OUSDT830A300-Watt UHF Digital Transmitter

Instruction Manual DM8-R Digital Modulator Tray AXCERA, LLC 103 FREEDOM DRIVE, P.O. Box 525 LAWRENCE, PA 15055-0525 USA (724) 873-8100 • FAX (724) 873-8105 www.axcera.com • [email protected] DM8-R Digital Modulator Tray Table of Contents DM8-R Digital Modulator, Rev. 0 1 DM8-R DIGITAL MODULATOR TABLE OF CONTENTS SECTION...................................................................................................PAGE Overview......................................................................................................2 Inputs and Outputs........................................................................................2 Front Panel Interface......................................................................................2 DM8-R Modulator Board Configuration..............................................................3 Detailed Circuit Descriptions............................................................................3 DM8-R Modulator Board Description..............................................................3 SMPTE-310 Input.....................................................................................3 Channel Coder.........................................................................................3 Analog Output Section.............................................................................4 Pilot Frequency Generation.......................................................................4 DM8-R Front Panel Board Description............................................................4 Initial Setup..................................................................................................5 Drawing List..................................................................................................6 DM8-R Digital Modulator Tray Tray Description DM8-R Digital Modulator, Rev. 0 2 DM8-R Modulator Tray Overview The DM8-R modulator Tray is an ATSC compliant 8 VSB modulator that mounts in a standard 19” rack. The DM8-R modulator accepts a SMPTE-310 MPEG data stream and outputs a 6 MHz wide IF output centered at 44 MHz with a pilot carrier at 46.69 MHz. The DM8-R modulator provides linear and nonlinear correction capability for the transmission path as well as internal test sources that are used during initial transmitter installation. All of the functions of the DM8-R modulator are controlled from the LX Controller LCD display and pushbuttons. Inputs and Outputs The inputs and outputs of the DM8-R modulator are described in the table below. Description Reference Designator Function IF Output J4 Provides a 44 MHz IF Output with a 50 ohm output impedance 10 MHz Input J3 10 MHz input to the DM8-R modulator. Provides the reference frequency to the pilot VCXO. SMPTE-310M Input J2 SMPTE-310 input that provides the MPEG stream to the modulator. 110/220 VAC J1 Input Power to the Modulator Front Panel Interface The following table describes the connectors and indicators on the front panel. LED Indicator or Connector Function PWR Indicates that the DC power supply is operating MPEG LED Indicates the presence of a valid MPEG stream at the J1-2B input PLL A LED Indicates that the DM8 symbol clock is locked to the frequency of the 10 MHz reference. PLL B LED Indicates that the pilot frequency is locked to the incoming 10 MHz reference. IF Sample Jack BNC Provides a sample of the IF output from the modulator at approximately a –20 dBm level. RS-232 SERIAL Serial Port used for initial modulator alignment DM8-R Digital Modulator Tray Board Descriptions DM8-R Digital Modulator, Rev. 0 3 DM8-R Modulator Board Configuration The Digital Modulator Board in the DM8-R is setup through a configuration header located on the board. The configuration header contains 8 jumper positions between pins on J26 and J27. The functions of these positions are given in Table 1. Table 1 J26/J27 Configuration Header Definition Function when Jumper Position Jumper Is Present Jumper Not Present 1 Header Enabled RS485 Enabled 2 CW Zero Normal Mode 3 Internal PRBS External Source 4 Linear Equalizer On Linear Equalizer Off 5 Nonlinear Off Nonlinear On 6 Preset Table 1 Preset Table 2 7 AGC Tracking AGC Fixed 8 Spare Detailed Circuit Descriptions Digital Modulator Board (1304884) SMPTE-310 Input The DM8-R modulator accepts a SMPTE-310 input the BNC Jack J2 located on the rear panel of the tray. This input is connected to J42 on the Digital Modulator Board via a RG-179 cable. This input is applied to a high speed window comparator that adjusts the level to a low voltage TTL signal to be used by the Altera FPGA, U3. The SMPTE-310 signal is input to the FPGA to recover the clock and the data. A portion of the clock and recovery circuit is performed by a high speed comparator, U17, that functions as an external delay circuit. Channel Coder The FPGA subsequently uses the SMPTE-310 clock and data as the input to the channel coder contained inside the FPGA. The channel coder is a series of DSP blocks defined by the ATSC