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As-Portable-As-Possible GEM

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#1 wyundiv

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Posted 25 April 2013 - 09:35 PM

Hi All,

I've done a lot of reading and walked around NEAF last week but I'm still in a conundrum; hopefully y'all can help me out here. For my light portable telescopes, I have a SolarMax 60mm and plan on purchasing a 4 inch APO (Televue, Stellarvue, etc.). If I'm going to use the APO for DSO's, I'll likely put it on an alt-az mount (DiscMount or Gibraltar), but for planets and the Sun, I want to buy a portable GEM.

I've had a Unitron on a GEM for the past 20 years and have always enjoyed the views and the ease of viewing Jupiter/Saturn/Mars/Moon for a long period of time using the manual RA knob, so I would say my criteria for a German equatorial are as follows:

1. As portable as possible, maybe portable enough to carry the entire mount/tripod/counterweight outside without disassembly.
2. Stable enough to handle a 4 inch APO for visual use (not photography).
3. Electric drives, Go-To is really not needed (I'm pretty efficient as starhopping). If it has huge PEC, it does not matter to me.

That leaves me with the following options: Losmandy GM-8, Vixen GP2/GPD2, Celestron Advanced VX, Meade LX80, maybe an Orion mount. They all have the positives and negatives, but I'm looking for your experiences with using these mounts in terms of ease of use, portability and quality.

Thanks!
Walter

#2 orlyandico

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Posted 25 April 2013 - 09:40 PM

An old Vixen Polaris will do the above. Cheap, too (under $200). Or barring that, an old Vixen GP (buying Vixen new is not such a good bargain).

#3 jrbarnett

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Posted 25 April 2013 - 10:49 PM

CG5-GT. $549. Those Vixens are costly and do not have motor drives. Those cost "extra". The CG5-GT is a much better deal IMO. As for GOTO versus star hopping, bear in mind that star hopping with an equatorial mount is a different kettle of fish than star hopping with and alt-az mount. The latter is 100% intuitive. The former is anything but intuitive. On a GEM, GOTO is a true convenience as a result. Besides, the CG5-GT has really, really good GOTO for a lot less than the non-GOTO mounts you mentioned.

Good luck!

- Jim

#4 mpgxsvcd

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Posted 26 April 2013 - 07:44 AM

I second the CG5. I have carried my entire setup fully assembled(CG5+AT8IN+2 12 lb counter weights) from inside my house to my backyard. It weighs about 70 lbs but it is possible to do.

With a much lighter scope and a lot less counter weights it wouldn't be that big a deal.

Also the CG5 breaks down so easy that you really don't even need to carry the whole thing assembled.

#5 dbledsoe

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Posted 26 April 2013 - 09:21 AM

Avoid the iOptron Smart EQ. Flimsy and unstable. Probably OK if you only image and have an electronic focuser but if you're a visual observer and ever have to touch the focus knob the mount shakes horribly and takes a long time to damp out the vibrations. Otherwise, if you never have to touch the scope or mount while in use, well it tracks well.

#6 ubermick

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Posted 26 April 2013 - 10:22 AM

Another one for the CG5-GT. Really impossible to beat those at $549. And used they can be had for about $400.

#7 EFT

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Posted 26 April 2013 - 10:36 AM

If you don't need or want goto or tracking, then I would recommend the CG-4. Tracking can be added to the CG-4. The GM-8 and LX80 will be too heavy. The Vixen is too expensive for what you get. The VX or CG-5GT are fine, but they are needlessly complex if you don't need goto.

#8 Jon Isaacs

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Posted 26 April 2013 - 11:05 AM

CG5-GT. $549. Those Vixens are costly and do not have motor drives. Those cost "extra". The CG5-GT is a much better deal IMO. As for GOTO versus star hopping, bear in mind that star hopping with an equatorial mount is a different kettle of fish than star hopping with and alt-az mount. The latter is 100% intuitive. The former is anything but intuitive. On a GEM, GOTO is a true convenience as a result. Besides, the CG5-GT has really, really good GOTO for a lot less than the non-GOTO mounts you mentioned.

