RF Shorts for March 15, 2013

By Doug Lung
published

More Information on Carbon Fiber Antenna Masts
Thanks to Kris Kirby, KE4AHR, to alerting me to these carbon fiber towers. He commented that it will be interesting to see how they interact with antennas. A well worded Google search immediately returned Investigation of the RF Properties of Carbon Fibre Composite Materials from the Industrial Electronics Electromagnetic Interference Department at ERA Technology. The report is from 1982. Based on this and on the research on RF reflections from carbon fiber reinforced wind turbine blades, I would expect these towers to behave similar to a steel tower, although perhaps with a bit more loss if the tower becomes part of the antenna system.

In any event, I’d love to put one of these in my back yard to test if my wife and neighbors would approve.

Air Force Seeking B-2 Bomber Antenna Coupler Replacement
MilitaryAerospace.com reported this week that the Air Force scours industry for replacement part to nuclear bomber communications system. The part they are looking for is a replacement for the CU-2421 antenna coupler for the AN/ARC-211 HF radio system made by Rockwell Collins in Cedar Rapids, Iowa for the B-2 nuclear bomber aircraft. The article notes that: “In the absence of satellite communications, HF radio could be the B-2's only method of contacting home bases or national command authorities while on distant missions. The ability to communicate reliably over long distances is essential for the B-2 because it can carry nuclear weapons.”

More information is available from the GSA.

FCC Cracks Down on Tower Violators
The FCC is issuing fines to broadcasters for antenna tower registration discrepancies, such as improper lighting and not modifying the registration when the ownership changes. See the Radio World article FCC Says Updating Tower Registration Data is Vital. You can check tower registration information on the FCC Antenna Structure Registration Search page. Cavell Mertz and Associates’ FCCInfo.com site will show any tower registrations associated with a broadcast or broadcast auxiliary license and allow you to map it using several Websites to check the location.

Comments and RF related news items are welcome. Email me at dlung@transmitter.com.

Doug Lung
Doug Lung

Doug Lung is one of America's foremost authorities on broadcast RF technology. As vice president of Broadcast Technology for NBCUniversal Local, H. Douglas Lung leads NBC and Telemundo-owned stations’ RF and transmission affairs, including microwave, radars, satellite uplinks, and FCC technical filings. Beginning his career in 1976 at KSCI in Los Angeles, Lung has nearly 50 years of experience in broadcast television engineering. Beginning in 1985, he led the engineering department for what was to become the Telemundo network and station group, assisting in the design, construction and installation of the company’s broadcast and cable facilities. Other projects include work on the launch of Hawaii’s first UHF TV station, the rollout and testing of the ATSC mobile-handheld standard, and software development related to the incentive auction TV spectrum repack.
A longtime columnist for TV Technology, Doug is also a regular contributor to IEEE Broadcast Technology. He is the recipient of the 2023 NAB Television Engineering Award. He also received a Tech Leadership Award from TV Tech publisher Future plc in 2021 and is a member of the IEEE Broadcast Technology Society and the Society of Broadcast Engineers.