Hi Don,
This paragraph below illustrates only one of the many challenges we face
when attempting to model an antenna like this. We must, for example,
know the (parallel) L, C, and R values for each and every trap. Those
values are not easy to determine, requiring very good test equipment
someone who knows how to use it, and how to turn the raw data into L, C,
and R values. Not only that, R values can change with frequency!
We must know dimensions, both lengths and diameters, for every element,
including the tapering of diameters, and we must figure out the diameter
that correctly represents the conductive part of the element where it
mounts to the boom.
73, Jim K9YC
On 10/31/2017 10:09 PM, Don W7WLL wrote:
Was told by a MFJ tech not long ago that the TH7 R 15 M traps
(different PN's from those in the DE's) are built to measure out 100
kHz higher (?) than the 15 M DE's. Have not thought this through yet.
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