PlaneWave Instruments EFA Guide

Mounting the Electronic Focus Accessory (EFA) for the
CDK12.5
The EFA kit for the CDK20 comes built into the back plate of the telescope, but the EFA
Kit for the CDK12.5 comes in a separate box that is mounted outside the telescope. This
is because the CDK12.5 doesn’t have much room between the primary mirror and the
back plate.
Mounting the EFA Electronics Box
The EFA Electronics box can be attached to several places on the telescope back plate.
There are eight ¼-20 threaded holes on the back of the telescope. The EFA mounting
bracket, already attached to the electronics box, can be mounted to any one of the eight
¼-20 threaded holes. Use the supplied ¼-20 bolt to attach the EFA box as shown in
Picture 2.
Focus Motor Jack
Hand Control Jack
12VDC Power Input
Telescope connector
jack
Picture 1: The EFA Control Box.
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Picture 2: EFA Box Mounted on the CDK12.5
Connecting the Cables
Once the EFA box is mounted on the CDK12.5 back plate it is time to attach the cables.
•Attach the 5 pin coiled cable, shown in picture 2, to the 5 conductor jack on the
back of the telescope and to the 5 conductor jack on the EFA box.
•Insert the focus motor cable in the jack labeled FOCUS on the EFA Box.
•Take the Hand Control and plug the phone jack into the port labeled H/C.
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Picture 3: The CDK12.5 electronics plate
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Picture 4: Hand control plugged into EFA box
NOTES:
•For balance reasons it would be best to mount the electronics box on the opposite
side of the finder scope.
•There are two 12VDC power jacks, one on the EFA box and one on the back plate
of the telescope. When using the EFA, you want to plug the power jack into the
EFA box, not the power jack on the back plate of the telescope. And the power
jack on the telescope back plate is bypassed when using the EFA box. So it
doesn’t matter if the power of the back plate is on or off.
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