Radio World - November 19, 2008 - (Page 10)

Radio World, November 19, 2008 Past columns are archived at radioworld.com What’s Wrong With This Picture? by John Bisset Do you enjoy hidden word puzzles? They’re supposed to be great for exercising your brain. Well, here’s a spin on that concept, which we call the hidden problem picture. Let’s say you showed up at the FM site in Fig. 1 as the new CE. Make a list of problems you can identify from the picture, and compare them to the list at the end of this column. ### Reliability of today’s transmission equipment can cause a mentality of “out of sight, out of mind.” With so many spinning plates, you may only have time to worry about the ones that are about to crash. But if all you can schedule is one hour a month at each site, do it! What should you check? Salisbury University Chief Engineer Bruce Blanchard grabs a spiral notebook for each site and starts writing. The notebook will eliminate the need to write on equipment panels and can provide you a history of inspec- tions. Bruce adds that veteran engineers will remember FCC-required maintenance logs, which documented a variety of inspections at the station. Start with your STL and record the operating parameters. If you’re fortunate enough to have the factory test data, compare that information to what you read, to form a baseline for normal operation. Signal strength and DC voltages may come in handy in the future; write them down. When a piece of equipment fails, you’ll be grateful to have a starting point to compare readings for quicker diagnosis and repair. Make it a general rule to measure anything with a power supply. Power supply capacitors are under constant stress and their complete failure can ruin your day. Catastrophic failure is pretty easy to spot; but aging capacitors also can leak, allowing ripple on the DC power supply rails. This slow failure can be more insidious in its effect on equipment. Has equipment been in service for more than seven years? It’s probably time to replace the power supply electrolytic capacitors. This proactive replacement may help you spot other problems. A can of compressed air comes in handy to clean the dust off heat sinks while you’re inside. Clean sinks allow cooler operation. Outside, keep fans and filters clean, as seen in Fig. 2. See TROUBLESHOOT, page 12 Fig. 1: How many problems can you spot in this photo? Fig. 2: Keep fans and filters clean, like this exciter. Just how good (or bad!) does your AM signal really sound? You’ll know in a jiffy with Inovonics’ latest-generation AM Reference Receiver and Modulation Monitor. Our 525 is a sensitive, wideband off-air monitor with a proprietary detector that reduces interference and ignores IBOC “Hybrid Digital” carriers. AM-mod measurements have full 10kHz+ bandwidth, but a menu-programmable filter in the audio-monitor channel allows you to preview the audible effects of proposed transmission cutoff characteristics or to emulate the response of typical AM radios. Menu-driven from the front panel, the 525 tunes in 1kHz steps and has five station memories that can be preset to your own station and to market companions. The highresolution, peak-holding LCD readout shows positive and negative modulation simultaneously, and also switches to display the incoming RF level and asynchronous noise to qualify modulation readings. Two sets of peak flashers indicate both absolute and userprogrammed modulation limits, and programmable frontpanel alarms (with tallies) give overmodulation, carrier-loss and program audio-loss warnings. The 525 is supplied with a weatherproof loop antenna at no extra cost. www.inovon.com 1305 Fair Ave. Santa Cruz, CA 95060 TEL: (831) 458-0552 FAX: (831) 458-0554 www.inovon.com e-mail: info@inovon.com http://www.radioworld.com http://www.inovon.com http://www.inovon.com http://www.inovon.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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