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Navigating the night sky
The Sky-Watcher EQ-6 mount and the Argo Navis Digital Telescope Computer

About a year ago I decided to get a new mount for my TAL 200K. The main reason was that I wanted a mount that could be equipped with some sort of go-to system or digital setting circles. I had been suffering from serious back-problems for quite some time, and I was fed up with kneeling down and crouching under my telescope to locate my favourite deep sky objects, especially in the cold winter period.

Sky-Watcher EQ-6
While deciding which new mount to buy, there where a few things that I took into consideration: I wanted a mount that could carry larger and/or heavier OTA's in the future, but still could be transported to a dark sky site. The mount would not be used for long exposure photography and finally, as always, there was the money issue: how much can you spend?

The search for the mount quickly narrowed down to the EQ-6. The Sky-Watcher EQ-6

- could take heavy loads (up to 22 kg) using a standard dovetail;
- should be OK for taking short exposure images of the Sun and Moon;
- could be equipped with several types of digital setting circles;
- could be transported to a dark sky site;
- fitted nicely into my budget;
- seemed to be good value for money.

EQ-6/Argo Navis on "wheels"
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Argo Navis Digital Telescope Computer
Once I decided to go for the EQ-6 I started looking for digital setting circles (the EQ-6 wasn't available with a goto system in may 2004). There where several systems on the market, but there was one that really stood out from the others, the Argo-Navis Digital Telescope Computer from Wildcard Innovations. This computer can be connected to a wide variety of mounts, including dobs mounts, with encoders that are produced by JMI. The Argo Navis can be ordered, completely with encoders, from JMI in the US or from Wild Card Innovations in Australia. The specs of the Argo Navis computer blew away all other systems at that moment (may 2004). You can read all about the Argo Navis by following these links:

JMI NGC Super Max (Argo Navis)

Argo Navis Digital Telescope Computer by Wildcard Innovations

but here are the specs what made me decide for this unit:

- very easy to use out in the field, even when wearing gloves;
- a big rotary dial and two buttons do all the operations;
- the display comes with a dew heater;
- the display is dimmable with 100 settings and has a digitally contrast control;
- its database with more than 29.000 objects
- a wealth of bright stars, variable stars and doubles stars in the database;
- data on most objects: position, size, magnitude, surface brightness, class, star chart cross reference etc,
- the tour mode: let Argo Navis take you on a tour along your favourite objects;
- add 1.100 user-defined objects;
- can be used on many different equatorial mounts but also on dobsonian mounts;

image image

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So the combination I went for is the Sky-Watcher EQ-6 and the Argo Navis Digital Telescope Computer. As you will read in the next paragraphs, I don't regret it.

Setting up and using the EQ-6
I have been using the Sky-Watcher EQ-6 mount for more than a year, and I'm very satisfied. The setup is done within minutes. You just have to assemble three parts: tripod, mount and counterweights, connect the battery and the hand-controller, and you're ready to go. The mount itself is the heaviest part, weighing 16 kilograms, but it can definitely be carried around and transported in a small car. Taking the EQ-6 apart also takes only a few minutes.

After assembling the Sky-Watcher EQ-6 I usually align the mount with the celestial pole, using the built-in Polar Scope. This only takes about five minutes. Once the EQ 6 is polar aligned, it keeps all stars and deepsky objects right in the centre of the field of view. I have been indoors once for more than two hours, leaving my telescope centred on M 37. When I returned, M 37 was still visible right in the middle of the eyepiece. When using digital setting circles, it also pays of to align exactly on the pole (see next paragraph). The EQ-6 has no different speeds for stars, moon and sun, but I never experienced any problems with that. The Sun and Moon are kept in the eyepiece nicely. Every now and again you need to perform minor adjustments.

I mounted different telescopes on the EQ6, my 8-inch TAL 200-K Klevtzov-Cassegrain (12 KG), the TAL 100RS 4-inch refractor (6 KG) and the 40mm Coronado PST (2-3KG). I also mounted the TAL 100RS and the Coronado PST together using a Duo-Mount bracket from Teleskop-service in Germany. The mount proved to be very stable on all occasions and changing telescopes was very easy using the standard EQ-6 dovetails.

