RF systems

In looking through the maze of RF products on display at NAB this year, two items bubbled up to the top of the list with respect to on the show floor.
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In looking through the maze of RF products on display at NAB this year, two items bubbled up to the top of the list with respect to “buzz” on the show floor. First, there was a literal flood of new microwave systems, antennas and related accessories to address the 2GHz BAS relocation process. Every microwave vendor at NAB had its own version of new or upgraded transition equipment and convincing stories to match.

The second hot spot was the unveiling of new transmitters and processing equipment to address the emerging DVB-H market. DVB-H refers to the ETSI standard for Digital Video Broadcasting to Handheld terminals. In other words: video IP streaming to cell phones, PDAs and similar devices. Services are in the trial phase at this point; however, many transmitter manufacturers are adding 700MHz and 1.6GHz DVB-H models to their product portfolio to be ready for large-scale implementations. Our report, however, begins with the microwave transition.

BAS is center stage

Traditional companies such as Broadcast Microwave Services (BMS), Global Microwave Systems (GMS), Microwave Radio Communications (MRC) and Nucomm all showed new or revised ENG product lines.

In the BAS-upgraded Truck-Coder II transmitter and Central De-Coder II receiver, BMS featured a substantial facelift with a new user-friendly control interface. Eight push buttons and a rotary encoder allow up to 100 channel pre-sets to be programmed and accessed rapidly. Its new Field-Coder II COFDM transmitter is a compact 1W portable that can be tripod-mounted for digital remotes.

Continuing the tradition of portables for every occasion, GMS introduced the High Definition Messenger Transmitter (HDMT), an HD version of its wireless COFDM camera link, along with a matching Messenger Smart Receiver (MSR) that can support multi-input diversity combining.

MRC focused on enhancement over replacement, a message that the company re-enforced by showing new accessories that add BAS transition enhancements to its existing ENG line-up. When connected to an existing CodeRunner 4 Central Receiver, the new MRX4000 integrated demodulator-decoder leverages existing technology to provide integrated functionality. It supports new and old FCC band plans for both analog and digital transmission. Full BAS enhancements are available for CodeRunner 2 ENG transmitters. The company also introduced the SCM4000, a variable rate digital modem; the DVC4000 MPEG-2 codec system, a fully integrated IP over ENG platform; and new features to its airborne HDTV package.

Moseley Associates continued to build its presence in television with the introduction of its Event HD ENG portable systems for 2GHz and 7GHz. The company emphasized its choice of 32 carrier OFDM transmission as the optimum choice for data rates up to 85Mb/s in the BAS bands.

At Nucomm, the new ChannelMaster TX1 ENG portable transmitter integrates digital and analog transmission, FM, CODFM and VSB modulation, and an integrated MPEG-2 encoder all in one user-friendly package. The Newscaster CR6D Central Receiver has a new Smart Display front panel with expanded diagnostics and includes all of the BAS upgrades. The Newscoder TX3 got a similar facelift and now offers a DVB-S option for satellite uplinking. The company also introduced the Go-Pack, a mini-COFDM transmitter with integrated MPEG-2 encoder and a new IP over ENG system with a diversity combiner receiving option.

With so much activity surrounding the NEXTEL-related 2GHz transition, it was no surprise to see newer players such as RF Central and Microwave Service Company (MSC) at NAB with a suite of products aimed squarely at ENG. The RF Central product line now includes a rack-mounted ENG transmitters and central receivers, plus a camera back transmitter with a suitcase docking station that converts it to a 10W portable.

MSC has been known for years as the folks that fix any microwave. This year, it introduced its own line of COFDM equipment, but with a new twist. Its Genesis systems can support two or more videos in the same RF channel without significant degradation.

Both NSI and RadioWaves had a lot to say about antenna upgrades in light of the 2GHz relocation. NSI has specific upgrade or replacement plans, depending on the age of the original installation, and it also has a sophisticated control system that has been updated to support all of the new central receivers.

RadioWaves, which provides antennas under private label agreements, has a complete kit of feed assembly and antenna replacements to support the BAS relocation.

DVB-H solutions

In the heavy-duty TV RF department, some of the manufacturers showed a significant interest in DVB-H, with new equipment on display from Axcera, Harris, Rohde & Schwarz and Thales. Antenna manufacturers, including Dielectric products and Micro Communications, also showed DVB-H products.

Broadcast transmitters

Axcera introduced a new dual-use transmitter that can switch between analog and digital on command. The rationale is that one transmitter can serve as a total spare for both analog and digital sides of a transmission plant.

Dielectric introduced the TFU-UT antenna, a new UHF bowtie slot antenna for low-power applications. The antenna is extremely broad, with a VSWR of 1.1:1 across the band. Its RF Scout is a new remote monitoring system that provides real-time Web-based transmitter metrics, including power output, VSWR, line pressure and temperature. VSWR is calculated in real time, and all data can be stored for up to one year.

Harris continues to invest in ATSC related products and upgraded its liquid-cooled Atlas solid-state UHF transmitter line to 30KW this year. Harris also showed its Truepoint digital microwave system combined with NetVX as an STL for 7GHz, 13GHz and 18GHz.

ERI showed a new and interesting UHF channel combiner. Optimized for N+2 spacing, the combiner requires about half the space of a traditional constant-impedance combiner, with a significant reduction in purchase price as well.

Larcan displayed its new Plus DTT500 transmitter that is positioned for digital LPTV applications, once the FCC digital rules are solidified. The new transmitter is a clever integration of MPEG-2, EBS and RF equipment that will support up to four digital streams on one channel.

Myat has added semi-rigid air dielectric coaxial cable to its product portfolio, with sizes ranging from 1/2in to 6in diameter.

RFS highlighted the RD slot cavity antenna for UHF DTV applications at power levels up to 220KW. The antennas operate over 10 to 20 channels and are available with a variety of pattern options.

Rohde & Schwarz showed its new NH/NV 8200 series air-cooled UHF transmitters, available at power levels from 500W to 2KW for analog operation and from 200W to 1.2KW for digital operation.

RF Technologies featured its new SFNstar UHF slot transmitting antenna, which dramatically reduces ground-level RFR with no impact on the main lobe. This is particularly useful in side-mount and short tower applications with high-power analog or DTV transmitters.

George Maier is the founder of Orion Broadcast Solutions.