Details 2-El.-4m-Yagi 3-El.-4m-Yagi 4-El.-4m-Yagi (12.5+50Ohm)
5-El.-4m-Yagi (28+50 Ohm) 6-El.-4m-Yagi 7-El.-4m-Yagi (28+50 Ohm) 9-El.-4m-Yagi

Three different Yagis for 70 MHz

Type 1: 3-El.-18-Ohm-DK7ZB-Yagi

3-El-18-Ohm-Yagi

Boom 1,55 m

Gain 6,55 dBd

F/B 17,5 dBd

Broadband Design

The SWR with 

12 m RG213

The match is made with two quarterwave pieces of 50- and 75-Ohm-cable in parallel. For details see table below.

Here it is RG58 and RG59

Coax cables for the 18-/50-Ohm-DK7ZB-Match

Cable length (screen) 

 Coaxcables

VF
715 mm RG58 + RG59 0,66

875 mm

 Aircell5 + CATV

0,82

You can use 10-mm-elements or a piece of 300 mm 11,5x1,5-mm-tube with tips of 8-mm-tubes 

(second lengths in the table)

 

Element-position 

 Element-length (10mm)

Element-length (11,5+8 mm)

Reflector

 0 mm 2142 mm 2164 mm

Radiator

600 mm

 2038 mm

2065 mm

Director

1535 mm

 1874 mm

1907 mm

Type 2: 3-El.-28-Ohm-DK7ZB-Yagi, 70MHz

Gain 5.7dBd

 F/B 27dB

Boom 1,35 m

Broadband design

Narrowband design see down

 

Element-position 

 Element-length (10mm)

Element-length (12mm)

Reflector

0mm

 2154mm

2150mm

Radiator

660mm

 2026mm

2020mm

Director

1320mm

 1890mm

1880mm

Type 3: 3-El.-12,5-Ohm-DK7ZB-Yagi, 70MHz

Gain 6,3dBd

 F/B 19dB

Boom 1,35m

Narrowband design

 

Element-position 

 Element-length (10mm)

Reflector

0mm

 2120mm

Radiator

430mm

 2006mm

Director

1330mm

 1886mm