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Page 67
CHAPTER NINE
SECTON 9.0
OPTIONAL 40/30 ELEMENT TRUSS KIT
INSTALLING THE TRUSS SUPPORT MAST
The great advantage of telescoping fiberglass poles are that they are flexible and extremely strong. This is a
significant benefit for such adverse weather situations as high winds, icing or snow accumulation. The only neg-
ative to this, is because of the flexibility, there is a slight natural
“
droop
”
at the element ends. This droop has no
impact whatsoever on performance, but some people do not care for the look. For this reason we offer the loop
element truss kit.
The 40/30 loop truss kit allows for the leveling of the Director, Driven and Reflector loop elements to the same
latitude. This makes for a better overall profile for the Yagi. These trusses do not have any impact on load
bearing, they are used for aesthetic improvement only.
NOTE:
The truss support arm for the Driven loop ele-
ment is also used for the optional boom truss kit. Refer to chapter Eight, Section 8.0 for installation of the truss
support arm and to
figure 9.07
and
9.08 below.
The truss mast needs to be mounted so that it is centered on the halfway point between the EHU center
-
point
and the return tube center
-
point. The overall length between the two center
-
points is 30 inches, so the halfway
point is 15 inches. Make a mark on the boom 15 inches between the two center
-
points as shown in
figure 9.01
.
Locate the truss support (PN 10
-
1054
-
01) and two
1
-
3/4”
aluminum saddle halves (PN 10
-
1601
-
03). Place the
saddles so that the edge of the saddle is on the edge of the mark as shown in
figure 9.02
. This will ensure that
the support is indeed on the centerpoint. Insert two of the
5/16”
x
3
-
1/2”
hex head bolts (PN 60
-
0065) and se-
cure with
5/16”
Nylock nuts (PN 60
-
0046). Remember to use anti
-
seize on the stainless steel fasteners. Level
the support before tightening as shown in
figure 9.03
.
Attach each of the 4 inch stainless steel turnbuckles (PN 60
-
0083) using the
1/4”
x
1
-
1/4”
hex head bolt (PN 60
-
0110), two of the
5/16”
stainless steel flat washers (PN 60
-
0033) and
1/4”
Nylock nuts (PN 60
-
0030) as shown
in
figure 9.05
. The stainless steel washers are both positioned between the eye of the outside turnbuckle and
the Nylock nut as shown in
figure 9.06
.
Figure 9.07
shows the truss mast assembly for the Driven element which is different than the truss mast for
the Director and Reflector. Place two
5/16”
flat washers (PN 60
-
0033) on the
5/16”
x
2
-
3/4”
hex head bolt
(PN 60
-
0107). Place one of the 4 inch turnbuckles (PN 60
-
0083) on the bolt and slide the bolt through the
truss support. Place two more
5/16”
washers and the other 4 inch turnbuckle and then secure with a
5/16”
Nylock nut (PN 60
-
0046).
Figure 9.08
shows the completed Driven element truss support arm.
FIG. 9.01
FIG. 9.02
FIG. 9.03
FIG. 9.04
FIG. 9.05
FIG. 9.06
FIG. 9.08
FIG. 9.07