Wednesday, May 29, 2013

EME and Satellite Antenna Mount

Mike in Texas emailed me recently to ask about the construction of the antenna mount that I use with the Yaesu G-5500 rotator.  The mount allows for two 2m yagis to be used on the same az/el rotator as a 70cm yagi.  Here's an overall photo of the current antenna array:

And here are the construction details of the "bridge" mount:

The advantage of the bridge mount is that it lets me use the same array for V/U satellites, U/V sats, and 144 MHz EME.  The antennas (a M2 440-18 and two M2 2M7's) have more than enough gain for the current fleet of amateur satellites -- typically only 2.5 watts is necessary to work the sats.

I use a metallic crossboom so that I can use vertical polarization on the VHF antennas, and run the feedline along the crossboom without adverse interactions.  To keep the antennas low-profile (tucked in behind the roof corner of the house) I need to keep the feedlines from hanging off the rear of the array, therefore vertical polarization is suitable.

So far I haven't been able to detect any adverse interaction between the 70cm yagi and the two 2m yagis for EME operations.  The 70cm yagi is horizontally polarized, and placed roughly mid-way between the two 2m yagis which are installed as per manufacturer's specs for stacking.  With the two 7-element 2 meter yagis, I've been able to make around 130 EME QSO's with 100 unique stations in 25 countries over six months of operating.


  1. Dave,

    More good info that I may be able to incorporate before the soon to be
    mounted mast/rotor at my QTH.

    Thank you,
    _Rick WA6RAI

  2. How much would your local noise measurements change if your polarization was horizontal instead of vertical?

  3. I am using the same rotor. but i have a difficulty in understanding how to mount two antennas on this rotor. I am using X-quad 2m yagi antenna for transmission and X-quad 70cm yagi antenna for the receiving side. please help with the mounting of these two antennas on G-5500 rotor. if you could show me some will it move the antenna in elevation?


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