Sunday, June 06, 2004

Get your exact latitude and longitude quickly and easily

There is no easier way to get your exact lat/long than this web site:

Type in the street address of where you plan to observe, and press SEARCH. Done. No popups, no banner ads - it just works.

Sunday, May 30, 2004

The Good Points

Putting aside the issues already discussed, there are some really good points about the Meade Autostar. The usual complaints on websites have been with the "goto" feature of this scope.

The GOTO part isnt fully automatic. It needs some direction from the user, and that can be summed up as "point me in the right direction". The manual tries to take a very casual approach to this, and it repeatedly states that its important to be generalized, not exacting, when setting up the scope.

Understanding how the GOTO works goes a long way to enjoying this scope. It all comes back to 12th century technology - navigation. It uses the same method of navigating that Columbus used: if you know what time it is, and you know what you're looking at, you can determine where you are.

Say you're standing on a ship, somewhere at sea. You look at your watch, and its 10:34pm. You look up, and note that its 42 degrees to the north star. Thats your latitude. Now, look up and you note that the star Arcturus is just setting on the horizon.

Take these three ovservations, and consult the Ephemeris - which is a printed book listing the rising/setting of a given star for each day of the year, and for each latitude. Its all you needed to know exactly where you are (within about 70 miles). Not bad for a book.

The pages of the book are the results of some poor slob's life work to work out all the trigonometery for all the equations for all the locations. And were very expensive. Worse, they were made of paper, and would be used on a ship, where the dampness would wage war on the paper. The books didnt last long. It was a good business to be in.

Back to the telescope: Your scope will ask for the Time and Date, and to be pointed Northerly, with the scope being level. The scope beeps and asks that you center a particular star in the eyepeice. The scope will whine and wiggle itself to the general area. With a low power eyepeice (40mm), you should be able to see the star. Spend some time in centering it. Now you will be asked to center another star. Again take some time on your adjusting, the Autostar unit is tracking your corrections, and back corrects errors on the other parameters.

Now, you should be able to reliably go from one star to another and get the new star to show up in the lowest power eyepeice. Some centering and adjusting will be necessary, but, you are now set.

I am simply amazed at Meades software. They have some very clever programmers! I found that the Meade scope will work reasonably well if the time is correct to 1 or 2 minutes, the location selected is within 20 miles of where you actually use the scope, the mount is really pointed at north, and the scope starts off level.

Sunday, May 23, 2004

Meade DS2130 - More about problems - UP/DOWN Motion Does Not Work

I went to try out my new Autostar "base" unit (the motorized arm for the telescope). After a few minutes of use, the up/down action stops working reliabily. It goes up, but wont come down, yet I hear the motors whinning.

According to the manual, when this happens, the user should "first check to see they've tightened the up/down lock sufficiently"
"Check...did that..."
"secondly, the user should check to see if these batteries are fresh"
"Running off my car's ciggarette lighter - there's enough power"
"...if you are unable to remedy the problem, please contact Meade customer support...."

It was the same problem I had with the first unit. I saw this mentioned once or twice on another web site, so I determined to figure out why it wasnt working.

Details on repairing the unit here.

I opened the case up, easy enough to do, see pictures below, and saw that the retaining pin slipped out of its groove on the axel - causing the clutch plate to flop around and not drive the gears. SUCKS - and it was supremely easy to fix - pop the retainer back in its groove. While I was in there, I sprayed some WD40 on all the gears, and was impressed at how Meade made the scope operate - using cheapy RadioControl Car type DC motors.

The process took about 20 minutes with no complications or suprises, and it works fine again. until next time it pops out... Next time I will try to use the hog-nosed-retaining rings.

Saturday, May 22, 2004

Meade DS-2130 Telescope - Garbage ?

I bought one, $200 bucks on eBay. I bought it for two reasons: the first reason is that the scope has the computer based "GoTo" feature. (Goto means 'choose a star from a list, press a button, and the scope will do the rest'). The second is that the scope will automatically track and stay with, a star for hours.

