On Thu, 08 Apr 2004 20:04:12 GMT, T.E.O hath writ:
Many of us use 1 wl horizontal loops configured in a square or rectangular
shape. When these loops are operated at frequencies greater than the
fundamental, the horizontal pattern changes from a nearly circular pattern
to one with lobes & nulls.

For example, if I operate a 60' high, 1 wl, side fed, square, 80 meter
horizontal loop on 40 meters, the horizontal pattern is that of a
4 leaf clover with four fairly broad lobes and four nulls.

Now this is great if you intend to QSO with a station in the
direction of a lobe but not so great if your target is in the
direction of a null.

Now if I move the feed point to an adjacent side of the square, the
lobes become nulls & the nulls become lobes. In essence, I have "rotated"
the pattern by moving the feed point.

There was a feller in north Denver a couple hundert years ago that
had a rotatable rhombic. He had a circular track in place for ore
carts -- he had four ore carts with telephones poles installed in
them (with concrete, or the somesuch.) This was *LONG* before
(affordable) digital electronics and I am unsure how he co-ordinated
and synchronised travel of all 4 ore carts.
I know for sure that he had a lot of acreage, _and_ a very
understanding wife...


73
Jonesy
--
| Marvin L Jones | jonz | W3DHJ | OS/2
| Gunnison, Colorado | @ | Jonesy | linux __
| 7,703' -- 2,345m | config.com | DM68mn SK