Lake Cedar Group Transmission Facility brings full-power DTV to Denver

Category

New studio or RF technology – station

Submitted by
5280 Broadcast Design Team
5280 Broadcast: Tony Roccanova, dir. of eng.; Randy Reed, sr. eng.; Chris Kinsella, Phase 1 proj. mgr.; Jeff Combs, Phase 2 proj. mgr.
KCNC: David Layne, dir. of ops and eng.; Eric Buckland, eng. mgr.; Paul Deeth, transmitter maint. supervisor
KMGH: Rick Craddock, dir. of eng.; Dave Stromberg, asst. chief eng.; Mike Shanahan, broadcast eng. Technology at work
Belden
Coaxial, audio and data cable
Fiber-optic terminations
DTV Innovations TSC5000 TS converters
Evertz 7700 fiber-optic transmitters and receivers
Harris
6800+ DAs and conversion
Panacea routers
OPTO TEST fiber- optic test equipment
VTM signal monitoring
KTech DVM-150E demods
Triveni Digital StreamScope stream monitors

Lake Cedar Group Transmission Facility brings full-power DTV to Denver

The Lake Cedar Group Transmission Facility is a 20,000sq-ft building housing the control and monitoring equipment, STLs and TSLs, central receive equipment, and digital transmitters for a group of Denver TV stations. The plant serves a new 730ft tower shared by four stations. It was designed to consolidate the stations’ DTV operations and will allow the dismantling of four towers and three transmitter buildings after the February analog shutoff.

5280 Broadcast assisted with the design, equipment procurement and integration of the baseband video and audio, transport stream, data and control signals within the facility. Although the ultimate goals of the stations were similar, each incorporated a unique system design based on its own needs, budgets and transition timeline.

Each station occupies its own access-controlled rack room for monitoring, control and STL/TSL equipment with transmitters located in an open, central area of the building. The stations also share an equipment room known as “the vault,” which houses ENG microwave and two-way radio equipment. The vault is connected to the main building by a 250ft underground tunnel, which also contains the transmission lines. Due to the length of the runs, grounding considerations and the obvious potential for RF interference, connectivity between the main building and the vault was via a single-mode fiber infrastructure running through the tunnel alongside the transmission lines and terminating at patch panels in each control room and the appropriate racks within the vault. One station required fiber runs to its on-site satellite dish farm as well as 500ft run up the hill to its analog transmitter building to accommodate monitoring and integration of its analog operations.

Challenges included the lack of permanent heat and power sources for much of the construction period as well the logistical challenges of working alongside electricians, plumbers and painters. The Harris transmitter crew, Radian tower crew and Thin Air Communications microwave crew were extremely helpful.

The final phase of the project was the fabrication and installation of custom I/O panels on the east and west ends of the building’s exterior and the creation of a tie-line network throughout the facility. These panels — which allow for the connection of video, audio, transport streams, Ethernet data and telco lines — terminate into each station’s control room at a custom patch bay. They allow for quick connectivity for disaster recovery, portable microwave links or the sharing of news pool feeds or other signals between stations. Due to cost and security considerations, this option was favored by the stations over the installation of a common routing system. The facility was brought online in May 2008.

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