Revised 14 June 2003
A-1
Appendix A
Specifications for 2D-40A
Description: The 2D-40A is a 2-driven-element array for the 40-meter amateur band. It
features full size elements, an internal phasing line, and an innovative integral BALUN
feed system. This beam has gain comparable to a 2-element Yagi, and a front-to-rear
ratio comparable to a 3-element Yagi.
Physical Specifications:
Materials:
Elements:
Aluminum, 6061-T6.
Accessories:
Aluminum, Steel, PVC, and Acrylic
Size:
Element Diameter:
Elements taper from 2.500 inches to 0.375 inches
Element Overall length:
Front, 66.2 feet Rear, 70.2 feet
Element sag:
Front, 27.9 inches Rear, 30.6 inches
Turn Radius:
36 feet
Weight:
163 pounds, including mounting plates and hardware
Projected area:
16.8 square feet
Wind survival (no ice):
100MPH (85 Knots)
Electrical Specifications:
Operating Bandwidth:
For 2.6:1 VSWR:
295 kHz (36% of the range is below F
0
and 64% is above)
For 2.0:1 VSWR:
206 kHz (39% of the range is below F
0
and 61% is above)
For 1.4:1 VSWR:
94 kHz (45% of the range is below F
0
and 55% is above)
Minimum VSWR:
Set to 1.0:1 at F
0
Gain:
6.5-dBi minimum (free space), 11.9 dBi (approximately -
NEC2 model) when array tuned for F
0
= 7.1 MHz and
mounted 70 ft (21 meters) above local earth.
Front to rear ratio:
20-dB minimum
Takeoff angle:
26.5 degrees
Vertical Beam width:
33 degrees -3dB 13 and 46 degrees
Horizontal Beam width:
74 degrees
Note:
Please see APPENDIX B, ‘PATTERNS AND GRAPHS” for more
information.
Note:
Cal-Av Labs, Inc. reserves the right to make and implement design
improvements without notice.
