3DX® AM Transmitter Family

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 3DX 25/50/100 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).

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.