LUHPM300FM Broadcast Radio Transmitter

DB ELETTRONICA TELECOMUNICAZIONI S.p.A. PM 300 - FM Broadcasting Transmitter - USER’S MANUAL1 /108 FM Broadcasting Transmitter User’s Manual Release 2.0 - DB ELETTRONICA TELECOMUNICAZIONI S.p.A. - - Via Lisbona, 38 - 35127 Z.I. SUD PADOVA ITALY -- Ph. (049) 870-0588 - Fax. (049) 870-0747 - - http://www.dbbroadcast.com - DB ELETTRONICA TELECOMUNICAZIONI S.p.A. PM 300 - FM Broadcasting Transmitter - USER’S MANUAL2 /108 SAFETY NOTICES WARNING To avoid risks of electrical shocks or fire, only qualified personnel should execute the procedures specified in this manual. WARNING When the protective covers of any device or component connected to a 110 / 240 VAC source by a power cord are removed, voltages and currents dangerous to life may be exposed. WARNING Contact with 110 / 240 Volts of alternating current and associated direct current and voltages can be fatal. DANGEROUS RISK OF ELECTRICAL SHOCK DO NOT OPEN CAUTION To reduce the risks of electrical shock, do not remove the cover (or the back). Refer, for servicing, to qualified service personnel. This installation should be done by a qualified person and should comply with to all local applicable laws. NOTICE: ALL THE SPECIFICATIONS AND TECHNICAL INFORMATION IN THIS MANUAL ARE SUBJECT TO CHANGE WITHOUT NOTICE. DB ELETTRONICA TELECOMUNICAZIONI S.p.A. PM 300 - FM Broadcasting Transmitter - USER’S MANUAL3 /108 INDEX 1.PM300 FM TRANSMITTER...................................................................................................................6 1.1GENERAL DESCRIPTION ................................................................................................................6 2.TECHNICAL SPECIFICATIONS........................................................................................................11 3.INSTALLATION ....................................................................................................................................13 4.FREQUENCY SETTING.......................................................................................................................14 5.ADJUSTMENTS AND MEASURES ....................................................................................................16 6.POWER SUPPLY SECTION ................................................................................................................18 6.1GENERAL DESCRIPTION ..............................................................................................................18 6.2SWITCHING POWER SUPPLY MODULE PART LIST................................................................22 6.3EQUIP. PWR SUPP. BOARD PARTS LIST (DB 0206_090)..........................................................31 6.4DB 0201_070 PRINTED BOARD PARTS LIST .............................................................................35 7.MODULATION STAGE (SINTEL 96).................................................................................................36 7.1GENERAL DESCRIPTION ..............................................................................................................36 7.2“SINTEL 96” MODULATOR PARTS LIST ....................................................................................44 8.AMP30 DRIVER STAGE ......................................................................................................................47 8.1GENERAL DESCRIPTION ..............................................................................................................47 8.2AMP30 PRE AMPLIFIER PARTS LIST..........................................................................................50 9.RF AMPLIFIER STAGE .......................................................................................................................51 9.1AMP300 AMPLIFIER BOARD ........................................................................................................51 9.2AMP300 AMPLIFIER PARTS LIST ................................................................................................54 9.3LOW PASS FILTER AND DIRECTIONAL COUPLER .................................................................55 9.4L. P. FILTER AND DIR. COUP. PARTS LIST................................................................................56 10.PROTECTION STAGE......................................................................................................................57 10.1 PROTECTION /CONTROL STAGE N°1 PARTS LIST.................................................................67 10.2 PROTECTION /CONTROL STAGE N°2 PARTS LIST.................................................................74 11.METER STAGE ..................................................................................................................................75 11.1 GENERAL DESCRIPTION ..............................................................................................................75 11.2 MICROPROCESSOR BOARD PARTLIST .....................................................................................78 11.3 DISPLAY BOARD PARTS LIST .....................................................................................................81 12.IN-AUDIO BOARD.............................................................................................................................82 12.1 IN-AUDIO BOARD PARTS LIST....................................................................................................84 12.2 IN-AUDIO BOARD JUMPERS SETTING ......................................................................................85 13.STEREO ENCODER BOARD (OPTION) .......................................................................................86 13.1 CHANNELS PRE- EMPHASIS SETTING ......................................................................................86 13.2 STEREO ENCODER PARTS LIST..................................................................................................98 14.CONTRAVES BOARD (OPTION) .....................…

Text truncated - open the document above for the full version.

