Meade RCX400. For Sale
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The RCX Advanced Ritchey-Chrétien Optical System
It is generally accepted that the Ritchey-Chrétien or Classical RC system is the premiere optical design for medium to large aperture astronomical telescopes. The primary benefit of a Classical RC is the fact that it is an aplanatic design which means it is coma-free. Coma is an optical aberration that causes star images to appear comet like with tails that point away from the center of the field of view. The further from the center, the larger the effect. Fast Newtonians suffer from this aberration the most, followed by other reflecting optical systems of various designs. The Schmidt-Cassegrain or Schmidt-Newtonian design typically has ½ the coma of a Newtonian of the same focal length. The Classical RC design uses a hyperbolic primary mirror and a hyperbolic secondary mirror to create an aplanatic optical system which has no coma. This system produces small round star images all the way to the edge of the field of view.
Meade’s engineering team recognized the advantages of the Classical RC design but explored the possibility of using Meade’s unique engineering and manufacturing expertise to improve on the basic design. The result is the RCX optical system which is also an aplanatic, coma-free design with small round star images to the edge of the field. The RCX design is very similar to the Classical RC and achieves the same benefits by using a hyperbolic secondary with a new advanced front corrector plate and primary mirror that together perform as a hyperbolic primary. This design has several advantages over the Classical RC design.
The RCX eliminates the secondary mirror holder support vanes (spider) that cause diffraction spikes. Because almost all reflecting telescopes produce diffraction spikes, many people are used to seeing them and don’t consider them an aberration. But in reality, they are a large distortion that reduces image contrast, lowers resolution and presents an unrealistic view of the sky to the eye or the astro-imager.
The RCX design reduces the amount of astigmatism that is inherent in the Classical RC design.
The RCX, due to the front corrector plate, is a closed tube design. This keeps the primary optical components protected from dust, moisture and other contaminates that might fall on the optical surfaces of the primary and secondary mirrors.
While the RCX optical system is significantly more expensive to manufacture than a Classical RC, it was chosen because of its superior performance (i.e., no diffractions spikes, reduced astigmatism and closed tube). Due to Meade's years of experience in designing and manufacturing sophisticated corrector plates and optical systems, we are in a position that very few, if any, other companies enjoy. Applying this expertise and Meade's resources, we are able to produce this advanced optical system at a fraction of the price that other companies would have to charge, if they could produce it at all.
Precision GPS Alignment:
Telescope alignment is accomplished automatically using signals from the Global Positioning System (GPS), a satellite system that enables extremely precise communication to the telescope of the observer's latitude and longitude, as well as local time. Integrated True-Level and North electronic sensors in combination with a high-sensitivity Sony GPS receiver located in the left-hand fork arm result in accurate telescope alignment to the sky at the touch of a button: Just press the ENTER button on the Autostar II hand controller and watch as the telescope measures level, points North, and slews at 8°/sec. to its first alignment star. Magnetic declination compensation designed into the telescope software automatically engages during the alignment process.
Software Downloads and
The software included in Meade RCX400 telescopes is under continuous factory review; updates to this software are published at regular intervals on Meade's website. Importantly, the latest software version, as well as custom and updated guided tours, comet and asteroid positions, may be downloaded in minutes from Meade's website. Additionally, current Earth satellite orbital data (including the International Space Station, Space Shuttle, etc.) may be downloaded; the telescope then automatically acquires and tracks the satellite at the correct tracking rate. The telescope's flash memory may be upgraded through one of the RS-232 ports with new software or data as they become available on Meade's website.
