Τρίτη 10 Δεκεμβρίου 2019

Installation Antennas to rotator (Tower-Mounted Antennas)


In the preferred tower-mounting configuration, the antenna Wind Loading Area must be less than 1 m2 (G-450A) or 2 m2 (G-650A), and the “K” factor (see below) must not exceed 100 (G-450A) or 180 (G-650A), where K = [Antenna Turning Radius (m)] x [Antenna + Mast Weight (kg)]. Refer to the antenna manufacturer’s specification sheet for determining the turning radius and weight of the antenna
  
Example: In this example, a 14 MHz 3-element Yagi of Turning Radius 7.5 m, Weight of 14 kg, and Surface area of 0.7 m2 is proposed for tower mounting below a 3-element 21/28 MHz trapped Yagi of Turning Radius 3.5 m, Weight of 13 kg, and Surface Area of 0.3 m2 . The mast weight is 5 kg.
 The antenna system K factor, then, is the sum of the two antenna K factors:
 K1 = K factor of 14 MHz 3-element Yagi.
K1 = Turning Radius (7.5 m) X Weight (14 kg + 2.5 kg) = 123.75
         |              |
Antenna Weight      Mast Weight (5 kg ÷ 2)
  K2 = K factor of 21/28 MHz 3-element trapped Yagi.
K2 = Turning Radius (3.5 m) X Weight (13 kg + 2.5 kg) = 54.25
         |              |
Antenna Weight      Mast Weight (5 kg ÷ 2)
 KTotal = K1 + K2 = 123.75 + 54.25 = 178
 The antenna system Wind Loading Area is: 0.7 m2 + 0.3 m2 = 1.0 m2|
 Note: In such “Christmas Tree” installations, compute the mast weight separately for each antenna, using the relative heights of the two antennas to apportion the mast weight.
Refer to the antenna manufacturer’s specification sheet for determining the weight and the surface area of the proposed antenna.

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Δευτέρα 2 Δεκεμβρίου 2019

Installation Antennas to rotator (Pole-Mounted Antennas)



Pole-Mounted Antennas
Mounting of the rotator on a pole or mast results in a significant de-rating of the size of the antenna which can be mounted, due to the tremendous bending forces applied to the rotator’s clamps. For pole mounting, the attached antenna must have a net mounted weight (combined weight of antenna plus mast) of 10 kg or less, and the product of multiplying the [Antenna Wind Load Area (in m2 )] by the [Height of the Antenna Mast (in m)] must be 0.25 or less.
[Antenna Weight] + [Mast Weight] ≤ 10 kg.
[Antenna Wind Load Area] X [Height of Antenna Mast] ≤ 0.25
Refer to the antenna manufacturer’s specification sheet for determining the weight and the surface area of the proposed antenna.
Yeasu Rotators:
The antenna Wind Loading Area must be less than ,=<0,25 (G-450A) & (G-650A), or =<0,45 (G-1000DXC), or =<0,80 (G-28000DXC)
Example:
For a 50 MHz 5-element antenna of surface area of 0.3 m2 , the above specifications for pole mounting will be met if (A) the antenna is mounted on a mast not longer than 0.8 m (0.3 X 0.8 = 0.24 < 0.25), and (B) if the mast weight plus the antenna weight is less than 10 kg. However, if the mast is 1 meter long, the specification will be exceeded (0.3 X 1 = 0.3 > 0.25).

More: https://www.yaesu.com/indexVS.cfm?cmd=DisplayProducts&ProdCatID=104&encProdID=9CD2145C24AE53C5A6C62D7D703A9F3C&DivisionID=65&isArchived=0