Power Supplies 30 Watt Amplifier300 Watt Amplifer Low-Pass Filter & Directional Coupler Out I n p u t B o a r d Audio Filter Stereo Generator Audio Filter Display & Metering Board SCA 1 SCA 2 SCA 3 FM Modulator XLR-Left XLR-Right MPX PLL Stage Frequency Control 96.7

R & L MEDIA SYSTEMS, INC FCC ID: LUHPM300 MODEL PM-300 S/N Hendersonville, TN 37075 Label Location Upper Left Rear of Transmitter

Operational Description The overall theory of operation for the PM-300 is provided on this page. Detailed theory of operation is outlined in the technical manual for each major sub-assembly. The left and right audio signal is fed to the audio input board where one can select 0, 50 us or 75 us pre-emphasis and is then fed into an audio peak limiter to minimize over modulation. The left and right channels are fed into the optional digital stereo coder with stereo separation in excess of 65 dB and a SNR of more than 80 dB. The composite stereo signal and the SCA subcarriers are just amplified or attenuated by the correct modulation depth adjustment. The mono input signal is filtered by a 7 th order elliptic filter with a very flat response (20Hz to 15kHz with _ 0.25 dB) and an optimum out of band attenuation (>50 dB for frequencies higher than 19 kHz). Before the VCO stage, an adjustable and bypassable deviation limiter prevents the FM carrier from an excessive modulation depth and adjacent channel interference according to FCC standards. The VCO is controlled by a digital PLL circuit with a high stability quartz reference to obtain a very stable synthetized oscillation, the frequency setting is customizeable using on board dip-switches (the minimum step size is 10 kHz). Furthermore, an automatic locking circuit enables the output modulated signal only when the internal PLL is locked properly, in order to avoid unwanted emissions. The output of the VCO is fed into the pre-amplifier/driver stage using a 30W MOSFET amplifier. This board is basically composed of four amplification WIDE BAND stages. The pre-amplifier / driver board is equipped with an initial 5-6 seconds delay to avoid accidental out of band emissions in the initial PLL locking period. The next stage is the 300 watt amplifier, using Philips MOS transistors which are Class C rated at 80% efficiency (typical) 300 W Output Power with 22 dB gain. An output LP filter ensures a pure RF spectrum, compatible with the most stringent international requirements. The PM 300 transmitter power supply is composed of a switching power supply to power supply the mosfet amplifier and the equipment power supply board which is capable of _12 VDC (6A max) and +24 VDC (10A max) to power supply the Protection and control boards, meter stage, modulator board, 30 watt pre-amplifier/driver stage and all optional boards present . The transmitter has three main protections: 1) VSWR protection: When the output reflected power becomes greater than a preset value (normally 30W), the output power reduces to maintain the reflected power below the preset value. When the protection is active the front panel “VSWR” led lights on. 2) PWR LIMIT protection: When the output forward power becomes greater than a preset value (normally 300W), e.g. because of a high driving power, the amplifier gain reduces to maintain a stable output power level (+/-2%). When the protection is active the front panel “PWR LIM” led lights on. 3) Temperature protection: When the heat sink temperature becomes higher than 70°C the output power decreases to a preset value (normally 40W). When the protection is active the front panel “OVERHEAT” led lights on.

Media Systems 116 Beaumont Drive * Hendersonville, TN 37075 * (615) 826-0792 Fax (615) 824-3282 * http://rlmediasystems.com The parts list and tune up procedure are included in the PM-300 manual.

Media Systems 116 Beaumont Drive * Hendersonville, TN 37075 * (615) 826-0792 Fax (615) 824-3282 * http://rlmediasystems.com The schematics are included in the PM-300 manual.

