HF ten elements log-periodic array

 

Spacing d(n-1),n

Shortening factor t = d(n-1),n / d(n-2),(n-1)

Element length L

Wavelength l = 2.L

Spacing factor s = d(n-1),n / 2.L(n-1)

 

Lengths are in mm

Element

N.

Element spacing

t

Element length

l

s

Region gain (dbi)

1

1174

0.8

8300

16600

0.070

6.5 - 7.0

2

939

0.8

6800

13600

0.069

6.5 - 7.0

3

751

0.9

6200

12400

0.060

6.5 - 7.0

4

675

0.9

6000

12000

0.056

6.5 - 7.0

5

608

0.9

4900

9800

0.062

8.5

6

547

0.9

3800

7600

0.071

8.5

7

492

0.9

3000

6000

0.082

8.5

8

442

0.9

2200

4400

0.100

8.5

9

n.a.

0.9

n.a.

n.a.

n.a.

n.a.

10

n.a.

0.9

n.a.

n.a.

n.a.

n.a.

 

Hardware : three pieces aluminum boom 6 m long, 0,5 m aluminum support, 1,2 m plastic support, 6 m plastic support, plus perimeter nylon rope.

Balun - various types tried :

(the last two baluns weren't of good feature ...)

 

See also Log-Periodic experiments

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