YAESU G-5500 AZ/EL Rotor

  • hello - i have a m2 leo antenna for both 70 and 2M. that is the only thing i have nothing heavy.


    what i am trying to find out is why it hangs on to the other side more when it goes to opposite side.


    0 is actual 0

    90 is close to 90

    180 degree is more like 190....

  • Well , the position is indicated by a voltmeter with a scale showing degrees azimuth. It is the operators task to set the minimum voltage to be shown as 0 degrees and the maximum voltage as 360° (180°) . Everything in between might be correct or far off. It depends on the accuracy of the potentiometer , driven by the motor and changing the voltage for the scale. The same is true for the elevation.

    You can do this: Remove the scale from your rotator and make your own. Set the rotator to 0, mark it on the scale. Set the rotator to 45°, mark it on the scale. The more measurements and marks you have, the more accurate is your scale. But again, the 3 dB angle of your antenna seems to be so wide, a few degrees offset won't be noticeable in your receiver.

    Another reason may be a slip in the gear or the potentiomenter.


    73, Martin

  • DB2OS

    Changed the title of the thread from “New Ham, help requested for G-5500 rotor” to “YAESU G-5500 AZ/EL Rotor”.
    • Official Post

    0 is actual 0

    90 is close to 90

    180 degree is more like 190....

    It's called FULL SCALE ADJUSTMENT, please see Page 4 in the Manual, see the link from DM4IM.


    First do the ZERO adjustment of the meter with the screw below it (with power off), than bring your EL rotator *mechanically* into exact 180° position and use the Elevation Full Scale potentiometer on the backside to adjust the meter to show 180°. That's all... same procedure for AZ. This way you calibrate both meters on the Controller.




    73 Peter

  • hello peter, meter functions properly and full scale adjusted - but the actual physical movement of the rotor arm is what I mentioned about going to 190 degrees or so. the picture i posted is about the antenna and not rotorator control box needle

    • Official Post

    hello peter, meter functions properly and full scale adjusted - but the actual physical movement of the rotor arm is what I mentioned about going to 190 degrees or so. the picture i posted is about the antenna and not rotorator control box needle

    Yes, but how did you make the Full Scacle Adjustment than? I'm confused...


    You have to use the UP/DWN button carefully and turn your actual position of the rotor arm physically into exact 180 degrees... not as shown on the meter, physically!

    Then you adjust the potentiometer on the back side accordingly, so that the EL meter shows 180 degrees.


    From now on, whenever the meter shows 180° the rotator arm should be physically also 180°..


    If that's not the case, something is wrong.


    73 Peter

  • Hi,

    so what you are trying to say, is, your meter shows the exact elevation of your system, but the rotator elevation physically goes below 'horizon' when the meter has reached 180° and you still push the button? Meaning elevation is less than zero (or more than 180) when you drove your rotator from 0° to 180° and a bit beyond? If that is the case, the mechanical range of your rotator simply is a bit larger than 180° .

    The only rare occasion to elevate the antenna further than 90° is when the satellite passes EXACTLY overhead, meaning you point your antenna to the azimuth where the satellite will show up over the horizon, then rotate elevation ALONE until it disappears below horizon again. All other passes are less than 90°, meaning you elevate your antenna while you also change azimuth. The elevation will never be more than 90° (= straight up) . I think no satellite calculation program will ever calculate an elevation greater than 90°. The meter of the control box to me is stupid. It shows a half circle of 180° on an instrument with 135° (?) range. The same is true for the azimuth, where it shows a 360° full circle on a 135° instrument. But that is another story.


    73, Martin

  • Hi,

    a few more thoughts: Your problem will disappear as soon as you hook up your control box to a computer running satellite prediction software and let the program do the job. I'm pretty sure you will do that , because it's a fast paced job to control azimuth, elevation, tx-frequency and rx-frequency by hand while noting your qso-partners callsign, locator, name and report. This is especially true for the ssb satellites and even more when you do cw. Not so much for the fm transponders.

    Let's say , a satellite's AOS (Acquisition of signal - or is it arrival of signal?) is at 300° azimuth, LOS (loss of signal) will be at 120° azimuth. That would be an overhead pass. Your satellite prediction software will rotate to 300° azimuth and to 0° elevation. By the time the satellite rises above horizon, the software will rise your antenna in small steps to the calculated elevation up to 90°. Once reached , it will rotate azimuth by 180° and begin to lower elevation when the rotator has reached 120° azimuth. Never will elevation be greater than 90° (which isn't possible anyway, because when you go beyond 90°, you decrease elevation, not increase it)


    73, Martin

    • Official Post

    Never say Never.. ;)

    Good tracking programs are actually able to flip-over..

    Which means that with an 90° overhead pass you will have EL >90° ... <180° flip over...

    This is important with LEO satellites, in particular when you need to rotate AZ by 360° depending on where your Rotator Stop is (either Noth or Sourth)..

    If you have done the 180° calibration correctly, the 90° should be OK too.

    Again.. you have to mechanically bring it into 180° and make sure the antenna is horizontal aligned and only than you adjust the Potentiometer FULL SCALE ADJUSTMENT. And yes, the mechanical stop of the rotator is slightly more than 180°.. So you have to go in front of your house and check with your eyes if it's 180° or not :)

  • Hey guys,

    I reopen this thread to search some help.

    I have bought the G-5500 but I have some problems to calibrate it.

    I did this:

    first I did the ZERO adjustment of the meter with the screw below it (with power off), than I brought the EL rotator *mechanically* into exact 180° position (I aligned the 180 markers on the rotor) and I used the Elevation Full Scale potentiometer on the backside to adjust the meter to show 180°.

    Now when I return to zero I noticed that the 90° on the controller is no longer aligned like the markers on the motor... and also the 0°.

    Is this normal or I'm doing something wrong?

    Thanks in advance for your help.


    Vito