Observation Session: Saturday, 02 Oct 2004

[Airconvent]

More Pics

[coolcat]

Actually the height was a mistake. We extended the tripod legs fully and realised it was too high after all the stuffs, mount, counterweight, scope etc were fixed on. By then it was kind of tough to readjust the height. So we left it as it was.

I saw Saturn thru Clemen's and Weixing's scopes. Very nice indeed! By the time mine was slewed to Saturn, the clouds came in. So I couldn't take any pic.

Looking forward to the next obs!

[VinSnr]

When we successfully aligned the autostar after several attempts, the goto did not put any object in its FOV (20mm eyepiece). Elton concluded that unlike the forkmounted ETX/LX90, this scope needed to be polar aligned to North and since we did not have a compass, that was not possible.

Do it the same way like the fork mounted scopes. First align all those arrow stickers on the RA and DEC axis. (It took me a long time to get them align..so use them). Then point the scope to North. Elevate the mount head a little, since we are about 1 degrees and not totally 0 degrees at the equator.

After this, do it the express way. Forget about alignment. Just GOTO a star you know. The scope will be out. Use arrow key and your finder to get that star. Once you got it in your eyepiece, press and HOLD enter for 2 seconds. Autostar will ask you to synch. Synch it. Then GOTO another star you know, preferably far from the first star. Once you get it, press and HOLD enter again. Then synch it. The more you synch, the more accurate GOTO becomes.

If you want to do alignment first, it is also possible, but sometimes the stars you know may not be in the alignment star list.

[carlogambino]

I realised what was wrong, cos I didnt approach the alignment stars in certain direction to prevent backlash, so accuracy suffered.

[weixing]

Hi,

Elevate the mount head a little, since we are about 1 degrees and not totally 0 degrees at the equator.

I was wondering how to do that in the LXD55 yesterday when trying to figure out how the LXD55 work?? The altitude was below 0 degree on the mount marking. We try to rise the altitude, but it seem that you need to adjust both altitude adjustment which one of them is block by the RA motor. So how do you do the adjustment??

Have a nice day.

[VinSnr]

Hi,

Elevate the mount head a little, since we are about 1 degrees and not totally 0 degrees at the equator.

I was wondering how to do that in the LXD55 yesterday when trying to figure out how the LXD55 work?? The altitude was below 0 degree on the mount marking. We try to rise the altitude, but it seem that you need to adjust both altitude adjustment which one of them is block by the RA motor. So how do you do the adjustment??

Have a nice day.

that two bolt act a bit like a push pull. The bolt nearer to the RA motor is actually quite irrelevant for our latitude, but it acts as a stopper in case someone overtilt the mount especially for those who are at higher latitude (and for higher latitude, the bolt will clear the RA motor).

So this is what you do. Totally unscrew the bolt that is away from the RA motor. Then lift the mount up until the RA motor clears the nearer bolt. Remove this bolt. Then slowly screw back the other bolt until you get the right elevation.

However, although that bolt looked like being obstructed by the RA motor, you can still turn a couple of rounds (tight but possible). Then turn the other bolt in until it "pushes" the mount to the right elevation. This way, you don't have to completely remove any bolts.

[coolcat]

Will try it. Thanks!

[Airconvent]

Do it the same way like the fork mounted scopes. First align all those arrow stickers on the RA and DEC axis. (It took me a long time to get them align..so use them). Then point the scope to North. Elevate the mount head a little, since we are about 1 degrees and not totally 0 degrees at the equator.

After this, do it the express way. Forget about alignment. Just GOTO a star you know. The scope will be out. Use arrow key and your finder to get that star. Once you got it in your eyepiece, press and HOLD enter for 2 seconds. Autostar will ask you to synch. Synch it. Then GOTO another star you know, preferably far from the first star. Once you get it, press and HOLD enter again. Then synch it. The more you synch, the more accurate GOTO becomes.

If you want to do alignment first, it is also possible, but sometimes the stars you know may not be in the alignment star list.

hi vincent,
I know this method is called synchronisation and used to make the goto more accurate but seems you are using it to initially align the scope.
Is this method more accurate than the other method? I'm only afraid that it may become too out of the FOV of the star to do fine adjustment but this really is something new and I'll try it the next opportunity I get...
thanks

rich

[Airconvent]

I realised what was wrong, cos I didnt approach the alignment stars in certain direction to prevent backlash, so accuracy suffered.

ah yes...so you spoke to Samuel? taking into consideration backlash when aligning can improve your goto significantlyas feedback by him.
this is different from Meade's autostar in which you train the autostar once and it remembers the values until you train again...

rich

[VinSnr]

hi vincent,
I know this method is called synchronisation and used to make the goto more accurate but seems you are using it to initially align the scope.
Is this method more accurate than the other method? I'm only afraid that it may become too out of the FOV of the star to do fine adjustment but this really is something new and I'll try it the next opportunity I get...
thanks

rich

I dunno which method is more accurate, but I do know that this method gets you up and running much faster. I use both methods depending on sky condition. If there is cloud cover one or both of the alignment stars...what can you do except to try the synch method?

I think both methods give you the same accuracy.