Copyright (c) 2005 Cloudy Nights Telescope Reviews
MEADES 12 RCX400 TELESCOPE

INTRODUCTION

Few (if any) new product introductions have created quite the stir that Meades RCX series did. Of course, Meade went out of their way to help things along with their preannouncement that a new model would be announced shortly and that it would have a major impact on amateur astronomy. This created plenty of buzz on the various astro Groups and Fora as to just what the news would be. When the details were released, the buzz only grew larger. It was described as an Advanced Ritchie-Cretien telescope on a dual-arm forkmount similar to that used on current LX200GPS models. Since the existing RC models on the market are in the lofty price classes and chosen for use by some of the most serious imagers in amateur astronomy, this raised three issues. One question frequently raised was just what Meade had in mind producing an obviously imaging-optimized telescope on a forkmount instead of the far more commonly-used German equatorial mounting? How could it match the performance of the $8000+ GEMs used by imagers? A check of the prices offered made those answers clear; this series was aimed at a lower price point; a complete 10 RCX system cost considerably less than most high-end mounts alone. It apparently was intended not to compete with the highest-end gear, but instead to fill the gap between the forkmounted SCTs and the premium imaging setups - at a price of about double that of current SCT offerings. Another issue related to optical quality - how could a 10 complete system for $5000 match a conventional RC when a 10 RC optical tube from RCOS costs $13,000? Again, the answer is apparent to me. Despite some of the marketing language used, its not meant to compete, but to make enhanced imaging performance available at a performance and price point attractive to a different (and presumably much larger) market. Whether it can do that is a much more interesting question. The third topic generated by far the most activity. What was Meade doing describing this as an Advanced RC when its not identical to a conventional RC? The actual optical design wasnt described by Meade for some time, permitting folks to embark on an orgy of uninformed speculation as to the optical configuration. Some such speculations were published so widely and in such an authoritative tone that confusion remains, despite the fact that the configuration is now well-documented. For the record, the system consists of a hyperbolic secondary (as in a conventional RC) and a spherical primary with a new design of corrector lens (NOT a Schmidt corrector) added; the combination of the corrector and the spherical primary behaves much as a hyperbolic primary by itself would. Thats the RC connection - a conventional RC uses two hyperbolic mirrors. Not surprisingly, I was curious about this offering. Ive owned and used most of the forkmounted SCTs currently offered, and have dabbled at imaging for a while. I wanted to see if this series would provide a performance boost above the SCTs without requiring the investment involved in a higher-end imaging platform. When Astronomics offered to provide a 12 for review purposes, I cheerfully volunteered. I had just
removed a 12 Meade SCT from the observatory, so I figured Id have a pretty good feel for comparing them visually. I had taken enough recent images that Id be able to repeat the shots with the RCX for direct comparison.

WHAT IS IT?

As mentioned above, the RCX400 series consists of optical tubes and mounts bundled together. Its currently offered in apertures of 10, 12, and 14, with a 16 version in the works. The Giant Field Tripod has been replaced by a new unit that looks to be even more stable than the GFT, with the added benefit of removable legs for portability. Despite the imaging orientation of this model, it is not provided with a wedge, but is compatible with the Superwedge and others in the market. Due to the base design and to the extra hardware associated with the focusing system, the RCX models weigh significantly more than the corresponding SCT models. For example, a 12 LX200GPS weighs about 75 pounds, while the 12 RCX400 comes in at a hefty 91 pounds. In the 12 version, this is offset to some degree by the fact that the shorter optical tube of the RCX can be parked between the forks rather than remaining pointed upwards during setup as required by the 12 LX200GPS. The optical tube is the most innovative portion of the setup. The tube itself is made of carbon fiber (used to reduce focus shift with temperature changes). A cooling fan and dew heater are incorporated into the OTA. Like an SCT, the secondary mirror is mounted to the corrector plate, but unlike an SCT the primary mirror is fixed. Focusing and collimation are achieved by moving and tilting the corrector plate - and thus the attached secondary mirror - by three servomotors via carbon fiber shafts. The apparent intent is to provide very smooth, repeatable focus action with no image shift. A collimation preset can be stored, as well as several focus positions. Thats a lot of extra hardware and electronics; the longterm reliability of these items wont be known for a while. The mounts are derived from (and very similar to) the 14 LX200GPS mount. Like the LX200GPS, they offer a large library of targets for GoTo operation, periodic error correction in both RA and DEC (referred to as Smart Drive), multiple-object mapping capability (Smart Mount Technology), provisions for autoguiding via either a serial port or an autoguide port, High Precision Pointing, and compatibility with the Drizzle feature of the Deep Sky Pro imagers software. Firmware and object updates can be done by the user from materials available on Meades website, although no firmware updates have yet been released for the RCX series. Unlike the LX200GPS, the drivebase also includes a USB hub and interface permitting the telescope and one or more imagers or guiders to be controlled via a single USB cable. It also includes controllers for the optical tubes built-in dew heater, the cooling fan, and the motors used for focusing and collimation. Substantial internal cabling permits the ancillary USB devices and the guider to be connected at the optical tube rather than at the base, reducing cable clutter and tangling opportunities.

