# 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’ve 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.



2 Responses to “# 6m/4m Yagi #”

  1. Graziano Says:

    Puoi mandarmi il progetto dettagliato della dual band 50-70 mhz?

    • Provo a dettagliare:
      1) comprare/rimediare una 6jxx6
      2) comprare/rimediare 7 elementi diametro 12mm e i relativi isolatori
      3) tagliare gli elementi a misura ed inserirli lungo il boom della 6jxx6, le misure sono nella foto sopra.
      4) realizzare il trasformatore d’impedenza con un parallelo di cavi a 75 Ohm lunghi un quarto d’onda e collegarli al dipolo
      Non mi viene in mente altro, ciao.

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