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In the period I've been using the EQ-6, it always worked correctly. The hand-controller though looks a bit cheap and has a bright green LED in the middle. A little sturdier box and control buttons, and a red LED would be great improvements for the future, but then again everything worked just fine until now. I also have used the EQ-6 for short-exposure photography with the Coolpix 4500 connected to the eyepiece (Scopetronix / Vixen adaptors). The images of the Moon and Sun I got were just perfect. I am not interested in deep sky photography, so I can't tell you what the EQ-6 is like, when using it for long-exposure imaging.

After using the EQ-6 for more than I year I can say that I'm very satisfied with this mount. I paid 999 Euros but it is worth every penny, a fantastic mount for a very down-to-earth price. What other mount can carry 22 KG in this price range? I couldn't find it, so the choice was very simple, and I do not regret it for a moment! This is definitely value for money.

Setting up and using the Argo Navis Digital Telescope Computer
I ordered the Argo Navis and a set of encoders (8192 steps) for the EQ 6 from JMI. The package arrived in good order, and the installation of the encoders took me about 15 minutes. The only piece of equipment I used was a screwdriver (on the images below you see the RA and DEC encoders mounted on the EQ6). After the installation of the encoders I installed 4 AA 1.5V batteries to provide the internal power for the computer (at the moment I use an external DC power cable to connect the Argo Navis to 12V power pack). Finally, I connected the computer to the encoders using the encoder cables. After printing out the manual, I was ready to do the initial setup.

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After going through the initial setup (which you only have to do once and takes about half an hour) I started the alignment procedure. This procedure has to be done every time you setup your telescope. The alignment procedure is very simple for the EQ6. Connect the Argo Navis to the encoders (and to the external power source). Be sure that the telescope is polar-aligned exactly. Power up the Argo Navis and align the telescope on a star that you select from the alignment star list and you are ready to go.

You can also use the "rough align" mode, but you have to align on two stars. I have not used this mode, because I always had Polaris available to align the EQ-6 mount. However, when you cannot see Polaris from your observing site, you can use the rough-align mode from the Argo Navis. What I've heard from other users, this works fine.

After using the Argo Navis for more than a year I can only say that I am impressed with this great piece of equipment. If the mount is exactly aligned to the pole, you can align the Argo Navis within one or two minutes, and from there it will take along any number of objects. One night I just tested the Argo Navis for locating different targets. I let the computer take me to 40 different targets: double stars, open clusters, planetary nebula's, planets and globular clusters. They all ended up in my 45' field of view the first time. The Argo Navis did not miss one! And then the wealth of details you get on all the objects is fantastic. Here's an example (M 31):

M31, also known as NGC 224, Galaxy in Andromeda, _size=3.18 degrees x 1.03 degrees, mag=3.3, SB = 14.5 _morph=SA(s)b, Andromeda Galaxy M31, very bright, _RA= 00:43:00, DEC = +41deg 17’35” above horizon, _SA=4

(The last data “SA=4” means that you find M31 in the SkyAtlas 2000 on map 4. You can change this into the Millennium Star Atlas or the Uranometria edition 1 chart numbers)

Another great feature of the Argo Navis is the Tour mode. One night, when I came home from work the sky was covered in clouds, but later that night suddenly the clouds disappeared, so I could observe for an hour or two. I had nothing like an observing list or program ready, but the Argo Navis has a "Tour Mode". In this mode I simply chose a constellation and objects I would like to see, and let the computer do the rest. I let him take me along all different kind of objects within Orion, brighter than the 10th magnitude. I had a great time and I really felt like an astronomical tourist. Clusters, asterisms, double stars, nebulae, they all came along. This option is fun!

In the end I can say that the Argo Navis amazes me every time I use it. This unit proves not only to be very reliable and accurate, it also is very easy to use. The whole unit is controlled with two buttons and a big rotary dial, very basic and simple. You don't have to take of your gloves to use the controls. I never had any dew problems or technical failure due to outdoor conditions. Uploading a list with user data is a piece of cake with the software that accompanies the Argo Navis. The wealth of detail that is displayed on the adjustable two-line LCD screen is just another great bonus you get from the Argo Navis. The tour-mode is wonderful, and the manual that is supplied on a CD-rom is very accurate and detailed.

If it comes to navigating the night sky, the Sky-Watcher EQ-6 and the Argo Navis Digital Telescope Computer form a great team. If you have any questions or remarks, please feel free to post a comment.

Clear skies to all of you!
Posted by Math on 08/15 at 07:06 AM
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