SteppIR 3 Element Yagi, Instruction Manual

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Connect the Boom to the Mounting Plate
The mast plate has a total of eight pre-drilled holes. Four are used for the 2” stainless steel mast
clamps and four more are used for the 1-3/4” stainless steel boom clamps.
Connect the mast to the mast plate using the included 2” stainless steel U-Bolts, with saddles, and Ny-
lok nuts as shown in
Figure 7 . Tighten securely.
Note: If you are doing this on the tower it is advisable to test each U bolt for a proper fit and
bend if necessary to ensure ease of assembly on the tower.
Connect the boom to the mounting plate on the opposite side of the mast (
Figure 7 and 8 ), using the 1-
3/4” U bolts, saddles, and nuts. Align the boom so that the element brackets are level, then tighten se-
curely. The center balance point of the boom is at a splice, as shown in
Drawing 2A . There will be a
bolt on each side of the splice - make sure that the nut end of these two bolts are facing away from
the mast plate ( Figure 8 ). Otherwise, you will not be able to secure the boom snugly to the boom
clamps. To ensure a balanced weight load, the center of the mast plate should be reasonably close to
the center balance point of the boom.
Determining the direction of the antenna
The SteppIR Yagi has three “directions” in which it can be used. Normal, 180 degree and bi-
directional. This can make it complicated to describe the actual “aiming” direction of the antenna!
When you are installing the Yagi, you will want to position the antenna so that the “normal” direction
coincides with your rotor heading. When you are in normal direction, the forward, or “aiming” element
is a director, and the element behind the driven is a reflector. In the normal direction, the director is the
element that is closest to the driven element (89.50” between the two). In the 180 degree mode, we
swap the reflector and director positions by changing their respective lengths. However, we do not
simply swap the actual element lengths, we create a new antenna based on the new element spacing.
So you will always have an optimized antenna.
SteppIR Antennas - 3 Element 13
Figure 7
Figure 8
Figure 6
2” Mast
2” Mast
1-3/4 Boom
1-3/4 Boom