The
assembled "machine" mounted on a tripod. Shown with the 8x50 finder
and EZ finder. The stock ETX finder is still usable, and is attached in
its original position (beneath the 8x50 finder). Also shown in the
picture
are the adjustable tripod wedge and the hand controller for the RA
drive
corrector.
Addition
of a 8x50 right angle finder strapped to the OTA of the ETX plus
an Orion EZ finder. The EZ finder attached via sticky tape while the
8x50
finder sits on two rails made of 1/2" square aluminum bar. The two
rails
are attached to the OTA via sticky tape and two electrical tie wraps. I
can't recommend a good, large aperature finder enough. It makes hunting
for those deep sky object so much more of a pleasure!!! (makes the
stock
8x21mm finder seem like a waste of time)
The
home-made adjustable wedge, shown with the RA drive corrector hand
controller. The design of this wedge is optimized for 40-50 degrees
latitude,
as it places the centre of gravity of the telescope over the centre
column
of the tripod for maximum stablility. It's made mostly of 3" wide by
1/4"
thick aluminum bar. An threaded rod and hand crank allows for easy
adjustment
of the wedge at the viewing site, as well, an Manfrotto quick releas
adapter
allows for attachment of the telescope in seconds. A mohogony ledge at
the back of the wedge holds two eyepieces.
The hand controller will allow you to use either; the original
drive circuit, supplying 1.8V to the motor, or to switch to the new
drive
circuit, where you can vary the voltage to 1.5 volts to 6 volts. With
this
I can fine adjust the tracking speed of objects such as planets, the
moon
or comets. (ex. with the R.A. drive corrector I was able to keep
Jupiter,
at 250X, at the edge of my FOV for over 30mins.) Also, I find, that at
the factory settings, the ETX drive is a little too fast. It's also fun
to play around, as you can move Jupiter around your FOV in the R.A.
axis
at will! A "TURBO" button is also added, to bypass both voltage control
circuits, allowing you to quickly take-up the backlash in about 2
seconds.
It puts about 8.3 volts across the motor. A 9V battery supplies the
power
and is calculated to last about 15 hrs. An additional switch on the ETX
body allows for the use of the original power supply and circuit as a
backup.
Modifications
and conections to the
ETX base printed circuit board.
The
assembled hand controller
shown with the new 9V battery
installed into the base
Electrical
schematic for the drive corrector. BIG DICLAIMER: a few modifications
must be made to the original circuit board. This will definitely VOID
your
warrenty! I CANNOT guarantee that this circuit will work or not burn
out
the ETX drive motor. (There's a reason I went into mechanical
engineering
and not electrical!) This is not for the squeamish. If you don't
understand
why and how this circuit works, don't even attempt these modifications.
I will not take responsibilty for any damage you may do to yourself or
your ETX. I've only put the schematic here at the request of other
ETX'ers
around the world.
Picture of Venus. Small cresent.
Mars, slight whitening at the poles is visible, black "canal" strip
through
the middle.
Jupiter,
with two cloud bands visible. This is better than any picture
that
I've have taken on film with my OM-1 and ETX!
Saturn,
with shadow visible on the back rings.
All photo's taken with the QuickCAM connected with the Meade photo tube onto the back port of the ETX, ie. no eyepiece projection.
Sunspots, hard
to believe each of those spots are larger than the Earth!
Thousand Oaks Polymer Plus filter. (ps. some of those spots are on the
CCD, forgot to clean the darn thing!)
A small
impatient flower bud, about 20 feet away. Taken through my living
room window. Not a bad "macro" lens.
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