Last updated: 13 November 2006
Subject: Observations and ideas about ETX105PE Sent: Sunday, November 12, 2006 03:38:22 From: henrik.van.holthoon (email@example.com) 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 France firstname.lastname@example.org The following equipment is used ETX105 PE/ ETX70AT 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 construction. 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. Focusser 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 market. 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. Backlash; 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 consequence. 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. General; 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. Henrik
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