BMTTTU500FAUHF LPTV Transmitter

Page 1 Revised June 1999 MODEL 2000 FIXED CHANNEL CABLE MODULATOR AND MODEL 2000 I.F. MODULATOR EXCITER OUR MODEL 2000 FIXED CHANNEL MODULATOR HAS BEEN DESIGNED AS A WORKHORSE FOR DEMANDING APPLICATIONS WHERE A HIGH QUALITY, STABLE, AND RELIABLE LOW NOISE FIXED CHANNEL MODULATOR IS REQUIRED AT A REASONABLE PRICE. OUR MODEL 2000 I.F. IS A HIGH QUALITY, LOW POWER BROADCAST MODULATOR, MMDS MODULATOR, OR EMERGENCY ALERT REPLACEMENT I.F. WHICH IS GUARANTEED TO EXCEED ALL FCC REQUIREMENTS FOR CATV, LPTV AND MANY OTHER EXCITER APPLICATIONS. AVAILABLE IN SYSTEM ‘M’ (45.75MHz) SYSTEM “B” (38.9MHz) AND SYSTEM “D” (38.0MHz) I.F. CONFIGURATIONS. FEATURES A switching power supply is utilized for worldwide applications. Output Bandpass filtering is utilized to obtain very low out-of-channel noise. The Audio Modulator is phase locked to a crystal reference for stability. A crystal upconverter oscillator is used for low phase noise. Video, Audio, and combined IF loop-thru’s are standard for use with IF scrambling techniques. A Group Delay Precorrection Filter is included to meet the latest requirements. SAW filtered +45 or +60dBmV output available. Front Panel Controls and Test Point BTSC Stereo compatibility is available. Standard Rack Mount Available in most international television standards. Page 2 Revised June 1999 MODEL 2000 FIXED CHANNEL MODULATOR SPECIFICATIONS: (NORTH AMERICAN NTSC) 1)MAXIMUM OUTPUT LEVEL+60dBmV 2)SPURIOUS OUTPUTS5-750MHz: Less than 60dBc 3)DIFFERENTIAL PHASELess than 2 degrees 4)DIFFERENTIAL GAINLess than 3% 5)VIDEO SIGNAL-TO-NOISE RATIOBetter than 60dBc 6)FREQUENCY RESPONSE TO 4.1MHz±1dB 7)GROUP DELAY PRECORRECTION±50ns 8)CHROMA-LUMA DELAYLess than ±50ns 9)VISUAL CARRIER FREQ. TOL.±500Hz or better 10)AURAL CARRIER LEVEL7 to 25dB below Video Carrier 11)AURAL CARRIER FREQ. TOL.±500Hz or better 12)AUDIO RESPONSE50 to 15kHz or ±1dB 13)AUDIO DISTORTIONLess than 0.2% 14)AUDIO PRE-EMPHASIS75)s Standard (flat, or 50)s opt) 15)AUDIO INPUTBalanced or unbalanced, line level 16)VIDEO INPUT75 Ohms .5 to 2Vp-p 17)AC POWER85-260 Volts; 20 Watts 50-60Hz 18)OUTPUT FREQ.US System M, PAL B, PAL D/K 19)IF IMPEDANCE75 Ohms 20)STANDARD RACK MOUNT Page 3 Revised June 1999 MODEL 2000 TELEVISION MODULATOR INTRODUCTION : The Model 2000 Television Modulator is designed for use in broadcast and other applications where high quality stable signals are required. This unit, in the NTSC format, exceeds all Part 74 and 76 requirements for broadcast exciters. This product is also available to meet most International standards. STANDARD FEATURES: 1.75 Ohm 1 volt p-p video input 2.Baseband audio input usable balanced or unbalanced 3.Utilizes SAW filter for high quality vestigial sideband output 4.Low spurious and harmonic signals 5.Many options available (consult factory) 6.Meets applicable Group Delay characteristics 7.Switching power supply for efficiency and wide voltage range — 85-265 volts 50-60Hz. (Dc power options also) 8.Conservative design for long life and high reliability AVAILABLE OPTIONS: 1.Audio subcarrier input for BTSC encoders that provide a subcarrier output. This option is also provided with switch selectable baseband audio (internal subcarrier oscillator/modulator) input for conventional use. 2.Composite input (Audio subcarrier included with Video) for applications such as signals from microwave equipment. This option is also provided with switch selectable baseband audio (internal subcarrier oscillator/modulator) input for conventional use. 3.Wideband audio input for BTSC stereo encoders that provide a baseband output. 4.Separate audio and video carriers for use with separate aural and visual transmitter upconverter/ amplifiers (one non-SAW filtered visual IF loop standard). 5.Composite output containing both aural and visual carriers where one transmitter upconverter/ amplifier is utilized. Triple IF loops for testing or use with scrambling systems are standard (aural, visual and SAW filtered composite). 6.Choice of output levels +45 or +60dBmV. 7.Channelized output with user’s choice of carrier frequency. (7 to 850MHz at +60dBmV level) (three IF loops standard) 8.Dc coupled video for use with many baseband scrambling systems. (This option does not provide clamping, white clip or modulation depth indication for the video.) MODEL 2000 TELEVISION MODULATOR Page 4 Revised June 1999 9.Slow clamping for certain baseband scrambling methods. We can provide many other optional configurations. Contact factory for information. INSTALLATION: MOUNTING: This product is designed to be mounted in a standard EIA 19-inch wide rack. Space should be left above and below the unit for ventilation. A climate controlled room is ideal but proper operation will occur over a wide range of operating conditions. Depending upon other heat producing equipment in the rack, forced air ventilation of the rack may be necessary to prevent excessive temperatures. If the mounted unit will be subjected to severe mechanical shock, such as mobile use, the rear of the chassis should be supported. POWER: This product is equipped with a three-wire cord. The third prong should not be removed or otherwise defeated. A SHOCK HAZARD COULD RESULT. This product will operate properly from power sources almost anywhere in the world, although some cautions are in order: 1.Ac voltages of 85 to 265 volts and 50 to 60Hz only may be used. If the voltage may exceed the above maximum for even a short time, a step-down transformer or power line regulator is recommended to reduce the maximum to well within the above range. 2.Lightning and surge protection should be provided at the power entry of the building where this equipment is installed. 3.Proper grounding is important and should include bonding of racks together and connection of racks to a good earth ground. REAR PANEL CONNECTIONS: Audio: The audio input may be used balanced or unbalanced. The audio is connected through a three-pin quick connect plug. To connect wiring pull the …