Good luck!

- Jim


I have to agree with Jim on this one. A modern CG-4 would do the trick except that those old stepper motor drives are frustratingly slow. The CG-5 Drives are make it all worthwhile... I never use mine in the GOTO mode but the fact that I can push the button and expect the scope to slew at a reasonable rate makes it all worthwhile...

Jon

#9 REC

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Posted 26 April 2013 - 02:15 PM

I have an Orion EQ2 that is under $200 and I grab the whole thing with the scope and counter weight on it and carry it out to the backyard. I also remove the weight sometimes and use it in the AZ mode.

#10 *skyguy*

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Posted 26 April 2013 - 02:40 PM

The trouble with GEMs ... when it comes to "one hand" portability ... are the heavy counterweights. The iOptron GoTo alt-az mounts offer everything you're looking for in a lightweight, portable GoTo/tracking package. You can even do planetary imaging with them.

http://www.optcorp.c...muth-mount.html

http://www.optcorp.c...-smartstar.html

#11 wyundiv

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Posted 26 April 2013 - 03:03 PM

Wow, a lot of CG-5 fans on here! I think High Point is the only one that has them left in stock; anyone know any other places?

Thanks all for your suggestions. I'll steer clear of Vixen/Losmandy/iOptron and will take a closer look at Celestron mounts now.

#12 wyundiv

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Posted 26 April 2013 - 03:10 PM

Another question about the CG-5: If I wanted to sight in just one object (ex: Jupiter), is there an option to just have the telescope track in the RA axis without any alignment? I guess more simply, if I turn the mount on, does it just start tracking right away, or do I have to initialize something?

I knew I should have stopped at the Celestron booth at NEAF!

Thanks again guys for all your help.

#13 RTLR 12

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Posted 26 April 2013 - 03:29 PM

Once you have the mount set up, level and pointed north, you can choose "Quick Align" and the mount will start tracking immediately without any further input.

However, if you are going to do AP work you will want to do a complete alignment followed by some sort of polar alignment. I can align my mount, polar included in about 10 to 12 minutes.

Stan

#14 wyundiv

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Posted 26 April 2013 - 03:37 PM

OK, good to know. Not to fight anyone, but I have one more question prompted by a discussion I had last night: why not the Losmandy GM-8? I have a G-11 currently and love it but it's not portable enough. Has anyone had any experience with a GM-8 vs. a CG-5? They are about the same weight with counterweights+tripod.

#15 gdd

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Posted 26 April 2013 - 04:50 PM

How about the Losmandy StarLapse? It is based on the GM-8 and can be purchased as a single axis or a dual axis GEM that can be put on any heavy duty camera tripod.

Gale

#16 beatlejuice

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Posted 26 April 2013 - 04:59 PM

A modern CG-4 would do the trick except that those old stepper motor drives are frustratingly slow



You must mean for slewing don't you Jon? The RA motor tracks really well and slewing would be done by hand unlocking the mount clutches accept for small corrections.
The Dec motor is not necessary for visual and in fact I think adds unnecessary complexity to the procedure.
Works for me anyway.

Eric

#17 Qwickdraw

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Posted 26 April 2013 - 06:03 PM

CG5-GT. $549. Those Vixens are costly and do not have motor drives.
- Jim


I dont know about that. I bought This Vixen with a 4" refractor (Bosna) for only $350 and both were pretty much mint. I think you would be hard pressed to find one for sale that is over $300 by itself.

#18 jrcrilly

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Posted 26 April 2013 - 06:32 PM

CG5-GT. $549. Those Vixens are costly and do not have motor drives.
- Jim


I dont know about that. I bought This Vixen with a 4" refractor (Bosna) for only $350 and both were pretty much mint. I think you would be hard pressed to find one for sale that is over $300 by itself.


Plus - he didn't say "as cheap as possible"; he said "as portable as possible". A Polaris, Super Polaris, or Great Polaris will be much lighter than a CG5-GT. The higher quality will often demand a greater price, though.

