Ledge1962

Just to confirm it isn't a faulty encoder, go into the handset menu, Utility Func - Show Position, and move the mount up and down, then around and check if the Coordinates are updating. I had a similar issue with the scope aligning correctly, but as soon as I used Goto, it would just drop down and bottom out on the mount. It turned out the ALT Encoder was broken and we only found it because the Azimuth coordinates were updating, but the Altitude coordinates remained the same when raising and lowering the scope by hand.  If this is your problem, the Azimuth coordinates probably wont alter.

It may not be the issue, but worth ruling it out.

I had a similar problem to this on a Sky-watcher 250P.  It would align perfectly, then once I tried to Goto a target, it would head of in all sorts of directions, usually bottoming out on the mount.

I went into the handset, and in the Utility Func menu, - Show Position, the ALT coordinates did not update when moving the scope up and down. It turned out the Alt Encoder was broken. I hope this isn't your problem, but it is worth checking it to rule it out.

It is a truss  (Orion xx14g) , but does have a shroud attached. Being a 14" mirror, I am wondering if it isn't cooling down enough. It has a heater on the secondary, but it didn't change the look of the stars both on and off. 

Thanks Ruud, I will give that a try. It is a concern when the scope cost $5000 NZD. I was worried the mirror may have warped somehow.

Hi all.  I have a 14"Dob (f4.7) that is well collimated, and used to have really sharp views, but not so much any more. Nothing has been changed, the mirrors are clean, the secondary is heated, it has 3x 80mm fans on the primary. It is stored in an insulated garage. 

I use the Sky-watcher 82 degree EPs and the scope cools for an hour at least before use.  The stars look like they are suffering from atmospheric turbulence (on fire) according to astrobaby's guide, but I have a 10in dob (250p) that shows clear stars on the same night at the same time.  I am at a loss as to why it is like this?  I have tried collimating using a Cheshire, a farpoint 2" laser and a barlowed laser.  The results are similar. 

When looking at the Orion Nebula, the nebula is fine but the stars look like they have little spikes coming off them. When defocused, the star test does have the concentric rings but the star still looks like it has small spikes.

Has anyone had any issues like this before? 

I would appreciate any suggestions or further tests to help find a solution.

Thanks

My posty is getting plenty of exercise, a Skywatcher 8" Collapsible, Astronz 2" 42mm EP, Shroud for the Skywatcher, heater band for EP's, Turn left at Orion book, autocollimator, Bobs Knobs for the Dob and th eposty still has more to do. Just preparing for my retirement in 7 years time

Beautiful shots! 

I can not argue with the Moistons theory, I bought a Skywatcher 8" Dob, and it was a clear night right up until I finished assembly and went outside. The moistens must have escaped into the atmosphere when I opened the door, as it clouded over immediately. They have not dispersed since...

Nobody nearby that can swap handsets to cancel out a faulty one?

I had similar issues with the XX14g, but it turned out to be the balance. I had is so well balanced that the slop in the gears was the issue. I made it front heavy and problem was gone.

I have the 1.25" XCEL-LX barlows (2x and 3X) and they do a good job in my f10 sct. Out of interest, I put them together to see if they would act as a 5x Barlow, but the magnification was laughable. I find I prefer to use the straight eyepiece without the Barlow, but if I need one, the LX certainly does the trick. 

The LX Barlows struggle around the edges on the F4.6, but that is to be expected, and as I prefer deep space, I rarely need to use them.  

Let us know how the star test goes please

As an after thought, I did have to adjust the mirror by adjusting the spider vanes as it was off to one side. The photo of your secondary clearly visible in the tube looks like it is in need of centering via the vanes too??

I had a problem similar, so I took the mirror out completely and placed it on a piece of clean white paper and traced the outline of the mirror. After cutting out the shape, I then folded the paper in half horizontally and vertically, so I could find dead centre of the shape. I marked the centre of the paper with a black dot and attached it to the face of the mirror with very soft tape on the edges and put the mirror back in the scope. Then using a laser, I adjusted the rotation and tilt until the laser hit the mark on the paper. After gently removing the paper, I took a photo and measured how central the mirror was, and it was pretty close. After that, Astrobabies guide did the rest ...

"i've seen eyepieces for sale that "guarantee" bringing out the colour in nebula etc"... There are a lot of filters on the market that increase the contrast of colours, but I have not heard of an eyepiece that does it. As Waldemar states, we use the rods around the outside of the eyes to get night vision, and rods are not colour sensitive. It is a shame we have that limitation in our eyes as seeing colour in the stars would be amazing. 

I can not see (no pun intended) how looking through any EP could change what the Rods pick up.

Personally, I actually enjoy the setting up and tearing down the scope  

I started with a 4", then went to a 10" SCT and now a 14" Dob. I have a good area in New Zealand that doesn't suffer from light pollution, and have a good view of the sky so I do not need to move them, so housing them gave me the freedom to go to whatever size I could afford. I have looked at 16" but the change from 14 to 16 is not worth it, so a 22" will probably be next.  If I had gone straight to a 22, it would have been a lot cheaper and then I could have started saving for the 36".  Aperture fever is very contagious. 

The wife would definitely agree with me being a Nebula, she is always complaining about the gaseous clouds I leave behind.

Hi all. Has anyone tried the heater pad around the circumference of the tube to any great degree of success. I too am getting hit with dew on the XX14G so would be interested in success stories. I ordered the Kendrick Split heater but that is a few weeks away. I will post the results once it arrives. I did try a 12v hair dryer, but it barely heats up and was only good for the eyepieces..