UHF Slot Antennas for the U.S

UHF Slot Antennas for the U.S

Company Project Summaries Products o UHF Antennas o VHF Antenna o Filters o Combiners JAMPRO ANTENNAS Oldest U.S. broadcast Antenna Company Since 1954 Jampro has designed, tested and manufactured FM and TV broadcast systems thereby establishing itself as a leader in RF technology throughout the world. From Alabama to Afghanistan; Jampro has over 15,000 active worldwide installations. DTV Ready Since 1993 Commitment to innovative solutions for DTV JAMPRO was the first to develop antennas that would accommodate a DTV signal while conserving tower loading. Only domestic U.S. manufacturer of complete DTV systems Jampro was the first U.S. manufacturer to design, test and build a broadband UHF panel antenna in the United States. A UHF antenna panel, combiner and waveguide ensures total DTV system integrity and quality. First to introduce and develop Circular Polarization to TV One of the largest contributions to the broadcast industry was the development of Circular Polarization for TV when helical Spiral antenna was introduced. Today, many Spiral antennas are in service including WBBM, WLS and the #1 independent station in the United States - KTVK in Phoenix, Arizona. One of the largest number of slot antennas delivered More than 20 years ago, Jampro began designing and producing UHF Slot antennas for the U.S. domestic market. Today, there are hundreds of slot antennas in service around the world. Largest number of batwing antennas produced * Leading the way again in VHF broadcasting was the development and production of the Batwing antenna. Jampro has been manufacturing Batwing antennas longer than any other RF manufacturer in the world. This harsh and rugged antenna is the choice for many TV broadcasters. * By an existing company Unequal customer service and support Jampro 24-hour, 365 days-per-year customer service is unmatched by any other antenna manufacturer worldwide. The expansion of Jampro’s regional office is a strong commitment to unequaled customer service and support. AlanDick Broadcast Ltd. AlanDick is unique in its ability to provide services, products and solutions on a global basis to satisfy the infrastructure needs of the broadcast markets throughout the world. With offices across 5 continents, AlanDick is a world leading organization with the ability to plan, deploy, maintain, manage and upgrade DVB-T, DAB and DRM technologies for broadcast markets. A reflection of the company’s growth is the development of successful relationships across the globe. Alan Dick is committed to offering both quality products as well as supporting services to their partners worldwide. Through an extensive product portfolio, high levels of experience, competence and skills, Alan Dick provides practical solutions and confidence to their client base. AlanDick Broadcast is involved primarily in one distinct market, the Terrestrial Transmission of TV & Radio programs. Terrestrial is the original, most widely used, predominately Free - To – Air and easily accessible means of receiving TV and Radio signals and in most cases quicker to install and less expensive than cable or satellite. AlanDick has gained an excellent reputation for the supply, installation and commissioning of complete transmission systems using the latest high quality TV & Radio digital technologies. PROJECT SUMMARIES PROJECT SUMMARY Indonesia, Jakarta High Power UHF Antenna & Combiner System for Television Project Brief: The project involved the supply, installation & commissioning of a 400m hybrid tower, 16 bay UHF antenna system, quad transmission lines and 5 channel digital and analogue combiner. The total combined transmitter power is 320kW, with the highest single powered station having an ERP of 10MW, making it the highest power system in Asia. 6340 Sky Creek Dr, Sacramento, CA 95828 | T: 916.383.1177 | F: www.JAMPRO.com PROJECT SUMMARY Singapore Main Antenna & Channel Combiner System for National Digital Television Project Brief: The project involved the supply & installation of a replacement 12 bay broadband UHF antenna system, dual main transmission lines (~250m / 820ft ea.), low loss dual chain 6 channel combining system with critical mask filtering, cross-site patch panel switching system to back up tower and a power, VSWR & U-link monitoring system with alarms. 6340 Sky Creek Dr, Sacramento, CA 95828 | T: 916.383.1177 | F: www.JAMPRO.com PROJECT SUMMARY Singapore Rooftop Gap Filler Antenna Systems for National Digital Television Project Brief: The project involved the supply & commissioning of rooftop gap filler antennas using a selection of designs based on a broadband UHF antenna system. Each antenna was designed to meet a specific pattern requirement as well as certain physical limitation due to limited rooftop space. After an initial 11 sites, over 100 sites have been required. 