Talk:Equatorial mount

Merging telescope mount articles
Hello. I was browsing the various telescope mount articles recently (see Telescope mount, Altazimuth_mount, Equatorial mount, Dobsonian), and I'd like to propose merging them into a single Telescope mount article. Does anyone have any thoughts about this? If so, could you please visit Talk:Telescope_mount and perhaps comment? Izogi 04:02, 18 July 2005 (UTC)

Replaced image
I replaced image:Equatorial mount.jpg with image:Forststernwarte Jena 50cm-Cassegrain 1.jpg because the former is hard to understand since it is blury, has no telescope attached, and has no counter weight attached. 69.72.7.12 19:28, 8 January 2007 (UTC)
 * Wow if you think that picture is better there's something wrong. I am going to take a higher resolution image of the previous image and replace it back onto this article unless I see any objections.  The article isn't about telescopes, it is about the mount, so I don't necessarilly think the telescope itself needs to be in the image.  I'm not even sure what I'm looking at in the current image, so I think it needs to be replaced. --ScottyBoy900Q 22:04, 19 February 2007 (UTC)
 * The current guideline on Wikipedia is to make technical articles accessible. It is hard to explain the function of a telescope mount to the layman if the illustration does not include the telescope. Images of just the mount bring up the question "huh?, what?, the telescope goes on this thing where?". Articles such as this are not sub-manuals in a telescope book so they need to be pretty much self expaitory. 69.72.2.71 21:04, 4 August 2007 (UTC)

Diagrams needed
Hmm. Serious need for some real pictures, rather than the word pictures of the "English Fork", "German mount" etc. Agree. The principles are not well described by examples of those principles in practice. Clear, simple diagrams of the axes and their interrelation to each other an the Earth and celestial sphere are badly needed. —Preceding unsigned comment added by 76.88.4.187 (talk) 06:51, 25 November 2010 (UTC)

Not parallel?
"However, since the geostationary orbit is not very distant from the Earth compared with the Earth's radius, the tracking is only approximate, and the optimal alignment of the axis is not parallel with the Earth's rotation axis."

rm above to talk. Satellite dish equatorial mounts have to be exactly parallel to the Earths axis in order to function (personally know from setting them up). There is a (4 degree?) depression angle off the equator due to our view angle. But that is a declination difference, not an equatorial difference. Needs clarification. Fountains of Bryn Mawr (talk) 17:11, 12 November 2010 (UTC)

As seen from a north-temperate latitude, the declination of a geostationary satellite is more negative (southerly) if the satellite is at roughly the same longitude as the observer than if it is close to the eastern or western horizon. This is because the observer is closer to the satellite if the longitudes are equal, but the linear difference in position in the north-south direction is the same. The apparent declination is the arc-tangent (or arc-sine, depending on how you measure the distance) of the ratio of these. Since the declinations of the satellites vary, the slewing axis should NOT be exactly parallel with the earth's rotation axis. It should be closer to vertical than a polar axis.

Out of curiosity, today I took a look at some dishes mounted this way. I'm at about 44 deg. north latitude, but the axes of the dish mounts were, I estimate, about 55 degrees from the horizontal.

Even with optimal alignment of the slewing axis, the dish cannot (except if it is on the equator) point precisely at satellites at all longitudes. However, the aim is good enough for most radio communication.

DOwenWilliams (talk) 22:48, 12 November 2010 (UTC) David Williams
 * Thanks for the clarification, found a ref for it. You should supply references in the future. Its an important part of the Wikipedia process and allows other editors to check "facts". Fountains of Bryn Mawr (talk) 23:32, 12 November 2010 (UTC)


 * Well, let's not open that can of worms. Suffice it for me to say that I have had plenty of reasons during my life to put my trust in direct experience (which I do have, in this matter) rather than in citations of other people's writings, which can be wrong no matter how authoritative they may appear to be.


 * Still, if you add some citation to that sentence about satellite mounts, I guess it will make some people happy.


 * P.S. Just did it myself.


 * DOwenWilliams (talk) 01:59, 13 November 2010 (UTC) David Williams


 * Take a look at User:DOwenWilliams and its associated "talk" page to see some background about my scepticism of citations.


 * DOwenWilliams (talk) 15:35, 13 November 2010 (UTC) David Williams


 * Hmmmm... one may ask why you bother to edit a project that requires verification with reliable secondary sources and definitely not first hand original research... but I won't, at least not on this talk page. This is a case where sourcing comes in handy. The clarification and sources brought up a problem, leading me to not bother ref'ing or expanding the edit. The paragraph is the right description but the refs point to it being in the wrong article, re: the thing under a satellite dish is a Polar mount which seems to be a different enough device encyclopedically to move the description there, which I did. Fountains of Bryn Mawr (talk) 03:47, 17 November 2010 (UTC)


 * Ok. I saw it there.


 * Of course, this whole topic is now somewhat dated. Slewable satellite dishes are used much less now than they were a couple of decades ago. Most of the ones I've seen around here are clearly disused and in disrepair.


 * Sometimes I do edits to fix typos, grammar, confusing language and the like. I used to be an editor of a computer magazine. Old habits die hard.


 * As for editing statements which I *know* are factually wrong, but for which I don't have references, what am I supposed to do? Leave the errors so they can continue misleading people?


 * I have some doubts about the whole Wikipedia project...


 * DOwenWilliams (talk) 15:44, 17 November 2010 (UTC) David Williams

External links modified
Hello fellow Wikipedians,

I have just modified 1 one external link on Equatorial mount. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Added archive https://web.archive.org/web/20090102184846/http://mathis-instruments.com:80/fork_german.html to http://www.mathis-instruments.com/fork_german.html
 * Added tag to http://brunelleschi.imss.fi.it/museum/esim.asp?c=202501

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 06:02, 25 December 2016 (UTC)

Explanation needed
Came here looking for a description of how this thing works (ie process by which is it aligned with rotation, etc), didnt find it.

47.29.68.71 (talk) 20:11, 16 October 2017 (UTC)


 * Not sure what you are looking for. How to align one? Wikipedia is not a "how-to". How observatories align theirs? That could be added if sources exist. Fountains of Bryn Mawr (talk) 21:36, 16 October 2017 (UTC)

Center Balanced Mount (CEM)
I am not sure if this is new design but for few years iOptron was producing ZEQ and CEM series mounts. They are center balanced mounts, with a Ra axis in a shape of Z. The CEM120 has a bit different design, but also is center balanced. They say it is a new design, presumably patented, but maybe there is a prior art on this, or similar mounts in some observatories? 81.6.34.246 (talk) 22:13, 6 April 2018 (UTC)
 * Looks to be a GEM with a $4000 name. There are many ways to skin the cat, but I think it still falls under the basic GEM design and would be a sub type. Worth mentioning there if there is RS on it. Fountains of Bryn Mawr (talk) 17:23, 7 April 2018 (UTC)