25, 50 and 100 kw Digital Solid-State AM Transmitters

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1 3DX AM Transmitter Family 25, 50 and 100 kw Digital Solid-State AM Transmitters The Harris 3DX family comprising 25, 50 and 100 kw models provides an all-new level of performance, efficiency and peace of mind. The 3DX line of digital, solid-state AM transmitters features Direct Digital Drive (3D) technology, which provides a host of new capabilities and benefits, including elimination of the RF driver section. This enhancement results in simpler design, greater efficiency and improved reliability ultimately reducing operational costs. In addition, comprehensive diagnostics, which show exactly how the transmitter is performing at all times, along with hot-pluggable power amplifier (PA) modules and unprecedented redundancy, make all three models of the 3DX family exceptionally easy to service. Complete IP-based control and monitoring of 3DX transmitters in any location is possible by using the Harris WEB Remote system tied to the station's LAN or directly to the Internet. And because all 3DX transmitters are digitally modulated, transitioning to DRM or HD Radio is effortless. Simply add the appropriate exciter, and 3DX is on the air in digital broadcast mode. HD Radio is a trademark of ibiquity Digital Corp. FEATURES Harris Direct Digital Drive modulation technology improves signal linearity and provides typical overall efficiency of 88% Harris-patented Digital Serial Adaptive Modulation (DSAM) makes the 3DX family virtually auto-servicing Hot-pluggable power amplifiers enable easy service without taking the transmitter off the air Optional dual digital exciters, dual low-voltage power supplies, dual binary amplifiers and dual binary amplifier power supplies available all with automatic switchover deliver unmatched redundancy Harris-patented Direct Digital Drive ensures unprecedented reliability 1

2 PRODUCT DETAILS Intelligent User Interface The entire 3DX family the 3DX 25, 50, and 100 is designed for easy use through IntelliStat, the ultimate in control and diagnostic user interfaces. This combination of large, internationally identified control buttons, a status panel with selectable metering and ¼ VGA color display provides all important control and status parameters needed to know exactly how the transmitter is performing. A Reliable Reputation Put your mind at ease with the 3DX AM transmitters, a product that has a proven reputation of reliability. Digital Serial Adaptive modulation (DSAM) continuously monitors each serial modulation encoder and RF PA module, and makes automatic module reassignment should the need arise. Digital Exciter The 3DX 25, 50, and 100 exciters use Direct Digital Drive to accurately produce the RF signal. A low-level digital signal drives the PAs, eliminating the RF driver section therefore reducing complexity. This approach improves signal linearity and bandwidth for digital broadcasting, and provides high overall efficiency. Additionally, it facilitates easier frequency changes. Safety The /100 transmitters are IEC215 compliant. The 3DX100 offers a higher level of safety through the use of keylocks. This standard safety feature ensures that AC mains are disconnected while DC supply and RF outputs are mechanically earthed before access is allowed. Serial Modulation Encoder Each encoder provides the direct drive to 16 RF power amplifier modules, which are turned ON or OFF to produce the modulated RF signal. All serial modulation encoders are interchangeable with the auto-servicing feature. RF Power Amplifiers These modules protect themselves from over-temperature, loss of RF drive, loss of power and shorted RF output conditions, and are hot-pluggable for on-air servicing. These modules are of simple construction with easy access to the individual RF output transistors. RF Combiner Output from RF power amplifiers is summed in a simple, field-proven combiner. The combiner assembly is readily accessible from the rear of the transmitter for easier servicing. This allows individual RF motherboards to be easily removed. Output Network The output network ensures the transmitter is properly matched into a 50 ohm antenna. The internal bandpass filter provides VSWR protection in addition to improving turnaround loss. The transmitter uses a minimum of frequency-determined components for ease of frequency changes in the field. A VSWR detector, carbon arc gap, arc detector and static drain choke are all provided for protection against lightning, static electricity and other transients. Main Power Supply Voltage soft start protects the transmitter when it is turned on and eliminates separate step-start/run contractors and resistors. The power supply tolerates AC line fluctuations of +/-5% (full performance) and +10/-15% (operational). 2

3 Digital Broadcast Upgrade The 3DX transmitter family was built with digital broadcasting standards in mind. The simple migration to digital broadcast only requires the appropriate digital Modulator (HD Radio or DRM) to be connected to the inputs of the 3DXtransmitter. Harris AM Transmitter Power Reduction Algorithms U.S. Broadcasters Can Now Take Advantage of Energy-Saving MDCL Technology Power efficiency is an extremely important factor for broadcasters, both in dollars spent annually on energy consumption and the ever-growing need to be environmentally conscious. Harris Power Smart technology continues to deliver energy-savings for broadcasters, and the company now extends Modulation Dependent Carrier Level (MDCL) power reduction algorithm technology to AM transmitter customers in the U.S. 3

4 IMAGES/DIAGRAMS 3DX-50 Block Diagram 3DX-100 Block Diagram SPECIFICATIONS Specifications and designs are subject to change without notice. General Type of Modulation Transmitter Type All Models: Harris patented Direct Digital Drive Modulation All Models: Medium Wave, 100% solid-state. Power Output Range 10 to 27.5 kw and 10 to 55 kw 20 to 100 kw 4