There are many websites that critique this model, and the general consensus has been that it's not worth the money. The critiques focus on the telescope's "GoTo" feature, often stating that the GoTo feature is inaccurate. Of course, I hadn't checked the web reviews BEFORE buying the scope. (If your going to look for reviews on a product, the LAST place to look is any company that sells the product - every camera/telescope shop that sells this product gives it rave reviews).

The scope arrived in a large box, and it was partly assembled. I'm competent enough with assembly, but, thought that my assembly skills would lead to half the problems. I was pleasantly suprised as there really isnt any assembly. The "peices" are logical peices - tube, stand, and base. The Meade people spent alot of time and clever thought making the peices idiot proof. The scope is designed to be quickly dis-assembled, brought to the middle of nowhere and re-assembeled WITHOUT TOOLS, and without the need for light. Good job.

But, some components are cheapy, and do not meet the price and reputation of Meade. When plastic is used, its thin, and feels brittle. The focuser is well machined but the eyepeice holder is cheezy plastic. The eyepeice holder doesnt thread onto the focuser very well - the threads on the metal eyepeice tube are rough.

The finder-scope is garbage. I should say that the holder for the finder-scope is garbage. Its plastic, with plastic screws, and uses a terrible method of setting up the finder scope - three screws that all have to be loosened/tighthed in sync to adjust the scope. Yuck. I found a site that details how to make an easily adjustable holder out of PVC pipe - more on this in a later posting. I made the PVC holder and it works excellently.

The batter holder is garbage. It uses eight 1.5v batteries (total of 12v), but has a 9v connector. The eight batteries will probably give a few hours of usefulness, but, not much more. The 9v connector would lead you to think a 9v battery could be used (it wont last 2 minutes though). It would have been better to have a non-standard connector with a cord that allowed a user to plug into a cigarrette lighter (since cars are 12v). After two attempts with batteries dying on me, I made a connector that I can plug into my cigarette lighter (10 foot cord - gives me lots of room). More on this connector in a later post.

The base unit was a problem. When I turned on the unit and tried to position the scope around, the motors would spin, but the scope didnt move. I read on the web that this is a problem, and needs to be returned for service. Great! This really really annoyed me! The eBay seller (William Vorce) was excellent - he exchanged the base reasonably quickly, and the new base has been excellent.

The telescope comes with a 2" focuser tube - nice and big, big enough that I should be able to slide my digital camera into it (a later post..) but the factory ships the scope with .965" diameter eyepeices. These are the older style low quality eyepeices. I have another scope that uses 1.25" eyepeices, and the quality of those eyepeices is SO MUCH BETTER. The quality is SO better that you will not even want to use the .965 ones. I made my own adapter plate so that the 1.25" eyepeices could be used in the scope. If you look in "astronomy" magazines, the 1.25" eyepeices run for $75 and up, but, I bought several on eBay for $20 each. And they have been excellent.

The tube had some small dents in it. Nothing that would make a difference, and it probably occured during shipping, but, it was dissapointing anyway. There was a handful of loose crud inside the tube - you could hear it when lifiting the tube. I turned the scope upside down and the loose crud turned out to be bits of glass. Glass. From the main mirror. Brand new - and chipped. The chips were from the outside edges of the mirror - nothing that affects usage. I suspect that my scope got bounced around by the gorillas at UPS when it came from the eBay seller.

The stand is overall OK, the way the base locks into the stand was cleverly done. The small support struts that attach to the legs are held in place by small metal pins (tubes really). These pins slide fall out after a few open/closings of the stand. They should have been nuts & bolts. So I replaced the cheezy pins with nuts and bolts.

The next post will review the good points of the scope, but the summary of the bad points: Cheezy construction. A few more bucks spent on construction would make a big difference, especially in the points I made.

Friday, May 21, 2004

Telescopes - Now that you found it, what about it?

A few years ago, I bought a telescope. I thought it would be great fun to see the stars, planets and all that stuff, but, after a few nights of looking at the moon, and unable to see anything else, it was sent to the closet.

Then it went to the basement. And stayed there. A few weeks ago I came across it, and I've been playing with it since. I like to tinker around and see if I can improve the scope, the results will be posted here.