standard for 8 VSB data transmission. These blocks include the data randomizer, Reed Solomon Encoder, data interleaver, trellis coder, and sync insertion. The channel coder portion inside the FPGA generates the 8 distinct levels in an 8 VSB transmitter. These levels are subsequently input to a linear equalizer that provides for frequency response correction in the transmission path. The linear equalizer is a 67 tap FIR filter that is loaded with tap values from the microntroller, U1, located on this board. The output of the linear equalizer is then input to two pulse shaping filters, an in phase (I) and a quadrature (Q) filter that are also located inside the FPGA. The pulse shaping filters are FIR filters that have fixed tap values that are preset inside the FPGA. The output of the pulse shaping filters is then applied to a Pre-Distortion Linearizer chip, U4, which can be used to correct for nonlinearities in the data transmission path. The output of the Pre-Distortion chip is …

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INSTRUCTION MANUAL DT830A 300-WATT DIGITAL UHF TRANSMITTER AXCERA, LLC 103 FREEDOM DRIVE, P.O. Box 525 LAWRENCE, PA 15055-0525 USA (724) 873-8100 • FAX (724) 873-8105 www.axcera.com • [email protected] 300-Watt Digital UHF Transmitter Table of Contents DT830A, Rev. 1 i TABLE OF CONTENTS CHAPTER 1 INTRODUCTION 1.1 Manual Overview...................................................................................1-1 1.2 Assembly Designation Numbers..............................................................1-1 1.3 Safety..................................................................................................1-1 1.4 Maintenance .........................................................................................1-2 1.5 Material Return Procedure......................................................................1-2 1.6 Warranty for Axcera Products – Limited One-Year Warranty ......................1-3 CHAPTER 2 SYSTEM DESCRIPTION 2.1 System Overview .................................................................................2-1 2.1.1 8-VSB Modulator Tray...................................................................2-1 2.1.2 UHF Digital Exciter Tray................................................................2-1 2.1.3 UHF Digital RF Output Components................................................2-2 2.1.4 Transmitter Power Requirements ...................................................2-2 2.2 Control and Status ................................................................................2-3 2.2.1 8-VSB Digital Modulator................................................................2-3 2.2.2 UHF Digital Exciter Tray................................................................2-4 2.2.3 UHF Amplifier Trays......................................................................2-6 2.3 Remote Connections..............................................................................2-7 CHAPTER 3 INSTALLATION AND SETUP PROCEDURES 3.1 Site Considerations................................................................................3-1 3.2 Unpacking the Cabinets .........................................................................3-4 3.3 Installation of the Cabinets and Trays......................................................3-5 3.4 Setup and Operation Procedures.............................................................3-5 CHAPTER 4 CIRCUIT DESCRIPTIONS 4.1 UHF Exciter Tray ...................................................................................4-1 4.1.1 UHF Filter....................................................................................4-1 4.1.2 UHF Generator Board ...................................................................4-1 4.1.3 10-MHz Reference Generator Board ...............................................4-1 4.1.4 PLL Board....................................................................................4-2 4.1.5 Power Entry Module Assembly.......................................................4-4 4.1.6 IF Phase Corrector Board ..............................................................4-4 4.1.7 ALC Board...................................................................................4-6 4.1.8 Visual/Aural Metering Board ........................................................4-12 4.1.9 UHF Upconverter Board ..............................................................4-13 4.1.10 Transmitter Control Board.........................................................4-15 4.1.11 +12V(4A)/-12V(1A) Power Supply Board....................................4-19 4.1.12 5-Section Delay Equalizer Board, 44 MHz....................................4-20 300-Watt Digital UHF Transmitter Table of Contents DT830A, Rev. 1 ii TABLE OF CONTENTS (continued) 4.2 8-VSB Digital Modulator.......................................................................4-20 4.2.1 Vector Modulator Board ..............................................................4-20 4.2.2 Switch Board .............................................................................4-21 4.2.3 Local Oscillator Board .................................................................4-21 4.2.4 LED Board.................................................................................4-22 4.2.5 VSB Modulator Interface Board....................................................4-22 4.2.6 VSB Filter Board.........................................................................4-22 4.2.7 DC Power Supply Board ..............................................................4-23 4.2.8 VSB IF Filter Board.....................................................................4-23 4.2.9 VSB Symbol Generator Board......................................................4-23 4.3 UHF Amplifier Trays.............................................................................4-23 4.3.1 1-Watt Amplifier Board Assembly.................................................4-23 4.3.2 1-Watt Amplifier Board ...............................................................4-24 4.3.3 4-Way Splitter Assembly.............................................................4-24 4.3.4 4-Way Splitter Board..................................................................4-24 4.3.5 Coupler Board Assembly .............................................................4-25 4.3.6 Dual Peak Detector Enclosure......................................................4-25 4.3.7 Dual Peak Detector Board, Single Supply......................................4-25 4.3.8 Dual Stage Amplifier Assembly, Mid Band, Class AB.......................4-26 4.3.9 Generic Dual Stage Amplifier Board, Class AB ...............................4-27 4.3.10 Amplifier Protection Board.........................................................4-27 4.3.11 Amplifier Control Board.............................................................4-28 4.3.12 Single Stage Amplifier Assembly, Mid Band, Class A.....................4-30 4.3.13 Generic Single Stage Amplifier Board, C…

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February 16, 2010 Federal Communications Commission 445 12th Street, SW Washington, DC 20554 Gentlemen: Axcera is submitting this FCC Equipment Authorization report for the DT830A, a 300-watt UHF digital television transmitter. We are applying for a low-power television, type acceptance approval for this UHF transmitter. The FCC identifier selected for this product is OUSDT830A. The DT830A is a complete 300-watt UHF solid-state digital transmitter. It operates at a nominal output power of 300 watts average, while meeting or exceeding the FCC Part 74 requirements. The transmitter may also be operated at 30 watts average with equivalent or improved performance. The enclosed application and test data report are intended to demonstrate compliance with FCC guidelines. Please contact me if you have any questions or if you need additional information. I can be reached by fax at (724) 873-8105 or phone at (724) 873-8100, extension 233. Sincerely, ______________________ David Brooking Principal Engineer

Axcera-DT830A FCC Equipment Authorization Report External Photos February 2010 2-1 2. EXTERNAL PHOTOS 2.1 Front view, complete Axcera-DT830A Transmitter Axcera-DT830A FCC Equipment Authorization Report External Photos February 2010 2-2 2.2 Rear view, complete Axcera-DT830A Transmitter Axcera-DT830A FCC Equipment Authorization Report External Photos February 2010 2-3 2.3 Rear view, complete Axcera-DT830A Transmitter

Axcera-DT830A FCC Equipment Authorization Report ID Label/Location Info February 2010 1-1 1. ID LABEL/LOCATION INFO 1.1 Front Panel FCC Label 1.2 Rear Panel Manufacturer’s Label Axcera-DT830A FCC Equipment Authorization Report ID Label/Location Info February 2010 1-2 1.3 Rear view, complete Axcera-DT830A Transmitter with FCC ID Label & Manufacturer’s Label

Axcera-DT830A FCC Equipment Authorization Report Internal Photos February 2010 6-1 6. INTERNAL PHOTOS 6.1 Top view, Exciter Tray Axcera-DT830A FCC Equipment Authorization Report Internal Photos February 2010 6-2 6.2 Side view, 300-Watt Amplifier Tray x2 (left side) 6.3 Side view, 300-Watt Amplifier Tray x2 (right side) Axcera-DT830A FCC Equipment Authorization Report Internal Photos February 2010 6-3 6.4 Front View, DM8 Modulator Tray 6.5 Rear View, DM8 Modulator Tray 6.6 Top View, DM8 Modulator Tray

