[Elecraft] OT: Vertical doublets (was: Home made Sigma-GT5 & KRC2 or SGC?)

Tue Mar 23 11:50:01 2004

True, but keep in mind that ground losses (unless you live at the =
seashore)
pretty much wipe out any radiation below about 15 degrees in a vertical. =
The
44 foot vertical has maximum gain at about 15 degrees elevation, so it
actually represents probably the most efficient combination.=20

However, almost all verticals show maximum radiation at 0 degrees, and =
the
losses of any significant radiation below about 15 degrees are simply
accepted as part of the cost of not being in the middle of a huge, =
efficient
ground plane.

The "guru" who insists repeatedly that the losses in an ATU (or any =
matching
network) are significant is proof that saying something over and over =
again
doesn't make it so. The ATU easily can be the most efficient part of a
typical antenna system. As Don said, some ATU's are more efficient than
others. The L-match used in the Elecraft ATU's is, overall, the most
efficient system we have. But even the much-maligned "T" match networks =
can
be very efficient, if used correctly.=20

Ron AC7AC

-----Original Message-----
...Playing with Multinec, it looks like the higher angle lobe that =
appears
on 10 m with a 44' foot vertical doublet is reduced with a shorter =
hatted
doublet. It looks like the physical structure of the Sigma 5 is resonant
toward the higher frequency size with matching done at the antenna
feedpoint. Is this still the design goal if ladderline is used and =
matching
is by the KAT100 at the transceiver feedpoint?

73,
John K7JG.

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