SO WHAT DO YOU GET?

The telescope box is much smaller than that in which the 12 LX200GPS is shipped. This means that Fedex Ground can be used to ship these. Thats both less expensive and more convenient than freight. This one was shipped from Astronomics. Everything appears sealed and not repacked so Im gonna consider it a random, non-selected sample.

THE TRIPOD BOX

The tripod box is square and squat rather than the tall, thin box used for the Giant Field tripod. This is due to the fact that this tripod doesnt permit the legs to be unspread; the legs are removed instead.
The box is not so sturdy as the GFT box was; this one arrived with one corner split. Nothing was missing or damaged, fortunately.
Opening the box reveals the feet - just as with the GFT
Here are the legs and tripod head ready for assembly (gee, that Styrofoam debris didnt look that bad without the flash!).
The tripod legs are slid onto the leg segments and the leg attachment locking levers tightened. Thats it; the tripod is assembled. As can be seen in the photo on the right, the leg adjuster release levers simply hook onto the release arms. And whats this? I see that Meade has implemented a springloaded center bolt, similar to the popular Springy Thingie LX200 accessory. Well see pretty soon if thats a good thing.

THE EVERYTHING ELSE BOX

Unlike the LX200GPS scopes, the inner beauty box doesnt slide into the outer box Both open the same way, so both top sections can be removed at once, revealing the top layer of packaging material. Removing that material reveals the telescope and accessory box. The foam is the kind thats sprayed into a plastic liner rather than the diecut foam used with the LX200GPS series. It protects during shipping at least as well but would be less convenient to re-use in a transport container for portable telescope use. To me, this isnt a portable setup anyway.

ACCESSORIES

Lets look in the accessory box first.
In that box are: the Autostar II controller (same as the one used with the LX200GPS) A the finderscope - its extra nice, with the focuser at the eyepiece end where it belongs a 2 star diagonal with UHTC a beefy 2 visual back a USB cable a HUGE 24mm 5000 series UWA 2 eyepiece Autostar Suite software and USB drivers on a single CDRom the same flimsy handbox holder as is supplied with the LX200GPS.

Hmmm. No AC supply or DC cable. Like the LX200GPS, there are primary battery holders in the fork arms so I guess they figure thats sufficient. As with the LX200GPS, I have no intention of trying that -Ill use the jumpstart packs and DC cables I already have.

