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Friday, 8 September 2017

The Art of Rotator Control


I decided that there had to be an easy way to computer control my antenna rotators. I already have this on the Satellite antennas in Azimuth and Elevation, but not the "normal" antennas I have here for HF & VHF.

I looked on the big bad internet and found that Yaesu make a rotator interface for the G-1000 rotators that I have, but they are a simply staggering price.

So, there had to be a way....

The first thing I did was connect to the interface socket on the back of the rotator and figure out which pin did what. We have a voltage output that represents the heading, which plotted like this:

Using simple bit of maths we can then create an equation to calculate the voltage at any heading (to save me having to keep moving the antennas back and forth):

There are also two pins on the interface connector that you ground to turn the rotor left and right. There's also a fourth pin you can use to set the rotator speed.

I then figured that Arduino was certainly the way to go, but then I found this:

Now, this interface does all I want and a million things more, it's been written in a way that allows you to configure the bits you want and exclude the bits you don't.

To get this to work with my G-1000 series rotator, I configured the following:


in the rotator_settings.h file; that's about it!

That setting defines the rotator as one that turns around 0 degrees (rather than 180 being the end stop).

Once I had done that and defined the pins (I just used the defaults) and also defined Digital pin 10 as the speed output:

#define azimuth_speed_voltage 10

in the rotator_pins.h file

I compiled the code for a Arduino Nano with an ATMega328 processor (because that is what I had lying around).

I then built the simple interface needed:

Now, the next step was to calibrate the software. Instead of turning the rotator from fully CCW to fully CW (including the 90 degree overlap), I just used the equation I established above to calculate the voltage and set the bench PSU to deliver same.

Then once that was complete, I connected the Arduino board to my Radio Control PC, fought with COM port settings (a favorite hobby of mine) and then configured my logging software to use a rotator controller emulating the Yaesu GS-232B command set.

So now I have this display above, it shows where the antennas are pointing and allows me to click on a heading to send the antennas there. I can also configure the system to auto turn the rotator based on selection of DX spot if I like too.

Neat, egh?

Sunday, 3 September 2017

I'm forever blowing bubbles? No! bulbs!


I have a couple of Yaesu Rotators here, and the controllers were stacked one on top of the other with a small cardboard box propping up the top controller. The cases are kind of slanty topped and the whole arrangement meant that they both fell to the desk regularly. This in turn ensured that the bulbs illuminating the front scale blew farily soon after purchase.

My local friendly emporium LAM Communications sent me some replacement bulbs some time ago, I just never got round to replacing them - mainly because I couldn't find any instruction on how to do so.

So, here's how to replace the bulbs in a Yaesu Rotatorbamob (or certainly the 1000DXC variety).

Firstly we remove the main external case:

Now, the bulb is clearly part of the main dial thingy on the front, so that had to be removed also (there are 4 screws):

The bulb is under the silver paper I've highlighted below:

So it's just a case of peeling back the tape carefully, and soldering in a new bulb.

I've also made a wooden stand thingy so the controllers stack without the need for cardboard wedges and other jiggery-pokery and hopefully the wont fall over any more:

Local conditions.