Uncle Rod's Astro Blog

“Wait just one cotton-picking minute, Unk. I know you and Miss Dorothy have been married for dang near twenty years.” Right you are Skeezix. My honeymoon with my lovely bride is not the subject this morning. What I am talking about is what I recounted in this post many a moon back, muchachos. A honeymoon is, among other things, traditionally “a period of adjustment,” and I dern sure went through that with my ETX125, Charity Hope Valentine.

I see the blank and puzzled expression on your mug, Johnny B. Novice. And that makes me feel a little sad. I still have a hard time believing the legendary and beloved ETX is no more, and that some newbies have never even heard of it. OK, OK, I’ll tell you what an ETX was; it was the Maksutov Cassegrain telescope (MCT) that made Maks popular and affordable for us proles in amateur astronomy.

Not that MCTs hadn’t been sold to amateurs for at least 40 years before the coming of the Meade ETX; there’d been the legendary Questars and Quantums and others. The amateurs who owned ‘em liked ‘em. They packed long focal length (usually their focal ratios came in at around f/15) into short tubes and had a reputation for high optical quality. That quality came at a price, however, and before the ETX few of us could afford the Mak species of quality.

The mid 1990s changed everything. Not only was Meade selling a 7-inch Mak in LX200 Classic garb, there was a flood of Russian MCTs from Intes, Intes Micro, Lomo and others. The prices were not quite as low as what you’d pay for a Schmidt Cassegrain of similar aperture, but they were far cheaper than what we’d been accustomed to. Quite a few amateur astronomers began to find out they’d been right—and wrong—about Maks.

“I don’t get it, Unk. How is an MCT different from an SCT? They look the same.” And they are similar at heart. The two major differences are the scopes' main mirrors’ speeds—their f-ratios—and the designs of the corrector plates. The primary in an MCT is almost invariably slower than an SCT primary. Instead of f/2 or thereabouts, most Maks come in at f/3 or higher. That results in longer tubes, but also flatter fields.

If you ain’t sure whether you are looking at an MCT or an SCT, take a gander at the front of the tube. An SCT uses a thin-lens corrector with a complex curve. It looks like a flat piece of winder glass. An MCT’s corrector couldn’t be more different. It is thick and it is deep. It is, in fact, sometimes called a “salad bowl corrector.” Its advantage? It is easier to make well than an SCT’s lens and can potentially do a better job than an SCT’s corrector at removing—correcting for—the primary mirror’s spherical aberration. Like SCTs, MCTs use primaries that are spheres (or close to it), and the corrector is essential.

Disadvantages of the design? There are some, but probably not the ones you think. The biggest problem is making the thick corrector requires a right expensive piece of glass. That’s not fatal at smaller apertures, but as you get over 6 – 7-inches, it causes the price of an MCT to skyrocket.

Otherwise? I know what you’ve been told, “The thick corrector makes Maks impossible to cool down. They never achieve thermal equilibrium and, so, never live up to their potential.” I used to think that till I was schooled by a maestro, Roland Christen. Seems as it is not the corrector, but the overall design of the tube that makes some MCTs hard to cool-down. For example, Meade’s 7-inch had a hard time adjusting to outdoor temperatures because of the big, heavy, heat-absorbing weight in the rear cell used to make its long tube balance on an LX200 fork.

“That’s cool and all, Unk, but everybody knows the real problem with MCTs. They are slow, high magnification scopes and are only good on the Solar System, not the deep sky.” Now, that couldn’t be more wrong. Contrary to what some Newbies think, an f/15 scope delivers an image every bit as bright as an f/5 telescope when they are used at the same magnification. You just need a longer focal length eyepiece in a Mak to achieve the same power as the fast scope.

More importantly, I reckon, folks forget most of the objects we look at are actually on the small side. I’ll see your handful of M31s and NGC 7000s and raise you a passel of small and medium sized galaxies, clusters, and nebulae. One of the strengths of the MCT is its potential for delivering high contrast, and that can make it not just usable on the deep sky, but a deep sky powerhouse.

