Mods to Celestar 8

[louie_the_fly]

Well it's happened. I've started looking at a few mods on my Celestar 8 that I recently bought. The stock finderscope is a bit small (6 x 30 I think) so I will replace it soon. Deciding if I should I go for a Telrad, red dot finder, or a higher powered version of the original type. Opinions? If I fit a telrad or red dot should I remove the stock finder or leave it there?

Does anyone know what size plug the 12V DC adapter is, and is it +outer or +inner?

:thumbsup:

[Poita]

I'd keep the stock finder, and definitely go the telrad. I've tried just about everything, but the Telrad is what I kept.

[mental4astro]

No arguement should go unchallenged, Peter! :D

I actually prefer the red dot finder. I find the co-centric circles of the Telrad distracting and gives too much glare/interference with where I'm wanting to aim the scope. One single dot, dim, and straight to the point - pun intended, ;).

Stewart, I don't see a problem with removing the existing finder if you find it problematic. I have a C8 too, and changed its finder for a straight-through 50mm. But, depending on my mood, I can swap it for an rdf, which is what I mainly use. The 50mm stays in its case most of the time, :rolleyes: . But it has its place, like when chasing Neptune or Uranus.

An rdf is all you may need at a dark site. Even in urdan areas if you are confident enough (mostly what I use at home). But optical finders are almost madatory in urban areas because of the light pollution killing our capacity to efficiently star hop. It won't hurt to have both in your kit. Andrews sells modest rdf's for around $30 - all that I use rdf wise from my 8" dobbie & C8 to my 17.5" light bucket. But an optical finder is never far away incase I'm struggling with the rdf.

There are charts specifiacally made for using Telrads with. Some folks find these useful. Me, I use charts that suit me, not my finder. See what I mean.

[louie_the_fly]

Thanks for the replies. I had looked at the red dot finders as well. Researching can just confuse the issue even more. I suppose I'll just have to decide between the 3 and try it.

Anyone know anything about the 12V DC plug arrangement?

Cheers

[mikerr]

Stew, this is from a Yahoo site......

"Incidently, my 9VDC adapter has a no
> > load voltage of 11.3 VDC. I also have a 12VDC adapter whose no load
> > voltage is 17.25VDC. I've used both of these without causing any
> > problems. For polarity, connect a plug into the base jack and use a
> > voltmeter to determine which way it is. On the Celestar 8 the tip is
> > positive and the sleeve is negative."

The Bold and Underline are mine.

Site..http://tech.groups.yahoo.com/group/sct-user/message/20974

I am about to remove the 6x30 finderscope and just leave the Telrad on my C8. I haven't used a Red Dot finder.

Michael.

[louie_the_fly]

Thanks Michael. I think I'm going to go for a red dot finder and leave the 6 x 30 on there for now as well.

I looked at the socket inside the control box it seems like it uses a 3.5mm mono plug. Like this. I tried one in and it feels like it engages properly as well. Also, there's no centre pin on the inside of the socket from what I can see.
http://www.jaycar.com.au/products_uploaded/productLarge_2113.jpg

Yet everything I read says it's the one below, 5.5mm, which definitely won't fit.. I can probably change it but I don't want to fiddle around with the PCB if I can avoid it. Help!

http://www.astronomics.com/main/images/imgs6_18_2008/2338nCU.jpg

[louie_the_fly]

Yet another question. And a real novice one at that. Last night I was out looking at Saturn and a few other areas. I reckon I had the scope polar aligned pretty right but the objects drifted out of view fairly quick. I have a suspicion the motor might be turning the wrong direction. If I were standing behind the scope, looking south, which way should the RA drive be turning, CW or CCW?

In the Celestron manual it says about reversing the drive direction for southern hemisphere by holding the up & down buttons, holding them, and turning the power on. The LED is supposed to blink after a couple of seconds indicating that it has changed direction, but nothing seems to happen.

The chap I bought it off said he never had to do this since he bought it (new). Could it have been set up pre sale so it only goes the right way for the SH?

Thanks heaps.