: ...7 CR8 to maximum attenuation until the IF signal is returned see description under J8 5 J8 7 LEVEL ADJUST The Level Adjust voltage controls the output power of the Exciter and therefore the transmitte...

Page 27: ...voltage is high transistor PC3Q6 will be forward biased causing the LED to turn on indicating the output AGC is active If the voltage at PC3J1 18 is low PC3Q6 will not conduct and PC3DS6 will not illu...

Page 28: ...zer will back bias transistor Q1 forcing lows from AND gates U1A B U2A B C D and amplifier U8A The low is forwarded via J10 21 PC3J1 21 LEVEL ADJUST PC3R16 PC3J1 23 J10 23 J8 7 and PC1 7 causing buffe...

Page 29: ...ected output power the voltage at U6A 3 will exceed the reference at pin 2 a level determined by VSWR OVLD REF potentiometer R12 which is typically set for 25 reflected power Output pin U6A 1 will tur...

Page 30: ...lip flop U9A to change polarity As U9A 5 goes negative gate U2D will output a low on pin 11 sending U2A 3 and U8A 1 low The low at J10 2 proceeds to PC3J1 21 LEVEL ADJUST PC3R16 PC3J1 23 J10 23 J8 7 a...

Page 31: ...9 From AGC ADJUST PC3R15 this PWR REFERENCE signal reaches PC1J6 8 of the IF Converter by PC3J1 17 J10 17 and J8 8 This voltage acts as the reference for the IF Converter s output AGC loop by controll...

Page 32: ...ll be shut down J4 5 VIDEO SENSE A high low indication for the presence or absence of video pro gramming is delivered to this input from the Video Detector Switch VDS TALLY jack With video present at...

Page 33: ...eflected power at the output of the Exciter or transmitter initiates a VSWR overload pin 6 of flip flop U9A will shift high causing VSWR OVERLOAD LED PC3DS8 to illuminate via J10 11 PC3J1 11 and PC3Q8...

Page 34: ...decreasing the output signal level to its proper value J10 18 AGC MANUAL LED This output line connected to U4C 8 via R23 controls front panel AGC ACTIVE LED PC3DS6 through PC3J1 18 and switching tran...

Page 35: ...F attenuation of PIN diodes PC1CR7 CR8 and significantly reducing the output power of the Exciter transmitter effectively placing the unit in standby J10 22 SYNTH LOCK LED This output controls the act...

Page 36: ...he front panel of the drawer and contains the indicator lights adjustments and switches necessary to operate and maintain the EMEX1 Exciter Control Interface Board Interface PC4J10 Jack Pin Function J...

Page 37: ...causing Q8 to conduct and DS8 to light J1 13 VSWR RESET S3 is a momentary switch which sends a ground to reset pin 4 of VSWR overload flip flop PC4U9A changing the states of pins 5 6 to their normal...

Page 38: ...forcing the output of PC4U4C high J1 19 PWR REF IN This voltage proportional to the monitored output power originates from either the Exciter A3J3 5 or transmitter A7A1J3 5 Metering Detector and is bu...

Page 39: ...2A1J3 A as an operational indicator for the Synthesizer A low synthesizer locked from PC4J2 8 to the base of PC4Q1 will place a high at the inputs of AND gate PC4U1A 1 2 forcing its output high This h...

Page 40: ...eplacement 2 3 500W UHF POWER AMPLIFIER DRAWER Interconnection Diagram 30394008 Rev 54 t A3 Frequency Response 470 806MHz RF In J1 18dBm peak visual RF OUT J2 58dBm peak visual Gain J1 J2 40dB 1 2dB T...

Page 41: ...t to each Capacitors C3 C4 C5 C6 in conjunction with C50 C53 provide the proper input match for Q1 Q3 Coupling capacitorsC1 C2 bring in out of phase equal amplitude signalsfrom 90 hybrid coupler CP1 w...

Page 42: ...s and parallel capacitors e g C10 C11 C12 C127 C19 C20 for Q7 terminated in coaxial balun transformers Z5 Z6 Z7 Z8 The amplified signals from Z5 Z6 are then combined in hybrid coupler HY3 as the signa...

Page 43: ...drops below 28V U1A 1 U1B 7 will turn positive creating a negative at the base of Q1A through U2B shutting off the Control Metering POWER SUPPLY indicator Concurrently a low will be sent to the IF Con...

Page 44: ...avoid cycling the affected amplifier back on as it cools capacitor C3 charges with the appearance of a high at the collector of Q2 placing a permanent ground latch on the base of Q2 through forward b...

Page 45: ...nel related harmonics Unless a network analyzer and knowledgeable technician engineer are available it is recommended that this filter be returned to the factory for repair and or retuning 2 4b Direct...

Page 46: ...and includes the Control Monitor board PC1 and a 5V 15V Power Supply PS1 both mounted on the rear of the panel 2 5a Control Monitor Board Schematic Diagram 40400045 Rev 55 t A5PC1 The Control Monitor...

Page 47: ...xtinguishing AMPLIFIER TEMPERATURE LED DS10 If one of the 300W heat sinks becomes too hot 175 F opening its associated thermostat the Thermal Interface board will develop a short at R44 turning on Q9...

Page 48: ...deo present at INPUT A9 A of the VDS an open is sent from A9J1 NO to J8 1 and is looped to J3 5 placing a high on the Exciter s Control Interface gate A2PC4U2C 10 If a loss of video occurs a ground ap...

Page 49: ...of the above conditions change creating a logic low at J3 3 then the 500W UHF Power Amplifier will be shut down J3 8 GND From A2J4 8 Audio Video Remote Panel Interface A8J1 Jack Pin Function J4 1 REFL...