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4)EXTERNAL PHOTOS TTU500FA Front TTU500FA Rear EMEX1 2 Watt UHF Exciter Front EMEX1 2 Watt UHF Exciter Rear 500W UHF Amplifier Drawer Front 500W UHF Amplifier Drawer Rear

3)IDENTIFICATION LABEL/LOCATION INFO The certification identification label for the aforementioned transmitter is shown below. This label shall be displayed conspicuously on the transmitter’s top rear cabinet frame.

5)INTERNAL PHOTOS EMEX1 2W UHF Exciter Internal 500W UHF Amplifier Drawer Top Side 500W UHF Amplifier Drawer Bottom Side Transmitter Cabinet Top Power Detector and UHF Bandpass Filter

161 1)OPERATIONAL DESCRIPTION The EMCEE Model TTU500FA UHF Low Power Television Transmitter, which will be manufactured in quantity, is an internally diplexed unit rated to provide 500 watts peak visual and 25 watts average aural on any FCC specified UHF television channel extending from 470 to 806MHz (Ch.14 to Ch.69). The TTU500FA is completely solid state and comprised of five different assemblies. The RF sections begin with a standard television modulator which supplies diplexed visual and aural modulated IF carriers (45.75MHz visual/41.25MHz aural) to the EMEX1 2 Watt Exciter drawer. Here the carriers are converted to the desired UHF frequencies, filtered and amplified to the 100mW level. The television signal is then split into equal parts to drive two 300 Watt Power Amplifiers contained in a single 500 Watt Power Amplifier drawer. The output of the amplifier drawer is then connected to a six-section UHF Bandpass Filter where the unwanted products created by combined amplification are reduced to the appropriate levels. Other assemblies in the TTU500FA Transmitter include a Control/Metering panel to monitor the various transmitter circuits and an Ac Distribution panel to dispense power throughout the transmitter. The data contained in this Certification report was obtained from tests performed on an EMCEE production unit having an output frequency of UHF channel 56 (722-728MHz) using an SA6340 Modulator. However, to better serve our customers, EMCEE also wishes to use the EMCEE EM1 and RF Communications 2000 as appropriate substitutes for the SA6340. These modulator models, which also comply with Part 74, are used in all current EMCEE LPTV, MMDS and ITFS type accepted equipment requiring modulators. Also, we are requesting that the high stability (0.5PPM) Vectron CO-254D57 oscillator with a X16 multiplier be used in the TTU500FA. This oscillator, replacing the standard synthesizer, will provide the customer with precision offset capability. Tests on both the oscillator and synthesizer are also found in this report. In order to meet the requirements of Section 74.750(c)(5) of the FCC Rules, the TTU500FA switches to a nonradiating condition in the absence of a modulating video signal. Additionally, an optional Code Identification Unit, capable of shifting the frequency of the transmitted carriers, may also be included to satisfy 74.750(c)(7) of the Rules. A complete list of the test equipment utilized to obtain the certification data can be found in Section 1.3 of this report. Information relating to the description, operation and maintenance of the transmitter can be found in the TTU500FA Transmitter and RF Communications 2000 Modulator Instruction Manuals. Information concerning the EM1 and SA6340 Modulators can be found in the previously submitted type acceptance report for the TTV1000ES (BMTTTV1000ES Grant 09-30-99).

