Table 1
Cross Brace Spacing from Reflector
Both 
Rails 
1 
18.8 cm 
2 
39.8 cm 
3 
60.7 cm 
4 
81.7 cm 
5 
102.7 cm 
6 
123.6 cm 
7 
144.6 cm 

Acknowledgments
Thanks are due to Gordon Grant, VE3DY, for all of the drafting.
**WARNINGS**
Working with Fiberglass
Some people are adversely affected by fiberglass. In any case, precautions
should be taken when cutting drilling
or filing fiberglass to protect against
the dust. Wear glasses, a mask and gloves. Wash areas where the dust comes
in contact with the skin.
************************************************************
23 cm Helix Antenna 
Specifications 
Frequency = 1269MHz 
Theoretical Array Gain = 25 dB 
Circumference = 1 wavelength 
Probable Gain = 23 dB 
Number of Turns = 27 
Theoretical Beam Width = 11 degrees 
Pitch Angle = 12.5 degrees 
Antenna Gain = 19 dB 
Spacing Between Turns = 52.4 mm 
Helix Diameter = 75 mm 
Beam Width = 21 degrees 
Reflector Side = 200 mm 
Sources for Chain Link Fence Fiberglass Tension Bars
Manufacturer: MasterHalco, Inc.
The Home Depot
Lowe's
ACE Hardware
True Value Hardware
Local Fence Contractor


Bottom
Rail 
Top
Rail 
1 
4.4 cm 
1.8 cm 
2 
9.7 cm 
7.0 cm 
3 
14.9 cm 
12.3 cm 
4 
20.1 cm 
17.5 cm 
5 
25.4 cm 
22.8 cm 
6 
30.6 cm 
28.3 cm 
7 
35.9 cm 
38.5 cm 
8 
41.1 cm 
43.7 cm 
9 
46.3 cm 
49.0 cm 
10 
51.6 cm 
54.2 cm 
11 
56.8 cm 
59.4 cm 
12 
62.1 cm 
64.7 cm 
13 
67.3 cm 
69.9 cm 
14 
72.5 cm 
75.2 cm 
15 
77.8 cm 
80.4 cm 
16 
83.0 cm 
85.6 cm 
17 
88.3 cm 
90.0 cm 
18 
93.5 cm 
96.1 cm 
19 
98.7 cm 
101.4 cm 
20 
104.0 cm 
107.0 cm 
21 
109.2 cm 
111.8 cm 
22 
114.5 cm 
117.1 cm 
23 
119.7 cm 
122.3 cm 
24 
124.9 cm 
127.6 cm 
25 
130.2 cm 
132.8 cm 
26 
135.4 cm 
138.1 cm 
27 
140.7 cm 
143.3 cm 
Table 2
Notch Spacing from Reflector
