1	WFCR-HD Western Massachusetts' First "HD" Digital Radio Station On November 9^th, 2004, WFCR launched WFCR-HD into the world. WFCR-HD is a new form of digital radio. Utilizing state of the art digital broadcasting methods, WFCR-HD's digital signal actually is embedded in our transmission at 88.5 on your dial. You will need a special HD Radio receiver in order to decode WFCR-HD. HD Radio delivers very high quality stereo audio, and eliminates the effects of "picket-fencing" and static caused by signal reflections in areas with hilly terrain. WFCR-HD will gently blend back to standard FM in your receiver should the digital signal become unstable in areas far away from our transmitter location.
2	How WFCR Creates Its HD Signal For years, WFCR has relied upon its Broadcast Electronics FM transmitter to provide 11 kW of power, which is amplified slightly at the antenna to result in 13 kW of power output. Because this transmitter is relatively new, WFCR kept it in place, using a Technique called "high-level Combining" to help generate the HD portion of transmission. The FM transmitter remains at its job as before with only a slight modification necessary for the addition of HD at the plant.
3	WFCR Utilizes A Second Transmitter for the HD Signal WFCR purchased a Harris Z6HDs Transmitter for the purpose of generating the HD signal exclusively. Its power output is 1,100 watts, with only 110 watts of that reaching the antenna! Much of this transmitter's power is indeed lost in the method used to embed the HD signal with the FM signal. But that 110 watts of digital signal will indeed cover much of our service area quite effectively.
4	Putting It All Together The FM and the HD transmitters are both generating a lot of power, so you’d think that any device that combines the FM and HD energy would be rather sizable. Surprisingly enough, this device- the Shively HD "Injector", is all but 20" in length and 6" in depth and width! It connects snugly with the transmission line to the antenna (which is 3" in width), barely taking up any noticeable space in the building. Only its associated dummy load (which dissipates the unused HD energy for reasons beyond the scope of this presentation) requires floor space. In the image above, you can see the inputs (FM, HD transmitters) and outputs (dummy or "reject" load, and main antenna system) connected. The copper transmission line above is the analog backup transmitter’s feed to its antenna. The backup transmitter system does not support HD radio.
5	Additional Equipment to Make HD Radio Happen The Studio To Transmitter Link (STL) A good studio to transmitter link is essential for any high quality broadcast. This link is the connection from the WFCR studios to the remote transmitter itself. With the advent of HD broadcasting, the bar is raised, as limitations in frequency response and problems caused by previous methods of audio delivery to the transmitter (noise, audio compression artifacts, etc) become apparent. In order to overcome this at WFCR, we are replacing our older digital STL with a Moseley Starlink uncompressed digital audio system. The result is crystal clear audio without the effects on the clarity and quality that arise from older techniques, which were good in their day but are antiquated by today's demanding standards. The Moseley Starlink also allows one to add more audio streams should WFCR decide to implement Tomorrow Radio, a currently experimental flavor of HD transmission in which multiple programs can be delivered to your specialized receiver simultaneously, allowing you more choice in your WFCR listening enjoyment. But for now, the Starlink improves our audio delivery to the transmitter site for the benefit of both HD and FM broadcasting.
6	Additional Equipment to Make HD Radio Happen Audio Processing For HD radio to work well, the audio originating from our studio must be treated differently than in conventional FM radio broadcasting. FM requires a number of "processing" elements that simply aren't needed for digital radio such as "pre-emphasis" (an intentional increasing of "treble" prior to broadcast). The manner in which audio peaks are controlled (which can create undesirable effects in transmission) is different for HD than it is for FM. Some manufacturers have put state of the arts digital audio techniques to work to create "audio processors" which conditions the audio separately for HD and FM as appropriate.
7
8	To facilitate the blending feature of the HD receiver, the FM audio is looped through the HD exciter in order to precisely delay it before it is sent to the FM exciter and transmitter. Without this delay of the FM program, the HD audio would be severely misaligned from the FM transmission. A listener in an area where the HD signal is unstable would experience a jumping back and forth in the timing of the program as the receiver would change from HD to FM and back depending on the signal strength.
9	How To Hear WFCR-HD Radio As of the time of this writing, a few major car-radio manufacturers offer HD Radio-capable receivers, with many more signed on to come out with car and home HD receivers. Prices range from $500-1000 currently, but are expected to drop dramatically in 2005. Here are a few websites that can assist you in further exploration of HD Radio and associated products: http://www.ibiquity.com/ http://www.crutchfield.com/ http://www.kenwoodusa.com/ http://www.jvc.com/ http://www.bostonacoustics.com/
10	Some companies licensed to produce HD Radio Receivers Alpine, Clarion, Delphi, Fujitsu Ten, Harman Kardon, JVC, Hyundai AutoNet, Kenwood, Mitsubishi, Onkyo, Oritron (Orient Power), Panasonic, Sanyo, Visteon and Yamaha, Denon & Marantz