Expanded Database and
Larger User Memory:
The RCX400 database has been expanded over the standard library of the LX200GPS to include 180,000 objects. In addition to more stars from the Hipparchos/Tycho catalog, we have added::
• The popular "Lunar 100" with the finest features to see and image on the Moon
• A subset of the finest visual doubles from the Washington Double Star Catalog
• The PK Catalog of Planetary Nebulae
• The Hickson Catalog of Dense Galaxy Clusters
• The Gleason Catalog of Nearby Stars
• The Landolt Catalog of Photometric Standard Stars
• The Sharpless Catalog of HII Regions
Laser Aligned, Fixed Primary Mirror:
The primary mirror is laser aligned to the true optical path, then float bonded in place. It is fixed, but literally floats on a layer of adhesive that results in zero stress to the glass and no distortion to the optics (unlike mirror cells or floating point pads). There is no mirror movement.
RCX400 scopes operate from eight C-cells neatly stored inside the fork arms. Alternately, telescope powering may be effected from an automobile cigarette lighter plug (using the optional #607 Power Cord) or from a standard home outlet (using the new optional AC Adapter).
#929 2" Diagonal with UHTC:
Standard equipment on all RCX400 telescopes, attaches to the rear cell of and permits the use of wide-field 2" O.D. eyepieces. Each diagonal includes a Meade optical-flat mirror of Pyrex glass, UHTC-coated for maximum reflectivity.
Built-In Dew Heater:
Instead of wrapping a heating element around the telescope's optical tube assembly to send heat through the telescope's front cell to prevent dew from forming on the corrector plate, the RCX400 incorporates a nickel-chromium wire heating element that is in contact with the glass of the corrector plate that quickly, efficiently, and safely sends heat through lens using the lowest power drain possible. With two onboard temperature sensors, one to measure ambient temperature (placed inside the fork arm) and one to measure the temperature of the corrector plate, the RCX400 can be set to have the built-in dew heater keep the corrector plate warmed to a user-defined setting above ambient temperature. By only using the dew heater precisely when needed, battery usage is managed to its optimum. All functions to operate the dew heater are controlled by the AutoStar II handbox. Precision Encoder-Measured
With a laser aligned primary mirror fixed in position, focusing is performed electronically and digitally by precisely moving the entire front cell in increments as fine as 1/100 of a millimeter. Digital readout of the focus position can be read on the telescope's AutoStar II handbox. There are 4 different focusing speeds from fine to fast. Since the process is accomplished without moving the primary mirror, the entire assembly is virtually free from image shift.
High-Precision Pointing (HP) Capability:
Meade RCX400 models permit the most accurate pointing capability ever offered in a commercial telescope. Now you can command the telescope to GO TO an object located on the opposite side of the sky (for example, a distance of 120 degrees in sky-angle) and, in conjunction with the telescope's unique SYNC command, the RCX400 locates and centers the desired object. HP capability is accessible in either the altazimuth or equatorial orientations.
Precision Electronic Optical Collimation:
Collimating a Cassegrain telescope has never been easier. RCX400 owners will make precision collimation adjustments to the secondary mirror of the telescope by using the arrow keys of AutoStar II handbox, allowing a single person to simultaneously make adjustments and see the results. In addition, Meade precision collimates the optics at the factory and then sets that position as the default setting. So in the case where one may make a mistake in making a collimation adjustment, the default setting can always be used.
Smart Drive Permanent Periodic
Error Correction (PPEC):
Included as standard equipment, the Smart Drive permits a professional level of drive-rate precision. No longer are large systems required, worm gear when smaller gears coupled to Smart Drive software can achieve periodic errors of 5 arc secs or less-an observatory standard of precision. All worm/worm-gear combinations, no matter how well made, have minor inaccuracies that manifest themselves as periodic errors in the telescope tracking rate, with the period dependent on the worm's rate of rotation. To program the Smart Drive the observer guides on an object visually, making corrections with the handbox controller. The software then remembers these corrections, stores them in memory, and in the future automatically compensates for the periodic errors of the gear system. Smart Drive user programming is stored in the telescope's computer memory forever, independently of any power source, unlike other periodic error correctors that must be reprogrammed each time you use the system. The Smart Drive can be erased, updated, or even averaged with future programming at the user's option. The significant value of the Smart Drive is immediately appreciated during long-exposure astrophotography, where the resulting low periodic error of the system enables relaxed guiding with a minimum of handbox corrections. In CCD imaging, where short exposures of deep-space objects are often all that is required for stunning results, the Smart Drive often permits imaging without any guiding requirements at all.
