"Cecil Moore" wrote in message
...
...
But I've given you all the information in Kraus' book
about that particular antenna. Laid on its side:

| + - +
|----------/////--------------------
| 1/4WL coil 1/2WL

The coil is a 180 deg. phase reversing coil. [snip]
73, Cecil,

Yep and this makes it a "phasing" coil and the antenna a colinear. The
phasing coil causes the current in the two sections of the antenna to be in
phase. Note my addition of polarity indicators to the above diagram. The
right end of both elements are the same = in phase currents. Now you have a
half wave and a quarter wave in phase, yielding gain by a flatter pattern
(whicn is vertical in this drawing).
You can stack half waves up like this and this is done in common cellular
gain antennas - probably WiMax as well. There are several ways to do the
phasing... Coils like this, quarter-wave shorted stubs (parallel-line),
reverse connecting alternate sections of coaxial t-line as elements, phasing
harnesses on the feed line... Probably more.

73, Steve, K;9'D.C,I