Last updated: 16 January 2003
Subject:	ETX 90RA with Telrad
Sent:	Wednesday, January 15, 2003 17:18:52
From: (David Buckley)
I m generally a big aperture guy.  I own a 13" light bucket that I use
for finding faint fuzzies from my back deck.   I also teach astronomy
and physics at a small public university in the northeast, so I get to
play with quite a variety of telescopes in my work.  In our department
we have scopes that range from a classic 3.5 Questar to a new 16 LX200. 
So from experience I know that for resolution, size matters.

Still, when looking at the Moon and planets from home at high power, its
nice to have tracking  something my big low-tech Dobsonian lacks. So I
was looking for a nice little grab-n-go telescope primarily for lunar
and planetary viewing from my back patio or deck.  So just before the
holidays I found an ad for an ETX 90 RA with deluxe tripod for only $300
and decided to treat myself.  Your website was very helpful in making
this decision  thanks!

Anyway the telescope arrived in 3 days from Apogee and
uncharacteristically, it was clear that night so I was able to use the
telescope to observe the Moon and Saturn right away.  I was very
impressed by the optical quality and the sharp, crisp views.  I even did
a side by side comparison with our departments classic Questar.  The
little ETX fared surprisingly well.  In a nutshell, at similar
magnification, the Questar had slightly better resolution, but the ETX
had better contrast.  In high-power lunar views, the Questar would show
a few more craterlets, but the shadows and sky were darker in the ETX
and more washed out in the Questar.  Now, does that mean I got a
telescope as good as a Questar for basically a hundred bucks?  Heck no.
Mechanically, the Questar has it all over the ETX.  The ETX RA is very
quirky.  All the things I was warned about on your website were true.
The finder scope is ridiculous, the RA slow motion control and lock are
very hard to get at unless you have the fingers of a surgeon, the
objects drift a good way across your FOV before the clock drive kicks
in, and you cant use the RA slow motion control when the RA drive is
engaged!  Yikes!  Lousy telescope huh?  Nope I love this little scope
and have used it almost every clear night since I got it!  If I had paid
the original 1996 price of $600, sans tripod, I might not be so
forgiving, but $300 for the whole package?  How can I not be ecstatic?
(I may just buy another one.)  The quirks are just a challenge to
overcome, which brings me to the next topic.

Probably the most annoying quirk of the RA is the inability to use the
RA slow motion knob when the clock drive is engaged and one is observing
the Moon at high power.  I like to be able to scan the lunar surface
east  west as well as north  south.  My solution to this is that when I
plan on doing lunar viewing, I usually use the tabletop tripod legs and
a sturdy backyard picnic table instead of the tripod.  When I want to
scan lunar surface east  west I just nudge the legs manually one way or
the other slightly and use the Dec slow motion controls to scan north
south.  My polar alignment is only approximate anyway, so the tracking
doesnt really suffer and I dont have to bother with unlocking the RA
lock.  It makes lunar viewing at high power trouble free.  And Im very
impressed with the lunar views I get at 208x using a Vixen LV 6mm
eyepiece.  Optically, this is a nice little scope.

As everyone who has an ETX that comes with the straight-through finder
knows the thing is almost un-useable.  Even though I generally only use
my ETX - RA for lunar & planetary viewing, its hard to use the finder to
point at anything, even really bright objects.  I always have to take my
glasses off to get my eye close enough to the finder and I usually have
to remove the telescopes eyepiece to keep my forehead from bumping into
it.  I wanted to attach a red-dot finder to the ETX but the lack of
mounting screws made that problematic.  Then I remembered the extra base
I purchased when I bought a Telrad for my Dob.  Still, I hated to stick
an unsightly telrad base onto such a cute little telescope (I like to
keep the ETX on my desk at home).  Besides, to keep ones head from
bumping into the telrad while viewing you have to have about a third of
its length hanging over the end of tube.  So I fashioned a couple of
straps out of Velcro   and stuck the two straps to the base so that I
can easily strap it onto the ETX optical tube.  I strap it on about a
third of the way up the tube and slightly to the right of center.  Let
me tell you, once you get the telrad aligned, finding even bright deep
sky objects is a breeze.  The Orion nebula, M35 and even M36 were pretty
darn nice in that little scope.   I can now jump from the Moon to Saturn
to Jupiter and back again in a flash and with no neck cramps.  And I can
still keep my little ETX on my desk when I bring it in and put the big
ugly (but incredibly useful) Telrad back on my big Dob where it belongs!

Anyway, I hope this helps other ETX-ers out there.  If the old saying
that the best telescope is the one that you use the most is true, then
the ETX  RA is one terrific little scope for me.


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