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KUAT ‘On Air’ With New COMARK 55kW PARALLAX UHF DTV Transmitter

KUAT is now on-the-air with a new COMARK 55kW PARALLAX UHF DTV transmitter. AZPM (Arizona Public Media, KUAT-TV) is the PBS member television station based in Tucson, AZ serving the Southern Arizona market.

KUAT’s former 20+-year-old primary IOT-based DTV transmitter on Mt. Bigelow sustained irreparable damage during winter storms and as a result the station was forced to run at half power via an FCC STA until a replacement could be acquired. Earlier this year, COMARK supplied, installed, and proofed their new PARALLAX model HPTV-PRLX-U32 DTV transmitter to meet the customer’s 54.83 kW TPO requirement.

The new transmitter consists of 2 rack cabinets each equipped with 16 UHF power amplifiers. The PARALLAX transmitter has been delivered with dual EXACT-V2 ATSC exciters (in main/standby configuration) and the liquid cooling system. In addition, COMARK supplied the complete RF mask filter system that incorporates Constant Impedance Filter (CIF) technology and the high-power external hybrid’s for combining both of the transmitter’s PA cabinets.

PARALLAX provides a future proof design to broadcasters:

  • High efficiency with wideband Doherty technology
  • Unique vertical high-gain power amplifiers, providing 2kW per PA module for UHF
  • Asymmetrical Doherty; provides same power in 8VSB (ATSC 1.0) and OFDM (3.0)
  • EXACT-V2 DualCast ATSC 1.0 / 3.0 upgradeable; preserves investment
  • Hot-swap AC to DC rectifiers with >96% efficiency

COMARK worked with the staff of KUAT to coordinate the shipment, offloading, and placement of the new equipment in the transmitter facility. Mechanical installation of the new transmitter system was completed by late May, followed by the turn on, where COMARK performed the complete proof-of-performance testing.

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