Takahashi - Mewlon 300 12 inch Dall-Kirkham on EM-500 Mount with SQ-LL Pier

The Mewlon series of Dall-Kirkham Cassegrain telescopes from Takahashi offer the experienced observer a level of performance and
portability not found in other Cassegrain telescopes mass produced for amateurs. Classical Cassegrain telescopes offer excellent
performance but they are extremely expensive to produce at large apertures. By concentrating on the Dall-Kirkham Cassegrains, the
Mewlon offers a professional level of performance within reach of most amateurs.

The Mewlons use an ellipsoidal figure on the primary mirror and a spherical figure on the secondary. By focusing on very tight
tolerances for these surfaces, Takahashi is able to deliver a compact telescope with reasonable aperture and high resolution.
Where fast F/ratios are not required, the F/12 Mewlons provide excellent contrast by utilizing a smaller secondary mirror than
comparable Cassegrain designs. Secondary obstruction as a percentage of diameter is 29-31% on the Mewlons. Classical Cassegrain
telescopes usually have secondary obstruction of 32% or greater. Commercial Schmidt-Cassegrains have secondary obstructions of
approximately 38% for F/10 systems. Ritchey-Chretien Cassegrains have even more secondary obstruction making them less suitable
for visual, high contrast applications.

Takahashi uses extensive knife-edge baffling to minimize stray reflections as well as a specially designed tube that also acts as
a light baffle. The result is an instrument that rivals an excellent long-focus Newtonian or refractor for contrast and sharpness.
Some opticians have criticized the Dall-Kirkham design as having unacceptable coma. With most eyepieces (including Panoptics &
Naglers) the coma is negligible and well outside the field of view. Stars are much smaller and sharper than in commercial
Schmidt-Cassegrains. Coma may be a problem for wide-field astro-imaging, but these instruments were not designed for such tasks.
With Takahashi's field flattener/reducer, these instruments offer superb off-axis images at F/9.

The 250mm and 300mm models have electronic focusing accomplished by moving the secondary mirror. This eliminates the image-shift
problem inherent to commercial Schmidt-Cassegrains with moving primary mirrors. Because of the loose tolerances required in moving
large and heavy mirrors on a baffle tube, most SCT's will not maintain perfect collimation. Image quality is then compromised in
such optical systems. The large Mewlons also have removable covers for their primary mirror cells, this aids in rapid mirror
cooling so that the observer can take advantage of favorable seeing conditions more quickly. These features make the large Mewlons
ideal for high-resolution CCD imagery

Mewlon 300 - 12" f/11.9 Dall-Kirkham on EM-500 Mount w/SQ-LL PIER Includes:

    * Takahashi Mewlon 300 Optical Tube Assembly
    * Tube Holder
    * 11X70 Finder
    * Double Finder Bracket
    * Tube Weight
    * Diagonal
    * 30mm LE 1.25" Eyepiece
    * EM-500 Temma II Equatorial Mount
    * SQ-LL Pier
    * Dual-Axis Hand controller
    * Illuminated Polar Finder
    * Cables
    * Software 
    * The 300 has 11.8" of aperture and a focal ratio of 11.9.       
    * This system comes with the EM-500 mount and Takahashi's SQ-LL Pier.       
    * The OTA comes with Fraulhaber German electric focus motor for secondary (no image shift!) 

Takahashi EM-500 Temma II Mount

The state-of-the-art EM-500 Temma II mount has a tracking accuracy that is guaranteed to +/- 3.5 arc seconds without periodic
error correction and it runs off of 24V DC. The EM-500 Temma II slews at 560X the Sidereal rate. The Temma II GoTo System can be
operated via The Sky, Level IV software and is closed-loop. This means that the telescope can be moved manually without restarting
the GoTo system. The mount can also be operated in manual (non-GoTo) mode without connecting to a computer and dual-axis tracking
is available in this mode.

The self-contained illuminated polar finder is accurate to two arc minutes of the pole. Autoguider and CCD cables are available
for most CCD cameras including serial, RJ-11, and USB connectors. Main gears are phosphor-bronze with matching poly-steel worms
for greater accuracy and durability vs. aluminum & stainless steel. New, precision micro-stepping motors provide high durabilty
with softer pulse-peaks for better imaging. No need for servos and variable-voltage systems that reduce longevity.

    * Type: German type, Dual-Axis Drive
    * R.A. Slow Motion: Electric
    * DEC Slow Motion: Electric
    * Self-contained illuminated polar finder: Accurate to two arc minutes of the pole
    * Operation: 12V/24v
    * Slewing speed: 520x sidereal @ 24v
    * Mount Worm Screw Period: 10 Minutes
    * Input Terminal: For Auto Guider (ST-4)
    * Loading Capacity: 40kg. (89lbs.) but it can reasonably handle 120lbs.
    * Tracking Accuracy: +/-3.5"
    * Operational software: The Sky, Level IV software and is closed-loop 

SPECIFICATIONS for the M-300 (Tube assembly only)

Effective aperture 300mm
Focal length 3572mm/2739mm w/reducer
Focal ratio F/11.9-F/9.1 w/reducer
Resolution 0.40"
Limiting magnitude 14.2
Light grasp 1837x
Image circle '25mm/'42mm w/reducer
Photographic field 45' w/reducer
Total length of main tube 1094mm
Diameter of main tube '324mm
Primary mirror 310mm F/3
Secondary mirror 95mm /X4
Secondary Obstruction  29%
Finder scope 11x70 4.2°
Gross wt. of main tube assembly 26kg (57.2lbs)