Axcera-DT830A FCC Equipment Authorization Report Operational Description February 2010 8-1 8. OPERATIONAL DESCRIPTION - MODEL Axcera-DT830A 8.1 General Description The DT830A is a complete 300watt UHF solidstate, digital television transmitter. It operates at a nominal output power of 300 watts average. 8.2 Technical Specifications Type of Emission......................................................................6M00K1D Frequency Range ....................... 470 MHz to 608 MHz and 614 to 806 MHz Output Power.............................................................. 300 watts average 8.3 Performance Specifications Operating Frequency Range ........ 470 MHz to 608 MHz and 614 to 806 MHz RF output  Nominal: Power.............................................................. 300 watts average Impedance..................................................................... 50 ohms Connector .......................................................................7/8” EIA Regulation of Output .........................................................................3% SignaltoNoise Ratio (SNR) ........................................... 27 dB or better Carrier Frequency Stability ........................................................±1000 Hz Out of Band: Compliant with FCC Mask (Measured in 30 KHz RBW, relative to total average power Channel Edge ± 500 KHz .................................................47 dB or better 6 MHz Channel Edge......................................................110 dB or better Data Interface: Input Rate.....................................................19.39 Mbps, 6 MHz Channel Input Interface.......................... SMPTE 310M, Serial Differential ECL & TTL Electrical Requirements Power Line Voltage........................ 230 volts, 1 phase or 3 phase 50/60 Hz Power Consumption................................................................3000 watts Environmental Maximum Altitude ...................................................................8,500 feet Operational Temperature Range ...........................................0°C to +50°C Axcera-DT830A FCC Equipment Authorization Report Operational Description February 2010 8-2 Mechanical Dimensions: Width ........................................................................... 22 inches Depth ........................................................................... 34 inches Height .......................................................................... 55 inches Weight.......................................................................... 375 lbs 8.4. System Overview The DT830A is made up of the trays/assemblies listed in Table 81. Table 8-1. DT830A Major Trays and Assemblies MAJOR ASSEMBLY DESIGNATOR TRAY/ASSEMBLY NAME A1 DM8 Digital Modulator A2 UHF Exciter A3A4 Amplifier Array 8.4.1 UHF Exciter Tray The UHF Exciter Assembly contains a UHF Exciter Tray (1142445), two Variable Gain/Phase Trays (12451200), a Metering Panel (1061456), an AC Distribution Assembly, Exciter (12451500) and a Remote Interface Assembly (1061198). The UHF Exciter Tray (1142445), takes the Digital IF Input that is upconverted to the On Channel RF by mixing it with a L.O. signal generated by the Channel Oscillator Assembly. The RF Output of the UHF Exciter at J15 connects to a Splitter, which splits the RF two ways with the RF Output #1 connected to the input of the 1st Variable Gain/Phase Tray (12451200) and RF Output #2 connected to the input of the 2nd Variable Gain/Phase Tray (12451200). The output of the 1st Variable Gain/Phase Tray connects to the Side A Amplifier Assembly (12781300). The output of the 2nd Variable Gain/Phase Tray connects to the Side B Amplifier Assembly (12781300). 8.4.1.1 Control and Status The Control and Status of the Transmitter are provided by the Meter indications on the Metering Panel and the Variable Gain Phase Trays. There are also Control, Status and LED Indications located on the front panel of the UHF Exciter Tray. The switches and LED indicators, which are mounted so that the switches and LEDs are operated or viewed from the front Panel of the UHF Exciter, are part of the Transmitter Control Board (12451101). On the UHF Exciter Tray, switch (S1) is an Operate/Standby Switch that provides the Operate Commands (Enables), when in Operate, to each of the Amplifier Arrays. The Enable is needed to turn on the Switching Power Supplies located in each of the UHF Amplifier Trays. When the UHF Exciter is in Operate, the Green LED (DS2) is On and when in Standby the Amber LED (DS1) is On. NOTE: If the Transmitter does not switch to Operate, when S1 is switched to Operate, check that a Dummy Jumper Plug is connected to Jack J7, with a Jumper between Pins 1 & 2, located on (A9) the Remote Interface Assembly in the Single UHF Exciter Assembly. The Jumper provides the Interlock to the UHF Exciter needed for the operation of the Transmitter. If the Interlock is present, the Green LED (DS5), located on the Transmitter Control Board, should be lit. Axcera-DT830A FCC Equipment Authorization Report Operational Description February 2010 8-3 Operation of the Transmitter is controlled by the front panel switches located on the UHF Exciter Tray. During Normal operation of the Transmitter, Switch S2 should be in the Auto position. The front panel of the UHF Exciter also has LEDs that indicate a Video Fault (Loss), Red LED (DS9) and a VSWR Cutback, Amber LED (DS7). 8.4.1.2 Digital Input and Remote Connections The Digital Input to the Transmitter, connects to the (A9) Remote Interface Panel located on the rear of the Single UHF Exciter Assembly. The Digital Input connects to Jack J2 that is cabled to J2 on the DM8R Modulator. Remote Monitoring and Operation of the Transmitter is provided through the Jacks (J8, J9 & J10) located on the Remote Interface Assembly mounted toward the rear of the Single UHF Exciter Assembly. Jack (J7) should have a dummy plug connected to it, which has a jum…