6340 Sky Creek Dr, Sacramento, CA 95828 | T: 916.383.1177 | F: www.JAMPRO.com Alan Dick Broadcast and the CN Tower When completed in 1975 the CN Tower was, at 1805ft. (550m) the world's tallest free standing structure, it rose from the Toronto waterfront to dominate an already impressive skyline. At its top is a broadcast antenna system designed, engineered, supplied and commissioned by Britain's EMI antenna group which in 1978 became part of Alan Dick Broadcast. The group has long been associated with the challenges of television engineering and the challenge continues. The realisation of any project on the scale of the CN Tower confronts engineers of many disciplines with a new and complex set of problems which have to be solved at every turn in the long road from planning to completion. The provision of the antenna system for the tower was no exception. Although the final objective was the radiation of improved television and radio signals to the city of Toronto and the surrounding area, many related problems had to be recognised and solved in the course towards achieving this ambition and ensuring its continuing reliability. Many of these problems were directly related to the physical size of the project. Viewed from the ground the antenna system appears as a deceptively tapering needle. The taper, in fact, is in steps from a base diameter of 26ft. (7.9m) at 1480ft. (451m) to a tip of 5ft. (1.5m) at 1805ft. (550m, the top of the tower. The core of the antenna array is a 300 ft. (91m), 220 ton steel column with a pentagonal cross section from its base for 90% of its length, changing to a square for the topmost antenna. Structural mechanics determined the size of this core and set the antenna engineers the first of their many problems. The horizontal radiation patterns of the antennas are basically omnidirectional although, in some cases, the radiated power is reduced over a small arc to provide protection for adjacent service areas. An initial feasibility study was undertaken to determine the best solution to produce these patterns from antennas mounted on such large cross sections. This study was an integrated approach of precision scale model measurements and R.F. theory, from which the detailed design for the complete array emerged. Vertical radiation patterns provided an equal challenge. The sheer height of the tower and its position relative to its service area demanded patterns filled to very large depression angles. Reliability of service has been greatly assisted by designing arrays that may be used in separate halves rather than resorting to the expensive and space-consuming practice of providing separate stand-by antennas. Alan Dick Broadcast Ltd Tel: +0044 1242 820972 Email: [email protected] www.alandickbroadcast.com In pursuance of continual product improvement, Alan Dick reserve the right to change specifications without prior notice. Alan Dick and the CN Tower An extremely important feature of the antenna design and indeed of the overall tower design is the G.R.P. (Glass Reinforced Plastic) radome. This massive cylindrical enclosure which weighs well over 50 tons provides the antenna with complete weather protection and greatly reduces the enormous forces that would result from the wind acting on its irregular surfaces more than a third of a mile above Lake Ontario. The radome was fabricated by the British company Hunting Industrial Plastics. The R. F. power from the radio and television transmitters is fed to the individual antennas by semi-flexible coaxial feeders up to 6 1/8 inches in diameter. Over 10 tons of this cable were supplied to EMI by the West German company Kabel und Metallwerke, of Hanover. At each antenna the power is distributed and monitored to achieve the precisely tailored radiation patterns through more than 2 1/2 miles of highly sophisticated transmission line complexes. Compensated half-wave dipoles were developed by the antenna group for the actual radiating elements of the VHF antennas. The UHF arrays were based on the already highly-successful multi-channel Emislot panel. The circularly polarised crossed dipoles for the Master FM array were developed for broadband, very high power operation by the Alford Manufacturing Company, of Boston, U.S.A., and manufactured under licence in the UK. The final challenge came with installation and, here again, new techniques and equipment had to be developed. The installation was carried out under EMI supervision by their appointed Canadian sub- contractor, Skyhook Construction Ltd., with some additional specialist installers being hired from Alan Dick Broadcast. The Tower, including the steel antenna support column reached its final height of 1805ft. (550m) in April 1975. The next stage was weatherproofing the whole antenna aperture by installing the radome. Four hundred and fifty individual G.R.P. panels went to make up the complete radome, each was lifted outside the main concrete tower to the 1480 ft. (451m) level. Here they were landed on a specially-constructed head frame and gantry and then placed into position from a swing stage platform which was also specially designed and constructed for this project. Alan Dick Broadcast Ltd Tel: +0044 1242 820972 Email: [email protected] www.alandickbroadcast.com In pursuance of continual product improvement, Alan Dick reserve the right to change specifications without prior notice.

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