Polar aligment TAL 2

[Andy McK]

evening all.

With the TAL, latitude setting is a bit of a pain, as there is no fine adjust. Anyhoo, Set the Latitude/RA axis to 52 n a bit deg. and pointed the, inclined end of the RA to Polaris.

If I have this right, If my RA axis is pointing at the celestial pole, when I "twiddle" my RA adjust, Polaris should stay more or less in the center of my FOV.?

So, when I'm setting up, set lat. to 52 deg ish and then fine tune to Polaris, but only move Lat and Az (RA n DEC at "home")

Am I close, or completley blown it?

Yours,

Andy (running out of fingernails) McK

[ronin]

It is the mount that gets aligned to due north, not necessarily the scope.

Polaris is about 1 degree off of due north so if the view through the scope is less then 2 degree then when pointed accurately due north along the axis. Polaris would not be in view.

Also the scope and the mount must be aligned exactly if using the scope only.

Aligning to Polaris is close but not the ideal and there are inherent errors by doing so.

[AndyH]

This is how Tal explain it in their modern user manuals. Whilst it's not specifically for the 2M/MT-2C, it's just as valid.

Precise polar alignment

for the MT-1 and MT-1C mounts

For precise polar alignment for MT-1 and MT-1C mounts observe

two bright stars in the west and in the east by turns, using the eyepiece

f’=25mm with reticle.

If during the observation of the star in the east it slowly shifts, so

that you have to lower the top end of the telescope to follow it, then

the northern (upper) side of the R.A. (polar) axis of the mount should

be slightly lifted up.

If you have to lift up the top end of the telescope to follow the star

in the east during the observation, then the northern (upper) side of

the R.A. (polar) axis of the mount should be slightly lowered down.

For the precise azimuth adjustment follow the same procedure to

observe a bright star on a celestial meridian in the south. If during the

observation the star slowly shifts, so that you have to lower the top

end of the telescope to follow it, then the northern (upper) side of the

R.A. (polar) axis of the mount should be slightly moved west.

If you have to lift up the top end of the telescope to follow the star

in the south during the observation, then the northern (upper) side of

the R.A. (polar) axis of the mount should be slightly moved east.

After 20-30 minutes of such observations and adjustments, it is

possible to achieve a precise polar alignment, when any observed

star would stay on the intersection of the crosshairs (reticle) of the

eyepiece for 10-15 minutes without additional correction needed on

the Dec. axis.

I'm in the process of(next clear night) trying out a mod that'll let me use a Tal polar scope or a Tal 6x30 finder as a easier way to get reasonably decent polar alignment. Whether it works or not is another matter.

Andy.