Tuesday 15 February 2011

Inadequate User Manuals

Well - my purchase of a new telescope has been the kiss of death for clear skies over the North West of England. However, last evening I managed to get outdoors for a few minutes...

I've been very pleased with the optical performance of the new Skyliner-200P FlexTube AUTO, but very disappointed with the tracking function - I couldn't get it to track at all.

I thought about the geometry involved and what must be going on inside the telescope's control system and realized that it was necessary for the telescope to know where it is pointing in azimuth to have any chance of tracking. I searched around on the internet, eventually finding an owner's manual for a scope from the same manufacturer (SkyWatcher) with a tracking AZ mount (which shares the same controller). That manual said you have to power up the 'scope with the tube facing North, thereby creating a known azimuth reference (my manual mentions NOTHING about that).

I tried that last night - and it still didn't work.

At the same time as realizing that the scope needs to know which way it is facing in AZ to be able to track, I recognized that it also needs to know where it is pointing in EL - but I had assumed that it has absolute angular sensing in EL (the elevation axis is limited in range and has an angle scale marked on the mount)...

After the "pointing North doesn't work" failure last evening, I wondered if the angular sensing in EL also needs a start reference (i.e. if the EL angular encoder is relative) and remembered reading (in the manuals for the other scopes) descriptions of powering up facing North AND with the tube at 0 degrees EL - the "home" position.

I tried that and - hey presto - tracking!

This is awful - there is absolutely no mention of this in the manual. OK - so I can figure it out, but what about all the other poor sods who buy one? Of course, we can pretend that anybody who wants a tracking 200mm telescope enough to buy one would be smart enough to figure out how to operate it despite the handicaps that "User Manuals" represent. The cynic (not to mention the realist) in me doubts that is true.

The fact is the manual is a disastrous "cut-and-paste" of segments from manuals for other products which, together, does not add up to a complete statement of how this device ought to work. Caveat emptor.

gotten that off my chest, I must say how very pleased I've been with the limited observations we've made so far. Obviously, looking at the moon is child's play - here's the result of my first experiment with the webcam adapter I got from my cousin at Sky's the Limit and a throw-away webcam...

The image was taken before I figured the tracking issue (above) and before I learned how to drive RegiStax, so I hope to do better in future!

Also, views of Jupiter have been stunning (until it sinks under my neighbour's garage) and the Great Nebula in Orion, m42, has been amazing too (once I got my bearings by figuring out I was splitting wide open the trapezium, theta-1 Orionis, even at lowest magnification). Now I'm waiting for Saturn to get its act together and appear higher in the sky at a decent hour (later this month / early next).

Why - I might even be able to track it!

...-.- de m0xpd

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