Broadcast Wind DTV RF Probe

Broadcast Wind DTV RF ProbeOne bit of technology coming out of our current USDA Phase II project was the development of automated probes to be used to capture DTV RF signal parameters over a long period of time in diverse locations, distances, weather conditions, in the vicinity of wind farms. We developed an inexpensive, easily deployed field monitoring probe to record key television signal metrics, over a one year period, at remote, unattended measurement sites and transmit the data back to our central location for logging, processing and analysis. The metrics captured include date, time, 8VSB lock, RF frequency, signal strength, signal modulation error ratio (MER), receiver AGC gain, frequency offset, and transport stream (TS) data,  packet error rate (PER), reception margin over threshold of visibility (TOV) and detailed multipath (equalizer tap) data showing signal reflections (or echoes) from the wind turbines and other objects in the field.  The probe is able to … [Read more...]

Broadcast Wind – USDA Contract Announcement

Broadcast Wind LLC announced today that it has been awarded a two year contract by the US Department of Agriculture to develop the powering of broadcast transmitters with wind energy.  Research and New Technologies coming from the Project Include: Local Television Research Broadcast Wind has partnered with the Iowa State University to research, survey and document the important socioeconomic linkages between local television and rural America.  Previous social science research indicates that positive socio-economic outcomes, such as community cohesion, retention of population, business investment, and many other measures of quality of life are associated with the presence of local broadcasting in smaller-sized, non-metropolitan communities.  Locally generated wind power will help sustain local broadcasting in rural communities by reducing the cost of electricity, which is broadcasters’ largest operating expense.  Predictive RF Interference Modeling Broadcast Wind is developing … [Read more...]

AWEA 2012

AWEA conference this week. Ted Turner Keynote: … [Read more...]

Robustness of Broadcast Systems to Multipath Interference from Wind Turbines

Robustness of Broadcast Systems to Multipath Interference from Wind Turbines by: Charles W. Rhodes for: Broadcast Wind, LLC Transmitted TV signals are waves of energy and act like waves in water and/or light waves.  That is, they are reflected when they strike an object.  They can also be diffracted (change direction) when they encounter an edge such a mountaintop or the blade of a wind turbine. Basic Facts about TV Signal Propagation TV signals are strongly reflected by metal surfaces whose dimensions are greater than a critical length of the reflecting surface.  This corresponds to about 18 inches for signals in the UHF TV band (Most TV signals are in this band.) and to about 53 inches for FM radio signals.  (FM radio reception can be affected by extremely strong echoes.)  The steel tower and to a lesser extent, the non-metallic blades of a wind turbine will reflect TV signals.  These waves move at the speed of light.  That is about one sixth of a mile per microsecond (1 one … [Read more...]

Road Trip – Iowa AWEA Distributed Wind Energy Conference

Business partner, Frank Marlowe and I hit the road last week to visit with broadcast engineering professionals at the Chicago Radio Show and discuss AM radio / wind turbine interference and the latest theory in mitigation techniques.  Following our Chicago meetings, we drove to DesMoines to see what was happening at the AWEA Distributed Wind Conference.  On our way through Illinois, we passed by the Council Bluffs wind farm. Council Bluffs - On the Farm The show was relatively small venue but chuck full of interesting new offerings within the distributed wind energy space.  We raided the floor over a 5 hour period exploring new (and old) business offerings. Frank (right) discussing WTG transport and installation with a Barnhart Sales rep ( Brian Kuhn of Aeronautica Windpower (Right) takes a moment to pose for the camera.  Aeronautica (  has begun shipment of their "Made in USA" 750 kW turbine to community … [Read more...]

Broadcasting on Wind Energy

Broadcasting on Wind Energy  - Windustry Event – State College, PA I recently had the opportunity to participate in a forum for Distributed Wind Energy, hosted by Lisa Daniels and the “Windustry” team at my Alma Mater, Penn State University, in State College, PA. Attendees included half a dozen Wind Industry pioneers, site developers, turbine manufacturers, staff and students from 8 Universities, financial experts, municipal administration, and State and Federal funding agencies. Brian Kuhn - Aeronautica Wind   Panel discussions covered turbine manufacturer product comparisons (I counted 4 US and 4 foreign manufacturers in attendance), wind project development, community education, permitting, financial planning and structuring, federal and state funding opportunities and national policy. The following are some of my notes from the event: Community education and involvement is frequently overlooked yet, it is a key first step to a successful … [Read more...]

Wind Farms: TV and Radio Interference

Over the past several years, wind turbine blade construction has advanced considerably, moving from an aluminum composition (prone to reflect and scatter radio signals) to a much more “radio friendly” construction of fiberglass composites. Despite these advances, “big wind farm” developers still face two challenges with signal interference:1) Radar interferenceWind farm turbine blades are known to interfere with the radar tracking of weather systems and airplanes. The tip of a turbine blade may reach 170 MPH creating “doppler clutter” and cause the radar to misinterpret the data it is receiving. For example, a weather radar may reflect the wind shear between the fast moving blades as a tornado. An air traffic control radar, on the other hand,  may temporarily lose track of an aircraft flying near to or behind a wind farm’s blades. In 2008, the Department of Homeland Security commissioned a study that stated “Despite these difficulties, there is no fundamental physical constraint … [Read more...]