Page 50: ...E AGC ON OFF This input control begins at REMOTE jack A8J1 7 and by applying a ground this pin can be used to deactivate the voltage that controls IF Converter output AGC attenuator A2PC1CR9 CR10 From...

Page 51: ...tage that drives the AGC meter A2PC3DS12 located on the front panel of the Exciter drawer This voltage is a representation of the IF Converter output AGC voltage taken from Control Interface amplifier...

Page 52: ...upplied to FORWARD POWER meter adjust amplifier U5A the gain of which is dictated by the setting of potentiometer R31 Connected to front panel FWD REFL meter switch at S1 3 the output of U5A is essent...

Page 53: ...d power present at the transmitter s output The signal buffered by U4B is sent from J5 3 to A2PC4J5 3 to be moni tored by VSWR overload comparator A2PC4U6A on the Exciter s Control Interface board If...

Page 54: ...362 3 3b EMEX1 Exciter Drawer Indicators 363 3 3c Troubleshooting Chart 365 3 4 ALIGNMENT 367 3 4a Exciter UHF Bandpass Filter 367 3 5 OUTPUT POWER CALIBRATION 367 3 5a Forward Power 368 3 5b Reflect...

Page 55: ...No lubrication needed 3 2 RECOMMENDED TEST EQUIPMENT EQUIPMENT MANUFACTURER MODEL Digital Multimeter HEWLETT PACKARD E2378A Oscilloscope TEKTRONIX 2232 VHF Sweep Generator WAVETEK 2001 50 Ohm RF Dete...

Page 56: ...tors in the 500W Power Amplifier drawer has failed If a qualified technician is available the defective transistor can be replaced otherwise replace the affected 300W Power Amplifier assembly A3A1 A3A...

Page 57: ...provides verification that an IF signal of appropriate amplitude and frequency is present at the Exciter s input Loss of IF input from the modulator will cause this LED to shut off 4 The AMPLIFIER STA...

Page 58: ...that the AGC system has been properly calibrated and that the transmitter is operating correctly With the AGC MANUAL switch A2PC3S2 in the AGC in position and a loss of gain in the transmitter the AG...

Page 59: ...if necessary SYNTH LOCK UNLIT POWER SUPPLY UNLIT RF POWER METER 0 Defective Synthesizer Check synthesizer for correct output level and frequency Replace if necessary OPERATE UNLIT POWER SUPPLY UNLIT R...

Page 60: ...y LOW OUTPUT POWER OR DISTORTED OUTPUT No Fault indicated Output Power Calibration is incorrect See Section 3 5 Modulator malfunction Replace modulator High loss in one of the modules Test each module...

Page 61: ...quency as shown in Table 361 UHF Synthesizer Programming Chart Program the synthesizer for the new channel and look for the LO carrier on the analyzer Tune the analyzer 44MHz 36MHz for PAL B G below t...

Page 62: ...ing a small tuning tool rotate the OUTPUT LEVEL ADJUST for an external power meter reading of 323W 195W Notice that 500 watts of peak visual power at 0 50 APL plus 25 watts of average aural power at 1...

Page 63: ...11 Check the VSWR OVLD trip point by pressing the momentary VSWR RESET switch on the Exciter front panel which will reactivate the transmitter As the transmitter power rises to 25 the VSWR overload ci...

Page 64: ...brated and should need very little readjustment Also be aware that while manipulating the corrector the transmitter s output must be carefully monitored since changes in linearity can significantly al...

Page 65: ...monitoring of the transmitter provided on the REMOTE connector A8J1 located on the rear Video Audio Remote panel NAME PIN I O TTL TYPICAL LEVEL REFL POWER 1 O 1V AGC VOLTAGE 2 O 7 5V FWD POWER 3 O 3V...

Page 66: ...available to the technician at all times TTU500FA INTERCONNECTION DIAGRAM 40400003 DESCRIPTION VENDOR PART DESIGNATOR Fans 10 560CFM 220Vac EMCEE 4C829 B1 B2 Control Monitor Board EMCEE 30400047 2 A5...

Page 67: ...A2PC1 2 Watt UHF Amplifier EMCEE 40404059 1 A2A1 UHF Synthesizer EMCEE 60367103 1 A2A2A1 Reference Oscillator EMCEE 60368055 1 A2A2A2 Metering Detector EMCEE 40400053 1 A2A3 28V 15V 5V Power Supply IP...

Page 68: ...A C D 21 513 25 559 0 A E B 22 519 25 565 0 B 0 9 23 525 25 571 0 B 2 7 24 531 25 577 0 B 4 5 25 537 25 583 0 B 6 3 26 543 25 589 0 B 8 1 27 549 25 595 0 B 9 F 28 555 25 601 0 B B D 29 561 25 607 0 B...

Page 69: ...5 727 0 E 3 3 50 687 25 733 0 E 5 1 51 693 25 739 0 E 6 F 52 699 25 745 0 E 8 D 53 705 25 751 0 E A B 54 711 25 757 0 E C 9 55 717 25 763 0 E E 7 56 723 25 769 0 F 0 5 57 729 25 775 0 F 2 3 58 735 25...

Page 70: ...0 A E 6 28 527 25 566 15 0 B 0 E 29 535 25 574 15 0 B 3 6 30 543 25 582 15 0 B 5 E 31 551 25 590 15 0 B 8 6 32 559 25 598 15 0 B A E 33 567 25 606 15 0 B D 6 34 575 25 614 15 0 B F E 35 583 25 622 15...

Page 71: ...0 E A 6 52 719 25 758 15 0 E C E 53 727 25 766 15 0 E F 6 54 735 25 774 15 0 F 1 E 55 743 25 782 15 0 F 4 6 56 751 25 790 15 0 F 6 E 57 759 25 798 15 0 F 9 6 58 767 25 806 15 0 F B E 59 775 25 814 15...

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