Retro Fit Go To on a CG11

[Eris (Gerard)]

Hi everyone,
I'm considering doing a retro-fit on my C11 using a Losmandy Gemini Go To system. As I'm currently doing my homework is there anyone out there who can tell me if this system is as good as the hype is suggesting? Is it worth instead considering using digital setting circles and just "push" the scope into place if it's going to do the same job?
Thanks to all who are able to assist on this question.

Regards,
Eris

[gbeal]

I havn't had first hand experience with the Gemini (I use a different goto system), but would lean towards the push to, unless you really want actual goto.
The combination of a set of encoders, and these can either be after market, or the genuine Losmandy, and the spectacular Argo Navis computer is hard to look past.
I am sure you will get some more knowledgeable folk giving advice both ways here,
Gary

[[1ponders] (Paul)]

Having used both Gemini and Argo Navis regularly on a G11 imho they both have their positives and negatives. For a permanent imaging setup my recommendation would be for a Gemini. It will integrate fairly well with most and very well with a few planetarium programs and image capture programs (eg The Sky 6 and MaximDL or CCDSoft etc). This allows much greater flexibility in how you image and the accuracy of your mounts pointing. It will also allow you to automate some of you imaging, creating mosaics, photometry, astrometry etc.

While the AN will integrate with planetarium programs it won't help you automate you image capture, nor will it (as far as I know) integrate with MaximDL, CCDSoft etc. (Though I could be mistaken here)

For a mobile setup I like the ANs flexibility and ease of setup. It's pointing modelling tends to be a lot quicker than the Gemini to setup. Plus it's quiet!!!! And quite often quicker to get to where you want to go .

As far as pointing accuracy both are great, it depends on how well you set up the pointing model each time, but given a choice I'd say out of the box and set up AN would beat Gemini in the field but in the office Gemini offers imaging flexibility.

If you were just looking for visual observations I'd suggest the Argo Navis, if only for the piece and quiet.

[JohnG (John)]

Got to agree with what both Paul and Gary have said.

I have the Gemini fitted to my G-11 which is permanently mounted in an Observatory, there is no need for me to go into the pluses or minuses, Paul has covered that.

I also have an Argo Navis fitted to my field mount which is a Losmandy GM-8, the beauty of which is just plonk and play when set to Rough GEM Align, basically setup, point at the Celestial Equator, align on 2 stars and your away. As said, no noise with the AN but it is Push to, intergrates nicely with Star Atlas Pro, the Gemini, has a little noise, not a lot but I would certainly only use it in the Observatory.

Another thing to consider if your going into the field with either of these systems is the Gemini draws about 2-3 amps when slewing and does require a good power source, on the other hand, the AN only draws around 500 milliamps, very easy on your power supply.

From memory, the cost of a Gemini unit is quite high, the AN being the cheaper of the 2.

Cheers

[Eris (Gerard)]

The scope in question is in a permanent observatory with mains power so I think I may go with the Gemini System at this stage. As for the sound it makes when it's on the slew is it as noisy as a hair dryer working on a corrector plate on a SCT?

Thanks again,
Regards,
Eris

[JohnG (John)]

Not much difference, probably quieter, the Gemini is an excellent Observatory System on a G-11.

The only thing extra I would say is to make sure you have a good 13.8V, 4 amp regulated power supply, I use a GME 11amp version.

Cheers