#19 Patrick

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Posted 27 April 2013 - 03:20 PM

I'm an advocate for the Vixen GP2 mounts. They are well made and light weight. For your application, you'd want to add at least the RA drive motor and hand controller. Both axis motor control would be a little more expensive, but nice if you can swing it. I have the GP2 with single drive motor on the RA axis and it works very well. I bought mine with the intent of using it for astrophotography, and I have to some extent because it's such an accurate mount. I like to use it for wide angle shots with the AT66ED refractor unguided.

The HAL130 tripod is sturdy yet lightweight. The total package makes for a very portable setup and it's accurate as well. I've used scopes up to a C8 and 6" Mak Newt and it has always done the job very well with minimal vibrations. My main test is "can I focus the scope without it vibrating?", and the answer is yes for the GP2. :smirk:

Regards,

Patrick

#20 Geo.

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Posted 27 April 2013 - 07:10 PM

OK, good to know. Not to fight anyone, but I have one more question prompted by a discussion I had last night: why not the Losmandy GM-8? I have a G-11 currently and love it but it's not portable enough. Has anyone had any experience with a GM-8 vs. a CG-5? They are about the same weight with counterweights+tripod.


That's my conclusion. A very nice GM-8 came my way and I'm lightening up my mount collection to one Polaris, the GM-8 the Giro 3 and the CGEM. The GM-8s head is a bit heavier than the CG-5's as it has the 1.25" counter weight shaft, but the tripod is lighter. The shaft alone may be to much for just a camera. Guess that's why you need the Polaris.

#21 watcher

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Posted 27 April 2013 - 09:04 PM

If money is no problem, you are best off with the GP2. It is as light as an Orion Astroview, and can be had with motors that can both track and slew. If you need to work with a lower budget, you would do very well with the Astroview mount and a single drive. I have a CG-4 that I love for light weight portability, but I ended up using the steel legs on a Vixen GP2. The problem I find for extreme portability with the CG-4 legs is that you need to remove the eyepiece holder/leg spreader to move it through doorways easily. I now use it with the less stable aluminum legs off of an EQ-something. Pretty much the same as Astoview legs but with white trim instead of the Astroview's black. Still plenty good for my 80mm F/7 and I have used my Omni 120 F/8.3 on it in a pinch. OK with the steel legs. Barely acceptable with the aluminum, but it should be more than doable with a shortish 4" APO.

#22 beatlejuice

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Posted 28 April 2013 - 01:05 AM

The problem I find for extreme portability with the CG-4 legs is that you need to remove the eyepiece holder/leg spreader to move it through doorways easily.


Thats what I thought until I finally realized that all I had to do was loosen the tray and twist it to the side so that the legs can fold in such that there is no longer a problem going through doorways.

Eric

#23 Benson

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Posted 28 April 2013 - 02:31 AM

I have a GM8 and consider it a high quality, sturdy mount.

#24 watcher

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Posted 28 April 2013 - 03:44 AM

The problem I find for extreme portability with the CG-4 legs is that you need to remove the eyepiece holder/leg spreader to move it through doorways easily.


Thats what I thought until I finally realized that all I had to do was loosen the tray and twist it to the side so that the legs can fold in such that there is no longer a problem going through doorways.

Eric


Thanks Eric. I do that with my steel legs, but it's still a little more awkward than the aluminum legs. I get three legs dangling separately and clanging on the spreader. The aluminum legs just fold up into a single unit. Not really that big a deal, but when the load is light and the aluminum legs are sufficient, I'm glad I have them on the CG-4.

#25 foggylenses

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Posted 28 April 2013 - 10:06 AM

Walter, There are several light mounts to choose from out there. I think with portability in mind lighter is better however, lighter usually limits you to lighter tubes. I have never had any trouble with my CG5 and it allows room for growth. It is very reliable and has a very good data base. You can get them cheap and save money for eye pieces. I own a CGEM DX and LX80. they are not very portable but I have had no problems at all with either.






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