THE TELESCOPE

Now comes the moment of truth. This thing is heavy; at 91 pounds its about 15 pounds heavier than a 12 LX200GPS. My hope is that itll still be easier to assemble to the tripod because the shorter optical tube parks between the forks like the smaller SCTs. It turns out that it IS easier to mount than a 12 LX200GPS. I lifted it out of the box and onto the tripod fairly easily. The springloaded center bolt made it unnecessary to place it perfectly; I just plopped it on there and slid it around a bit until the bolt snapped up into place. The large, comfortable handle made tightening the bolt into the telescope base quick and easy. On the other hand, the fork arm handles are just as poorly placed as they are on the LX200GPS models - but at least the balance is much closer. Theres lots of room between the telescope base and the drive base for hardware; about 2.5 more room than is available on the 12 LX200GPS.
The rear cell of the optical tube has an approximately 3.25 threaded fitting for optical accessories. I found that both my Moonlight crayford-style focuser and a Lumicon Giant EZ-Guider fit just as they would on a 10 or larger Meade SCT. A reducer is supplied with the RCX that takes this down to a standard SCT thread fitting. All the standard SCT accessories I tried fit the reducer normally. The RCX is also supplied with a surprisingly massive 2 visual back which attaches to the reducer and accepts the supplied refractor-style 2 UHTC diagonal or other 2 accessories.
Those UHTC coatings really make the corrector disappear!
Heres the OTA rear, showing the connections available there.
This detail shows the massive tripod head and the leg level release levers
The carbon fiber tube (with Meade blue fibers!) is attractive. Note the manual slow motion controls - you wont be able to focus this baby without power but you can move the tube around!
This photo is included just for scale (honest!). INITIAL CHECKOUT Fit and finish are great, just like the LX200GPS models Ive owned. I see no cosmetic flaws and everything that must be assembled went together fine except the finderscope holder; a little paint on the dovetail kept it from going into the base until I scraped it a bit. I really, really like the new tripod. I see that there are no accessory mounting holes at the top center of the optical tube, meaning that I wont be able to add a guidescope using hardware lying around here. That may hold me back a bit later in evaluating its imaging potential. I dont know whether dedicated hardware is available yet for this model. There are tapped accessory holes that would accept radius blocks such as are supplied with Losmandy dovetails so I presume that if those arent yet available they soon will be. Applying power from my jumpstart battery, everything came up just as it should. Running the focuser back and forth I noticed that it seemed fairly loud at high speed. I suspect it wont be used at high speed very much, though. Digging through the menus I found the dew heater and OTA fan under Utilities; that seems an odd place but now I know where they are. Unlike the 7 Meade Maks, which use two fans, this model uses only one, which draws filtered air into the rear of the tube and exhausts it out the front. Slewing around a bit, it the drive motors sounded similar to the LX200GPS (as expected). I did my usual indoor alignment; I pointed the optical tube North and the control panel

South after ensuring that it was midway between the hard stops. Upon being told to do an automatic alignment, it did the usual Meade Mambo, checking level at three orientations, then seeking North and level. At this point it wanted a GPS lock. As with all the other GPS-equipped telescopes that have been in my dining room, I couldnt acquire an indoors GPS lock. I entered time and location manually and off it went to the first alignment star. I told it that it was centered and it slewed to another. I told it that one was centered also, and received an alignment successful message. A few GoTo requests resulted in pointing attitudes that were reasonable, so I pronounced it functional. I strongly recommend this sort of thing with a new instrument, as if theres a problem either with the telescope or the operator its easier to sort it out in a well-lit room. Im not going to draw or report any conclusions at this point; I havent even looked through the telescope yet! What I can say is that so far everything seems to be as it should be. If it works as well in the observatory as it seems to in the dining room itll be a very nice instrument.

TAKING IT OUTSIDE

The next step was to haul it up into the observatory and plant it on the wedge there. I made sure I had help with that phase of the project. Its definitely a two-man job - but I believe that its easier than either the 12 or 14 LX200GPS. As you can see in the photo, the soft dewshield from my current 12 LX200 Classic fit the 12 RCX just fine. The dustcap is also the same size, as is the prefilter for my Ha filter setup.
Clearly, most of what we really care about will be learned in the next phase of this trial. Ill be able to see how well it operates compared to the various Meade & Celestron forkmounts and GEMs Ive used in this observatory. Ill evaluate goto and tracking accuracy. I will be able to measure and evaluate periodic error and periodic error correction. I will be able to take some images with the Canon 300D DSLR and the LPI,
and to compare them directly with those I have taken using the same cameras and the 12" Meade SCT. Ill be able to check focuser range with binoviewers. Ill see how the views are in the eyepiece, and how they compare to what Im accustomed to in the SCT. In addition, Ill be able to get a feel for just how well all the extra technology works together. I want to see if it gets in the way, or makes it easier and more convenient to use. Ill also watch for any functional oddities with the newer and untried features. Finally, if time and weather permit, Ill take it out into the field and see what setting it up in altitude/azimuth mode on that great-looking tripod is like. It should be of interest to the folks wherever I take it! John Crilly 7/8/05 jcrilly@neo.rr.com

