TWIN-BOOM YAGI ANTENNAS FOR 432 MHZ

Slobodan Bukvic – Boban, YU7XL, yu7xl@mts.rs, http://www.qslnet.de/member/yu7xl/

 

         

Introduction     

Following the article about the twin-boom antennas for 144 MHz in Dubus 1/2017, I have designed a collection of these antennas for 432 MHz. The results obtained deserve to be announced, and now I have developed two antennas for 432 MHz for the Dubus readers exclusively. The first one is 2 meters long (2.88 WL), the second is 4205 meters (6.06 WL). Both of them are made of Ø6 mm Aluminum tubes. Potential makers need to choose if their booms have to be made of Aluminum tubes or of dielectrical material (polyesther fishing rods), keeping in mind that the boom correction is not calculated.

Note: As VE7BQH suggests, all my models for 70 cm band, are designed for f0 = 432.100 MHz, assuming Sky temperature Tsky = 20 K and Earth temperature Tearth = 350 K. Both models have 200 Ώ impedance. The gain and G/T ratio given in the tables comprise the KF2YN convergence correction included.

 

ANTENNA X722O6XL4Q

Fig. 1: – Layout of the X722O6XL4Q antenna

Dimensions:

 

Ref

De

D1

D2

D3

D4

D5

D6

D7

D8

D9

D10

D11

D12

D13

D14

D15

D16

D17

D18

D19

D20

Position (mm)

0

125

183

309

469

597

767

1005

1256

1512

1774

2000

Length (mm)

333

269

301

297

293

289

287

283

281

279

277

267

Height (mm)

0

±80

±65

±115

±155

±180

±200

±233

±240

±243

±243

±230

 

Figure 2 – Sketch of the radiator, H = 269 mm, V = 80 mm

 

Performance:

G

(dBi)

F/B

(dB)

F/Sh

(dBi)

F/Sv

(dBi)

Hor

(◦)

Ver

(◦)

Temp

(◦K)

Tlos

(K)

G/T

(dB)

16.32

36.46

22.19

17.48

32.8

27.2

29.2

3.0

+1.67

 

 

Fig. 3: Radiation patterns for X722O6XL4Q

 

 

Working condition:

Frequency for SWR=1.5 (MHz)

Z (Ώ)

at 432.100 MHz

SWR

at 435.000 MHz

Lowest

Highest

Bandwidth

415.800

443.800

28.000

200.1

1.08:1

 

 

Fig. 4: Frequency diagram for SWR better than 1.5

Fig. 5: SWR diagram from 432 to 435 MHz

 

 

Four antennas x722o6xl4q in h-stack

Horizontal

distance (cm)

Vertical distance (cm)

G

(dBi)

F/B

(dB)

F/Sh

(dBi)

F/Sv

(dBi)

Hor

(◦)

Ver

(◦)

Temp

(◦K)

Tlos

(K)

G/T

(dB)

136

176

22.40

43.16

8.29

7.58

12.8

9.8

27.8

3.0

+7.96

Fig. 6: Radiation patterns for 4 x X722O6XL4Q in H-stack

 

 

 

 

ANTENNA X73806XL1Q

Fig. 7: Layout of the X738O6XL1Q antenna

 

Dimensions:

 

Ref

De

D1

D2

D3

D4

D5

D6

D7

D8

D9

D10

D11

D12

D13

D14

D15

D16

D17

D18

D19

D20

D21

D22

D23

D24

D25

D26

D27

D28

D29

D30

D31

D32

D33

D34

D35

D36

Position (mm)

0

122

178

316

474

578

754

1008

1255

1518

1784

2056

2322

2593

2863

3138

3411

3686

3968

4205

Length (mm)

334

276

303.5

297

289

287.5

287.5

285.5

281.5

279.5

277.5

273.5

269.5

265

261

258.5

257

256.5

255.5

253.5

Height (mm)

0

±80

±65.5

±109

±148

±174

±195

±220

±240

±249

±253

±254

±256

±258

±260

±262

±263

±263

±263

±252

 

