The coming of HD Radio to WKSU

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The coming of HD Radio to WKSU began in 1991 on a tour bus in Las Vegas.
Facility Showcase, Jan 2010

Accepting the challenge

Challenge number one was how to get the analog, RBDS and the IBOC data stream (HD-1, HD-2, HD-3 and PAD) to each transmission facility. Terrain limitations, tower loading issues, and overall costs quickly eliminated the possible use of a microwave network. Ku band satellite delivery became a brief consideration; however, the northeast Ohio climate does not favor reliable Ku signal delivery. Internet delivery was not an option because of compression, timing and many other issues inherent with the Internet. Thought then turned to the use of T-1 lines. Through a special relationship with Kent State University and the state of Ohio, WKSU was able to obtain a T-1 line to each transmitter site with all lines originating from the Broadcast Center at a total cost that was the same or somewhat less than what monthly satellite delivered bandwidth costs would have been. With design assistance provided by Broadcast Electronics in conjunction with WKSU's IT department, an STL-IP delivery system was developed using the Audio TX by MDO-UK equipment along with Cisco Systems routers and switches. In addition, the STL from the Broadcast Center to WKSU's transmitter site now includes a Mosley Starlink microwave system that operates parallel to the STL-IP T-1 line delivered system with automatic switchover in the event of either path's failure. The new STL systems provide full 20kHz audio.

Flagship station WKSU's analog equipment row on the left and its Harris Z model IBOC transmitter on the right across from a Broadcast Electronics FM-20T analog transmitter installed in 1997.

Flagship station WKSU's analog equipment row on the left and its Harris Z model IBOC transmitter on the right across from a Broadcast Electronics FM-20T analog transmitter installed in 1997.

Next came the need to upgrade the analog transmitters at repeater stations WKRJ, WKRW, and WKSV. Based on power level requirements and costs, the Broadcast Electronics model FMi-301 solid-state transmitter was chosen for WKRJ, an FMi-201 for WKRW, and an FMi-1405 dual-cabinet system for WKSV. Ventilation system upgrades also had to be made at each of those stations because of the increased IBOC transmitter heat output. The existing analog transmitters at WKRJ and WKRW became standby units with the installation of a motorized RF switch for easy remote transmitter selection when required. While WKSV already had a standby transmitter, the main transmitter, a CCA FM-12,000, had to be removed from the Rohn 12' × 18' prefab building to make room for the new transmitter. The arranged logistics provided for the removal of the CCA transmitter first thing in the morning and the placement of the new transmitter that same morning. Broadcast Electronics model FXi-250 exciters were installed with each new transmitter. The WKRJ and WKRW projects took place in late May/early June of 2009 and the WKSV project was completed in July of 2009. Prior to these projects, the exciters at the 2004 constructed WNRK repeater station and at WKSU's transmitter site were upgraded to a Broadcast Electronics exciter model FXi-60 (WKSU in July of 2008 and WNRK in January 2009) to enable the broadcast of the IBOC stream. Broadcast Electronics RDi-20 accelerated RBDS generators were also installed at each transmitter location for broadcast of RBDS on the analog side.

To facilitate the independent multicast program distribution to each station, five Broadcast Electronics model IDi-20 importers and five model XPi-10 exporters were installed in the Broadcast Center's master control room — a set for each station. Additionally, five Orban 8500HD units for audio processing of the analog and HD-1 channels were installed in the newly placed master control room rack cabinets (seven new cabinets that include 30 Arbitron PPM encoders plus four existing cabinets). A Neural multi-channel audio processing system is utilized to establish the audio quality for the HD-2 and HD-3 channels. Audio sourcing and routing is largely managed by an Enco automated program delivery system (soon to be updated to all linear storage) along with the use of multiple Axia Livewire audio nodes. PAD and RBDS information is handled by a Broadcast Electronics TRE message managing system for each station. Monitoring of each transmission facility is accomplished via existing remote control systems operating in ATS mode and an on-site Audemat Golden Eagle HD monitor at each station — all networked for remote monitoring — along with Day Sequerra model M4 HD tuners.

Regional awareness and popularity is growing for WKSU's globally accepted folk music channel ( broadcast on the HD-2 stream and an all-classical music offering on the HD-3 channel. During WKSU's recent fall fund drive the station placed 589 HD capable radios in the hands of donors who pledged at the $180 level. Generous underwriting friends of the station provided those radios at no charge to WKSU. WKSU's HD-3 all classical stream is also heard over Cleveland's WNWV HD-3 channel by special agreement between the two stations. The station will continue promotion of HD Radio to the region and has received a grant from CPB to develop an HD-4 channel with cooperation from Ibiquity Digital and Broadcast Electronics. Existing Broadcast Electronics exciters and importers are to be upgraded by special arrangement from BE when the product becomes available. Pending IBOC signal power increases are to be addressed on a station-by-station basis if and when approved by the FCC.

A close up view of WKSU's split level IBOC combining system and main/standby antenna switch.

A close up view of WKSU's split level IBOC combining system and main/standby antenna switch.

WKSU's in-house IT staff of Chuck Poulton and Dan Kuznicki, both of whom have excellent broadcast background, played a pivotal role in the development of this system and continue to work hand-in-hand with my long-time assistant Bob Kruppenbacher and myself in maintaining our extensive IBOC/HD Radio broadcast system. And, it should be noted that this very large long-term project would not have been possible without the fund raising expertise of WKSU's Executive Director and General Manager Allen Bartholet and his development associate Pamela Anderson along with the splendid cooperation that we received from both the WKSU and Kent State University business offices.

It has been many years since I rode the bus on that balmy April day in Las Vegas and wore the required badge that gave me passage onto the bus. The badge reads, DAB '91 Demo. I have that badge on my office bulletin board and glance at it at least once each day just to remind me that what happens in Vegas doesn't necessarily stay in Vegas.

Equipment list

Audemat Golden Eagle HD/FM
Audio Science 6585
Axia Livewire AES/EBU audio node
Barix Exstreamer 1000
Belar RFA-4
Bird Electronic 3129 BPM, BPME1-VM, BPME3-VM
Broadcast Electronics FMI-1405, FMI-201, FMI-301, FXI-250, FXI-60, IBOC rack cabinets, IDI-20, RDI-20, TRE Message Manager, XPI-10
Day Sequerra M2.2R, M4.2 R
Dielectric R101873025
Moseley Starlink SL9003-4SLAN
Neural Audio Neustar SW4.0
Omnia One
Orban 8500FM

Bartlebaugh is director of broadcast engineering, the WKSU Stations, Kent State University, Kent, OH.

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