The bottom line:
This mount looks like a winner! I’m very pleased
with the initial performance of the mount. With a 12.5 lb OTA, the
dampening times are fast (generally under 2 seconds). I don’t
experience any “jiggles” at the eyepiece - this baby is
stable. The mount tracks smoothly without discernible vibration, even
at relatively high power. The mount worked, as it should the FIRST
time I set it up. After my experience with the LXD55, this was very
refreshing! The first night out, I simply entered my site data, followed
the prompts on the Hand Controller, did my 3 star alignments, and
started a tour of various targets. WOW again! Target in FOV every
time using about 60x at the eyepiece, usually near center portion
My main objective in purchasing this mount was to obtain
a relatively portable and stable VISUAL platform with GOTO that can
be used with several different optical tube assemblies. At this time,
I’m not planning on using the mount for imaging (I’ll
use the GM-8 for that). I suspect, however, that the mount will prove
to be a capable imager. It will be interesting to see what other users
Do I think this mount delivers what Celestron said it
would? YES. Does it appear to meet my needs and objectives? Most definitely.
Would I recommend this mount to other amateurs looking for a cost
effective GOTO that WORKS well? Absolutely!Tony Bonanno
Santa Fe, New Mexico USA
November 14, 2003
The author has no undisclosed interest in this product, its supplier,
or its manufacturer. All photographs are the copyrighted property
of the author.
UPDATE – December 1, 2003
A few more observations and thoughts about this mount.
First of all, I should correct the text in the above
review where I state the “setup routine helps compensate for
“cone error” (play in the gears)”. I was reminded
by Mike Swanson that cone error and gear backlash are really two different
entities. I should have said “cone error AND gear backlash”.
The 3-star alignment using two stars on one side of the meridian and
one star on the other side of the meridian compensates for the cone
error. Mike helpfully explained that cone error is the difference
between the optical axis (the line of sight of the optical tube) and
a line that is perfectly perpendicular to the Dec axis. The use of
the “up” and “right” direction arrows to center
the alignment stars is specifically the routine that compensates for
the backlash in the gears.
My Experience with the Meade LXD55 10”
Schmidt-Newtonian OTA and two Maksutovs on the AS-GT Mount
I’ve had several folks email me about using this
mount with the Meade 10” Schmidt-Newtonian (SN) OTA. I tried
using the two together, but my bottom line impression is that it is
not an ideal match. Its simply boils down to the weight and size of
the 10” SN. It will work, but it’s pushing the limits
of the mount. I think it will be fine for strictly visual use as long
as one balances the OTA/mount carefully and makes sure the mount base
and other fittings are tightened down appropriately. You will need
30-40 lbs of counterweights. The LXD55 10” OTA, with Telrad,
eyepiece, dew shield, etc. weigh in at approx 35 lbs. The OTA itself
is approximately 37 inches long and 12 inches in diameter. Add a little
wind to the observing site and I think you’ll agree that it
could be challenging. Everything is relative though. If you managed
using the LXD55 10” SN OTA on the LXD55 mount, then you will
be pleased to learn that, IMHO, the AS-GT mount is much more stable
and a better platform than the original LXD mount. Dampening times
are certainly improved.
For most of my observing with this mount, I’ve been using two
Russian Maksutov OTA’s. One is a short, relatively lightweight
(12.5 lb) Intes-Micro Alter 603 6-inch f/10 Maksutov-Cassegrain and
the other tube is a relatively large (and lengthy) 22 lb. Intes MN61
f/6 6-inch Maksutov-Newtonian. Both of these OTA’s, even the
larger and heavier Mak-Newt, appear to be VERY WELL MATCHED to this
mount. With the Mak-Cass, it is necessary to extend the tripod legs
to achieve a comfortable viewing position (similar to using an SCT).
With the Mak-Newt, the tripod legs are fully collapsed. Interestingly
enough, BOTH scopes show excellent dampening times with this mount.
Generally between 1 and 2 seconds at the eyepiece ! I suspect that
the fact that the tripod is collapsed when using the large Mak-Newt
helps keep the dampening times similar. • A Few More Setup and
Apparently the importance of centering the alignment
stars using the “up” and “right” direction
arrows is fairly important if you wish to obtain good GOTO’s.
