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ANTENNAS FOR 100 POUND DXPEDITIONS 9.5

Buddipole comparisons and conclusions

9.5.1 Gain and take-off angles of configurations Below is a table summarizing the gain and take-off angle for the Buddipole configurations discussed above. Buddipole Configuration Comparisons Standard BP

Standard BP

Standard BP

Long BP

Long BP

BP

Loaded Vertical

Loaded Vertical

Loaded Vertical

Full-size Vertical

Full-size Vertical

dipole

L

L

1 radial

4 radials

1 radial

16 feet

@ 8 feet

@ 16 feet

16 feet

8 feet

16 feet

6.93 dBi

4.62 dBi

5.21 dBi

0.03 dBi

1.62 dBi

0.03 dBi

30 deg

30 deg

20 deg

15 deg

20 deg

15 deg

6.38 dBi

3.77 dBi

4.67 dBi

1.71 dBi

1.47 dBi

1.77 dBi

35 deg

30 deg

20 deg

20 deg

20 deg

15 deg

5.89 dBi

3.48 dBi

4.57 dBi

2.38 dBi

1.41 dBi

2.31 dBi

40 deg

40 deg

25 deg

20 deg

20 deg

20 deg

5.67 dBi

4.52 dBi

5.49 dBi

2.53 dBi

0.87 dBi

2.03 dBi

50 deg

50 deg

30 deg

20 deg

20 deg

25 deg

X

3.11 dBi

3.87 dBi

2.53 dBi

0.44 dBi

1.52 dBi

X

70 deg

40 deg

25 deg

20 deg

20 deg

Standard

10m

12m

15m

17m

20m

10m

12m

15m

17m

20m

Table 4 Buddipole gain and take-off angle summary The dipole configurations have take-off angles too high for good DX. Further, they are difficult to match over 15m. Neither of these facts should be surprising. The “L� configuration has two problems: it is awkward on the top of the mast with the weight significantly off-center, and it still has a very high take-off angle on 20m. The numbers do indicate that there may be some value in having the radials level instead of sloping, however. The vertical configurations (loaded and unloaded) with a single radial provide low take-of angles and an interesting pattern. A vertical cannot have gain in one direction without 190

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Antennas for 100 Pound DXpeditions - volume 1  

Computer-based antenna modeling and direct experience with lightweight portable antenna systems. Volume 1: Selected high band antennas [20-6...

Antennas for 100 Pound DXpeditions - volume 1  

Computer-based antenna modeling and direct experience with lightweight portable antenna systems. Volume 1: Selected high band antennas [20-6...

Profile for ne1rd
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