Monday, May 1, 2017

Final Mods to the EA4TX ARS-USB Controller

Final Mods to EA4TX Box
If you read my previous post about Modifying the EA4TX ARS-USB Rotor Controller you will have seen where I added a connector to the controller box so that I could connect some remote switches for adjusting the rotors while standing at the base of the tower.  In doing that I had acquired FIVE SETS of Aviation Plugs (Male and Female) which have 6-conductors each for a very reasonable price.  I used one set for the Remote Switches.  But, while modifying the Elevation Rotor control box (so it could be controlled by the EA4TX ARS-USB), I decided to go ahead and use another set of those connectors to allow me to easily set up or move the components of the station.  I removed the grommet which was already installed for the J2 cables and quickly placed one of the 6-conductor jacks in its place.  (It fit perfectly!) I also drilled and punched another hole for one more jack that will be used to interconnect the inclinometer cable.

My EA4TX ARS-USB was purchased with a cable to connect to the Yaesu G800-DXA azimuth rotor.  That cable came already installed by EA4TX and it is the white cable that exits the controller at the J1 hole which you can see at the bottom of the image to the left. (Click on any image to see it larger.)

The red/white/green wires at the top right of the circuit board go to the Elevation Rotor control box.  The red wire brings the 29 VDC from the elevation rotor controller and the white and green wires allow the relays in the EA4TX unit to connect that voltage to the UP and DOWN circuits for controlling the elevation rotor.  The blue/yellow wires at the bottom right go to the inclinometer and provide feedback from it for the elevation angle of the antennas.

Oops!  In later testing of the unit, I found that I could only control the Elevation Rotor to move DOWN by pressing the front panel button on the ARS-USB unit.  The UP button did nothing.  In checking out the reason for that, I found I had forgotten to install a jumper between Pins J2-3 and J2-6 on the ARS-USB board.  I only had the red wire connected to J2-6 which supplied the 29 VDC just to the DOWN point in the Elevation Controller.  Once I connected that jumper, I was able to control both UP and DOWN directions from the ARS-USB unit.

Also today I wired the inclinometer to the cable which runs out to the tower and wired the plug to the other end to connect to the EA4TX unit.  Then I powered on the EA4TX ARS-USB unit for the first time and checked out the inclinometer.  It WORKS!  I can move the inclinometer and watch the Elevation reading on the EA4TX smoothly change.  Now I need to fabricate a small bracket to mount it to the fiberglass cross-boom.

I chose to go with the inclinometer because I felt my old elevation rotor might not have a good potentiometer for read-back of the elevation angle.  And, it was possible that I might have to use a satellite (TVRO) jack screw for my elevation system and would need the inclinometer for that.  You can see an image of the inclinometer on the right.

Finally, I connected the Yaesu G800-DXA azimuth rotor to the EA4TX ARS-USB controller.  The feedback of the rotor position worked correctly and when I rotated the Yaesu, the azimuth position could be seen changing on the EA4TX unit.  I was also able to push the buttons on the front of the EA4TX controller and cause the Yaesu to rotate.  That is what this box will do (under computer control) when the system is being used.

Today yielded several SUCCESSES in the 2-M EME Project process.  Step-by-step I continue to move forward.  Some of the additional project goals which are included in the total project are:  1.  Checking/Testing each component part as I complete it.  2.  Labeling of all cables, wires, etc. so there is no confusion at a later time.

This was helpful yesterday as it was one of those "1 step forward and 3 steps backwards" days for me.  I wasted a good bit of time unsuccessfully searching my junk box locations for a couple of parts that I know I have but so far have eluded me.  Then I proceeded to finish up the wiring of the EA4TX ARS-USB controller and when wiring a small 6-pin plug to the wires coming from the elevation rotor control box, I wired the UP and DOWN buttons to the wrong pins.  Of course, I did not realize that until I had completed wiring the connector including heat shrink and all.  Then, I had to take it apart and do it again!  Plus, I had done such a NICE job on it too!  At least the "Checking/Testing" portion of my work was successful in finding my error and I was able to fix it while everything was still on the bench.