Fig. 8:  Sketch of the radiator, H = 276 mm, V = 80 mm

 

 

Performance:

G

(dBi)

F/B

(dB)

F/Sh

(dBi)

F/Sv

(dBi)

Hor

(◦)

Ver

(◦)

Temp

(◦K)

Tlos

(K)

G/T

(dB)

18.69

33.41

20.48

17.66

24.8

21.2

28.2

3.6

+4.19

 

Fig. 9: Radiation patterns for X738O6XL1Q

 

Working condition:

Frequency for SWR=1.5 (MHz)

Z (Ώ)

at 432.100 MHz

SWR

at 435.000 MHz

Lowest

Highest

Bandwidth

408.000

442.600

34.600

199.8

1.07:1

 

 

Fig. 10: Frequency diagram for SWR better than 1.5

 

Fig. 11: SWR diagram from 432 to 435 MHz

 

Four antennas x738o6xl1q in h-stack

Horizontal

distance (cm)

Vertical distance (cm)

G

(dBi)

F/B

(dB)

F/Sh

(dBi)

F/Sv

(dBi)

Hor

(◦)

Ver

(◦)

Temp

(◦K)

Tlos

(K)

G/T

(dB)

200

200

24.76

33.23

7.64

9.58

8.6

8.4

27.1

3.6

+10.44

 

Fig. 12: Radiation patterns for 4 x X738O6XL1Q in H - stack

 

 

Comparison

The twin boom antennas were inserted in a part of the VE7BQH table, where they belong according to their boom length)

 

TYPE OF

ANTENNA

SINGLE ANTENA

FOUR ANTENNAS IN H-STACK

 

L

(λ)   

GAIN

(dBd)

Z

(ohms)

VSWR

Bandwidth

E

(m)

H

(m)

Ga

(dBd)

Tlos

(K)

Ta

(K)

G/T

(dB)

 

X722O6XL4Q

2.88

16.32

200.0

1.08:1

1.36

1.76

25.65

3.0

27.9

7.96

 

EAntenna 432LFA11

2.94

15.09

47.9

1.28:1

1.20

1.11

21.02

3.9

34.1

5.69

 

KF2YN Polly 12 CR

3.17

15.70

48.3

1.17:1

1.30

1.30

21.74

3.2

32.3

6.65

 

InnoV 12 LFA

3.29

15.48

50.1

1.07:1

1.23

1.15

21.37

4.0

31.0

6.46

 

YU7EF EF7012B-5

3.30

15.58

48.6

1.40:1

1.26

1.17

21.50

4.9

33.3

6.27

 

EAntenna 432LFA12

3.31

15.32

50.1

1.45:1

1.23

1.14

21.24

4.3

33.2

6.03

 

KF2YN Boxkite 13

3.37

17.38

50.9

1.09:1

1.63

1.50

23.29

9.3

39.4

7.35

 

Innov 13 LFA

3.72

15.92

50.1

1.15:1

1.30

1.22

21.83

4.5

30.8

6.95

 

YU7EF EF7013M-6

3.83

16.11

49.4

1.06:1

1.33

1.25

22.01

4.7

32.9

6.84

 

F9FT 19

4.02

15.96

55.7

1.14:1

1.33

1.26

21.88

6.1

39.1

5.96

 

DG7YBN Tonna 19 mod

4.02

16.17

44.7

1.15:1

1.35

1.27

22.07

6.1

33.8

6.82

 

InnoV 14 LFA

4.03

16.46

52.6

1.14:1

1.38

1.32

22.31

4.5

30.0

7.42

 

DG7YBN 14

4.06

16.38

49.4

1.51:1

1.38

1.31

22.30

3.5

30.7

7.42

 

YU7EF EF7014M-6

4.24

16.50

49.5

1.11:1

1.39

1.32

22.39

4.5

33.3

7.17

 

RA3AQ AQ70-14f

4.30

16.63

52.8

1.09:1

1.41

1.34

22.54

6.9

33.6

7.28

 

