WIXLIB

www.beradio.comViewpointAbusy month\en month when Isit down to write thiscolumn, Ireview the events of the past fewweeks to decide on atopic. This monthbrough‘ anew challenge, in that there areso many things happening it was hard todecide which one warranted the mostattention.Coding for IBOCThe pursuit of aterrestrial digital transmission system is rolling forward with renewed vigor. After stalling mid-flight with asubstandard encoding scheme, Ibiquityhas partnered with Coding Technologiesto introduce HDC, anew perceptualaudio encoder designed for the lowbit-rates of IBOC.After the NRSC nixed the PAC algorithm from its consideration, Ibiquityhad to move fast to before all momentum was lost. While Ibiquity isfairly mum about the inner workingsof the new encoder, the use of Spectral Band Replication, Coding Technologies' secret weapon to enhancing perceptual audio encoders, hasalready shown promise when it wasapplied to MP3pro and AACplus.Meanwhile at Ibiquity, some heavystaff cuts have also been made. The company maintains that the "staff departures"were not made for budgetary reasons andsays little more, but it makes one wonderif the encoder change and the staff cutsare related.Ownership bluesWhile much of the heavy debate hasebbed on the new ownership rules, theyare far from final. For radio, the marketdefinition issue is causing problems. Whilethe final outcome is still uncertain, Imustpraise FCC Chairman Powell for standingup to Congress.When the legislators said thenew rulesare no good and must be changed,Powell said fine—tell me how you wantthem to read. Iguess there were somelessons learned while trying to write theequal employment rules.Powell's new pet project is an increase in localism.Unfortunately, this appears to be away to push LPFM andnot reduce ownership limits.Meanwhile, the FCC has also taken on anew project tostudy the effects of communication towers on migratorybirds. Here we go again. I've heard the stories of entire flockscolliding to their deaths with tall towers, but Ihave neverseen aflock of birds fly single file.Don't get me wrong, I'm all for protecting other species.With our ability to change the environment comes theresponsibility of watching out for the animals we affect. Iexpect that the results of the study will show that just asmany birds have trouble navigating natural barriers—such atrees—as they do tall towers.Net disconnectAt the end of August came apersistent worm that sentunwanted e-mail messages everywhere. Awriter in theSanFrancisco Chronicle summarized the best defense to virus/worm infection:Just disconnect everything from the Internet. She went on to write that the excitement of the Internetpeaked in 1995; eight years later we are left with aform ofcommunications that is so overloaded with spam messages and odd returned messages that we never sent.Besides, one of the natural functions of the Internet—filesharing—has become acriminal act thanks to the freemusic downloaders.Maybe the RIAA can insist that all music file sharing mustuse the PAC algorithm. Then the quality will be so bad thatno one will want to listen anyway.Chriss Scherer, editorcscherer« ,primediabusiness.comLast year, Radio magazine asked youto help us find the oldest transmitter thatwas in working condition. Now wewant to find the oldest transmitter inuse as amain transmitter; that is, atransmitter that is used everyday. Do'ou have it? Send anote too@primediabusiness.com and letus know. We'll share the entries in ourDecember issue.Send comments to: E-mail: beradio@primediabusiness.cornFax: 913-967-19058 September 2003www.beradio.com

With new rock solid, fully digital modem technology, the Matrix is the most reliable, best soundincodec available. And now the Matrix offers another tool for your remote kit:fir fflifi rniereriBuilt-in GSM Phone.All this adds up tc better stability, improved audio,Aggressive Algorithm delivers 7 kHz on GSM.and greater flexib.ility. Already own aMatrix?Error Handling Technique.Call us and we'll upgrade you to the newestExternal Antenna.modem technology for FREE! Plus we'll be happyIncreased Power for More Reliiable Connections.to set up ademo of the new GSM module.Remarkably Stab eModem Technology. itup coos. tape in ee, .4111—Here is what somenumerous Beta Testers haClear Channel Director of Engineering for S:. Louis Daryl McQuinn said."Sounds much better than abad [ RPU], almost as good as agood [ RPU],and way better than you should ever expect from acell phone remoter"but all KLOU's Program Director Al Brock could say was,"Wow!"Shaun Kassity from Salem Commulications 104.7 The Fish inAtlanta: "Thanks to Matrix GSMehad the best soundingremotes ever on our station!"Steve Kirsch of Silver Lake Audio: 'The feed was rock solid.I'm very impressed—it sounds much better than Ithought it would."Collin Mutambo, Radio Simba, Kampala, Uganda:"We are indeed quite impressed."But our personal favorite, from Jerry Dowd of Jefferson Pilot's WBT in Charlotte, NC"We hope to keep the betas until you get nasty with threatening letters."Thanks Jerry. We'll take that as acompliment!Testing has been successful in 25 US states and on 6continents with more results coming in every day.The Matrix with the optional GSM Module celivers 7kHz on GSM wireless. Now accepting orders.Call us today at 800-237-1776 to learn more about the Matrix!00b11/1111911111e11/19 Pine Road, Devens, MA 01432 USATel: 9;8-784-1776 Fax: 978-784-1717 Email: info@comrex.com www.comrex.com

