Hi this is Graham from Jenham's Astro
This is a test of the Vixen Advanced Polaris mount
It's a test of the Polar alignment method, to see if it is effective and will achieve a good alignment in the field.
The alignment scope relies on a reticle onto which the positions of Polaris and two other stars are marked
The method is a little unusual, and relies on adjusting the azimuth and altitude bolts of the mount
And by rotating the polar scope within the mount's polar axis
until all three stars line up with the positions on the reticle
This is a test!
I've done an alignment
I think the positions are right
We will test it to see if it tracks accurately over a period of time.
I have set up a medium power eyepiece
We are tracking the moon
We will leave it to track and come back later
There is no PEC, nothing clever
We are just testing the basic sidereal tracking.
We'll look later and see if the Moon is still centred in the eyepiece
Then we will know if the method works without GOTO etc
It's a basic method
While we are waiting lets take a look at the reticle of the polar scope
There is a position for aligning Polaris
With a range of years from 2014 to 2040
Then you line up the other 2 stars
Cassiopeia and Ursa Major are shown to help you do the initial orientation.
There are also markings to do the alignment in the southern hemisphere
Let's look at the polar scope's controls
A button turns on the red reticle
It turns off automatically on a timer.
The timer is quite short but you can turn it on again if you need to.
There are eight brightness settings
It is a good feature and helpful during alignment process.
There is a focus ring like on a binocular
You can focus well even if you were glasses.
You need to get close to the lens to see all of the alignment stars
two of the alignment stars are at the edge of the polar scope view
The scope is free to rotate inside the axis
In summary the scope is well engineered
It is a novel method compared to using a clock face approach
It is expensive though, so it should be well made!
What else?
The AP mount is all about the clever use of friction
It stays where you point it without the need for clamps on RA or DEC
This works very well
The friction can adjusted as needed.
There is one friction issue that can cause problems though
It relates to the latitude adjustment
There is only one bolt to set and hold the latitude
It pushes against a stop and this rotates the mount up, as needed
It relies on the counterweight to lower the elevation when you turn the latitude bolt the other way
But friction can stop the mount from lowering when you do this
This is annoying when you align the mount
You make small adjustments on elevation during alignment.
It is an iterative process
Unwanted friction can make alignment take longer
I think the mount could be improved with a better method for adjusting and holding the elevation
2 latitude bolts could be used, or maybe a worm gear arrangement
OK so it has been tracking for a hour
The RA motor is very quiet
The tripod is OK.
If you kick the leg it will move and lose alignment
Let's have a look!
There it is. The moon is still centred
This non scientific test has passed.
The alignment method works
More tests are needed to test its accuracy for photography
It is back to basics, grab and go!
Thanks for watching