Subsessions

• The Usefulness of Guy Wire Top-Loading on Vertical Antennas at MF, LF, and VLF

  Monday, April 20 | 3:30 – 3:50 p.m. | N261

  Benjamin Dawson

  Top loading of monopole antennas can improve their efficiency and impedance characteristics. The use of portions of an upper level of guy wires on guyed towers can provide increased base resistance but does not necessarily improve horizontal plane efficiency at MF. At lower frequencies the increase in base resistance from guy wire top-loading can benefit efficiency as radiation resistance of he monopole declines with decreased electrical length. Horizontal "wheel" or "cross" top loading is effective so long as it is sufficiently dense so as to increase capacitance to ground substantially. This presentation will show the effects of various types and amounts of top loading. Because AM station antenna site availability has become more limited, shorter antenna towers with top-loading at new or modified sites can sometimes be beneficial.

• Dude, Where’s My Signal? Utilizing UAVs to Find and Validate missing AM Radio, FM Radio and TV Signals through Full Antenna Pattern Verification.

  Monday, April 20 | 3:50 – 4:10 p.m. | N261

  Jason Schreiber

  Title Option 2: The Broadcast Blind Spot: Utilizing UAVs to Find and Validate Missing AM Radio, FM Radio and TV Signals through Full Antenna Pattern Verification. Abstract: For broadcast engineers, the primary question after commissioning is, “Are we transmitting what we say we are transmitting? Is my antenna operating as expected?”. Yet, the installed antenna performance remains the greatest unknown critical component in the transmission chain. While the transmitter, combiner, and feedline are rigorously verified, the antenna's performance is often only checked via a VSWR test, which confirms impedance match but not whether the radiation pattern meets specifications. This critical lack of knowledge regarding the actual antenna pattern—the "missing signal"—can result in significant coverage loss, non-compliance with the FCC license, and potential interference issues. Traditional land-based signal verification techniques are severely flawed: they are cumbersome, time-consuming (taking up to a week or two), are limited by terrain, and offer only spot checks, failing to provide an accurate, 360-degree reconstruction of the antenna pattern. Moreover, modern computer simulations, while valuable, rely heavily on accurate tower models and cannot reliably account for real-world "unknowns" such as installation defects (e.g., misalignment or incorrect phasing), adjacent structure effects (which can cause significant notches in the pattern), and even manufacturing defects. This paper presents an Airborne Radio Measurement System as the definitive solution for finding and validating the complete antenna pattern. Using autonomous Unmanned Aerial Vehicles (UAVs) equipped with high-precision GPS (centimeter resolution positional accuracy) and integrated, calibrated spectrum analyzers, these systems can perform full antenna characterization (azimuths and elevations) in a near free space situation that is typically completed in just 1–2 hours. The measured pattern data acquired by the airborne system provides the absolute, authoritative baseline against which all modeling must be checked. This high-quality, calibrated measurement data allows broadcasters to instantly diagnose and characterize all major causes of pattern deviation and signal loss, ensuring their infrastructure is working to its full potential and eliminating the persistent question of where their signal is truly going. The solution offers increased accuracy and efficiency with instant, repeatable results for auditing and long-term performance tracking.

• Finding and Engaging New Talent for Broadcast / Media Engineering

  Monday, April 20 | 4:10 – 4:30 p.m. | N261

  Bud Williamson, Andy Gladding

  This session will provide insight and ideas in how to identify sources of new talent in addition to how to present opportunities in broadcast / media engineering to prospects. Andy Gladding, Vice Chair SBE Chapter 15 NYC, has had great results with cultivating talent from WRHU / Hofstra University. Teamed up with Bud Williamson, Chair SBE Chapter 15 NYC, this effort has been refocused and expanded to include outreach to additional sources of talent, including colleges and high schools. Examples of how new talent have been engaged in studio and transmitter projects will be presented along with a model of how existing engineers can mentor and teach new talent in a receptive and non-overwhelming manner.