MEADES 12" RCX400 TELESCOPE (PART 2) For an overview of this telescope, see Part One of this article: http://www.cloudynights.com/documents/meadercx1.pdf

INTRODUCTION

This portion of the review will concentrate on operation and setup of the instrument. Ill include a few low resolution images just to show how things look and to demonstrate that the telescope is capable of taking photos but Ill reserve in-depth discussion of its imaging capabilities for Part Three.

WEDGE INSTALLATION

Finally - Im ready to take a look through this thing rather than just looking at it. I installed the RCX400 in the observatory in place of the 12" LX200 on the existing Superwedge (with assistance). Installation was a little easier than with the 12" LX200 despite the extra weight. Being able to park the optical tube between the forks lowers the center of gravity to a point much closer to the handles, making it less awkward. Because of the increased weight of the RCX models its recommended to use the " X 13 center bolt in addition to the normal three wedge mounting bolts but I havent yet drilled an extra hole in the wedge tilt plate so I used only the usual three bolts. I connected it to an LX200GPScompatible power supply offered by Scopestuff. I also connected the autoguide port to my Shoestring Astronomy parallel port adaptor and the RS-232 port to the Dell PC in the observatory. It was very convenient not to have to install a dew heater and controller and the accompanying cables. I used the flexible dewshield I had been using with the 12" LX200.

FIRST LIGHT

As the wedge was already polar aligned I didnt use any of the alignment procedures offered by the Autostar II; instead I slewed to a convenient star, selected that star from the Object database, and performed a synch. I then slewed the
telescope to point South and level (a position that permits the rolloff roof to clear and keeps the OTA out of my way), and established that as the park position. Next time I turn it on I wont need to do any alignment at all. On a later session Ill use and describe some of the alignment procedures provided. First light was hindered by scattered clouds but I grabbed a look at the Moon as it passed through a gap. The supplied 24mm UWA eyepiece is quite a handful but delivered a nice view. Focus with this telescope is very smooth and easy. I found that I used only two of the supplied focuser motion speeds offered. Between the Moon and the clouds deep sky views were uninspiring so I decided to grab a couple of quick shots with the unmodified Canon 300D and call it a night. I decided to grab the Moon and M5. I quickly discovered that I had shifted the wedge during the equipment switch; DEC drift limited me to 30 second exposures. Remember that the DEC drive doesnt operate in EQ mode unless commanded by autoguiding, so the telescope isnt to blame for this. Ill have to align the wedge before any more imaging attempts. I saved PEC programming and autoguiding setup for another time. The other thing I noticed right away was that the field is illuminated more evenly than in the 12" SCT; Ill spend less time fighting gradients with this setup.