www.beradio.comRF EnulneerinuStaying neutralBy John Battison, P.E., technical editor, RFtthe heart of radio transmission is theoscillator. Without an oscillator to generate abasicsignal, which can be multiplied astimes as required to reachthe desirating frequency,transmitters would make good boat anchors. Theuse of controlled oscillation in an electrical environment makes the system function. Unfortunately, because the averagetube or transistor stage has so many random potential inductive (L) and capacitive (C) circuits associated with it, it isoften easy for undesired and usuallyunwanted oscillations to be generated inan amplifier stage.Sometimes these random L/C circuitswill resonate and develop unwanted RFvoltages. Depending on the physical char-Figure 1. For inductive neutralization, coil L,provides apath to the grid. Capacitor C, blocks thehigh voltage. The inductive reactance of L, isadjusted to cancel the capacitive reactance of thegrid and plate elements.acteristics of the tube, RF can be developedbetween various tube elements, often depending on the relative voltages on theseelements. An often unanticipated problemcan be caused by coupling between theplate and grid elements.In the early days of radio when triodetubes were the mainstay of radio receivers, the simplest and most popular typeof receiver was the regenerative. It used10September 2003an early version of feedback that controlled externalcoupling between the plate and grid circuits. By adjusting the amount of feedback—positive in this case—thesensitivity and gain of the stage could be controlled. Itwas controlled until the positive feedback became sohigh that the stage broke into oscillation. Many years ago,it was common to hear whistles and squeals on astationbecause another ham-fisted listener turned his regeneration controls up too far and into oscillation. In the1920s, receiver feedback control was usually accomplished by varying the coupling by means of aknob thatphysically changed the spacing between the grid andplate coils.Tubes lend themselves more easily to the demonstrationand discussion of power-stage neutralization. Despiteincreasing use of solid-state devices in transmitters, thereare still many transmitters using power tubes in their finalamplifiers. Some transmitter handbooks contain information on neutralizing power stages in transmitters. Simplyreplacing afailed final tube with anew tube may not returnatransmitter to full normal operation, and it is essential tocheck neutralization when replacing aPA tube:Although it seems reasonable to assume that all tubes ofagiven type will have the same internal inter-electrodecapacities, this is not necessarily so. New models anddifferent manufacturers usually show some differences.Many chief engineers have simply pulled out the bad tubeand popped in anew one without checking that the stageis still properly neutralized. 1have seen transmitters inwhich tube types have been changed (with similar baseconnections) without checking neutralization. Then theywonder why the signal doesn't sound quite right.The fact that astage may not be neutralized, is unstable andis generating aspurious frequency may not be noticed byacareless operator.This oscillation does not usually occurat the station' slicensed frequency (the tuned frequency ofthe output circuit),but at aslightly lower frequency. This mayor may not be passed by the antenna system.The power tube is ahigh-impedance input device, whilethe transistor has alow input impedance and generally isless susceptible to spurious signal generation. Undesiredfeedback in a stage is usually due to the presence ofunintended magnetic coupling, produced by poor equipment design, or feedback/coupling between the plate andthe grid in the final amplifier. The former effect can becorrected by careful stage redesign. Oscillation because ofatube's internal capacitance coupling requires externalinductive or capacitive neutralization.Neutralization requires the introduction of an out-ofphase voltage of equal amplitude to the grid of the tube.Figure 1shows amethod of inductive neutralization. Thereis no control of feedback voltage; it's basically the circuitwww.beradio.com

simplydifferent.AT3032oseriesNever satisfied to rest on their laurels, our engineers were inspiredto improve upon the technical excellence and coveted sound ofvalve design. How? By making it simpler.The new AT3060 tube microphone offers the convenience andeasy setup of a standard studio condenser by operating exclusivelyon 48V phantom power — so there's no dedicated power supplyAl 3060phantom- powered tube microphonerequiring you to reconfigure your boom arm with special cables.An all- new large-diaphragm cardioid capsule , with the warm soundof a vintage tube mic, has been specially tailored to keep proximityeffect and P-pop under control. Meticulously crafted in a rugged,compact housing, the AT3060 is set in a low-profile shock mountfor easy copy reading.Top it all off with the exceptional quality and consistency you counton from Audio-Technica, and the result is, quite simply, somethingspecial, for a lot less than you'd expect.VaudietechnicaAudio-Technica U.S., Inc. 11221 Commerce Drive, Stow, OH 44224I330.686.2600e1Fax: 330.686.0719 1E-mail: prooatus.com 1vwwv.audio-technica.com