Where was we? Oh, yeah… Meade and the Russkies had brought the Mak to the attention of Joe and Jane amateur, but what pushed the design over the top was Everybody’s Telescope, the ETX90, a cute little Questar “clone,” that hit the streets in ’96. It looked a lot like the telescope, the Questar 3.5, that amateurs of my generation salivated over but could never afford. The Meade ETX90 wasn’t quite as pretty as the Questar. Well, it wasn’t nearly as pretty, honestly, but it damned sure was more affordable at a price of 500 bucks.

While most of us were mightily impressed by the price of Meade’s “Questar” and by the company’s big full-color ads for the little thing, we were also skeptical the company could deliver anything close to the Q3.5 for less than 1/6th the price. Unk was as wary as anybody else, but he sure got fired up when one of his mates bought a 90. Purty soon, we weren't just planning to test the little feller, but to do a shootout between the ETX and another Possum Swamp Astronomical Society member’s Questar 3.5.

That showdown got Unk in a heap of trouble with Questar fans. You see, I told the truth about it. Try as we might, we couldn’t see a lick of difference between the images in the Questar 3.5 and those in the ETX. On any object we tried, they were similarly excellent within the bounds of what’s possible for a 3.5-inch telescope. The mounts were another story. While the Q’s little fork is not perfect, not hardly, it was light-years ahead of Meade’s all-plastic-all-the-time build quality. That observation did not redeem me in the minds of the Questar fanatics, however; I had committed heresy.

Meade did more than just challenge the Questar—for optical prowess, anyway. They started a small revolution. Purty soon, it seemed like everybody owned an ETX, and a cottage industry of aftermarket accessories sprang up to support the scope. There were Yahoogroups and websites aplenty, too, including a legendary one, (Mike) Weasner’s Mighty ETX Site, which went on the air not long after the 90 came out and became the goto place for all things ETX.

Meade was aware they had a hit on their hands and were not slow to capitalize on it. They soon upgraded the original 90, adding goto with the Autostar hand control, which made the LX200’s controller suddenly look old. And… They brought out more ETXes, the ETX105, a 4-inch, and the ETX 125, a five-inch. “And everybody lived happily ever after,” right? Sorta. The ETX was not problem free, with most of the telescope’s difficulties being traceable to all that plastic and to computer bugs. Meade worked hard to get the ETX working right, however, while keeping the price down.

The ETX just rolled on year after year, for well over a decade, till Meade’s fortunes began to decline in the years after the turn of the century. At first, it looked like the ETX would be the winner during Meade’s transition period. ETX production moved to China and, despite a few initial hiccups, the telescope was soon arguably better than it had been in the beginning. The “Chinese” ETX125PE, for example, unlike earlier models, has a metal fork (plastic covered). Also, after years of expanding the Autostar’s features and squashing its bugs, there was little that needed improving there.

Then, last year, even before Meade went belly-up and was bought by the Chinese firm Ningbo Sunny, the hammer fell on my favorite Meade telescopes. The 105 had been gone for a while—it was always the odd man out in the lineup—and that was understandable, I reckon. What wasn’t so understandable was that the still popular 90 and the 125 were discontinued as well. Oh, there were still ETXes, but they were not real ETXes. For a while, Meade classified its new LightSwitch (LS) telescopes as “ETXes,” but they were SCTs, had little in common with the ETX, and soon became a separate product line.

Today, what is left is a beginner-centric pair telescopes, the ETX80 and the (new) ETX90. The ETX80 is an achromatic refractor on a mount like the one Meade used for years on its el cheapo refractor-design beginner “ETXes,” the ETX60 and ETX70. The 80s may (or may not) be nice starter scopes, but they have little in common with the ETXes we knew and loved; they are most assuredly not “everybody’s telescope.”

