Sky and Telescope - June 2016 - 62

S&T Test Report

The author tested the mount's guiding using a TMB 92-mm f/5.4
refractor as the imaging telescope and a 50-mm guidescope
with an Orion StarShoot autoguider. As the guiding graph from
PHD Guiding shows, the AZ-EQ5 guided very smoothly, with no
abrupt runaways or oscillations.

around the sky and it still retains knowledge of where it
is pointed. If you are using the mount in a public viewing session and someone accidentally grabs and moves
the telescope, even with the axes locked, no problem.
Just re-select the object you were aimed at and press
Enter, and the mount returns to your target. Very nice!
I found this feature worked great in either equatorial
or alt-azimuth mode, faithfully centering targets even
after purposely bumping the scope far oﬀ target.
Aligning the Go To system
proved fast and reliable, never

yielding a dreaded "Alignment Failed" message. Our
test unit, supplied on loan from Paciﬁc Telescopes in
Canada, came with the separate SynScan GPS module
(optional in most other markets) that automatically feeds
the current location and time to the hand controller.
This sometimes took a couple of minutes to acquire a
ﬁ x, but it always succeeded. With it, one still needs to
step through menu pages to conﬁrm your time zone and
Daylight Time status.
In equatorial mode, from the standard starting position with the mount roughly level, polar aligned, and
aimed north, you have a choice of 1-, 2-, or 3-star alignments. For the best accuracy in testing, I used 3-star
alignments, in which the mount picks two stars on the
west side of the meridian and a third star in the east.
The mount slewed to the ﬁrst star but was usually a few
degrees oﬀ, typical of most Go To systems. The mount
then aimed much closer to the next two alignment stars,
often placing them near the center of the eyepiece.
In alt-azimuth mode, you can have it automatically
choose the "Brightest Star" in a selected region of sky, an
option for those who can't identify any stars. Or you can
use a 2-star alignment, in which you select the stars and
manually slew to the ﬁrst star.
Once aligned in either mode, the AZ-EQ5 accurately
slewed to every object I chose no matter where it was in
the sky, usually placing it dead center or, as was the case
with the occasional target, in the central 50% of a lowpower eyepiece. This is a Go To system that just works.
Cord wrap wasn't a problem either. For one thing, the
only cable that runs from a moving to a ﬁ xed part of the
mount is the one for the declination motor, and not the
all-important power cord. So unlike some Go To mounts,
there is no concern about the power cord being yanked
out unexpectedly as the mount slews around.
Even so, the hand controller's intelligence nicely
prevented the mount from always going in one direction,
forcing the mount to backtrack and go the "long way
around" when slewing from object to object on either
side of the meridian near the pole. This prevented any
cord wrap problems.
The "Park" function also worked ﬁne in either mode.
This can slew the mount back to a standard home position or simply leave it where it is, where it can be turned
oﬀ then powered up later to resume Go To operation
with no re-alignment needed.

Polar Alignment

When set to 90° latitude and locked, the AZ-EQ5 becomes an
alt-azimuth Go To mount, for use with one telescope and the
supplied counterweights.

June 2016 sky & telescope

While in equatorial mode, the mount requires at least a
rough polar alignment for the Go To system to function. But for long-exposure imaging and tracking, polar
alignment has to be accurate. However, the design of the
AZ-EQ5 precludes any polar alignment scope mounted
within the polar axis itself.
Instead, the mount uses an optional polar scope that

Sky and Telescope - June 2016

Table of Contents for the Digital Edition of Sky and Telescope - June 2016