WEDGE ALIGNMENT

The RCX400 provides the same method of preliminary wedge alignment as the LX200GPS telescopes. The optical tube is placed upside down and the DEC axis set to 90 degrees while the RA is set to zero. The wedge align routine is then initiated, which points the optical tube to where Polaris would be if the wedge were aimed at the North celestial pole. The wedge is then adjusted to place Polaris in the center of the OTAs field of view. This gives an initial position close enough to make drift alignment fairly quick. I then used K3CCDTools2 and the LPI to drift align the wedge. With the wedge properly adjusted, I was ready to measure periodic error, and to train the periodic error correction in preparation for imaging.
PERIODIC ERROR AND CORRECTION
I used K3CCDTools2 and the LPI to measure and characterize the periodic error. With the pixel size and focal length entered, this program can calculate the error in arcseconds, and display it graphically. The first night I tried it, the seeing was sufficiently
unstable that I was unsure of the result, and realized that PEC training would have been a waste of time. The following night things were much better so I proceeded. I tuned off the PEC function so I would be able to observe the uncorrected errors. I found that the periodic error was about plus and minus 15 arc seconds. It took the form of one large sinusoidal wave with a smaller bump superimposed on it. There were no abrupt transitions; this would probably have been easy to guide out with no other corrections. Instead, I decided to examine and use the built-in periodic error correction routine. I set the LPI up to autoguide via K3CCDTools2 and the telescopes autoguide port via the Shoestring Astronomy adaptor. After ensuring that the guiding was working fairly smoothly, I selected PEC training and let it proceed, even though I did observe that the guidestar was bouncing around a little due to seeing. After an interval, a beep informed me that the process was complete. I rechecked the periodic error and found that it had been reduced to a little better than plus and minus 5 arcseconds, with no abrupt transitions. Additional training sessions, or training during better seeing conditions might have reduced this a little more, but thats an easy error to autoguide out so I considered it good.

EQUATORIAL OPERATION

I powered the telescope down, selected a convenient alignment star, slewed to that star, and used the synch function to align the Autostar II controller. From this point, the telescope automatically slewed to every object I selected with the accuracy typical of the LX200 series telescopes; very pleasing. During later sessions, I was able to operate remotely from inside the house, secure in the knowledge that if I chose a different imaging target Id be able to select it and go on shooting without any need to check or correct centering.

AUTOGUIDED IMAGING

Using the LPI and K3CCDTools2 (I just cant learn to love the Autostar Suite) plus a Lumicon Giant Easy Guider I was able to grab a few images using longer exposures. Ill go into more detail and show blowups in the next segment, but here are a couple of compressed images just for show. Please remember that these are shot at full resolution and compressing them down to a file size suitable for this article is an unkind way to treat an image. In Part Three, which will focus on imaging, links to full-size shots will be provided.
Heres a shot of M51 showing the recently-discovered supernova (red arrow points to it). It was taken with the Canon 300D at Cassegrainian focus, seven shots of 5 minutes each at ASA800. They were adaptively added and stretched by DDP using Images
Plus, then fine-tuned in Photoshop.

LPI EXPERIMENTS

The next night I was able to get out to the observatory was also cloudy but I was able to do a few experiments. I used the LPI to grab a shot of the Straight Wall during a cloud gap.
I then slewed over to the Double Double to see how the RCX handles the split. In the LPI it looks pretty nice.
Another easy double - Polaris. The star was dancing around quite a bit; probably a combination of a hot telescope and a hot roof to the North. I had to overexpose Polaris to get the companion, of course.
Next it was time to check in-focus and out-focus images. Heres Arcturus in focus (but boiling):
And here it is with the secondary shifted.3mm (according to the handbox) inside of focus:

.and with the secondary shifted.3mm (according to the handbox) outside of focus: Not identical by any means, but probably reasonable for a Catadioptric.

BINOVIEWING

Because the RCX focuses by shifting a mirror (even though its the secondary rather than the primary), it has a large focus range which is comparable to that of an SCT. I was sure that focusing a conventional binoviewer would be no problem but Ive run out of range with some SCTs when using a binoviewer with a focal reducer. The Denkmeier Standard binoviewer with PowerxSwitch looked like a good fixture so I hooked that up to see how it did. With both arms extended (no optics between the binoviewer and the telescope) it focused normally. Switching to 2X magnification, it reached focus again. According to the handbox, the secondary had moved inward about 3.5mm to achieve focus. Switching to reducer mode (about.7X) I found that focus was again achievable, though going past focus to evaluate the range revealed that there wasnt much excess motion available. The secondary had moved about 5.5mm outward from the neutral focus position. The light path through the Denkmeier binoviewer is about as long ( approximately 5") as the longest of the other popular units, while the current crop of Chinese imports are about an inch shorter. This tells me that any of the popular binoviewer sets available will come to focus without problems in the RCX.

