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Author Topic: QFH antenna question  (Read 1652 times)
KR6N
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Posts: 44




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« on: March 30, 2010, 07:02:35 AM »

MY questions is concerning the direction of the twist on a QFH for Right Hand polorization (RHCP).  I assumed this ...  Looking down at the top of the mast the coils progress in a (right) clockwise direction to connect to the opposite side lower. Hope I didnt mess this up..  Tnx
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W3JKS
Member

Posts: 197


WWW

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« Reply #1 on: April 01, 2010, 06:27:28 AM »

Well, here it is from Wikipedia:

In electrical engineering however, it is more common to define polarization as seen from the source, such as from a transmitting antenna. When using this convention, left or right handedness is determined by pointing ones left or right thumb away from the source and matching the curling of ones fingers to the temporal rotation of the field.[3] In this case the handedness of the helix does not match the defined handedness of the wave.

When determining if the wave is clockwise or counter-clockwise circularly polarized, one takes the point of view of the transmitter, and while looking in the same direction which the wave is propagating, observes the direction of the temporal rotation of the field.

73s,
john
W3JKS/AAT3BF/AAM3EDE/AAA9SL
This convention is in conformity with the IEEE standard.[4]
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XE1VE3OQC
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Posts: 20




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« Reply #2 on: April 01, 2010, 05:17:59 PM »

Hi Ed,
For RHCP the windings ae the helices are wound counterclockwise as viewed from the top. What you have is a LHCP, QFH´s are opposite of what concenventional wisdom dictates.
If you need some help with this let me know.

Glenn,XE1/VE3OQC
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KR6N
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Posts: 44




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« Reply #3 on: April 02, 2010, 06:25:28 AM »

Thanks, Thats exactly what I was looking for.  I Built it backwards !!
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