Radio World - November 19, 2008 - (Page 28)

28 Radio World | radioworld.com FEATURES November 19, 2008 MARKET PLACE Richardson Offers 1 kW FM Amp Module Richardson Electronics is offering the FM1K-108, a compact 1 kW FM amplifier module made by Res-Ingenium. The Class B amplifier is designed for FM and HD Radio FM broadcast applications. The company said it provides robust protection circuitry for security against overdriving, SWR overvoltage and thermal runaway. The amplifier offers 1 kW of linear CW output power (from 87.5 to 108 MHz), a 74 percent collector efficiency and superior harmonic suppression (–55 dBc), Richardson said. It uses four MRF6V2300NBR1 LDMOS transistors from Freescale Semiconductor. Enhanced gain (22 dB) allows the system designer to use lower input power (7 watts), eliminating one or more gain stages and saving cost. This module is intended for transmitter, translator and exciter designs. Data sheets and samples are available from Richardson Electronics sales representatives. The module can be used with the Wakefield 510-9M heat sink from Richardson Electronics. Info: www.rfwireless.rell.com/ amplifiers.asp. Satellite Continued from page 26 poles used with small dishes (24 inches or less), these can be as simple as drilling two holes near the bottom of the pipe and sending pieces of continuous thread (allthread) through those holes in quadrature. On larger poles it’s best to weld angle iron onto the pole. • In areas of severe frost heaves, make certain that any satellite mounting foundations are proper for the region and that they get under the “frost line.” In high latitudes, frost heaves can move even huge dishes way out of alignment. • Find a location that has a completely clear view of the satellite of interest in all seasons and, if at all possible, can “see” the balance of the equatorial satellite horizon. Cost pressures beat all of us into the ground; programmers will change carriers to follow the lowest cost, and you may need to find that new bird quickly. • Treat your sat RF connections even better than you would your STL. Use the lowest-loss, highest-quality connectors and cables available, avoid splices no matter how pretty, minimize the jumper count, ground and ground as often as possible especially the dish assembly, the LNB, the coax, the receiver frame, etc. • Make certain that the DC that powers the LNB is really pure DC and that it is the right voltage at the LNB. • Keep notes of signal levels and bit error rates over time and channels so that you have some benchmark data at troubleshooting time. • On digital systems a peak alignment using just the receiver is best obtained by minimizing the eb/no value. The receiver takes some time to update the display of the error rate so adjust very slowly while monitoring the demodulated audio to make certain that you are peaking up the desire signal. • Carefully seal up the feed horn assembly to avoid creating a year-round bug hotel. Bug bodies are great RF attenuators especially when a zillion of them are jammed in your feedhorn. • After peaking fixed dishes, you should mark their alignment with durable indicators so if the dish is moved by high winds or an aberrant auto bumper, you can quickly restore them to the approximately correct orientation to relocate the signal. The appearance of satellite technology for program delivery was a great leap, retiring frequency-limited and noise-challenged wire and radio circuits throughout the nation. As a young consulting engineer I visited one of the first stations on the RKO satellite network. The station’s production room had the net pot open, and just before the news I heard the network announcer practicing his opening copy. My comment to the station staff was that this fellow had a great voice. I asked, “How long has he been working here?” I thought the fellow was in the next room, not 50,000 miles away in New York. Doncha just love satellites? Charles S. Fitch, W2IPI, is a registered professional consultant engineer, member of the AFCCE, senior member of the SBE, lifetime CPBE with AMD, licensed electrical contractor, former station owner and former director of engineering of WTIC(TV) in Hartford, Conn., and WHSH(TV) in Marlborough, Mass. http://www.radioworld.com http://www.rfwireless.rell.com/amplifiers.asp http://www.rfwireless.rell.com/amplifiers.asp http://www.henryeng.com http://www.henryeng.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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