IN THE FIELD

I took the RCX400 out to three different observing sites to evaluate it as a visual instrument. This gave me the chance to try the telescope under differing sky conditions and to do casual comparisons with a variety of other, nearby instruments. I was also able to go through the setup and alignment procedures multiple times, and to spend a number of hours at the eyepiece.
A public function at our Club site gave me the first opportunity to take the RCX
out to the field. As can be seen in the photo, I continued to ignore the battery holders in the telescope, using instead my trusty jumpstart battery pack from Harbour Freight and a DC cable from Scopestuff. The tripod was easy to transport in four pieces and went together very easily at the site. Leveling the tripod was very quick using the provided clutch release levers - but after leveling was completed I disengaged them so nothing bad would happen if they were bumped later in the dark. The built-in center bolt spring again made installation of the telescope onto the tripod pretty easy, although this time I did manage to get the bolt to bind in its hole and not drop freely as it had in the dining room. Im guessing I was pushing it off-center. Lifting the telescope from the tripod and setting down again cleared that problem. I didnt experience the same issue on later setups. Setup and alignment from that point was the same as with an LX200GPS. First, I declutched it in azimuth and rotated it by hand (carefully!) to find a hard stop. I then rotated it to find the other. Placing it midway between the hard stops, I then rotated the base on the tripod until the control panel was facing South. To make sure everything was working properly I then selected auto align even though it wasnt yet dark. The telescope did the usual Meade Mambo, checking level at three orientations, determining North and level, and obtaining a GPS lock. It noticed I was not at home, so I accepted the default name for the new location (the nearest town). Then it slewed to where it thought the first alignment star would be. I pressed enter to accept that guess and it proceeded to seek the second alignment star. Pressing enter again, I received the alignment successful message. I powered it down and waited until dark for the next experiments.

OBSERVING - SESSION 1

Once it was sufficiently dark, I repeated the alignment procedure except that this time I centered the two alignment stars in the eyepiece before pressing enter each time. The rest of the evening I experienced the usual LX200 series accuracy; every object (if visible at all!) was well-centered. Sadly, the sky transparency was very poor
that night. For example, M51 was barely detectable in the eyepiece, and M13 was a faint fuzzy. Those of us who were set up settled for cruising open clusters and double stars. Among the other telescopes on the field that night were LX200GPS SchmidtCassegrains in the 10" and 14" apertures so those were the subjects of comparison. The RCX stood up to that competition very well. I thought the view of Polaris was the nicest, cleanest split Ive ever seen - as sometimes happens the seeing was as good as the transparency was poor. Open clusters were as good as Ive seen them in a compound telescope. M16 looked great even though the nebulosity wasnt there even in averted vision (although some observers appeared to be able to detect it in the RCX, I sure couldnt). Despite the slightly larger central obstruction, this telescope wasnt giving anything away to the SCTs in terms of contrast or detail. In this not-very-scientific comparo the RCX seemed to be putting up tighter star images than the Schmidts.

OBSERVING - SESSION 2

I was able to attend an informal star party hosted by some very friendly Cloudy Nights members. It was a good chance to spend a weekend using the RCX400 and the skies really cooperated this time. Although the first night was clouded out and the following day began with a rainstorm things cleared up nicely afterwards and the air had obviously been cleaned up by the precipitation. I installed my Thousand Oaks Hydrogen-alpha filter on the RCX, set the PST up next to it, and settled in for some solar viewing. The detail visible within larger prominences was far beyond anything my trusty 12" Meade SCT had ever shown me with the same filter. Of course, the PST with its narrower filter did a better job on surface details. This was the first RCX experience for the other party attendees and all seemed to enjoy it. Anyone who notices the strange-looking tripod in the above photograph is invited to read down a few more paragraphs for the explanation. That night I turned on the dew heater and proceeded to do some observing under skies that, while not absolutely dark, were very transparent. I primarily used the 24mm UWA supplied with the RCX400 and it was a very enjoyable experience. As expected, the mounts accuracy was spot-on all night long after an automatic alignment. The 17 Ampere-hour battery that had operated the telescope most of the day nearly made it through the night as well despite lots of slewing and a fairly high dew heater