161 7)PARTS LIST / TUNE UP INFO 1.4Active Device List The following is a complete listing of all the active devices used in the EMCEE Model TTU500FA UHF Television Transmitter. The devices are grouped together as seen on each specific schematic or interconnection diagram. Given with each device is its schematic designator, EMCEE part number and function. DEVICEPART #/DESIGNATORFUNCTION IF/CONVERTER Schematic Diagram 40404021 Integrated CircuitAD603AR/U1Variable Gain Amplifier Integrated CircuitSGA-3286/U8, U11, U20RF Amplifier PIN DiodeHSMP-3814/CR7-CR10RF Attenuator LINEARITY CORRECTOR Schematic Diagram 40404011 DiodeHSMS-2812/CR1-CR4RF Switch Integrated CircuitMAV-11SM/U1-U8RF Amplifier UHF SYNTHESIZER Schematic Diagram 30367094 Integrated Circuit3B160/U4Reference Divider Integrated Circuit3B166/U2Dual Prescaler Integrated Circuit3B161/U1Synthesizer Integrated Circuit3B149/U3Loop Filter Integrated Circuit3B141/U6Feedback Amplifier Integrated Circuit3B151/U5RF Amplifier VCOV707S001/G1Oscillator REFERENCE OSCILLATOR Schematic Diagram 10368037 Integrated Circuit3B130/U1RF Amplifier TCXORTX0771AD/G1Oscillator DEVICEPART #/DESIGNATORFUNCTION 162 UHF BANDPASS FILTER Schematic Diagram 20404015 Integrated CircuitSGA-4286/U1RF Amplifier X16 MULTIPLIER (With Vectron Oscillator) Schematic Diagram 30367226 Hybrid CircuitSK2/A1, A2, A3Frequency Doubler Integrated Circuit3B153/U1RF Amplifier Integrated Circuit3B141/U2RF Amplifier Integrated Circuit3B151/U3, U6RF Amplifier Integrated Circuit2B131/U4RF Amplifier Integrated Circuit2B130/U5RF Amplifier 2 WATT UHF AMPLIFIER Schematic Diagram 30404029 Integrated CircuitSGA-4186/U1RF Amplifier TransistorAH1/Q1RF Amplifier TransistorPTF10027/Q2RF Amplifier 300 WATT UHF POWER AMPLIFIER Schematic Diagram 40394135 TransistorPTF10027/Q1, Q3RF Amplifier TransistorPTF10007/Q5, Q6RF Amplifier TransistorPTF10159Q7-Q10RF Amplifier 163 3.1PERIODIC MAINTENANCE SCHEDULE: OPERATIONRECOMMENDATION ALIGNMENTUpon installation and at one-year intervals thereafter (Section 3.4). OUTPUT POWER CALIBRATIONSame as above (Section 3.5). FANSInspect as often as possible (at least monthly) and clean when necessary. No lubrication needed. 3.2RECOMMENDED TEST EQUIPMENT: EQUIPMENTMANUFACTURERMODEL # Digital MultimeterHEWLETT PACKARDE2378A OscilloscopeTEKTRONIX2232 VHF Sweep GeneratorWAVETEK2001 50 Ohm RF DetectorTELONIC BERKELEY8553 20dB/30dB AttenuatorNARDA766-20/30 30dB Directional CouplerNARDA3001-30 50 Ohm, 500W Dummy LoadNARDA785-30 Power MeterHEWLETT PACKARD435B Frequency CounterHEWLETT PACKARD5386A Spectrum AnalyzerHEWLETT PACKARD8594E NTSC Video GeneratorTEKTRONIXTSG100 3.3TROUBLESHOOTING: If the visual and/or aural output signals from the transmitter appear distorted, noisy or nonexistent, consider the following procedure as a troubleshooting aid. This procedure assumes the transmitter wiring as well as the cabling and connectors are trouble free. It also assumes the modulator is receiving baseband video and audio signals while providing the required visual and aural IF carriers at appropriate levels of 8dBm peak and 21dBm average, respectively. The general problem area will be indicated by simply checking the front panel diagnostic lights as well as the transmitter and 164 Exciter RF POW ER meters. The diagnostic indicators are located on the front panel of the EMEX1 Exciter and on the Control/Metering panel at the top front of the transmitter cabinet. 