Thank you for asking this, because I have always been fascinated with the concept of loaded Beverages (either BOGs or shortened overhead).
But what did you mean by "proper pattern"? I assume that you mean "usable pattern" and that realize that the pattern will change with frequency. See for yourself at www.w0btu.com/Beverage_antennas.html#Beverage_antenna_freq_range To me, those patterns are all "proper" and very "usable" much of the time. Although I have EZNEC+ 5.0, I have no experience with Beverage models with lumped loading. Hopefully, somebody reading this will. 73, Mike www.w0btu.com www.w0btu.com/Beverage_antennas.html On Fri, Aug 23, 2019, 1:40 PM Mikek <[email protected]> wrote: > I want a BOG that will have a proper pattern over 500kHz to 4Mhz. > As I understand it, "loaded Beverages show increased directivity because > velocity of propagation along the antenna is /*decreased*/." > > I assume that is for antennas that are shorter than what is required for > that frequency. > > Info from here, https://www.w8ji.com/slinky_and_loaded_beverages.htm > > > Is there any reason I can't load a BOG to make it directive at 500kHz? > My BOG length limit is 250ft. Assuming the answer is yes. > > If I do add the proper inductances along the length of the antenna then at > 4MHz the pattern suffers. (previously I used nine inductors) The inductance > must be reduced as frequency goes up. > > To that end I'm searching for a specific ferrite core geometry, like this, > https://www.dropbox.com/s/2bwsxrc58g51yu8/E%20Core%20Ferrire%20DB.jpg?dl=0 > Note, I dropped this and chipped the important part in the center, but > before that, it did what I wanted. > This material was not good at the frequencies I'm interested in. > So I need a material good to at least 4MHs and with an AsubL of 2000 to > 3000, or more, with a similar > geometry. Or any geometry that necks down to a smaller cross section. > > Where can I buy such a core? > > Thanks, Mikek > PS, if anyone here wants to model a 250ft bogit over that frequency > range, you would have my undying gratitude. > > _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
