Last updated: 13 November 2006
Subject:	Observations and ideas about ETX105PE
Sent:	Sunday, November 12, 2006 03:38:22
From:	henrik.van.holthoon (
Sorry if the English is not perfect but you have to excuse me it is not
my native language.
Observations and ideas about ETX105PE
Henrik van Holthoon
Lieu dit Born
40170 Mzos
The following equipment is used
Starry Night version 6.01 pro plus
Starry Night Bluestar (Bluetooth PC connection)
Tube design;
I have seen the feedbacks concerning the print on the optical tube
design on your site, I have a 105 with this print and to me it looks not
cheap or unprofessional on the contrary it looks rather nice, well that
my opinion of course.
Smart finder;
In the 105PE specifications Meade states 8 X 25 right angle viewfinder
this is rubbish to my opinion, there is no 8 X magnification and there
is no lens opening only spherical glass where a red dot is projected on
and certainly not at right angle but in line, but apart from this misser
it works quite good after proper aligning with optical tube.

I have experience with the sight of the ETX70 and I can tell you this is
really very bad the finder scope is always out of alignment it is a very
instable construction.
Alignment smart finder;
The handbook for the ETX105PE states find an terrestrial object about
1.5 mile away (2.4 KM  ) this I think is also rubbish try to find a
point without magnification at 2.4 KM away, bloody impossible. The max
distance you can define with the naked eye is I think about 500 meters.
Another thing they state do this during daylight well you have to find a
dark corner to setup the telescope and set the dot intensity at the
highest 14 otherwise it not possible to see the red dot and even then it
is not easy to find the dot. You could use a star after a good pre
alignment and after orientation of the telescope of course otherwise you
have a moving target.

The smartfinder keeps its alignment perfectly, it is a stable
Dew problems;
The smartfinder glass is covered with dew in only 2 minutes this
depending how damp your area is. I made a plastic cover to protect the
glass from dew when it is not in use.

For the ocular I use one part of the plastic ocular container when it is
not in use it fits perfectly.

For the optical tube I found a good solution at least for Europe they
use over here 120 mm PVC sewer line pipes, to connect 2 pipes you need a
joint. It is this joint (only 2.5 ) I have used. It has an internal diam
of 125 mm as the 105 tube diam is 124mm it fits perfectly. I glued a
filth strip inside the joint to keep the dew shield (joint) in place of
course you have to paint it black for this I used blackboard paint.

Maybe there is similar solution for the ETX 90 and 125, I do not know
the external diameters from the 90 and 125.
Another problem is when you want to bring outside a laptop. Laptops are
in general not fond of humid environments my solution for this problem I
bought a plastic tools cupboard in which I can put the laptop. In this
way the laptop is protected and because it is made of plastic no problem
with the Bluetooth connection. I t is also handy to store the components
you need i.e. oculars, filters ,Barlow lens etc.
12 DC power cable;
Getting accessories in Europe is not an easy thing it takes weeks to
months to get the ordered accessories. I therefore decided to adapt a
standard 12 Volt cable (cigar plug) to small 12 DC plug unfortunately
the hole (plus pole) in the small plug is too small for the ETX power
plus pin. This pin is 2.5 mm and the 12 V plugs standard used in Europe
are 2 mm. I enlarged the hole (2.5 mm drill) in the small plug and now
it fits perfectly. One has to check of course if the polarity is
correct, normally it is.

But if it easily available form Meade in the USA by all means use there
standard cable for this.
With my ETX70 experience where i.e. going from one ocular to another you
have to turn forever to get the telescope in focus and it is so slow you
do not know which way to turn anyway I could never remember which way to
turn. With this in mind I ordered a focuser for the ETX105 but I have to
say I ask myself if this is really necessary on the ETX105 (90 and 125
as well) you are so quick in focus that you see right away which way to
turn and you have a sharp image in a split second.
It might be useful if you use the image port for a CCD camera instead of the ocular.
Bluestar ETX/PC connection;
I bought from the Starrynight Company the Bluestar adapter, this unit is
a Bluetooth and serial/USB adapter in one. The Bluestar is connected to
the serial connector on Autostar. If you have a laptop with integrated
Bluetooth adapter, do not confuse with WIFI, you are ready to start
otherwise you have to buy a Bluetooth adapter and there are many on the

I use Starry night 6.01 pro plus, the control of the ETX with this
adapter is perfect as well with the Autostar updater.

The big advantage is there is no cable going from the ETX to the laptop
especially in the dark there is one thing less to stumble over, you can
still be floored by tripping over the tripod of course. Do not use the
AUX port on the ETX90/105/125 very bad idea the problem is that Autostar
serial port has the same connector as the AUX ports this might confuse
some people.
What can you expect of electronic controlled telescope under 1500
dollars, yes indeed backlash, Meade does not use precision counter
spring-loaded metal gears then you have no mechanical backlash but that
is much more expensive. That's why you must centre object during
train-drive in only one direction.

You can of course use the trick as suggested by dr. Clay to move the
telescope faster in short period  by a change direction but the
mechanical backlash stays the same. I put my AZ/RA and Alt/Dec percent
to 15% as he suggested.

It is not really a problem remember our telescopes are not precision
measurement instruments as long as positioning is ok, it is of no
Change power source:
If you change over from internal to external power and visa versa (input
in power plug or internal batteries) it is claiming we should do motor
calibration. I fail to understand why this is necessary, the drive
systems are closed loop systems with encoders in the loop for feedback,
changing the input voltage within limits should not have any affect. It
has not any effect on my ETX105 anyway. I might be wrong but I do not
think so.
Red flashlight;
I found in a French shop a headlight which can also be switched to red
light or white light very practical keep your hands free. If you can not
find this headlight you could buy a white one and paint the front glass
with red transparent paint.
Setting up tripod and telescope;
The handbook advises to put the base plate of the tripod in the polar
position in order to fix the telescope, you have indeed easier access to
the screws but I do not like it, you have to hold the telescope in one
hand. I leave the base plate horizontal and with a red mark on the base
of the telescope you find easily the screws fortunately they are spring
loaded they click in when your are more or less in position, you centre
the telescope on the tripod base plate and you will easily be able to
fix to screws with two fingers.
In general I am very satisfied with the telescope it is easy to operate
with a good optical image. Where I live in France there is no light
pollution at all, so a perfect site to look at the sky objects. When you
want to look up my location I give you the geographical coordinates
1d-7m W longitude and 44d-6m N latitude. If you have Google earths type
in the coordinates and of you go.
Well this ends of my user comments I wish you all a nice stargazing.

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