DB ELETTRONICA TELECOMUNICAZIONI S.p.A. 300W FM Low Power Transmitter TEST REPORT - DB ELETTRONICA TELECOMUNICAZIONI S.p.A. - - Via Lisbona, 38 - 35127 Z.I. SUD PADOVA ITALY -- Tel. (049) 870-0588 - Fax. (049) 870-0747 - - http://www.dbbroadcast.com - DB ELETTRONICA TELECOMUNICAZIONI S.p.A. The following document shows the technical performance of the PM300 FM transmitter. According to the FCC rules and regulations (applicable portion of Part 2 and Part 73). MEASUREMENT EQUIPMENT
Conducted Emissions Stereophonic and Monophonic configurations have been tested.
STEREOPHONIC MODE PILOT: set to 9% (6.75kHz deviation) LEFT (or RIGHT) input: 15kHz MAIN CHANNEL: 28.5kHz deviation STEREO CHANNEL: 28.5kHz deviation The transmitter was set at 300W RF output power Emission levels recorded on the ADVANTEST R3131 Spectrum Analyzer DEVICE UNDER TEST Audio Generator Attenuator PM300 RF Sampler Power Meter Dummy Load Voltage Measurement Spectrum Analyzer Modulation Analyzer DB ELETTRONICA TELECOMUNICAZIONI S.p.A. The FCC rule 73.317 limits the emission between 120kHz and 240kHz from the carrier frequency to –25dB, between 240kHz and 600kHz to –35dB and for higher frequency than 600kHz the emission may be at least 43+10 log P o , or –67dB referenced to the unmodulated carrier. In the stereophonic mode the emissions are below the limits. DB ELETTRONICA TELECOMUNICAZIONI S.p.A.
STEREOPHONIC MODE PLUS SCA An SCA channel has been added to the stereo channel. SCA input: 67kHz SCA input sub-carrier: modulated at 15% (11.15kHz) LEFT (or RIGHT) input: 15kHz adjusted to obtain 70% modulation (52.5kHz) DB ELETTRONICA TELECOMUNICAZIONI S.p.A. In the stereophonic mode plus SCA the emissions are below the limits.
MONOPHONIC MODE MONO input: 15kHz with 80% modulation (63.75kHz deviation) DB ELETTRONICA TELECOMUNICAZIONI S.p.A. As can be seen, the monophonic mode emissions meet the requirement.
MONOPHONIC MODE PLUS SCA SCA input: 67kHz SCA input sub-carrier: modulated at 15% (11.15kHz) LEFT (or RIGHT) input: 15kHz adjusted to obtain 70% modulation (52.5kHz) DB ELETTRONICA TELECOMUNICAZIONI S.p.A. In the monophonic mode plus SCA the emissions are below the limits. DB ELETTRONICA TELECOMUNICAZIONI S.p.A.
CONDUCTED HARMONICS Conducted harmonics are sampled in the output transmission line. The measured value must be adjusted using the directional coupler coupling value and cable loss. HARMONIC N°HARMONIC LEVEL 2 th 196MHz -79.9dBc 3 th 294MHz -77.2dBc 4 th 392MHz -95.4dBc 5 th 490MHz -90.2dBc 6 th 588MHz -99.5dBc 7 th 686MHz< -100dBc 8 th 784MHz< -100dBc 9 th 882MHz< -100dBc 10 th 980MHz< -100dBc All the measures are at least 43 + 10 log P o (or 67dB) or better.
Audio Frequency Response and Pre-emphasis curve The characteristics were measured from the Modulation Analyzer DB ELETTRONICA TELECOMUNICAZIONI S.p.A.
RF Power Output Stability With the audio generator not energized, the loss through the RF output cable , directional coupler and attenuator was calibrated. The carrier frequency was 98MHz.
VARIABLE TEMPERATURE The transmitter was turned on at a power output of 350W (at room temperature). Next the temperature was varied from 0C to +50C. Then the output power was reduced to 58W. TemperatureRF Power 0°C351W 25°C350W 50°C352W 0°C 58W 25°C 58W 50°C 57W
VARIABLE LINE VOLTAGE The transmitter was turned on at a power output of 300W (at room temperature). The line voltage was varied from 94Vac to 126Vac. Then the power output was reduced to 45WW. Line VoltageRF Power 94V AC 300W 110V AC 300W 126V AC 300W 94V AC 45W 110V AC 45W 126V AC 45W
Frequency Stability With the audio generator not energized, the loss through the RF output cable , directional coupler and attenuator was calibrated. The carrier frequency was 98MHz. The transmitter was turned on at a power output of 300W (at room temperature). The line voltage was varied from 94V AC to 126V AC . Line VoltageRF Frequency 94V AC 98.0000007MHz 110V AC 98.0000007MHz 126V AC 98.0000007MHz DB ELETTRONICA TELECOMUNICAZIONI S.p.A.
Cabinet Radiation The transmitter was set at 300W and the carrier frequency was 98MHz. The measured value must be adjusted using cable loss, antenna gain characteristics. Then the radiated power was calculated and compared to 300W. Frequency MHz Field Strength DBuV/m Field Strength V/m Equivalent Radiated Power W Relative to P OUT dBc 98560.000631119.4483E-9-93.9 196390.0000892.3763E-9-111.0 294380.0000791.8723E-9-112.0 392360.0000631.1907E-9-114.0 490340.0000500.7500E-9-116.0 588360.0000631.1907E-9-114.0 686350.0000560.9408E-9-115.0 784340.0000500.7500E-9-116.0 882320.0000390.4563E-9-118.2 980340.0000500.7500E-9-116.0
FCC rules and regulations (applicable portion of Part 2 and Part 73) - Part 2.1046 - Part 2.1053 - Part 2.1057 - Part 2.1033 - Part 73.1545 - Part 73. 333 - Part 73.297 - Part 73.317 - Part 73.319 - Part 73.322 - Part 73.1570
Equipment MODEL Spectrum AnalyzerADVANTEST R3131 Modulation AnalyzerRHODE & SCHWARZ FMAB RF Power MeterBIRD MODEL 43 HumidifierETT S.R.L. Thermal DetectorAZ 8703 Humidity DetectorETT S.R.L. Thermal RoomANGELANTONI TY 175 IU S Test LoadBIRD 8431 Directional CouplerBIRD 4275 DB ELETTRONICA TELECOMUNICAZIONI S.p.A.