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18"
NGT Telescope
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NGT-18
18" Split-Ring Newtonian
with GOTO

NGT18
$14,995.
Buy Now* |
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| NGT-18
Product Information
Features
• Open truss Newtonian
• Split-ring equatorial mount
• Rotating nose assembly
• Compact size
• Fast assembly
• 18-point flotation mirror cell
• Includes StellarCAT ServoCAT Jr.
Track/GOTO
compatible
with Go-To computers and planetarium software
•
NGC-superMAX (Argo Navis™)
Go-To
computer
• CCD Autoguider compatible
• Battery and AC operation
• Adjustable focal point
• Snap-fit Serrurier truss rods
• Massive 2" declination ball bearings
• Personalized name plaque
• JMI's celebrated quality construction
Specifications
Type: Newtonian reflector
Mount: Equatorial split-ring
Mirror: 18" f/4.5 enhanced primary, 4" enhanced diagonal
secondary
Power: 12vDC internal lead-acid batteries or AC adapter for fan
operation
12vDC
external battery power source (included) for ServoCAT and drive operation
Weight: approximately 245 lb., the heaviest single component is 75 lb.
Height: 80" assembled, 30" collapsed, Eyepiece height 76" at
Zenith
Width: 36"
Depth: 30"
Finder: 9x50 straight through
Standard Equipment
Rotating Nose Assembly for
comfortable viewing of any part of the sky.
EV-2n Focuser with Motor for motorized focusing. (upgrades
available)
Extension Tube for 2" Focuser.
25mm 1.25" Plössl Eyepiece.
9x50 Finder Scope (straight-through) with dovetail mount.
Piggy-Back Camera Mount for piggy-back photography.
Off-Axis Counterweight for attaching to the piggy-back camera mount
(2).
Serrurier Truss Rods snap fit into heat treated, spring steel cavities.
Adjustable Focal Point including three different nose assembly mounting
positions for visual and photographic work.
Sliding Counterweights positioned along the truss rods for fine tuning
the balance (4).
Split-Ring Equatorial Drive with 36" drive ring.
18-Point Flotation Mirror Cell.
18" Mirror. 92% reflectivity. (upgrade
available)
Primary Mirror Dust Cover with Two F-Stops providing 3" and
6" apertures.
Mirror Cooling Fan with filter and grill.
Integrated Optical Encoders and a StellarCAT tracking, slewing and
Go-To system.
NGC-superMAX (Argo Navis) Computer digital setting circles with an over
29,000-object database and too many features to list here.
Battery or AC Power with 12vDC 4.6A rechargeable lead-acid batteries,
audible low battery alarm, 12vDC cigarette lighter adapter and 110vAC/60Hz or
220vAC/50Hz (specify)
wall transformer.
External Battery Pack rated at 12vDC, 17 Amp Hours.
Built-In Lifting Handles permit easy transportation.
Latitude Adjustment with scale for fine adjustment of latitude
setting. Adjusts from 30º to 55º. (modification available—see Low Latitude Base Wedge
below)
* Telescope prices
are for the standard telescope
configuration. Upgrades and Options are at additional
cost. The listed price also does not include the crating
charge ($175)
and any shipping and handling charges. Please call
for a shipping quote.
A
10% DEPOSIT
is required with all telescope orders (5%
IS NON-REFUNDABLE).
Telescopes are custom-built based on the options selected by the
customer and therefore require time to build. The
remaining amount due must be paid before the telescope is
shipped. |
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18" NGT
Optional Upgrades
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Galaxy Optics Mirror Upgrade
With
Interferogram

MIRGALAXY
$1500
Buy
Now |
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Upgrade to Galaxy Optics Mirrors
This option upgrades to a Galaxy Optics precision annealed 2" thick Pyrex
diffraction-limited f/4.2 primary mirror with enhanced coating giving 96% reflectivity
and a matching Galaxy Optics precision annealed Pyrex secondary mirror with
98% reflectivity. An Interferogram is included.
(With Galaxy primary mirrors, two additional options are available: "Premium" mirror
selection based on Interferometric data and C2 enhanced coatings with 98%
reflectivity. Call for more information including pricing.)
NOTE: This is an upgrade from our standard primary mirror to a Galaxy
mirror, at the time of purchase only. This option cannot be purchased
separately.
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EV-1nM
Focuser Upgrade
Add Dual Speed Knobs and
a Dial Indicator

EV1NMupg
$90
Buy
Now |
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EV-1n Focuser with Motor
This option upgrades the focuser from the
EV-2 model (EV-2nM) to the EV-1 model (EV-1nM).
The EV-1 includes Dual Speed Knobs and a Dial Positioning Indicator.
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18" NGT
Optional Accessories
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Light
Baffle
Nose Extension

