Construction Details

2-El.-10m-50Ohm

2-El.-12m-12Ohm

2-El-12m-28Ohm

Dualband 12/17m

2-El.-15m-50Ohm

2-El.-17m-28Ohm

2-El.-20m-28Ohm

2-El.-30m-28Ohm

Dualband 10/15m

DK7ZB-Dualband-Beam 12/17 m

The beam has only one feedpoint with 50 Ohm and has an open-sleeve element for 12 m

12 m: 4,39 dBd     11,5 dB F/B

17 m: 4,15 dBd   11 dB F/B

 

 

 

 

 

 

 

 

The Yagi built by 

Marcos, PY2MR

 

The Yagi built by 

Nelu, YO9DL

The 2-El.-Open-Sleeve-Yagi built by 

Phil, ON4TA

 

The measurement of the SWR by Phil, ON4TA.

He reports no tuning on 17 m, resonance as expected. The dip on 12 m was a little bit to high and can be shifted with the 12-m-open-sleeve-radiator.

The scheme of the beam with the currents for 24,9 MHz

Element lengths for the two bands, keep the outer tubes 15 cm longer for the overlap. The open-sleeve-element for 12 m and the reflectors can be mounted direct above the boom (metallic connection), but do not use big metallic brackets. This can detune the beam!

Feeding with a current balun

The mechanical soultions for the element holding from Nelu, YO9DL

The element construction of Marcos, PY2MR