I need help understanding the setting circles on cg4 mount

I dont know how to set the RA on the CG4 mount. There is one circle 0-24 and
another 0-12. What I dont understand is when you turn the scope do both
circles move? And if I am setting them at Polaris, what should both circles
read? Please send info. I am stymied.
Thanks
john

"n3drk" wrote in message
...
I dont know how to set the RA on the CG4 mount. There is one circle 0-24
and
another 0-12. What I dont understand is when you turn the scope do both
circles move? And if I am setting them at Polaris, what should both
circles
read? Please send info. I am stymied.
Thanks
Polaris is not a good place to set these circles. It is so close to the
Celestial pole, that even a tiny error in position, will give a massive RA
error.
Technically, the circles on the mount, form a simple(!) 'slide rule' style
calculator. The 12 calibrations, are the months of the year (with days as
well, but most are only calibrated in perhaps three or four 'multi day'
steps for each month). The 24 calibrations are 'time'. The same dial is used
to read RA (which is normally measured in the same 'time' units). There
should also be an alignment mark, on the body of the mount, with numbers
each side of this. These correspond to the time shift east or west of GMT,
at which you are working. It is possible, to 'dial in' your current date,
align to the correct time zone, and then turn the scope to a particular RA
value on the 24 calibration dial, and be close to the desired object.
However generally, this is not worth worrying about. The best normal way to
work, is to simply polar align the scope, and then aim it at an object with
a known RA, preferably close to the celestial equator (rather than the
celestial pole). Turn the 24 calibration dial till it shows the correct
reading, and you can then move to another object in the sky, by moving the
scope, till it's RA reading is shown. The 'calculator' feature is useful
when dealing with daytime objects, or if nothing any reasonable distance
from the celestial pole if visible, but it is normally quicker and easier to
just use the 'nearby known object' setting.

Best Wishes

"n3drk" wrote in message
...
I dont know how to set the RA on the CG4 mount. There is one circle 0-24
and
another 0-12. What I dont understand is when you turn the scope do both
circles move? And if I am setting them at Polaris, what should both
circles
read? Please send info. I am stymied.
Thanks
Polaris is not a good place to set these circles. It is so close to the
Celestial pole, that even a tiny error in position, will give a massive RA
error.
Technically, the circles on the mount, form a simple(!) 'slide rule' style
calculator. The 12 calibrations, are the months of the year (with days as
well, but most are only calibrated in perhaps three or four 'multi day'
steps for each month). The 24 calibrations are 'time'. The same dial is used
to read RA (which is normally measured in the same 'time' units). There
should also be an alignment mark, on the body of the mount, with numbers
each side of this. These correspond to the time shift east or west of GMT,
at which you are working. It is possible, to 'dial in' your current date,
align to the correct time zone, and then turn the scope to a particular RA
value on the 24 calibration dial, and be close to the desired object.
However generally, this is not worth worrying about. The best normal way to
work, is to simply polar align the scope, and then aim it at an object with
a known RA, preferably close to the celestial equator (rather than the
celestial pole). Turn the 24 calibration dial till it shows the correct
reading, and you can then move to another object in the sky, by moving the
scope, till it's RA reading is shown. The 'calculator' feature is useful
when dealing with daytime objects, or if nothing any reasonable distance
from the celestial pole if visible, but it is normally quicker and easier to
just use the 'nearby known object' setting.

Best Wishes

Polaris is not a good star to set your circles by. Find a star in the
soulth that you know. Put the star in the field of view in your scope.
Then move the the circles and set it to that stars RA. Do that with the
0-24 circle. You should have a marker to show where the scope is pointed.
You should have another marker that does not move. That is your meridian
marker which will now show you local siderael time.

However you can only do this if your scope is polar allined.

Polaris is not a good star to set your circles by. Find a star in the
soulth that you know. Put the star in the field of view in your scope.
Then move the the circles and set it to that stars RA. Do that with the
0-24 circle. You should have a marker to show where the scope is pointed.
You should have another marker that does not move. That is your meridian
marker which will now show you local siderael time.

However you can only do this if your scope is polar allined.