RE: [amsat-bb] Whose Right and Whose Left--CP REPLY

["Howard Long" <howard@xxxxxxxxxxxxxx>]

Hi Ben

> In the picture the horizontal
> yagi is closest to him and the vertical one is 1/4 wave length ahead or in
> front of the horizontal one. The antennas are feed in phase. The high side
> of the horizontal antenna is to the right of the boom and the high side of
> the vertical antenna is above the boom. If a CP signal with the same CP as
> the antenna is being received, it first hits the forward yagi than rotates
> CW 90 degrees and intersects the second yagi. If one were to transmit from
> the same antenna the signal would be rotating CCW from the perspective of
> one standing behind the antenna.

You might be referring to http://www.g6lvb.com/images/rhcp.jpg, which sounds
the same as your description, although I didn't go into any details. As they
say, often a picture tells a thousaned words.

The way I look at it is that to consider how an imaginary point in front of
the antenna will see it from the same point of view as the camera's in the
picture, with our antenna transmitting. If fed in phase the vertical
wavefront is received first and then the horizontal wavefront, thus forming
a right-hand screw. If you turned the horizontal driven element round 180
degrees, it would be LHCP.

73 Howard W7/G6LVB

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