NGT18BAF
$75
Buy
Now |
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Light Baffle
nose extension
Prevents stray light from entering into the focuser.
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Telrad
Finder Mounting Adapter

BRKTTELRAD
$25
Buy
Now |
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Telrad Finder Mounting Adapter |
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Extra
Sliding Truss-Rod Counterweight
(Each)

CWTR
$25
Buy
Now |
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| Extra Sliding Truss-Rod Counterweight
(each) |
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Truss-Rod
Light Shroud
Light-Weight Black Fabric

NGTSHRD18
$109
Buy
Now |
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Truss Rod Light Shroud
Blocks stray light and air currents and helps keep dust off
of the mirrors. Made of light-weight black fabric with elastic at both ends.
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Replacement
Batteries
(Set of Two)

BAT6V
$78
Buy
Now |
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Replacement Batteries
The NGT-18 uses two 6 volt maintenance-free
rechargeable batteries.
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Low-Latitude
Base Wedge
for a Latitude Range of 15º
to 30º

NGT18WEDG
$200
Buy
Now |
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Permanent
Observatory Mounting Hardware

NGT18MNT
$200
Buy
Now |
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| Permanent Observatory Mounting Hardware
with Azimuth fine adjustment
The observatory mounting hardware allows
fine adjustment for final positioning. |
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Azimuth
Polar Alignment Base
for easier azimuth adjustments

NGT18AZB
$225
Buy
Now |
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Azimuth Polar Alignment Base
For easier azimuth adjustments.
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Handlebar
and Wheels
Wheelbarrow-style
Transportation

