"Joe Subich, W4TV" <[email protected]> wrote: > On 1/5/2024 12:53 AM, Robin wrote: > > > One thing to bear in mind throughout any analysis of such designs for > > 160M is that the total focus of the Broadcast designs and measurements > > and proofs is energy at zero degrees elevation. Our needs benefit from > > low angle radiation, for certain, but, little attention is paid by the > > broadcasters and by the modeling programs to position and shape of > > elevated lobes, or for that matter, the shape of the main lobe above > > zero elevation > Not exactly true. Many "modern" broadcast facilities are designed to > minimize high angle lobes that cause destructive *self-interference* at > the outer edges of the [night time] ground wave coverage. > At an MF broadcast station station I worked at 50+ years ago a qsy of 200KHz HF had been made. Severe fading was then encountered at the edge of the service area at night from a high skylobe. About 200 feet was lopped off the top of the 550' tower, which restored the fringe area reception.
-- Brian D G3VGZ _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