3.3a Control/Metering Panel Indicators: 1.Under normal operation the following indicators will be lit green: AMPLIFIER POWER SUPPLY RF POWER meter = 100% with FWD green/<10% with REFL green 2.In standby operation the AMPLIFIER indicator will be lit green. 3.If the POWER SUPPLY indicator fails to illuminate with the transmitter in OPERATE, it is signaling that one of the 32V power supplies in the 500W Power Amplifier drawer indicated (A3PS1 or PS2 / see Figure 361) has failed and needs to be replaced. Until that time, the IF/Converter’s output AGC circuit is deactivated allowing the transmitter to operate at reduced power. 4.If the AMPLIFIER light goes out with the transmitter providing power, it indicates that one of the output transistors 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, A3A2) or 500W Power Amplifier drawer (A3). In the interim, the fault indication has deactivated the IF/Converter’s output AGC control so that the transmitter can operate at lower power. 5.If the AMPLIFIER TEMP indicator lights yellow, this is a sign that one of the 300W Amplifier Assemblies in the 500W Amplifier drawer is operating at a temperature high enough to cause transistor damage. This fault usually occurs due to high ambient temperature at the transmission site, amplifier drawer cooling fan failure or lack of maintenance allowing for fouled fans and blocked front panel air vents. 6.Assuming that the transmitter had previously been operating at its appropriate power and none of the indicators discussed above are showing a fault, if the FWD RF POWER meter is now reading less than 100% with the Exciter RF POWER meter indicating 100% (AGC off) or more (AGC on), a loss of gain has occurred somewhere in the system after the Exciter’s output. Check first for faulty cables or a detuned/defective output UHF Bandpass Filter (A7FL1). Next, check the gain of the 500W Power Amplifier drawer. Neither the Splitter (A3CP1), Combiner (A3CP2) nor driver amplifier transistors contained in the 500W Power Amplifier are monitored and, if faulty, will cause loss of gain. Identify the problem component and replace the affected drawer, amplifier assembly, module or component as soon as possible. If it is necessary to operate the transmitter before repairs are effected, be sure to defeat the output AGC by releasing (out) the Exciter’s AGC/MANUAL button. 7.If the REFL RF POWER meter registers more than 10% returned …

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SECTION V SCHEMATIC DIAGRAMS MODULE SCHEMATICS ARE LISTED IN ALPHANUMERICAL SEQUENCE