Me and My ETX-125
I'm in my early 50s and am beginning to have foot, leg and back problems
so, sometime in November, 2003, I decided I'd had enough of the big telescopes.
I'd previously owned an 8" Dob and an 8" Newtonian on an equatorial
mount, and went looking for something smaller and more portable.
By chance, I found a Meade ETX-125ATC (with Autostar and deluxe tripod)
at Walmart for $935 (I still haven't seen this rig offered, even online,
at a lower price). I fell in love with this 'scope right out of the
box, and my delight with it grows almost daily. Naturally, I want to
take care of it so the first accessory I purchased was the hard case for
storage and transport (~$150). Then it was time to get really serious
about adding-on. I found there was really no good place to set the
Autostar controller, so I purchased the Scopetronix accessory tray (~$50),
which fastens to the two unused (if you use the tripod) table-top leg sockets
on the base. Finding it near impossible to focus with the 'scope pointed near zenith,
I also bought the Flexifocus from Scopetronix (~$30?).
[Later:Turns out there's a problem when the accessory tray is used with the Scopetronix Flexifocus. When the telescope is rotated while the tube is pointed above ~45 degrees altitude, the Flexifocus can and will snag between the telescope base and any eyepieces in the tray. This means you'll at least have to recalibrate your motors, and possibly even retrain them. If it's bad enough. a "reset" may be in order. I've now removed the tray and am using velcro on the Autostar.]
Not being rich enough (yet) for the Kendrick dew removers,
I ordered the Meade dew shield ($~17) which screws into the threads for the
lens cap (as others have noted elsewhere, this means you can't put the lens
cap in place while using the shield).
25 mm and 9 mm eyepieces
came with the 'scope, giving me magnifications of 78x and 211x, respectively;
since the maximum practical magnification for this 'scope is 250x, I'm still
mulling the need for a 2x Barlow. Meanwhile, I found a Meade Super
Plossl 40 mm eyepiece (used, for $60), which gives me ~48x, and I find the
sharper, wider views can be more satisfying than a fuzzy, faint image at
higher magnification. I already had a set of planetary filters, but
decided to get the Lumicon UHC filter (~$100) for deep sky (I'm still waiting
for this to arrive). Finally, an adjustable observing chair is absolutely
essential; I've seen this particular style as expensive as $200, but managed
to find mine from an online dealer (I forget where) for ~$75.
The Tune-Up (aka "Supercharge")
The 'scope seemed to work fine out of the box, with some minor niggles,
but I was surfing the web
one cloudy evening and ran across Mike Weasner's Mighty ETX site. This
is must-reading for all ETX owners and wannabes. I finally noticed
a link to something called "ETX Tune-up Service," which led me to Clay Sherrod,
the Arkansas Sky Observatory, and Clay's "ETX Supercharge"
service. Rather than my repeating the description, go ahead and follow
the link, then come on back here. Mind you, it's not cheap; the tune-up
itself costs $245, plus shipping ('scope and hard case, at ~40 lbs, ran almost
$80 each way, between Vermont and Arkansas). Is it worth it? Well,
I just happened to have a spare $400 sitting around the house that I had
no plans for, so I thought I'd try it. Here are scans of the two-page
checklist of things that Clay checked out about my 'scope, and the one-page
summary of his findings, repairs and adjustments (Warning: These
are scans of entire pages so, even as jpg files, they're each about 1 MB):
Page 1; Checklist, Page 2. Personally, I'm
very happy with what I got for my money, including the little extras that
Clay threw in; mainly, this took the form of guiding me through the shipping
process (I'm now the proud owner of my very own FedEx account) and all the
metaphoric hand-holding he did while I was seperated from my baby. ;-)
Setting Up for the Evening
With a Dob, there's no need to worry about polar alignment;
with an equatorial mount, polar alignment is pretty important. A Goto (computerized)
however, is virtually useless without polar alignment. Unfortunately, the
instructions supplied by Meade are also pretty useless, especially since the illustrations
have all been flipped and are consequently off by 180 degrees. The first
bit of advice is, forget about setting the tripod and 'scope up in equatorial
mode; I'm told equatorial mode makes tracking more accurate for astrophotography,
but I have no interest in taking pictures (my personal feeling is that the
camera inserts an unnecessary level of effort between you and your hobby,
but that's just me).
Anyway, these photos all show the ETX and tripod in the Home position,
alt-azimuth mode. The 'scope is level and both it and the tripod are pointed
true north. In this next photo, you can see the various things I've done
to make setting up a polar alignment dead easy. I can carry the 'scope out
to the deck and have it polar-aligned in 60 seconds or less, and this system works even in daylight:
First, notice the circular level placed on the base of the 'scope (it's
just placed there, not fastened in any way, and is removed after alignment).
Leveling a computerized scope isn't absolutely essential, but it makes
things easier. Now, notice two white markings near the level: there's
a white strip with a vertical black line and, below that, a small white
arrow; these tell me when the tube is pointing straight ahead. The
strip and the arrow are made from reflecting tape, available at Home Depot.
There's an embossed black arrow in the base that I placed a small
piece of tape over, then trimmed around, but the strip had to be measured
for. The part of the base that the strip is on revolves with the scope,
but the part that the arrow is on doesn't. When black line and white
arrow are lined up, the optical tube is pointing straight ahead. With the
optical tube pointed straight ahead, you can lift the two rear tripod legs
slightly off the ground and rotate the tripod on its front leg until
the tube, and therefore the entire assembly, is pointed true north. This
is where the compass comes in.
Again, the compass is only placed, not fastened, to the optical tube (I
suppose you could fasten it there if you wanted, but why?).
The compass is placed so that its rear edge is flush against the edge
of the primary mirror cell, thus ensuring that it is lined up directly towards
the front of the optical tube. Notice that the needle is not
pointed toward the front of the tube, but is pointing off to the left. That's
because the magnetic variation where I live is 16 degrees to the west, so
I've adjusted the compass accordingly. When the needle points to the
Black "N," the red arrow just above the "N" points to true north.
There's another embossed black arrow just beneath the Declension (Altitude)
setting circle. I again marked this with
white reflective tape. Then, using the bubble level, I made sure
the optical tube was level, loosened the screw on the trunnion and set the
setting circle so the "0" was directly over the arrow (and then retightened
So, to set up for an evening's session, I carry the 'scope and tripod
out on the back deck (I keep it set up next to the door), point the assembly
roughly north, make sure the tripod is level, set the altitude circle at "0,"
line up the azimuth markers, place the compass on top of the tube, rotate
the tripod on its front leg until the tube is pointing due north, remove the
compass, and I'm done.
How accurate is this system? If I pay attention to what I'm doing
when setting up, then raise the tube so the altitude reads 45 degrees (I
live three miles south of the 45th parallel), Polaris is in the field of
view of my 25 mm (78x) eyepiece. As I said above, this even works in full daylight (of course, Polaris won't be available for confirmation until after sunset :-))
I can then return the tube to 0 degrees altitude and I'm ready to do the
star alignment for the computer (which takes an additional 60 seconds). From
the time I pick up the 'scope while inside the house to the time I observe
my first object, the entire procedure takes far less than five minutes.
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