Heavy-Duty Fork Mounts:
RCX400 fork mounts are the strongest, most rigid mountings ever made available for telescopes of these apertures. Fork arms, are both longer and stronger. This allows the 10", 12" and 14" scopes to go all the way to 90 degrees declination on a wedge, allowing you to reach the horizon. The increased fork size also gives more back clearance to allow imaging all the way to the pole with most cameras. DC-servo-motor-controlled (12v DC) worm gear drives with almost two hundred selectable drive speeds, combined with the Meade Smart Drive on both telescope axes, permit observatory-level precision in tracking, guiding, and slewing. Photo-guide speeds are selectable from 0.01x to 1.0x sidereal, in increments of 0.01x; fast-slew speeds are selectable from 1°/sec. to 8°/sec. in 0.1°/sec. increments. Use the 8°/sec. speed for rapid motion of the telescope across the skies; once near the target, switch instantly to a speed of 1.5°/sec. or 3°/sec. for centering in the viewfinder. Observing in the main telescope, use the 16x or 64x sidereal speed to place the object in the center of the field.
Computer Optimized Internal Baffling: Unlike traditional Schmidt-Cassegrain designs, the primary mirror moves along a baffle tube in order to achieve focus, Meade's RCX400 primary mirror is mounted independent of the baffle tube. This allowed Meade's engineers to take full advantage of the baffle design to create full stray light cut-off performance, in order to produce the maximum contrast. Additionally the secondary baffle, machined of aluminum with its distinctive outer knife-edges further minimizes stray light in the optical path.
RCX400 Balanced Drives:
The drive mechanisms of many telescopes can be compared to the movements of fine chronometer watches. First utilized on the 14" LX200GPS, the RCX worm block design incorporates a unique balanced loading system to the keep worm and worm gear in the optimum contact position, regardless of the load stress that is normally encountered as the telescope is moved from one position of the sky to the next. The result is improved drive performance, with superior centering and slewing characteristics. RCX400 Balanced Drive assemblies are on both the RA and Dec. axes.
Focus Position Presets:
By setting up to 9 focus positions, RCX400 owners can customize perfect focus from observer to observer with different eyesight (similar to the custom settings in luxury cars to change the mirror, seat, and steering wheel settings from one driver to another). The feature is also very useful when using switching to various eyepiece and Barlow lens combinations or from a visual setup to a camera setup.
Standard on all RCX400 telescopes, the importance of Meade's proprietary UHTC group becomes apparent when comparing total telescope light transmission, or throughput, caused by the multiplier, or compounding, effect of the four optical surfaces. With each optical surface contributing significantly to telescope light throughput, the effect of all four surfaces combined is indeed dramatic. At the H-a wavelength of 656nm., total transmission increases from 76.7% to 88.5%, an increase of 15.4%; at the helium wavelengths of 588nm. and 469nm. - strong emission lines in hot planetary nebulae - total telescope transmission increases by 13.8% and 16.8%, respectively; at the two nitrogen II lines of 655nm. and 658nm. and at the sulfur II line of 673nm., transmission is increased by 16%. Averaged over the entire visible spectrum (450nm. to 700nm.), total light transmission to the telescope focus increases by about 15%.
More Info about UHTC
Revolutionary Smart Mount technology is standard equipment on all RCX400 telescopes. Smart Mount improves the pointing accuracy of your RCX400's telescope's "Go To" system with the following features:
• Constantly improved pointing accuracy with every object centered and sync'ed.
• Works with both equatorial and altazimuth configurations.
• Simple routine to refine pointing accuracy for the entire sky with your equipment configuration and alignment.
• Refined pointing data can be saved and reused for permanent and portable