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RF products

While the annual convention is an enjoyable time to catch up with colleagues and gorge ourselves at fine restaurants, most of us make the annual pilgrimage to view the new products being offered by the wide range of manufacturers. On the RF side of things, there were a number of exciting new products on display at the show this year.

Improvements in combiner technology abounded. Each of the major combiner and RF system manufacturers had their improvements and models on display. Two of the more notable ones this year are the Trinity offered by Andrew-Passive Power and the new RFS ‘N+1’ combiner. Both of these models use different innovative solutions to reduce aural carrier distortions in N+1 applications.

The Trinity model is an all-aluminum, waveguide construction and has high thermal stability. Trinity will handle 75kW DTV plus up to 100kW NTSC. Trinity has a triple function in that it may be used as a very low loss N+1 combiner, a high-power DTV filter or an N-1 combiner.

The RFS N+1 combiner continues the RFS design that utilizes a substantially smaller footprint than some of their competitors. Their design incorporates a waveguide pre-corrector to minimize group delay. The elegant solution for static group delay correction is accomplished through the use of a tuned all-pass filter that flattens the group delay around the carrier, making it symmetric and minimizing the effect on the audio.

Harris announced its “Cool Fuel” approach to DTV transmission, which offers performance and efficiency benefits. Its use of proprietary signal equalization techniques and a patent-pending filtering configuration provides a dramatic cost savings potential and ensures full compliance with the Commission's interference requirements.

The Odyssey series, a new line by Thomcast, completes its solid-state product line. The Odyssey is a cost-effective solution for broadcasters looking for a state-of-the-art design. This particular model, says Thomcast, has the smallest footprint and highest level of internal redundancy available today.

Thomcast also introduced the DCX Millennium transmitter. The DCX Millennium is an enhanced version of the DCX. Improvements include Total Power Management, which allows a wide range of flexibility in the power control of the transmitter in fault protection, while maintaining it at the highest possible safe power level. The Millennium also features improvements to the filament/bias/ion supply and utilizes an intuitive GUI and networkable remote control software.

Andrew increased its antenna product line dramatically. It now provides inverted antennas for use on candelabra-style towers. In addition, Andrew has teamed up with Alan Dick, and is now offering VHF Superturnstile and Panel Antennas. The Trasar LT antenna also adds to the line by creating a lighter-weight and lower-wind load package that still has big antenna performance.

Dielectric showed its TUV Series Dualband. This antenna is particularly suited for those broadcasters who have both a high-band VHF and UHF channel during the DTV conversion, but no additional tower space. This particular model incorporates both the VHF and UHF signals into a single pylon antenna. With the use of Dielectric's Shared Line Tees and EHT transmission line, the TUV Dualband can not only minimize tower loading at the tower top, but can also eliminate the need for a second transmission line run.

Dielectric also offered its VSWR Vision program. Dielectric will install monitoring hardware and directional couplers on your transmission line, and then monitor your line VSWR and pressure for you. The system samples your VSWR every few seconds, and you are provided with a quarterly report detailing trends.

SpectraSite's services allow multiple broadcasters to use a common tower site in order to shorten project timelines and lower capital investment. The company obtains the site or identifies existing tower space that is available and suitable for broadcast needs, obtains zoning approval and will even manage the facility.

Richland Towers was on hand detailing its custom-designed tower lease programs and multi-tenant tower projects for broadcasters. Likewise, LeBlanc was offering its tower-erection services and showcasing its Larcan line of transmitters.

NuComm featured its Microwave V Stream STL, offering digital signal monitoring with SMPTE 310 and ASI digital interfaces.

Acrodyne, traditionally a big player in the RF arena, continued that trend with the launch of its Quantum IOT-based transmitter. The Quantum can serve both analog and digital applications with power levels up to 280kW analog and 120kW digital.

Another transmitter player, Itelco, offered its 50kW UHF model, featuring an exclusive exciter system and a patented Switch Mode Beam Power Supply.

Marconi showed its IIOTD3100W, an IOT capable of 110kW peak digital or 5.5kW combined analog amplification. Marconi also showed the Stellar TWT, which covers Ku-band for individual unit powers up to 180W and DBS bands as well as multiband applications.

Broadcast Microwave Services showed its StarLink series of STLs, as well as its microwave link systems for helicopters and ENG units. NEC also presented a solution for ENG, its Digital Microwave Link (DML).

Multidyne showed its line of video and fiber optic transport systems, including its DVM-2500, 2700 and 4000.

Ktech Telecommunications showcased its VSB-ENC-200 8VSB modulator. The ENC-200 modulates MPEG-2 transport streams into an 8VSB signal using linear and nonlinear pre-correction techniques.

Litton Electronic Devices featured its L-4299 constant efficiency amplifier. The next-generation, high-power UHF operates at peak power up to 120kW, offering high-efficiency in comparison to standard IOTs when digitally operated.

Another manufacturer, CPI-Eimac also offered a new digital IOT, the K2D130. The newest of the K2 family produces 130kW average for DTV.

While there was not necessarily a tremendous amount of new items, those that were on display continued to offer more efficient and reliable solutions to accommodate our ever-changing industry.

Jeremy D. Ruck is chief engineer with Markley and Associates.