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.
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