5 Each transmitter is capable of combined operation; three adjustable power levels are provided Frequency Range All Models: 531 khz to 1,610 khz. Supplied, tuned and tested on one frequency as specified AC Mains Input 3DX25 3DX50 3DX to 240 VAC and 380 to 485 VAC (special order) 380 to 485 VAC 370 to 430 VAC and 460 to 500 VAC Power Supply Variation All Models: ±5% voltage, ±5% frequency meets full performance. +10/-15% voltage transmitter operational Transient Protection All Models: Meet ANSI / IEEE C requirements; includes high-energy MOVs Power Factor 0.97 typical 0.8 typically; 0.92 at 100 kw, 95% modulation Frequency Stability 3DX100 ±2 PPM over frequency range, 0 to 50 C ±2 PPM over frequency range, 0 to 50 C standard; ±0.25 PPM optional All Models: Higher stability is available with external reference Audio Input 10 to +10 dbm, adjustable transformerless input; 600 and 20 k terminators provided Optional AES3 digital input, 110 ohms, -20 dbfs -10 to +10 dbm, adjustable transformerless input; 600 and 20 k terminators provided. AES3 optional RF Output 3-1/8 EIA flange, bullet provided 4-1/16 EIA flange, standard; 6 1/8 optional RF Load All Models: 50 ohms, fixed, unbalanced, resistive VSWR 1.2:1 or better for full rated power. Typical 1.3:1 5

6 1.3:1 minimum Cabinet and Harmonic/Spurious Radiation Meets or exceeds FCC, IC and other world standards Meets CCIR requirements Overall AC Efficiency 3DX 25 3DX 50 85% or better at 25 kw, 87% typical 86% or better at 50 kw. 88% typical 86% or better at 100 kw. 88% typical Audio Performance Audio Frequency Response +0.2/-0.8 db at 95% modulation, 20 Hz to 10 khz, reference 1 khz +0.2 / -0.8 db at 95% modulation, 30 Hz to 10 khz, reference 1 khz Audio Harmonic Distortion 0.7% or less at 95% modulation, 20 Hz to 10 khz, ; 0.3% typical at 55 kw/25 kw respectively 0.8% or less at 95% modulation, 30 Hz to 10 khz. 0.3% typical at 100 kw Intermodulation Distortion 3DX % or less 1:1, 60/7000 Hz; SMPTE at 95% modulation, typical 0.4% 1:1, 1.0% 4:1 at 25 kw 3DX % or less1:1, 60/7000 Hz; SMPTE at 95% modulation, typical 0.4% 1:1, 1.3% 4:1 at 55 kw 1.0% or less 1:1 60/7000 Hz; 2% or less 4:1; SMPTE at 95% modulation, typically 0.4% 1:1, 0.7% 4:1 Transient Intermodulation Distortion 0.5% or less at 95% modulation, 2.96/8.0 khz, 4:1, typically 0.3% 0.2% or less at 95% modulation, 2.96/8.0 khz, 4:1, typically 0.3% Squarewave Overshoot All Models: 0.5% or less 400 Hz, 80% modulation, measured peak to peak, typically less than 0.3% Squarewave Tilt 0.5% or less at 40 Hz, 80% modulation 1% or less at 40 Hz, 80% modulation 6

7 Carrier Shift Less than 1% at 95% modulation at 1 khz, typically less than 0.5% independent of ±5% AC main voltage variation Less than 1% at 95% modulation at 1 khz independent of ±5% AC main voltage variation, typically less than 0.5% Hum and Noise -65 db or better below 100% modulation, reference 1 khz (unweighted), typically 70 db -65 db or better below 100% modulation, reference 1 khz (unweighted), typically -68 db Positive Peak Capability +145% or greater at 25 kw/55 kw respectively, audio program modulation, at nominal AC mains voltage Maximum peak modulation 135% at 100 kw Audio Performance Specifications for 3DX 25 and 50 Only IQM -36 db at 1 khz, 95% modulation; -40 db typical Duty Cycle Continuous 100% modulated sine wave Service Conditions Power Consumption 3DX 25 3DX kw or less typical at 25 kw, 0% modulation; 43.1 kw or less typical at 25 kw, 100% tone modulation 56.8 kw or less typical at 50 kw, 0% modulation; 85.2 kw or less typical at 50 kw, 100% tone modulation kw or less typical at 100 kw, 0% modulation; kw or less typical at 100 kw, 100% tone modulation Ambient Temperature All Models: 0 C to 50 C; derate 2 C per 1,000 ft (305 m) Above Mean Sea Level (AMSL) Humidity Range All Models: 0 to 95% non-condensing 7

8 Altitude Up to 13,000 ft (3,962 m) 10,000 ft (3,048 m) Size Without fan/filter assembly: 198 cm H x 260 cm W x 105 cm D (78 H x 102 W x 42 D) With fan/filter assembly: 198 cm H x 260 cm W x 137 cm D (78 H x 102 W x 54 D) Without fan/filter assembly: 198 cm H (without combiner cross over, 206 cm with combiner cross over) x 389 cm W x 107 cm D; 78 H (without combiner cross over, 81 with combiner cross over) x 153 W x 42 D). With fan/filter assembly: 198 cm H (without combiner cross over, 206 cm with combiner cross over) x 389 cm W x 137 cm D; 78 H (without combiner cross over, 81 with combiner cross over) x 153 W x 54.2 D) Weight 3DX 25 3DX 50 1,506 Kg (3,320 lbs) 1,644 Kg (3,625 lbs) Shipping All Models shipped as three cabinets DRM/HD Radio Compatibility Magnitude Input Response Group Delay Variation J3E Linearity Tests -3 db maximum, up 50 khz ±2 us, 200 Hz to 15 khz -55 db, 4/5 khz equal tones -55 db, 4/5 khz tones, 5 khz -1 db relative to 4 khz NOTES 1. All measurements made into test load at full rated power. 2. Noise may degrade if AC lines are unbalanced. 3. Audio performance measurements made with standard audio input, no special filters required to obtain these specifications. 8