The EA4TX ARS-USB Rotor Controller will handle the job of automatically keeping the antennas pointed at the moon. However, there are times when I will need to manually point them. For instance, when I need to bring the antennas down (to hide them from the neighbors!) or when I am installing or otherwise working on the antenna system. It would be difficult to run inside the shack and move the antennas a little then go back outside to see if it was enough. And, with the tower being right next to the house, the potential for having the antennas hit the roof or a vent pipe is large.
I felt that if I could control the antenna rotors from the base of the tower, I would solve this problem. That meant a set of switches to control (UP, DOWN, EAST, and WEST) movement of the array which needed to be wired to the EA4TX Rotor Controller. I found the perfect set of switches on eBay (see my Post Pointing my EME Antennas at the Moon.)
Now I needed to find a way to connect those switches to the EA4TX Rotor Controller. A short email to Pablo, EA4TX, gave me a quick reply with the points where I could connect the switches. It seems there was a insulation-displacement contact (IDC) connector on the LCD circuit board that would do the job. This IDC connector (also known as insulation-piercing contact) was something I had never worked with. But in looking around the wonderful Internet I learned about them and found a place where I could order a couple (along with a short piece of ribbon cable that could be installed in the IDC.) Cost was only $0.58 each and $0.32 per foot for the ribbon cable. Turns out it was from a company where I already had another item I needed to order so shipping was not an issue. (See the IDC connector in the photo on upper-left. Click on any photo for a larger image.)
To make the installation clean, I needed a 5-conductor connector to mount on the back panel of the EA4TX Controller. Again, eBay came to the rescue! I found a set of FIVE SETS of Aviation Plugs (Male and Female) that have 6-conductors (more than I need) for a total cost of $8.30 including shipping. These are similar to an 8-pin microphone plug and measure 11mm or 0.43 inches in diameter (for the portion that will go through the back panel of the EA4TX Controller.) (See photo on the right.)
Now all that was required was for me to connect a short piece of ribbon cable to the IDC connector and wire it to the female 6-conductor panel-mount connector. But, since I had never worked with those connectors before, it was back to the ubiquitous Internet for instructions and I quickly found a YouTube video that told me everything I needed. Now that those connections have been made, I can run the 5-conductor cable to the base of the tower and connect it to the fancy Rain Proof Hoist Crane Pendant and I will be able to manually control the antennas from the base of the tower. Excellent!
On the left you can see the modification I made to the EA4TX Rotor Controller to add the ability to remotely control the antennas from the base of the tower. The IDC connector is on the top right and I labeled it with the word "Top" as there is no keying to make sure it is connected properly. It connects to the LCD Circuit Board and passes down and across the bottom of the EA4TX Controller box to the rear panel where it connects to the 6-pin Female chassis mounted connector. Later the cable from the Remote Switches will plug into this connector.
The bottom portion of the image shows the rear panel with the pass-through grommets for the cables to connect to the Azimuth and Elevation rotors (as well as the cable for the inclinometer.) Also you can see the new 6-pin connector I added for the Remote Switches.
This modification of the EA4TX Rotor Controller took me just a couple of hours and will (in my opinion) greatly enhance my ability to utilize the controller to move my antennas. I am very happy with how it turned out.
The wires in the ribbon cable between the 6-conductor Female chassis mounted connector and the CN_KBD IDC connector on the LCD Circuit Board are connected in this order:
Pin 1 to CN_KBD-2: +5Vdc (This is VOLTAGE and not a Ground)
Pin 2 to CN_KBD-4: Manual Left/CCW control.
Pin 3 to CN_KBD-6: Manual Right/CW control.
Pin 4 to CN_KBD-8: Manual Down control.
Pin 5 to CN_KBD-10: Manual Up control.
The Remote Switches will have the +5VDC as the "Common" connection across all the switches. Closing any of the 4 switches, UP, DOWN, LEFT, or RIGHT, will simply apply +5VDC to the appropriate pin in the ARS-USB unit to cause the proper rotor to move in the proper direction.