Several users on the Yahoo Celestron_AS group report that they’ve
definitely noticed improved accuracy when strictly following this
routine. I’ve also noticed that the leveling of the mount using
the built-in bubble level seems to help the accuracy of my GOTO’s.
Typically I will setup and do a tour of 20-30 targets during an observing
session. I’m finding consistently good GOTO performance (generally
within the central 2/3rds of a 26mm eyepiece). There have been a couple
of instances when the GOTO slews did not seem to be working properly.
I suspect a software glitch rather than a hardware problem. Hitting
one of the arrow keys will stop the mount and then pushing the “enter”
key seems to put everything back on track without having to re-align.
• PC Computer Control
I can confirm that the mount appears to handle the ASCOM
PC control platform just fine. Using the free Cartes du Ciel, the
mount was responsive to the program’s commands. Be sure to use
the proper serial cable for connection to the Hand Controller. The
cable plugs into the base of the Hand Controller, NOT the mount itself.
I had to also update the BIOS on my Dell 4150 notebook.• Cold
I’m not very tolerant of the cold, so about an
hour at 18 deg (F) with medium wind was about all I could take for
this test. The mount with the 22 lb. Mak-Newt performed well. Every
GOTO target (about 20+) was in the FOV of a 26mm eyepiece. Not sure
what the wind chill factor was during this session, but it sure felt
cold. After about 30 minutes, I did notice that I had to hold the
Hand Controller buttons down somewhat longer for the command to execute.
The motors seemed to be okay, although a little slower. At one point,
the Hand Controller seemed to be unresponsive. I then noticed that
the cigarette lighter plug looked like it was not seated all the way
in the power supply receptacle. Sure enough, I re-seated the plug
and the Hand Controller came back to life. There is no question that
the power supply is a critical factor with these electronics, especially
with cold temperatures. I also realized that the power cord that came
with my mount is ridiculously LONG - probably 25 feet of small gauge
wire... I will replace it with something shorter and more substantial
soon. I suspect that will also help in the cold weather.
Regarding the grease in the mount. I didn’t notice
any problem on either axis as a result of the cold. I did notice a
little grease along the edge of the DEC mount. It was black and did
not appear to be affected by the cold temperature. I don’t think
this is the same lubricant that used to cause problems in the older
IMPORTANT ASSEMBLY TIP
There are two threaded holes drilled in the tripod base
in which the azimuth adjustment peg can be mounted. This is the peg
that the azimuth housing fits over when attaching the mount on the
base. It acts as a guide and a “stop” when using the two
azimuth adjustment screws to polar align the mount. One of the threaded
holes is located BETWEEN the two tripod legs. The other hole is OVER
one of the tripod legs. My mount arrived with the peg installed BETWEEN
two tripod legs which results in the counterweight bar and weights
being situated between the two legs rather than OVER a tripod leg.
Celestron advised me that they drilled the base with
the two holes so that the counterweight could be positioned between
the legs instead of over a tripod leg. They said that this is sometimes
necessary with certain setups at low lattitudes so as to avoid interference
with the legs. BE AWARE, however, that with the counterweight positioned
BETWEEN the legs it could lead to an unstable mount that will readily
tip over if you are not paying attention (I learned this lesson the
hard way). I found that with the legs fully RETRACTED (for example
when using a large Newtonian), with counterweights attached, and WITHOUT
an OTA on the mount, that the mount is pretty vulnerable to tipping
over with a relatively small nudge or bump (typically while trying
to attach your OTA in the dark). I would strongly suggest, just for
stability, that you ensure that the alignment peg is installed OVER
the tripod leg, not between them. Obviously, if you are located at
a low latitude, then there may be some situations with certain OTA’s
where you may not have a choice. The peg is easily moved simply by
unscrewing it and threading it into the proper position. (See picture).
In the current Celestron user’s manual that accompanied my mount,
there is no mention of the two mounting positions for the alignment
Overall, I continue to be very pleased with this mount.