setting. It never quite gave out, but I began to notice the slew speed dropping a bit during the dew heaters on cycle so I connected a 7 Ampere-hour pack in parallel with the first (to avoid powering down and realigning) and went on for the rest of the night. As before, I had the consistent impression that the RCX was delivering tighter star images than the various SCTs that have been a part of my arsenal in the past. Other observers with SCT experience agreed. Deep sky objects observed included galaxies, open clusters, globulars, and diffuse nebulae. All looked great in the RCX with the 32mm UWA. The only other EP I used for deep sky that night was my trusty 14mm UWA. The other object chosen was the Moon. Remembering how great the seeing had been the previous day, I grabbed the S-W 5-8mm Zoom eyepiece and cranked it all the way down to 5mm (nearly 500X) and the seeing (as well as the telescope) would have permitted more! Cruising the terminator was terrific. This was the first time I was reminded of a minor error someone made when loading the Jeep. Since I went alone, it MIGHT have been me. I had forgotten to load the head of that wonderful tripod! I had brought along an LX10 tripod to lend a fellow observer but was forced to rescind my offer so I could use it on the RCX. Being MUCH lighter than the correct tripod, it got a little shaky at 500X. Thanks are due to Cloudy Nights member Scott Horstman for permitting me to use his tripod and thus lose out on setting up the telescope he had planned to use with it. By the way - this session was an excellent test for the internal dew heater. It was the dewiest night I can remember; early on, everything was dripping except the RCX corrector. Those who werent running heat, despite smaller apertures, were either out of business or reaching for the hair dryers. I parked the telescope and shut down for a nap around 2:00 and when I came back the RCX had dewed up despite being pointed downward; I should have capped it. I guess thats one disadvantage of the integral dew heater; no way to keep it idling while the scope is powered down. The telescope otherwise recovered perfectly from park mode, with the great goto accuracy continuing without a sputter.
At the third session I was set up next to a UHTC-equipped, well-collimated 12" LX200GPS. After several hours to ensure proper cooldown (the air temperature was fairly stable) a number of A-B comparisons were made by myself and others, using a 31mm Nagler T5 in the SCT and a 26mm Nagler T5 in the RCX. This gave us very similar magnifications and fields of view with the same eyepiece design so any
differences in the views can be considered to be due to the designs of the telescopes. The SCT owner and I spent quite a while going back and forth between the telescopes with both aimed at various objects. The difference was subtle, but we both agreed the RCX was presenting tighter star images. The clincher was a tiny star grouping within NGC884 which definitely showed slightly better separation in the RCX. The SCT owner isnt ready to scrap his LX200GPS; as I said, the difference is subtle - but it puts to rest any concerns about the RCX design being inferior to the Meade SCT for visual use.

CONCLUSIONS

So - would I buy an RCX400? If I were shopping for a new forkmounted telescope, I well might. The 12" model reviewed here sells for $6900. Thats a big step up from existing popular forkmounted catadioptrics under 16" in aperture. The corresponding 12" LX200GPS sells for about $4100. For the price difference you receive the RCX optical system, the internal USB hub and dew heater, an optical tube that parks between the forks, a MONSTER tripod, a very cool 24mm UWA eyepiece, and the ability to collimate easily while looking into an eyepiece or at a video monitor screen. I found the package to be very convenient as an imaging platform, also. The USB hub got rid of the usual tangle of USB cables and things just seemed to be easier for me to do than with the SCTs that have been in my observatory. For the record, this pier has previously been occupied by a CGE1100, a 14" LX200GPS, a 10" LX200GPS, and a 12" LX200 Classic.

COOL LESS COOL

I. II. III. IV. V. VI.
great tripod nice eyepiece
12" version weighs 91 pounds relatively pricy
XI. tight star images USB hub for cameras internal dew heater extremely fine focuser
VII. remote collimation VIII. great LX200 series performance IX. internal fan
I have no commercial affiliation with Meade Instruments Corporation or any of its distributors beyond that of being a contributor to Cloudy Nights. All photographs published in this article are my property and permission is hereby granted to Cloudy Nights for their use in conjunction with this article.

John Crilly 9/15/05