Best of the Old & New

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Best of the Old & New

Jun 1, 2003 12:00 PM, By Roswell Clark, CSRE CBNT

Because the capital investment in a typical studio installation is expected to last several years, the need to forecast and plan for the future while at the same time retaining a foothold in today's world can certainly prove to be a challenge. Cox Radio Tampa's recent effort to overcome this challenge during a six-station consolidation project used a mixture of advanced technology and standard hardware and practices. The task was conceived from the beginning with flexibility in mind. Facility-wide design goals were set early on to reduce the need to change key infrastructure during the ever-present conversion to digital.

There were several key concepts incorporated into the plan for the final design. All wiring was to be digital-ready, regardless of present-day use. This was done to eliminate the need to replace cables when digital signals were later used.

We wanted to collocate all the technical support equipment including IT, telephony and studio systems into a single rack room. Because engineering supports all the technical needs of the facility, this would reduce complexity. Also, the environmental conditioning for the equipment became more centralized and was easier to manage.

The station paid special attention to electrical grounding and isolation, as well as environmental concerns pertaining to temperature and physical access. Most of the equipment was located in the rack room to simplify the management of what was considered the cocoon.

The WBBY control room looking into WHPT.

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Equipment is grouped into uses, making the rack layout highly organized. The cross-connect wall uses cable covers to preserve the neat appearance.

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The WHPT control room (above) and the WDUV control room (below).

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Two of the production rooms.

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Audio and power wiring follow separate paths along the rear of the racks. A great number of electrical outlets were provided to accommodate any future needs.

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The on-air studios were designed around the audio routing engine concept to allow for flexibility and sharing of resources within the group. Now, making adjustments to the console layout can be done electronically rather than physically.

Best of the old

To avoid throwing the baby out with the bath water, the station tried to find a purpose for existing infrastructure in the new facility. Rather than construct new facilities for all six stations at a separate location, the station renovated a recent station acquisition site. Although the chosen 18-year-old facility was showing its age, the existing studios and layout were able to be used in the new design, with some minor adjustments, saving a significant amount of time and money.

Other notable assets that have found a new life include the 120' STL tower and the existing generator. Both were in good shape and capable of supporting the additional load of antennas and equipment required for the three additional stations to be added to the site. Some of the existing Pacific Research and Engineering furniture as well as an Airwave digital console were also slated for reinstallation. Three of the stations had to stay on the air during the remodel and expansion. Because of the need to renovate the space while occupying it at the same time, detailed project phase plans were required. To make room for the contractors, some of the key studios, including the rack room, were relocated temporarily to allow the contractors to renovate these areas. The analogy of changing a tire on a speeding car seemed to adequately describe the challenge.

The typical relocation scenario for the three stations already present in the facility involved temporarily placing a station on the air from a newly constructed production room, then completely tearing down and rebuilding the on-air studio into a prepared room. This process usually took four engineers 24 hours of continuous labor to complete per station. The on-air staff would go home on a Friday and return on Monday to use the exact same equipment, except that it was now in a different room. Our goal was to minimize the disruption to the air staff by keeping the same room functionality during this intermediate step.

This procedure allowed the contractors to stay on schedule with the physical remodeling, leaving time for the engineering staff to complete the detailed systems integration, which revolved around the installation of the core new equipment. The newly renovated studios were outfitted with new furniture from Studio Technology. After the air studios were moved to their final destination, the temporary studios were revisited and rewired with new equipment.

Best of the new

Similar to the way that radio engineers borrowed best practices from the telephone industry 20 years ago by using 66-style blocks and cross-connect walls for wiring, the station decided that the best way to build a digital-ready facility would be to borrow the best practices from the IT industry, as they were obviously already firmly planted in the digital world. This concept proved to be cost-effective and feasible.

Observing recent success using CAT-5 cable to transmit digital and analog signals, reinforced the decision to mandate all wiring throughout the facility to be CAT-5-compliant regardless of the present use. This mandate included all the wiring in the facility � including PBX and office destinations. Even the Belden single-pair, cross-connect wire on the punch block wall is CAT-5 rated, although it looks like traditional analog 8451 without a shield or drain wire. While some signals currently used may be analog or control, if and when the needs change the wiring will be ready for digital.

Rack room

When the design of the rack room was considered, the IT industry once again provided the solutions. Rather than install traditional cabinet-style racks, four-post IT-style racks were chosen. This provided several benefits, the first being cost-effectiveness. Due to the massive market for IT infrastructure, the rack components proved to be cheaper than cabinet-style racks. Quite often, the rear doors of standard racks seem to find themselves removed anyway, and the lack of a top cover only made more sense for equipment cooling. Useful features that are commonplace in the IT-style racks are the wire-management components that are missing in traditional racks. The wire managers provide a place to dress the connecting harnesses somewhere out of the way instead of somewhere inside the rack. The high-density power strips were located to one of the wiring chases in each rack location solving the challenge of where to mount them, once again avoiding the possibility of crowding the inside of the racks. The result is an open and flexible rack space not hampered by wire bundles or power connections.

To preserve the functionality of 66-style blocks but still move into the modern age, we chose Krone blocks for all trunk-cable terminations in the facility. The footprint of these blocks is the same as a 66 block but they offer expanded features, such as support for multiple punches, high-density terminations, various patch and test-cord support and CAT-5 compliance. Belden 25-pair CAT-5 trunk cable provides the connection from the studios and racks, to the cross-connect wall where single-pair Belden CAT-5 wire is used for the cross connections between the two. To keep track of wire usage, an Excel spreadsheet was created that uses a page specially formatted for printing the center label strip on a color printer. Links within the spreadsheet automatically update the label fields when wire descriptions are changed within the master device list page. Links populate fields within the router documentation to keep system updates consistent. New labels are printed and applied when changes are made.