RF Enuineerinuused in the old regenerative receivers. It ismore difficult to vary the feedback voltagein this system of neutralizing. For thisreason this method is not often used.Capacitive neutralization is shown in Figure 2. Capacitor C2 controls the feedbackfrom the plate to the grid circuit.This circuitis generally easier to adjust than inductiveneutralization and is convenient to use if avBFigure 2. With capacitive neutralization, the tank coil Liis center-tappedand one end provides a180 voltagedifferential. Capacitor C2not onlyblocks the high voltage, but it providesa broad range of adjustment to cancelany internal tube coupling.MORMUSICSUPPORTS 2ND OUTPUT FOR HO RADIO OR NETCASTIN CSUBTERRANEAN BASS SLAMWITH NEW GREGG PRESETS'tube type is changed. Basically,a centertapped PA tank coil is used with Bi- beingfed to the center tap,with one end to thetube plate and the other through theneutralizing capacitor to the grid.There are several different methodsof obtaining the necessary out-ofphase signal.Screen grid tubesIWEST COASTDoug TharpVoice 866.673.9267Cell 818.398.7314Email dtharp, san. mcomCENTRALBernie O'BrienCell 731.695.1714Email bernieobgearthlink.netMID -SOUTHBob MaybenVoice 877.391.2650Fax 256.543.0595Email bobmayben , usanetMID -WESTSOUTH -WESTNORTH -EASTMary SchnelleTyler CallisVoice 1.800.245.4307Dan LohseCell 817.312.6338Fax 513.583.1343Voice 908.722.6015Email tylercalliseintegrity.com Email mschnellemaryschnelle.corn Fax 908.722.4359Pager 877.792.8024Email scmsnorth,aol.comOPTIMOD-FMM USICALCONSISTENCYSC M S. try(THAT8400BRANDSYOURvBSOUND.Trade-ins welcomeCORPORATE SALES OFFICE - PINEVILLE, N.Toll FREE 800.438.6040Fax 704.889.4540www.scmsinc.com12September 2003As tube and stage amplification figures increased, the screen grid tube wasdeveloped in an effort to avoid the needfor neutralizing circuits. An additionalgrid with apositive voltage lower thanthat of the plate is interposed betweenthe control grid and the plate. This isknown as the screen grid. This is connected to ground directly or through alarge capacitor. This low-reactance grideffectively shields the control grid fromthe plate and reduces the capacity between these two elements. This systemoperates efficiently in lower gain stages,but when stage gain is increased, it isnecessary to add aneutralizing circuit.The high-efficiency of a high-gainscreen grid stage requires that no RFcoupling occurs between the plateand the control grid. The circuit issimilar to that used for a triode andvaries depending on the level of feedback required.In solid-state amplifiers, a low-frequency parasite occasionally occurs.This sometimes appears as noise adjacent to the operating frequency. This isnot as common these days, however itis good to know about it in case someunusual phenomena should appear inyour signal.E-mail Battison at batcom@bright.net.www.beradio.com

"If you can think it, Logitek can do it."WKDF / WGFX Studio Console ConfigurationsTwo Logitek Audio Engines, with atotal of eight I024A caras ( up to 96 analoginputs and 96 analog outputs), five 108D cards (up to 40 stereo digital inputsand 40 stereo digital outputs), and network cards providing fibre opticconnections between Engines 24 mix-minus buses available per studio Supervisor software for complete control of fader assignments/router functions Custom scripting provided by Logitek to pass audio and control from the Numixto other studios in the facility that have old analog boards vRoute " virtual" router controllersWKDF: 1Numix-12 Console w/12 fully assignable faders, access to 8stereo busesWGFX: 1ROC- 5Console, 1ROC- 10 Console, 1RTE-3Router Controller"The limitations of average consoles and routers just don't apply."-Cameron Adkins, Citadel Broadcasting, Nashville, TennesseeTake what you know about the average audio router and console and throw out the normallimitations. The Logitek Audio Engine not only can accommodate any input or outputstandard, analog or digital, but automatically handles all remote machine controlfunctions within the engine and routes those functions to whatever room orcontrol surface at the same time. This is not your father's router!With Logitek at the heart of this facility, Iam most proud of what it has allowedme to accomplish here. The Logitek system has taken away the boundaries ofthe traditional project and allowed me to be abetter engineer.Logitek Electronic Systems, Inc.5622 EdgemoorHouston, TX 77081 ogitekCO 2033 Logitek Electronic Systems, Inc.

