Radio World - November 19, 2008 - (Page 8)

8 Radio World | radioworld.com NEWS November 19, 2008 AM DA Continued from page 1 tion of a hybrid method consisting of modeling and a set of field-strength measurements similar to that required for a partial proof.” Immediate savings? Despite reports that MoM will result in significant cost savings for AM broadcasters, at least some remain unconvinced that immediate savings will be evident. “We’ve heard of some compelling estimates because of the hours and hours saved because the time-consuming field measurements are not required,” one industry observer admitted. “Time will tell for sure. The real savings will likely be over time as the total cost of proof of compliance will be much reduced with a properly licensed MoM array.” Mark Mueller, president of Mueller Broadcast Design, a broadcast engineering consulting firm, said while modeling can help avoid lengthy field tuning and measurements, the field-intensity measurements themselves are not that difficult and should not cost as much as some charge to take them. “This new method to verify performance introduces additional costs upfront, as well as ongoing certification costs. The big savings seem to be a mirage,” Mueller said. the AM directional arrays in the United States are out of compliance in one way or another, and in many cases the cost of bringing them back into compliance has effectively prevented owners from doing so, several industry experts said. The FCC is permitting the use of the new computerized verification method for AM stations using series-fed radiators. However, towers that are shunt fed or top loaded are ineligible. The commission is requiring verification of the antenna monitoring system every two years. Nearly every large AM broadcast group in the country supported the rulemaking request, including CBS Radio, Clear Channel Radio, Citadel Broadcast Company, Cumulus Media Inc., Entercom Communications Corp. and Cox Radio. The groups, along with broadcast consulting engineers and equipment manufacturers, formed a coalition to support MoM adoption. For the new antenna certification rules to affect a broadcaster, the individual must file an FCC 302 application for a new or modified application. If the application is filed specifying MoM, the new rules will apply and magnetic field measurements will no longer be required when doing a full or partial proof, said Ray Benedict, chair of the AM Directional The antenna array of KCBS(AM), San Francisco; the station is licensed to CBS Radio East Inc. Antenna Performance Verification Coalition and director of spectrum engineering for CBS. “The coalition is satisfied. We have asked SBE to develop educational programs to help explain the new rules to station engineers and to assist them in gaining the knowledge necessary to comply with the new rules.” Benedict said he expects some radio stations and broadcast groups to have the internal expertise to do computer-modeling work in house. “It will save money and it is a simpler, less time consuming procedure,” Benedict said. Even with MoM certification as an option, the FCC retains the right to ask AM broadcasters for a complete magnetic field measurement if changes are made or parts are replaced in an antenna system, Benedict added. Barry Thomas, president of SBE and vice president of engineering for Lincoln Financial Media, said, “Licensing under MoM rules will eliminate monitor point readings and will greatly simplify and reduce the cost of all subsequent changes to the array. I believe it would be prudent for all stations eligible for MoM licensing to do so because of the benefits over time. “As long as there is significant care in the accuracy of the sampling mechanisms, computer modeling is at a level of sophistication such that models can be used more accurately to predict performance of an antenna system than limited field measurements.” Less expensive Training broadcast engineers and broadcast engineer consultants on computer modeling, which uses Numerical Electromagnetic Code-4 or MININEC, will be a crucial step in the adoption process, said Jack Sellmeyer, president of Sellmeyer Engineering. “The process requires qualified engineers trained in the use of Method of Moments calculations. The effort required is not trivial and requires certain skills to obtain accurate results which will stand up to scrutiny,” Sellmeyer said. The FCC said in its MoM decision that a minority of commenters dissented to the proposal in comments for MM Docket No. 93-177, “An Inquiry Into the Commission’s Policies and Rules Regarding AM Radio Service Directional Antenna Performance Verification.” Greater Media was the most notable broadcaster to dissent. In its public comments, Greater Media and Charles A. Hecht & Associates, a broadcast engineering consulting firm, wrote, “while the techniques specified in the coalition’s proposal produce a directional antenna pattern that is ‘reasonably close’ to the authorized pattern, the coalition’s procedures are not adequate in themselves for antenna performance verification. Greater Media advocates adop- Photo by CBS Radio San Francisco DOE Michael P. Smith The big savings seem to be a mirage. SMALL(ER) WONDER — Mark Mueller Mueller, who has worked with directional arrays since 1983, specifically questions the new costs likely to be associated with the re-certification of the antenna monitoring system every two years. “The station will have to go off the air to re-certify the sample system. This will also most likely require consultant fees and won’t be cheap — probably in the several thousand dollars range,” Mueller said. “At the end of the day, all that is really saved is the cost of the field intensity measurements, which for most smaller arrays only take a few days under the current rules. MoM antenna modeling is not foolproof. “A qualified, trained engineer will still have to visit the site with the proper test gear, verify overall construction, verify the antenna sample system, measure the self-impedance of the towers and generate the mutual impedance input data necessary for accurate modeling. Consulting engineer visits are usually expensive and this won’t be an exception.” Yet at least one consulting engineer disputed that view on cost savings. “Saving days and sometimes weeks of field measurements is a significant savings for a broadcaster. Not only that, but the validity of internal array measurement techniques for a proof is undoubtedly better than relying on magnetic field measurements in a perturbed environment,” said Ben Dawson, managing partner of Hatfield & Dawson Consulting Engineers. Dawson said the requirement for sample system measurements every two years is trivial. “It’s a few hours of work at the most. A reasonable percentage of the techs and contract service providers and virtually all consulting engineers know how to use an impedance bridge and an oscillator/detector,” Dawson said. The new AudioScience ASI8921 tuner adapter packs 8 radio tuners into a single 6.6" PCI card. That’s half the space (and half the power) of older analog tuner cards. Keep tabs on up to 8 AM or FM channels simultaneously, including RDS/RDBS info, all from a single antenna input. Monitor or record in PCM and MPEG-1 layer2 and MPEG-1 Layer 3 (MP3). Eight not enough? Install up to 8 cards in one system. Windows XP/Vista and Linux drivers available. To find out more about our small wonder, call +1-302-324-5333 or go to www.audioscience.com. www.audioscience.com http://www.radioworld.com http://www.audioscience.com http://www.audioscience.com http://www.audioscience.com

Table of Contents Feed for the Digital Edition of Radio World - November 19, 2008

Radio World - November 19, 2008 IBOC+Satellite? Subscribers Not Impressed The New World of AM DA MoM Contents Newswatch Buterbaugh Legendary in Upper Midwest From the Editor Buterbaugh: His Colleagues Look Back Workbench: What’s Wrong With This Picture? KFI Back at Full Power With New Tower 3G or Not 3G? That Is the Question Exploring HD Radio Availability in Philadelphia HD Radio Scoreboard Digital News GEP For That Bird Without a Wire A Chat With Bay Country Radiolicious Brings Radio to iPhones People News Belar FMHD-1 Clears the Skies Reader’s Forum Radio Thrives in Digital Age A Vote for Change

Radio World - November 19, 2008

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