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Axcera-DT830A FCC Type Acceptance Report Parts List/Tune-up Info February 2010 7-1 7. PARTS LIST/TUNE-UP INFO 7.1 Parts List The transmitter, can be subdivided as follows: DM8 Modulator Tray: -Digital Modulator Board UHF Exciter Tray: -Delay equalizer board -ALC board -IF phase corrector board -UHF upconverter board -UHF Generator Board - PLL Board -Transmitter control Board -Power supply board Amplifier Tray (x2): -Variable gain/phase board -1 watt UHF amplifier board -UHF filter -Single stage amplifier assembly, class A -Coupler board assembly -Dual stage amplifier assembly, class AB -4 Way splitter assembly -Dual stage amplifier assemblies, class AB -4 Way combiner assembly -Circulator -Dual peak detector board -Amplifier protection board -Amplifier control board -Switching power supply 7.2 Tune-up Information 7.2.1 Digital Modulator Tray The digital modulator receives an external SMPTE-310 MPEG stream input and provides a 44 MHz IF output to the UHF Exciter Tray. There are no internal user adjustments. 7.2.2 UHF Exciter Tray The Exciter Tray has been factory tuned and should need no alignment to achieve normal operation. The UHF exciter tray operates using the digital IF output from the DM8-R modulator or other digital IF source. The digital IF connects to J6 on the rear of the UHF exciter, which is cabled to the delay equalizer board, and then to the IF relays on the ALC board . Axcera-DT830A FCC Type Acceptance Report Parts List/Tune-up Info February 2010 7-2 7.2.2.1 Delay Equalizer Board The procedure for performing a delay equalization adjustment for the UHF exciter tray is described in the following steps: 1. Set J19 to the proper position (for either a 50-
or 75-
input) and monitor the output of the board at J10 with a spectrum analyzer. 2. Bypass all attenuation and equalizer sections, except delay equalizer #1. With W12 removed, tune L30 for the proper center frequency as shown in Table 5-2. Install W12 on J22 and adjust L21 and C43 for the best frequency response across the band. Jumper in attenuator equalizer #1. 3. Pull W14 from J26 and adjust L29 for the proper center frequency. Install W14 and adjust L18 for the best frequency response. 4. Repeat Steps 2 and 3 for each delay/attenuation equalizer while tuning the proper inductor for each section. 5. After all five delay/attenuation equalizers have been adjusted, individually jumper in all of the sections and fine tune, as needed, for the best group delay and frequency response. 7.2.2.2 IF Phase Corrector Board As shipped, the exciter was preset to include linearity (gain vs. level) and phase pre- distortion. The pre-distortion was adjusted to approximately compensate the corresponding non-linear distortions of the amplifier trays. Locate (A9) the IF phase corrector board (1227-1250) mounted in the UHF exciter tray. Because the amplitude correction portion of the board is not utilized in this configuration, the jumper W3 on J10 should be in the disable position and R35 and R31 should be fully counter-clockwise (CCW). R68 is the range adjustment and should be set in the middle. The phase correction enable/disable jumper W2 on J9 should be in the Enable position to ground. Set up a spectrum analyzer with 30 kHz resolution bandwidth and 30 kHz modulation bandwidth to monitor the intermodulation products of the RF output signal. There are three corrector stages on the IF phase corrector board, each with a magnitude and a threshold adjustment which are adjusted as needed to correct for any intermod problems. Adjust the R3 threshold for the cut in point of the correction and the R7 magnitude for the amount of the correction that is needed. The jumper W1 on J8 is set to give the desired polarity of the correction shaped by the threshold R11 and magnitude R15 adjustments. After setting the polarity, adjust the R11 threshold for the cut in point of the correction and the R15 magnitude for the amount of the correction that is needed. Finally, adjust the R19 threshold for the cut in point of the correction and the R23 magnitude for the amount of the correction that is needed. The above pots are adjusted for the greatest separation between the digital signal and the intermod at the channel edges. 