When I heard the ETX90 was going to be kept on, I initially rejoiced. Until I got a look at it in Meade’s magazine ads and read Gary Seronik’s review of the scope in the June 2013 Sky & Telescope. His verdict was that while the mount seemed more or less on a par with the old ETX mounts, albeit with less consistent goto accuracy, the optics were not.

The example he tested had “soft,” undercorrected optics. Poor optics in an ETX was a surprise, since one thing the ETX, and especially the ETX 90, always had going for it was outstanding optical quality. That may not matter, anyway. The days of the last of the ETX tribe may be numbered, too.

It’s not clear in which direction the new owners intend to take Meade, but both of these latter day ETXes are often back-ordered, and much of what Meade was showing at the 2014 NEAF astronomy gear extravaganza consisted of, I understand, small refractors and Newtonian reflectors like the ones its new parent, Ningbo Sunny, sells.

Anyhoo, there’s a distinct feel of things winding down in the ETX Universe, and I can’t help feeling blue about it. The premier ETX Yahoogroup once boasted message traffic of a dozen—or more—posts every fracking day. Now, if you see one post a month it is doing good. That was also the case with the Mighty ETX Site. While, it is still being updated, Mike only does that occasionally. 

Of course, the ETX story is not over for your old Uncle Rod. His ETX125PE, Miss Charity Hope Valentine, is still going strong almost nine years after I carried her over the threshold of Chaos Manor South. I still love her and we are still having fun together. Which is kinda ironic, since I never planned to buy an ETX125…

Set the WABAC Machine for the fall of 2005. Old Unk, not quite so old then, was on the horns of a dadgum dilemma. While I wasn’t as old as I am now, I was every bit as lazy. And the weather that year had been dern near as bad as it’s been this year. I had got to the point where I was reluctant to haul even the C8/CG5 out to the club dark site for just another skunking. I needed a portable rig, but one with some fraking reach in case the sky suddenly improved on them “iffy” nights.

The obvious choice seemed to be Celestron’s NexStar 5, the time-honored C5 on the NexStar goto mount. I knew the NS5 had excellent optics, since a buddy in the Possum Swamp Astronomical Society, my late friend George Byron, had one and I’d tested it extensively. Another plus was that I already knew how to work the NexStar hand control. A NexStar 5 it would be, then. Or so I thought. When I tried to buy one, I found out the C5 was on one of its periodic hiatuses from Celestron’s product line.

Hokay. What was similar? There was the ETX125. I looked a little askance at the scope’s build quality thanks to the one example of the “big” ETX I’d tested. However, those in the know informed me the scope had been improved to the tune of, as mentioned earlier, a metal fork. Further, the just-released incarnation of the ETX, the “PE,” had kicked things up another notch or two with plenty of new features.

There didn't seem to be an alternative that would suit me—a convenient, portable goto rig with an aperture of 5-inches—so I got my courage up and gave my credit card number to Scopetronix, a now-gone but much-liked little Florida dealer.  Scopetronix’s owner, Jordan Blessing, had made a name for himself selling fixes and enhancements to the owners of the ETX and other Meade scopes, and had gone on to become a Meade dealer, the closest one to me.

When the big box bearing my ETX arrived at the Old Manse, I was both excited and a little appalled. A new scope, any new scope, big or small, is exciting. The “appalled” part? That tube. I knew from the advertising pictures that the PE’s tube was tarted-up with a silkscreen deep sky image—kinda like the Moon map trope of the Questar OTA. I didn’t expect it to be quite as gaudy as my ETX125’s pink and red vista of the North America Nebula, though. After a little while, however, I decided I actually liked the 125’s looks OK. Like cats, all telescopes are black in the dark, after all, and the OTA sure gave her personality.

