BV6 Yagis by DJ9BV

The latest and best for 50MHz


Introduction

Here are two yagis for 6m, one 1 wavelength long with a gain of 9.5dBd, and the other a 2.1wl model with a gain of 11.8dBd.

The design rules follow the proven method used for the 70cm OPT yagis. Solutions for element lengths and distances have to satisfy a criterion based on an optimum current slope and constant phase delay in the array of parasitic elements. If a solution satisfies this criterion, high gain per boomlength together with an excellent pattern can be expected. 

Another constraint in the development of these Yagis was the requirement for 50 ohm input impedance. This allows simple feed structures like a folded dipole, which is electrically efficient and mechanically rugged. 

During the final verification with NEC-II software it was found that these antennas have excellent stacking capability, with high stacking gains in excess of 5.8dB (2x) and minimum mutual detuning.

If properly built, these Yagis are excellent performers. They are cheap to build, and can be made from easily available materials.

Common Mechanical Data

Performance

Model,
elements

 

Length Gain [dBd]

Front/
Rear
ratio [dB]

Beamwidth

Stacking 2x2

 [m]

 [wl]

E [deg]

H [deg]

E [m]

H [m]

Gain [dB]

BV6-1.0
6

5.850 1.0 9.40 >19 45.6 54.0 7.7 6.6 5.9
BV6-2.1
10
12.90 2.1 11.90 >25 36 40 9.4 8.6 5.9

 

BV6-1wl (6 El)


These lengths are correct.

Element

Position [mm]

Boom diam [mm]

Length [mm]

R 0 30 2966
DE 922 30 2850
D1 1232 30 2734
D2 2411 30 2734
D3 4329 30 2702
D4 5850 30 2670

 

BV6-2.1wl (10 El)

 

These lengths are correct.

Element

Position [mm]

Boom diam [mm]
(Note variations)

Length [mm]

R 0 30 2924
DE 1209 30 2844
D1 1706 30 2724
D2 2712 35 2705
D3 4012 40 2686
D4 5536 40 2656
D5 7222 40 2636
D6 9040 40 2616
D7 10970 35 2595
D8 12900 30 2584