BEFORE THE Federal Communications Commission WASHINGTON, DC 20554 In the Matter of ) ) All-Digital AM Broadcasting ) MB Docket No. 19-311 ) ) Revitalization of the AM Radio Service ) MB Docket No. 13-249 ) ) ) To: The Commission COMMENTS OF THE CRAWFORD BROADCASTING COMPANY Crawford Broadcasting Company (“Crawford”) and its affiliates are licensees of 15 AM commercial broadcast stations1, all but two of which currently operate in the hybrid analog/digital mode. As such, we have great interest in the Notice of Proposed Rulemaking to permit all AM stations to broadcast an all-digital signal using the HD Radio in-band on-channel (IBOC) mode known as MA3 on a voluntary basis (“Notice”), and we offer the following comments in support of this petition. I. Benefits of All-Digital AM Transmissions It has been well established for more than a decade of operation by many of our stations in the MA1 hybrid digital mode that AM stations stand to gain a great deal from digital operation. Greatly improved audio quality is at the forefront, with audio bandwidth comparable to FM broadcasts, stereo audio and receiver display of title/artist or program title information. When a receiver locks in the digital mode to one of our stations, particularly one playing music, as the receiver blends from analog to digital, the contrast is dramatic. The highs and lows of the audio open up, the stereo image widens out, and the noise that seems to be ever present on almost any AM frequency disappears. Listeners experiencing this effect for the first time are quite often amazed at how good an AM broadcast can sound in this mode. All that being said, the limitations of the hybrid mode are significant, and we have become well acquainted with them over the past 15+ years of such operation. From a listener perspective, the low power of the digital carriers in the hybrid mode makes them susceptible to interference, particularly from noise, and receivers frequently transition between digital and analog in noise- prone and/or weak-signal areas. At best, this is perceived as a narrowing of the audio response and stereo image; at worst, even with perfectly time-aligned analog and digital audio, if the bit- 1 Crawford AM affiliates include KBRT, Costa Mesa, CA; KNSN, San Diego, CA; KCBC, Manteca, CA; KKPZ, Portland, OR; KLZ/KLDC, Denver, CO; KLTT, Commerce City, CO; KLVZ, Brighton, CO; WDCX/WDCZ, Buffalo, NY; WYDE/WXJC, Birmingham, AL; WCHB, Royal Oak, MI; WMUZ, Taylor, MI; and WRDT, Monroe, MI. error rate is significantly high, it can result in a time-shifting of the audio during the blend process, which is an irritation to most listeners. Further, during lightning season when convective weather activity is present, even the strongest signals experience an almost continual transition into and out of digital. In terms of spectrum, the hybrid mode has the potential for interference to stations on adjacent channels. We have found that even though emissions are confined to remain well within the mask defined by 47 C.F.R. §73.44, they still have the potential to cause interference to spectrum neighbors, which is a significant problem. This same issue, namely the spectrum bandwidth required for hybrid mode HD Radio transmissions, places significant demands on AM antennas and transmission systems. In the process of implementing hybrid mode digital transmissions on many of our AM stations, we had to make significant modifications to our phasing and coupling systems. At the very least, we had to either make modifications to matching networks or construct and install phase rotation networks to provide for proper load orientation. In many cases we had to optimize the entire transmission system to equip it to pass the hybrid HD Radio signal. This represents a significant expense in many cases and is an impediment to conversion for many licensees. All-digital operation alleviates many of these issues. All the power transmitted is used for the digital carriers instead of a small fraction. As such, a much more robust RF signal-to-noise ratio is produced which in turn results in much more robust digital demodulation. There is no transition from analog to digital, and as such there is no need to maintain any kind of analog audio diversity delay to produce time alignment of demodulated analog and digital signals. Presumably the higher digital power also provides a much greater immunity to static discharges. Spectrally, the all-digital mode, for which the emissions are confined to within ± 5 kHz of the center frequency, has much less potential for interference to spectrum neighbors. Even if the secondary and tertiary carriers are transmitted, the occupied spectrum is within ± 10 kHz of the center frequency. This occupied bandwidth also places greatly reduced demands on the transmission system. Since virtually all AM transmission systems are equipped to pass analog audio transmissions