Personality was something my ETX, whom I quickly named “Charity Hope Valentine” after Broadway’s hapless heroine, wasn’t short on. She’s always had her neurotic quirks, that’s for sure. Some nights her goto is great, sometimes not so great (which means I just need to do a procedure Meade calls “drive training). Sometimes she makes such weird noises when slewing that I think she is about to collapse in a heap. But she never has; she always comes through in the end.

What was it like using Charity in the field? Turned out she was just what I needed for those semi-punk nights when I want to get going in a hurry and might have to shut down in a hurry, too. The “PE” in ETX125PE refers to a couple of enhancements that make the scope almost like a GPS without a GPS. Getting her goto aligned is almost identical to aligning my NexStar 11 GPS: quick and easy, that is.

The scope does not have a GPS, but it does have battery-backed memory that holds-in date and time. Unless I move to a substantially different observing location, I don’t have to enter any data into the Autostar; just turn on the scope and mash the Autostar’s “0” key to begin alignment. Charity then levels, finds north, and slews to the first of two alignment stars. I center the stars in her red dot finder (which houses the PE “LNT,” “north and level” circuitry and the battery that keeps the clock running) and I am done. Packing up when the thunder begins to boom and the lightning flashes? I can have Missy off her tripod and in the truck in five minutes or so.

Which brings us to a Saturday night a few weeks back, which wasn’t forecast to be any kind of iffy. The weatherman said “dead clear” and “cool, not cold.” So why was Miss Valentine involved? With the Deep South Regional Star Gaze Spring Scrimmage beginning the following Thursday, I had all my gear for the star party—C8, VX mount, etc., etc.—marshaled in the front parlor, and laid-out just so so I wouldn’t forget anything. I didn’t want to disturb it. Further, if you’ve been reading the Little Old Blog from Possum Swamp attentively, you know me and Miss D. are preparing to move to the suburbs. All the packing and throwing away and other work involved in buying a new home had Unk plumb tuckered. Sweet Charity it would be.

Sure was different from the run I talked about in “Two-and-a-half Years after the Honeymoon.” On that evening, I drove through a thunderstorm on the way to the PSAS dark site. Not this time. The weather was beautiful and obviously intended to stay that way.

I was surprised only two other PSAS stalwarts joined me on such an obviously superior night. Where was everybody else? I have no idea. Must have been a cotton-picking Mountain Monsters marathon on the cable TV. Anyhoo, I was happy to have some company, anyway, and got Miss on her tripod in two shakes.

It wasn’t yet dark when I fired up my little girlfriend. I wanted to check her LNT battery. Mashed the Mode button and had a look at date and time. Spot on. Which was surprising, since it had been over a year since I’d last used her, since the evening after Unk’s Awful Tooth adventure in February of 2013. The button cell that powers the LNT generally lasts no more than 6 – 8 months, but this one was still OK more than a year later. Maybe because the last time I replaced it I used a Duracell instead of a no-name battery from Big Lots.

I figgered I should train the drives while I waited for darkness. Charity’s goto would probably have been OK without out doing that, but I had time, so why not? I focused on a telephone pole a couple of hundred meters away, started the procedure, and re-centered the pole in azimuth and altitude after the Autostar slewed off it.

I don’t know if it was the drive training or if Charity was just awful hungry for starlight, but this was one of those times when my girl could do no wrong. She performed her little alignment dance like a trouper and headed for Sirius, which was close to the red dot when she stopped. I centered it, centered Capella, the second alignment star she chose, and we were off to the races. From then on, every single object I asked for was somewhere in the field of a 20mm eyepiece (about 100x). From horizon to horizon.

After a quick look at Jupiter, which was nice at 200x despite somewhat punk seeing, Charity and I started a four hour deep sky tour. What did we look at? I thought it would be fun to revisit some of the objects from the Two-and-a-half Years blog, the ones that weren’t too low in April—the observing for the old article was done in May.

M42 was getting awful low, and I figured this would be my last view of the marvel for this season. Looked good, mighty good. It always does in any scope, but Charity seems to sometimes pull out more than her share of dark lane detail.