NGT18WHLBLK
$240
Buy
Now |
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Handlebar and Wheels
For easily moving the fully assembled telescope over most
surfaces. Uses 8" solid rubber ball bearing wheels.
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The NGT-18's Handlebar and Wheels allow easy
transportation with the nose
assembly safely cradled inside the mirror tub assembly. |
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This and the
following pictures are of the original NGT-18. The new 18 is a GOTO
scope using the StellarCAT ServoCAT system with the NGC-superMAX (Argo
Navis) computer. There are some slight differences in the drive ring
area. |
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The NGT-18 packed comfortably in a mini-van with room for a C8 case. |
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The NGT-18 fits easily into any sub-compact station wagon. |
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The NGT-18 mirror
dust cover includes 3" and 6" f-stops. |
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The NGT-18 includes an 18-point flotation mirror cell as standard equipment. |
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The NGT-18
has a very low profile and aesthetic appearance. |
What is a
Next Generation Telescope?
The Next Generation
Telescope (NGT) is a uniquely designed equatorial Newtonian. It
features a low profile, split-ring equatorial drive, open Serrurier truss
rod design, rotating nose assembly, compact size, JMI's celebrated quality
construction and now a Go-To computer (NGT-18 Model). The NGT is a revolutionary
instrument that has won awards and acclaim throughout the world. It
is available in 12.5" (f/4.5) and 18" (f/4.5) apertures. |
Customer
Comments
"The NGT is an equatorial mount with no
field rotation, plus it is compatible with digital setting circles.
Also, there is no PEC to deal with as the RA drive is direct friction to
the ring. The all aluminum and stainless construction means little
maintenance. The low center of gravity gives it nice stability.
The best thing is the rotating nose assemble. It makes collimation
more difficult, but is so worth it." (G. K.)
"(12/31/09) I just wanted to let you
know that I have been enjoying my NGT-18 for ten years now; I guess I
finally found a cure for aperture fever. Quite aside from providing many
years of superb service, this great telescope has been the featured mainstay
of my three published books from Springer (Visual Astronomy in the
Suburbs, 2003; Visual Astronomy under Dark Skies, 2005, and the
upcoming Make Time for the Stars, 2009), in which it has done valiant
service in providing most of the illustrations, as well as being at the core
of the approaches I advocate. For some of my viewing, I will admit to
combining two Collins I3 image intensifiers (with a binocular viewer), or
even just one at a time (!), and have been simply astounded with what is
attainable in real time. The new Generation IV version is spectacular!! It
is possible to take sensational deep space virtual snapshots – even galaxies
like M51 or NGC 891 – that look like lengthy time exposures!
However, the main purpose of all of this is simply to let you know how
extremely happy I remain with my NGT-18. There can't be a more ideal or
satisfying telescope to use, and even more particularly, one that is more
comfortable and relaxing. The ready portability makes it possible to
dismantle it, move it 100 miles to a dark sky site, reassemble it, yet find
the collimation still at 100%! The quality, performance and practicality
remain beyond reproach, and even with the now relatively antiquated digital
circles from the '90's, I still have yet to exhaust the potential, or feel
the slightest need for 'go-to' capability, because the telescope is so easy
to manage and use. And accuracy of locating objects is more than adequate
for any purpose. I note that go-to capability is now offered with this
model, but the need is surely more as a luxury rather than fulfilling any
real necessity!
I have a new book in the works right now that will probably take up to 2
years to write. Once again, my trusty NGT-18 will be the workhorse for
everything in the book. I know you would like to sell more telescopes, but
what I have will probably take care of my needs for life! It seems
indestructible, completely reliable, utterly predictable and straightforward
to use. By all means use any of my words as testimonials in your catalog
or elsewhere.
Wishing you all success in 2009!" (Antony Cooke)
"It is a pleasure to do business
with a company that supports their products after the sale. ...My experience with
you and your company allows me to recommend your products and service, without hesitation,
to my friends and fellow amateurs." (M. H.)
"It is one of the great joys of
my life to have this superlative instrument." (A. C.) |
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Frequently Asked Questions
(FAQ)
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| Q. |
How long
does it take to set up an NGT-18? |
| A. |
Using
two people, the NGT-18 can be set up in about 10 minutes. |
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| Q. |
Does the
rotating nose assembly make collimation difficult or impossible? |
| A. |
Contrary to
erroneous reports on the InternetNo. Here are some comments from Tom Johnston
who builds the NGT-12.5 and NGT-18 telescopes: "Not only do
I build the NGT-12.5 here at JMI but I also own one. I use it primarily to monitor
faint periodic comets (using an ST7) for the IAU.
"There is a very simple pro and con relationship with
the rotating nose on the NGT. This ability to place the eyepiece at a variety of
comfortable positions in an enormous factor. The ease of use really cannot be
realized until you've spent a night observing with it. In addition, the rotating
nose allows you to place a heavy CCD camera in a more balanced and less stress producing
position above the tube instead of hanging off the side. I personally would not give
up my rotating nose.
"Here is the flip side. It is difficult to
collimate IF you have never done it before because it requires that you find the best
possible collimation position relative to the entire rotation of the nose. After
you've done it a few times, it's easy.
"Before the scope leaves JMI, a laser spot must stay
within the small white circle placed at the center of the primary mirror, throughout the
360 degrees of rotation of the nose. The spot may dance around a little bit inside
the circle but it remains INSIDE. Using a Cheshire eyepiece, we then adjust the
primary slightly until it is as close as it can get for the entire rotation. There
may be a few places in the circle where the Cheshire indicator is not perfect...but it
will be off only slightly. It's something you do not easily see visually or in a CCD
image...but people like to talk about it anyway. The only problems I have heard of
are when people try to collimate it like a normal (non-rotating) Newtonian." |
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| Q. |
Does the NGT
hold collimation? |
| A. |
We have found that
this telescope stays in collimation much longer than the average Newtonian. Most
Newtonian reflectors need to be collimated every other time they are used. A recent
floor model NGT-12.5 remained collimated over a span of at least 15 sessions. These
sessions included two trips to major star parties (RTMC and Okie-Tex) and periodic comet
observations and imaging in the mountains of both Colorado and Arizona. |
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| Q. |
How do you
polar align the telescope? |
| A. |
There is a latitude
adjustment screw that runs down the center of the telescope base. The screw is
parallel to the polar axis and can be visually pointed at the celestial pole. This
process can get you to within one-half degree of polar alignment in only seconds and, of course, you can use the good old stardrift
method (see Document no. 8 in our Document
Library). |
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| Q. |
Can the NGT
be leveled? |
| A. |
All NGT equatorials
have leveling screws and a bubble level located on the base. |
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| Q. |
How does dew
affect the telescope? |
| A. |
All components of
this telescope are rust proof. Water on the drive ring has no affect on the
tracking. |
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| Q. |
How accurate
is the split-ring drive? |
| A. |
Split-ring drives
have little or no periodic error. In a random test of a polar aligned NGT-12.5, it
held the Dumbbell Nebula in a 30 arc minute field of view for over an hour.
Autoguiding feedback data from an SBIG ST7 CCD camera has confirmed this precision. |
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| Q. |
How does the
wind affect the NGT? |
| A. |
All truss tube
Newtonian telescopes that use a shroud are subject to windy conditions. Sudden wind
gusts are more of a problem than sustained winds when imaging with a CCD camera.
However, we believe that this telescope is not affected by wind any more than a standard
German Equatorial Newtonian telescope. Tom Johnston, Production Manager and NGT-12.5
and NGT-18 assembler, routinely uses production scopes (as part of JMI's Quality Control process) for
gathering CCD images of periodic comets. He reports very good results in moderate
wind. |
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| Q. |
Can the
telescope be controlled by an autoguider? |
| A. |
With the proper
cables and relay box (if needed) any autoguider can control an NGT-12.5 or NGT-18
telescope. |
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