Matching on the MFJ-1800
On Wed, 18 Nov 2009 07:07:21 -0600, "amdx" wrote:
However, as to calling it a folded loop seems to be straying from
conventional usage as those loops are rather sweeping (large). This
may be deliberate if my data conforms to the usage found.
By this statement, do you mean the spacing between elements is large
so it looses it's folded loop characteristics?
Hi Mike,
I was a bit obscure on that last point. YOUR antenna's looped dipole
has rather large turns for a folded loop. A folded quarterwave (for
verticals) or folded halfwaves (for dipoles) generally show 4X
impedance boost for same sized wire/element in the loop. Some designs
use different sized halves of the loop to change the multiplication
factor as this is the primary determinant with closely spaced folds.
However, your antenna has rather larger spacing which may lower the
multiplication factor IF my model conforms to actual. This choice of
larger looping may show MFJ's engineering talent in achieving a
natural match. I don't think the rest of the array is going to matter
much in getting the "most" gain it could, but it is probably good.
73's
Richard Clark, KB7QHC
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