DobSTUFF - Sky Commander Cable

Sky Commander cable wiring info:

When I install a Sky Commander (or any encoder setup) on my telescopes, I like to put the altitude encoder on the "far side of the rocker box". It keep the wiring and encoder out of my way. It helps to have the altitude connection on a longer wire while the azimuth connector can be on a fairly short wire.

If you care to make your own Sky Commander cable, here's the way to accomplish this:

The US Digital S2 1000-NT Optical Encoder wiring diagram, below, assumes your Sky Commander encoder is the same as this one. Sky Engineering has been shipping these for some time. The wiring diagram, below, uses this encoder and connector configuration.

Pine #	Designation	Color of Wire on the Connector
1	GND (ground)	Black
2	NC (no connection)	No wire
3	Ch. A	Red
4	+5V	Green
5	Ch. B	Yellow

The wiring diagram. As you view this diagram, it assumes the RJ-11/RJ-45 jacks are oriented with the locking tab down and away from you. The smooth side is up and the wire, when inserted, is clearly visible.

Once the Sky Commander is installed, you'll need to configure the computer with information about the encoders. The Sky Commander User Guide is easy to read and understand (Download manuals: Version 3, Version 4):

Hold down the up/down arrows, turn on the SC and scroll through the setup. Here's the initial setup (this assumes you've mounted the DEC encoder on the "far side" of the telescope, on the altitude bearing away from the eyepiece):

1 Scope Mount Fork

2 Set Hemisphere North

3 RA Direction REV

4 DEC Direction REV

5 RA Encoder Res 4000

6 DEC Encoder Res 4000

Once you've tested the direction of the encoders with the motions of the mount in "scope mount in fork", change the scope mount to "DOB".

Turn off the SC and turn it back on. Go through the alignment procedure using 2 stars and you're ready to go. And DON'T FORGET to set the "Display Mode" to AZ-EL.

For more information about your requirements:
--Dennis Steele
--Tel: 650-315-6578 (anytime)
--Email: densteele@dobstuff.com

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