Because the racks, cable trays, trunk cabling, network cables and punch blocks specified were not alien to the typical IT installation crew, a local computer cabling company was able to perform the bulk of the installation for a significant savings, compared to a traditional broadcast integrator. The speed of the installation was also an advantage and testing of all the installed wiring met or exceeded CAT-5 specifications. This allowed more time to be spent on equipment wiring, installation and documentation.

With the goal of ultimate flexibility in mind, a decision to implement a centralized, router-based mixing engine for the on-air studios was chosen. Following the lead of Cox Radio Orlando, we chose the Epicenter system from Computer Concepts. The stability and flexibility of the system was given high marks and has proven itself in Tampa as well. The potential of opening communications between the two markets is a possible future enhancement. The system consists of a central router and mixer engine that is housed in four separate chassis connected to each other by redundant fiber-optic links.

Logitek control surfaces are used in the studios to direct the mixing and routing functions of the engine. The engine is located in the rack room adjacent to most of the source and destination devices for the facility, which simplifies wiring. Communication from the control surfaces to the engine is done via CAT-5 cable. With the control surface technology, not only can the console be reconfigured on the fly to fit the user or format, but other functions such as IFB, multiple mix-minus feeds and intercom functions are easily integrated without add-on devices.

All the control rooms were physically built to be the same, but customized to fit the individual user or format. To reduce the likelihood of a single-station outage, all the I/O was distributed throughout the four chassis of the router. This means that if a card fails, only portions of some stations will be affected and not one entire room. Each chassis has redundant power supplies that are fed from separate UPS systems for added fault tolerance. In the unlikely event of a complete router failure, an airchain selector was installed for each station that can engage alternate sources to feed the airchain by the push of a button. Alternate sources include either one of the two automation computers located in each air studio, or one of the six traditionally wired production rooms pre-configured for each of the stations.

Production rooms

The production rooms were designed aroundHarris Airwave Digital consoles. This allows flexibility in the conversion to digital, while at the same time retaining traditional console-centric design. Any module can be used for analog or digital sources by changing a SIMM module. All I/O in the console is pre-wired with digital wire to Krone blocks to simplify installation and maintenance. The consoles also provide analog and digital outputs simultaneously on all three mix buses. Each of the six production rooms is designed to serve as a backup studio to one of the control rooms by the push of a button. This allows for quick disaster management in the event of an on-air room failure. Once again, standards were chosen so that all of the rooms are relatively equal in capability with only a few minor exceptions. Protools was chosen as the main editor for the four primary production rooms with Cool Edit Pro available as well.

The lines of where the IT system ends and the audio systems begin have become blurred in recent years. The Cox Radio Tampa engineering department is responsible for the overall technical support services in the market including IT systems. To allow maximum efficiency in space and manpower, the department collocated all technical support equipment including the PBX in the same rack room. This allows for a focused approach in the conditioning of the environment needed to keep critical systems running. Also, connections between the systems are simplified. For example, all telco circuits, whether destined for the PBX or the studios, radiate from a common termination area. All the phone circuits are connected through CAT-5 cable terminated onto RJ45 patchbays to further expand cross connectivity and simplify migration to future technology such as IP telephony. By having all the phone circuits located at a common point, it is a casual matter to add or share a phone line with a studio or PBX for special needs, such as telethons, with simply a patch cord connection. A color code was implemented for patch cords to allow identification of use at a glance.

Implementing best practices

When each facet of the facility was considered, the station tried to implement the current best practices in each particular discipline wherever possible. Basics such as grounding, power conditioning and environmental concerns were each evaluated with an eye on eliminating single points of failure wherever applicable. A substantial star ground system was designed to eliminate ground loops and to ensure that surge protection on the incoming power lines have a good reference. After the generator transfer switch, the 480V power feed was divided to feed two separate step-down transformers before distribution to the facility and the input of the two separate UPS systems. Power from each of the UPS systems and the generator were distributed to all the rooms and the 25 rack locations. The idea was to provide an alternate power source at each location in the event of a failure in one of the nodes. In the rack locations, 30A twist-lock connectors connect the three sources of power to each group of power strips. UPS A, UPS B and generator power are available in every location. We load balance the power draw on the UPS units as needed by moving device plugs from one circuit to another; another benefit in the distribution scheme. Because lightning is a tremendous concern in Florida, fiber optic cables are used to provide electrical isolation from the nearby STL tower. Bi-directional digital and analog signals are passed to the tower using the Lightwave Systems Fibox products. T-1 equipment from Intraplex is also used to complement the Harris CD Link STL systems. The separate methods of delivering the digital signal to the transmitter sites over RF and telco adds an additional layer of fault tolerance to the communication paths from the studio to the transmitter sites.

The final test at the end of any day is the answer to the question, �how well does it work?� Happily, the facility, as a whole, has proven to be reliable and robust in performance, in measurements that are technical and operational. The synergy created by housing the operational staff in one facility with great workflow between departments is just beginning to show its strengths. Operationally, the studios have proven themselves to be both user-friendly and scaleable for future growth. As far as the sonic performance on the air, we found that by keeping the audio signals in the digital domain from ingest to the transmitter, including the mixing environment, a higher level of clarity can be achieved. Avoiding multiple analog-to-digital conversions through the airchain removes the cloudiness that can otherwise result. An added benefit is that the linear digital output from the system will further prepare the group for the pending implementation of IBOC.

With careful planning and consideration, it is possible to retain the best current technology while at the same time laying the groundwork for a graceful transition into the future. Cox Radio Tampa's facility has managed to bridge that difficult gap while keeping an eye on the future.

Clark is the director of technical operations for Cox Radio's six-station cluster in Tampa, FL.