KF2YN Boxkite 16

4.37

18.02

49.1

1.06:1

1.74

1.61

23.85

10.2

41.2

7.71

 

I0JXX 16JXX70

4.46

16.53

201.8

1.05:1

1.41

1.33

22.44

4.9

33.6

7.18

 

EAntenna 432LFA15

4.58

15.66

48.4

1.25:1

1.22

1.14

21.36

4.0

28.5

6.82

InnoV 15 LFA

4.59

16.68

51.1

1.08:1

1.42

1.34

22.57

4.8

30.0

7.81

YU7EF EF7015M-5

4.69

16.80

49.5

1.03:1

1.43

1.36

22.66

5.4

33.6

7.40

WiMo 15 (YU7EF)

4.89

17.06

174.5

3.05:1

1.46

1.30

22.87

4.3

30.0

8.10

InnoV 16 LFA

5.19

17.27

48.4

1.19:1

1.50

1.43

23.15

4.8

29.7

8.43

InnoV 17 LFA

5.33

17.25

49.9

1.03:1

1.45

1.45

23.11

4.3

29.5

8.41

YU7EF EF7017M-5

5.56

17.41

50.7

1.06:1

1.52

1.44

23.22

5.6

33.4

7.98

KF2YN Polly 18 CR

5.69

17.79

48.1

1.18:1

1.95

1.95

23.96

3.7

31.4

9.00

RA3AQ AQ70-18f

5.74

17.76

51.7

1.08:1

1.59

1.53

23.64

6.1

32.6

8.51

InnoV 18 LFA

5.76

17.49

49.8

1.05:1

1.52

1.45

23.33

4.3

28.9

8.72

Konni F20 DL6WU

5.94

17.52

220.4

1.07:1

1.58

1.51

23.39

1.5

31.7

8.37

DG7YBN 19

5.94

17.80

49.3

1.28:1

1.60

1.54

23.68

3.6

29.5

8.98

YU7EF EF7018M-5

6.00

17.61

49.3

1.08:1

1.54

1.48

23.39

5.1

31.7

8.39

X73806XL1Q

6.06

18.69

198.2

1.05:1

2.00

2.00

24.76

3.6

27.1

10.44

K1FO 22

6.10

17.85

200.8

1.34:1

1.63

1.56

23.75

4.8

33.6

8.49

EAntenna 432LFA18

6.13

17.88

47.6

1.42:1

1.61

1.55

23.76

5.6

29.7

9.02

YU7EF EF7019B-5

6.43

17.91

50.5

1.12:1

1.60

1.54

23.72

5.7

32.7

8.59

KF2YN Polly 20 CR

6.50

18.30

48.8

1.21:1

1.90

1.90

24.43

3.8

31.1

9.50

InnoV 19 LFA

6.54

18.18

47.6

1.09:1

1.68

1.63

24.10

5.0

29.2

9.45

Tonna 21 DX

6.61

17.91

58.4

2.32:1

1.67

1.61

23.80

6.7

41.3

7.63

KF2YN Boxkite 22

6.70

19.26

52.1

1.17:1

1.99

1.90

25.14

10.8

40.2

9.11

InnoV 20 LFA

6.99

18.28

50.5

1.09:1

1.73

1.67

24.31

5.0

28.1

9.82

YU7XL QY72110414

7.04

18.42

201.1

1.28:1

1.88

1.82

24.47

3.4

27.2

10.12

Z(ohms) - measured on 432.100 MHz

Bandwidth – VSWR measured on 435.000 MHz
                         

 

 

 

Conclusion

These antennas are calculated for Al tubing with Ø6 mm diameter. Available are other diameters, too. (5, 6 or 8 mm, or inch sizes). Just send me an e-mail if you need something different then the here presented. Also, if you build this antenna, please, send me your experiences and photos. Thank you.

You wount be dissappointed with this antenna, I am sure. The G/T results speak for themselves! Good DX!

 

Slobodan Bukvic, YU7XL