# Dual band 6m/4m Yagi #




 

Dual band 6m-4m Yagi based on 6jxx6 from Sandro I0JXX.

This antenna was optimized with the goal to minimize any changes
in 6jxx6 impedance/lobes.
The result is a 7 el on 70 MHz with a little loss of gain comparing
with the other monobands of the same lenght.
If you don't have so much space on your mast, like me, a dual
band antenna can be a nice solution.
I chose to separate the sources of the 2 antennas because i have
two rigs attached.


The 4m antenna has an impedance of about 27 Ohm, so we must
use a matching circuit. The easiest way is to use a quarterwave line of
about 35ohm, achieved with a parallel of 2*75ohm cable.
I simulated the antenna with nec2 engine and the results are
very close to the real values.
Thanks to Sandro I0JXX for hardware and Pino IK0SMG for help
in matchbox assembling.













  All measures are in meters.

Next image show the real pattern of antenna aquired with Polarplot by G4HFQ and a picture of installation.
Here some other PICTURES.