www.beradio.comFCC [Iodate14The ins and outs of the new duopoly desBy Harry Martinhe new multiple ownership rules forradio contain some important regulatory changes that go beyond the Commison's decision to use Arbitron methodology to define radio markets. Here aresome examples: JSA Attribution. The FCC has determined that it will now, for the first time,count abrokered station toward the brokering licensee's permissible ownershiptotals under the revised local ownershiprules. Thus, where abroadcaster owns orhas an attributable interest in one or morestations in alocal radio market, and has aJSA with another station in the marketunder which the broadcaster controlsmore than 15 percent of the brokeredstation's advertising time per week, theJSA station will be counted toward thebrokering station's ownership caps. Licensees with in-market JSAs entered intoprior to the adoption of the new rules thatnow exceed ownership limits have twoyears from the effective date of the rules toterminate the agreements or otherwisecome into compliance. Deadlines. Some new reporting deadlines apply to JSAs. ( 1) Parties with existing, attributable JSAs in Arbitron metrosunder the new rules are required to fileacopy of the JSA with the FCC within 60days of the effective date of the rules. (2)JSAs involving stations located outsideof Arbitron metros must be filed within60 days of the effective date of the decision in the pending rulemaking dealingwith market definition in non-rated markets, i.e., late 2004 at the earliest. New Forms. FCC forms are being modified to require applicants to file attributable JSAs at the time an application is filed,regardless of whether the markets implicated by the application are located inArbitron metros. Noncommercial Stations. Another important change is that the Commissionwill, for market-size purposes, now countcommercial and noncommercial stationsin the market. Previously,the Commissionignored noncommercial stations.September 2003Localism promotedFCC Chairman Michael Powell,at least partly in responseto criticism of the new broadcast multiple ownershiprules, announced in August that the Commission willpursue the following initiatives to promote localism:Speeding the activation of low power FM stations. TheChairman stated the FCC would shortly open asettlementwindow for low power FM applications, during whichexclusive applicants could amend to use all availablefrequencies to resolve conflicts and gain new stationlicenses. This settlement opportunity could rapidly pushthe total number of outstanding LPFM authorizations toover one thousand by year end.A Localism Task Force. This task force will:1. Conduct studies to rigorously measure localism andhow it may be affected by existing FCC rules.2. Organize a series of public hearings on localismaround the country.3. Advise the Commission on recommendations to Congress relating to the licensing of thousands of additionallow power FM radio stations.4. Make recommendations to the Commission within 12months on how the Commission can promote localism intelevision and radio.5. Advise the Commission on legislative recommendations to Congress that would strengthen localism.Notice of Inquiry In September, the staff was to deliver tothe Commissioners aproposed Notice of Inquiry (N01) onlocalism. The NOI will seek comment on awide range ofFCC rules and procedures aimed at promoting localism.FCC may relax LPFMthird- adjacent protectionsAn FCC-commissioned study has recommended, basedon technical measurements and analyses, that existingthird-adjacent channel distance restrictions be waivedto allow LPFM stations to operate at locations that meetall other FM requirements. This is good news for LPFMapplicants, who are likely to find more nooks and6111§mhalwes'Renewal applications are due Oct. 1for radiostations in Florida, Puerto Rico and the Virgin IslandsStations in the following locations must file theirbiennial ownership reports with the FCC, and placeIF their annual EEO reports in their public files and ontheir websites, by Oct. 1: Florida, Puerto Rico,Virgin Islands, Iowa, Missouri, Alaska, Hawaii,Oregon, Washington, American Samoa, Guam andthe Mariana Islands.wwwleradio.com

FCC ECFS search pagehttp://gullfoss2.fcc.gov/prod/ecfs/comsrch v2.cgicrannies in the spectrumwhere they can squeezethemselves. It is bad news forfull-service stations concerned about the potentialimpact of third-adjacent interference (although the report's conclusions may allaythose concerns).In December 2000, theCongress required that theFCC prescribe third-adjacent channel spacing requirements for LPFM stations. As aresult, many then-pendingLPFM applications were dismissed because they couldnot satisfy third-adjacent channel interference protection requirements.At the same time, Congress instructed the Commissionto conduct an experimental program to test whetherLPFM stations would interfere with existing FM stations ifLPFM stations were not subject to third-adjacent channelspacing requirements. The Co

Tieline is the "Clear" choice for POTS, ISDN and Wireless Codecs GICI113121:1 , 01201312 4* IP) _ * .4, 111 -ote e ,ore TSallnen The Essential Codec Checklist n Compatible with other 15kHz POTS codecs n Unrivalled link stability over POTS (Used for STL's) n Connects to other ISDN codecs via G.722 (ISDN option) 15kHz audio bi-directional over POTS