with sidebands extending to ± 5 kHz from carrier, those systems should pass the MA3 primary digital carriers without issue, although some load orientation optimization may be required in some cases. This effectively removes a big technical and economic impediment to digital conversion for many licensees. In short, the MA3 all-digital mode provides all the benefits of the MA1 hybrid mode without the negatives and difficulties, making the demodulated audio comparable in many ways to FM. II. Costs of Conversion It has been many years since Crawford has done any de novo IBOC conversions; those conversions, for the most part, took place during the initial wave of conversions in the early 2000s immediately after the Commission authorized such transmissions. As such, we have little recent experience with such conversions and the costs associated therewith. However, we have in recent years made equipment upgrades, replacing existing first- and second- generation HD Radio generation equipment with current-generation equipment. Assuming that the associated transmitter is a fairly late model and “HD ready,” this equipment upgrade does 2 represent most of the cost associated with conversion, exclusive of STL, audio processor and monitoring equipment upgrades that may be necessary in some installations. We find that these costs, which are less than $20,000 in most cases, are not a big impediment to conversion for many licensees, but we recognize that for many others this represents a small fortune. If other upgrades must also be made, such as transmitter replacement, STL upgrade and audio processor replacement, the costs can be prohibitive for stations that operate on thin margins to begin with. Add to that the cost of licensing by Xperi and the situation can be even worse. It is our conclusion, then, that the issue of conversion costs is highly dependent on each station’s (or licensee’s) individual situation, which is a big argument in favor of making the transition to the all-digital mode completely voluntary. III. Auxiliary Data Our observation in recent years has been that listeners have come to expect radio display of song or program title/artist, and that stations whose transmissions do not include such information are at a competitive disadvantage. For FM stations, such metadata transmission can be provided in the analog domain by RBDS, or in the digital domain by embedded program service data (PSD) streams. AM stations operating in a strictly analog mode have no means of transmitting metadata to receivers. Both MA1 and MA3 mode digital transmissions do have the capacity to convey metadata to receivers, although it has been our experience that metadata conveyance can be hit-or-miss in less than optimum conditions, such as in areas of interference, noise or during convective activity. Still, we would consider such a vital component of AM digital operation. We recognize that other uses can be made of auxiliary data streams within the MA3 framework, but we do not consider those to be primary. The exception would be EAS and other emergency alerts, for which we already employ some of the auxiliary data features of the MA1 digital mode for our hybrid-mode digital AM stations. IV. Nighttime All-Digital Operation We believe that for all-digital operation to succeed at all, it must be permitted both day and night. While we realize that there is increased potential for interference through skywave propagation at night, because MA3 emissions are confined to the bandwidth of the analog signal, we do not believe that such transmissions will produce increased nighttime interference. The nature of the interference may change – the interfering signal from a station transmitting in the analog mode will have identifiable audio, while the interfering signal from the same station transmitting in the MA3 mode will tend to sound like noise. We do not believe this is a significant distinction or impediment. In terms of coverage, it was well established in the WWFD all-digital tests that the nighttime all- digital coverage extended to the nighttime interference-free (NIF) contour. We believe that this would be sufficient in many cases. We also believe that the nighttime all-digital coverage of many stations will extend well beyond the NIF contour, depending on the nature of the nighttime interference. We believe that the only way to establish this is to authorize nighttime all-digital transmissions and gather data from stations over time. 3 V. Power Limits and NRSC-5 Adoption We agree that the allowed operating power limits for AM stations as set forth in §73.21 of the FCC’s rules should apply to the unmodulated audio carrier signal for stations that have converted to all-digital operation. We also agree that the HD Radio Emissions Mask, shown in Figure 11 of the NRSC-5-D Standard, should determine the allowable power for the digital sidebands.