I received an email from Joao in Mexico, who has just purchased an XT10i, and had a question for me about the Intelliscope unit supplied with his new XT10i telescope. He was confused because the Intelliscope altitude encoder board supplied seemed to be too large when he came to install it on the side panel. The board was larger than the pre-drilled mounting holes allowed for. I suggested this sounded like it might be that the wrong Intelliscope unit had been provided, and when Joao discussed the problem with his supplier, it transpired this was exactly what had happened. They had supplied the Intelliscope unit intended for the XX14i, instead of for the XT10i. Thankfully they are sending him the correct unit.
Much of my astronomy recently has been focused on my Celestron C6-SGT Goto scope on an EQ mount, mainly due to my interest in astrophotography with a modified webcam. Anyway, prompted partly by Joao’s question I decided it was high time I got my XT10i out again and enjoyed some nice bright views of the night sky with the XT’s larger aperture. English weather has at last abated and given some nice clear nights, so last night I took the XT10i out for a long overdue spin.
On the previous weekend I also did some spring cleaning of the XT10i to make it ready for good viewing; I re-glued some of the black “flocking” material down on the inside of the tube which had lifted (some Araldite did the trick), secondly its a good 2 years since I last cleaned the primary so I removed the mirror and washed it very carefully and gently using plenty of warm running water, soap+alcohol mix, cotton swabs and Q-tips, finally rinsing with distilled/de-ionised water, and third after re-assembling I checked and re-collimated both the primary and secondary mirrors. I also replaced the batteries in the Intelliscope computer, and the motorised Crayford focuser.
With the XT10i setup on my patio, I first did some manual alignment and viewing in the dwindling evening dusk of Venus’ bright disc, followed by some close-up observation of the half-Moon for half an hour or so until the sky was getting quite dark.
The new battery in the motorised focuser made quite a difference to the speed of adjustment, the old one was quite well run down.
Next I wanted to use the “Tour” feature of the Intelliscope to show me some of the highlights at this time of year. But after aligning, I couldn’t figure out why each tour object the Intelliscope was guiding me to was not showing the expected star, galaxy or cluster. The Intelliscope seemed to be pointing me to the wrong area of sky. Anyway, I put it down to something like the Azimuth encoder and base tightening bolt might have come loose, and rather than waste valuable viewing time, I thought it would be a nice challenge to hunt out some interesting stellar targets from my own memory and knowledge of the sky, and would sort out what is wrong with the encoders in the light of day.
So I enjoyed perusing Saturn and its moons, the Leo triplet of galaxies, followed by M101 and the Whirlpool galaxy in Ursa Major, and M81 Bodes nebula, and its close neighbour M82, and then M36, M37 and M38 in Auriga, and some general scouting around Cassiopeia and the Double Cluster. These are all favourites and fairly easily located by eye, with a little help from my iPod Touch and the astronomy apps that I use.
Next day I discovered the simple mistake I had made with the Intelliscope when I had attempted the alignment. As a result of replacing the battery, the unit had gone back to factory default setting of performing its “ALIGN DEC MARK” when powered on, which I had mistakenly used instead of the “POINT VERTICAL” option (I should have used the up/down arrows to select the correct initial mode).
The Point Vertical is intended for Dobsonians when you simply position the OTA in its vertical position against the backstop knob. However the Intelliscope system is also designed to work with other types of Newtonian telescopes on EQ mounts (e.g. SVP Intelliscope), when you create a mark on the Declination axis, which you position the scope to initially before the 2-star alignment. The result of using the incorrect mode is that you end up being pointed to the wrong part of the sky when searching for stellar objects to view!
Another lesson learned, and hopefully I’ll have better luck with the Tour feature next time out.