7.2.2.3 UHF Upconverter Board W1 on J10 in Manual. R10 is a gain control which is adjusted to give approximately +17 dBm Output at J5 of the Board with 0 dBm of IF into it. Axcera-DT830A FCC Type Acceptance Report Parts List/Tune-up Info February 2010 7-3 7.2.2.4 UHF Generator Board The UHF generator board is mounted in the UHF generator enclosure. This procedure should be performed to align this board. In the Manual Adjust Set Up position, W1 on J4 between Pins 2 & 3, on (A13) the PLL board (1286-1104), adjust R12 for –2.5 volts at J6 pin 2. Connect J1, the sample output of the section of the UHF generator board, to a spectrum analyzer, tuned to the crystal frequency, and peak tuning capacitors C6 and C18 for maximum output. Also tune L2 and L4 for maximum output. The output level should be about +5 dBm. The channel oscillator should maintain an oven temperature of 50° C. If a spectrum analyzer is not available, connect a digital voltmeter (DVM) to TP1 on the UHF generator board. Tune capacitor C32 for maximum voltage at TP1. Connect J2, the sample output of the channel oscillator, to a suitable counter and tune C11, the coarse adjust, to the crystal frequency. The fine frequency is controlled by the external PLL circuit when in the Auto mode. Caution: Do not re-peak C32. This can change the output level. Connect a spectrum analyzer to J2, the output jack of the board. Tune C32, C34, C38, C40, C44, and C46 for maximum output. Re-adjust all of the capacitors to minimize the seventh and the ninth harmonics of the channel oscillator frequency. They should be down at least -30 dB without affecting the output of the UHF generator board. If a spectrum analyzer is not available, a DC voltmeter can be used. When a voltmeter is used, the harmonic …

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Axcera – DT830A Equipment Authorization Report Test Report February 2010 4-1 4. TEST REPORT 4.1 RF Power Measurements Figure 4-1 shows the test equipment setup for the RF power measurements. Figure 4-1. Test Equipment Setup for RF Power Measurements The output power of the DT830A was adjusted to obtain 300 watts average RF output as observed on the power meter. At this power level, the final Measured Power: +14.77 dBm Coupling Loss: -40.0 dB Power: +54.77 dBm Power = 300 Watts With the power level properly set to 300 watts average, all required tests were performed and recorded in the following sections. DT830A Transmitter Hewlett Packard Power Meter Bird Model 8892-300 50 Ohm Termination Directional Coupler EFA Test Meas. Set HP Spectrum Anaylzer Device Under Test Bandpass Filter Axcera – DT830A Equipment Authorization Report Test Report February 2010 4-2 4. 2 Modulation Characteristics The modulator tray incorporates a modulation technique known as 8-Level Vestigial Side-band (8-VSB), which uses a layered digital architecture and a single carrier frequency. A pilot tone is provided, to allow rapid acquisition of the signal by receivers. The 8-VSB system transmits a serial data bit stream at a rate of 19.4 Mbps in a 6 MHz television channel. This type of transmission is far less susceptible to propagation impairments such as multi-path, noise and interference as compared to analog transmissions. Figure 4-2. Typical Demodulation Test Setup DT830A Transmitter Directional Coupler 50 Ohm Termination EFA TV Test Receiver 20 dB Attenuator HP Power Meter Device Under Test RFA 300 Test Measurement Set Bandpass Filter Axcera – DT830A Equipment Authorization Report Test Report February 2010 4-3 4. 3 Error Vector Magnitude (EVM) and Signal to Noise Ratio (SNR) The Tektronix RFA 300 was used to measure that the un-equalized patterns are within the ATSC/FCC EVM limit of 4% and SNR limit of 27db. Figure 4-3. Constellation Diagram Axcera – DT830A Equipment Authorization Report Test Report February 2010 4-4 4. 4 Frequency Response and Group Delay Figure 4-4. Frequency Response and Group Delay Plots Axcera – DT830A Equipment Authorization Report Test Report February 2010 4-5 4.5 Occupied Bandwidth Using the test setup in Figure 4-2, with the transmitter operating at maximum power, a photograph of the transmitter occupied bandwidth spectrum was taken and is shown in Figure 4-7. Figure 4-6. Channel Occupied Bandwidth Axcera – DT830A Equipment Authorization Report Test Report February 2010 4-6 4.6 Conducted Spurious Emissions Part 74.794 of the Rules states: (ii) Stringent mask. In the first 500 kHz from the channel edges, emissions must be attenuated no less than 47 dB. More than 3 MHz from the channel edges, emissions must be attenuated no less than 76 dB. At any frequency between 0.5 and 3 MHz from the channel edges, emissions must be attenuated no less than the value determined by the following formula: A(dB) = 47 + 11.5 (Df–0.5). Figure 4.6 shows the post filter response of the transmitter with the limit lines in the adjacent channel. The only other out of band energy measurable before the mask filter and low pass filter is at the harmonics of the channel frequency. The Hewlett Packard Spectrum Analyzer was used to measure harmonics before the low pass and mask filter. The levels were then added to the filter attenuation at the 2 nd and 3 rd harmonics for a reading of less than –110dB at output of the mask filter. Figure 4-7A. Reference ( MHz) = -19.70 dBm (Pre-Filter) Axcera – DT830A Equipment Authorization Report Test Report February 2010 4-7 Figure 4-7B. Second Harmonic (1342 MHz) = -60.00 dBm (Pre-Filter) Figure 4-7C. Third Harmonic (2013 MHz) =>-75.00…

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