M13:  Six years ago, I opined the Great Glob wasn’t much different in Charity than it is in a C8, and I felt the same on this night. Good amount of resolution around the edges and a grainy core despite the cluster still being way down in the Possum Swamp light dome.

M5 looked terrific, even better than it had in 2006. I’m always been surprised by how well Charity does with globs. I’d previously have thought you’d need at least a 6-inch to get the kind of resolution the ETX delivers. Her sharp optics bring back hordes of itty-bitty stars.

M82. I didn’t see the supernova, which is down to magnitude 14+ judging by the view I had of it in my friend Taras’ 15-inch Dob, but I did see plenty of detail in the galaxy. At 150x, the criss-crossing dark lanes were amazing.

M3 and M53, the spring globulars, were both nice. M3, in particular, gave up a bunch of stars despite being just outside the light polluted region in the east. It’s no competition for M13 or M5, of course, but is still nice. M53 was OK, showing a few stars here and there, but it really needs more aperture.

M67, the aged open cluster in Cancer is one of my faves. It’s reasonably rich and has some character, being composed of rather subdued yellowish stars. Charity showed plenty of ‘em, since, unlike in ‘06, I remembered to catch it before it got too low in the west.

M65 and M66 were subdued on the Two-and-a-half Years run. Not tonight. Not only were they bright in the 20mm eyepiece (an Orion Expanse) as they culminated, they showed plenty of detail and were easy to distinguish from each other. I even got a look at dimmer and larger NGC 3628, the third member of the Leo Trio.

M105 and company. I love this little galaxy group in Leo’s “belly” area. The ETX usually shows two of the three, but this time I was able to pick out all three members. Quite a catch for an humble five-inch.

Omega Centauri was probably the biggest surprise. It was just above the treetops, but actually began to resolve in the ETX despite a sky background that was bright gray.

M104, The Sombrero Galaxy is another favorite of mine, and Missy did right well. The galaxy is always smaller than I remember it being and a little tougher detail-wise than you’d think a bright Messier would be. Charity showed the dust lane nevertheless. Barely.

M87, the monster elliptical in Virgo, Virgo A, wasn’t just visible as a bright, round spot; it had company. Nearby NGC 4476 was easy and NGC 4478 peeped in occasionally.

The Ghost of Jupiter, NGC 3242, was one of the hits of the evening; it was big, bold, and slightly bluish in the eyepiece, floating in a rich field of southern stars. It even showed hints of internal detail at high power. Wished I’d brought along a cotton picking OIII filter.

The above weren’t all Charity and I essayed. The sky held in, and my girl was champing at the bit, picking off deep sky marvels like a kid gobbling penny candy. Centaurus A, the disturbed galaxy near Omega Centauri, was amazingly bright. The Eskimo Nebula over in Gemini showed some detail at 300X when the seeing cooperated. M97, the Owl Nebula, was easy, and I almost imagined I could see the eyes.

Finally, though, after we’d passed the “forty objects” number or thereabouts, the night began to grow old, Unk’s bones began to grow cold, and the heavy dew got me to thinking about Chaos Manor South’s warm den. A good look at Mars, who, at 300x, showed a tiny polar cap, plenty of dark detail, and a limb brightening, and I was done. Time to get Charity back in her case (a nice aluminum job I got from OPT). She was packed and in the 4Runner in less than five minutes.

Setting in front of the cable TV, sipping a warming draught of the Yell, I ruminated. Sweet Charity had done spectacularly well, muchachos. So good I almost wanted to promise myself I’d use her more frequently. Experience, however, says that will not happen. I usually want more telescopic horsepower. There will always be Charity Hope Valentine nights, though—and they will likely increase in number as Unk becomes ever more decrepit—and on those evenings I will have my sweet little ETX to turn to.

Next Time: The NEW Chaos Manor South...