Subject:Synta Skywatcher EQ-6 (EQ6): Equatorial Telescope Mount Review
Date:10:06:2003
Rev:0.2
After using a Meade DS2114 computer controlled reflecting telescope for almost a year and getting more and more frustrated with the lack of accurate tracking and bad optics. I decided enough was enough and ordered a decent mount and tripod. After much delibiration i chose the EQ-6 over the Losmandy GM-8 (far to expensive to avoid a divorce). The mount was proven to be solid and some people even commented that it is actually more stable than the Losmandy. GOTO for this mount is availible for about 800GBP from a local firm AWR Tech. This includes motor assemblys and a programmable handset. Also Synta now provide a GOTO computer controller and motors for some where in the region of 500GBP.
Ok got a nice shiny new equatorial mount and a really crappy scope to use with it. I start by putting the tripod out in the garden and leveling it, sorted. Now i go back indoors and get the mount, jesus its heavy. I add the mount to the tripod, take the polar scope protection cap off (both ends) then turn the DEC shaft such that i can see right through the polar scope to the grass. then spend about 20 mins adjusting the mount inm alt/az to get Polaris smack on the Xhairs, Yes, i know thats not the right place for perfect polar alignment but its good enough for visual work.
Now, how to mount the DS2114 to the EQ-6, hmmmmm me thinks. DISCO get a roll of insulating tape, get the engineer bloke next door to come round (woman untrustable for this sort of thing) to hold the scope onto the dovetail and wrap an entire roll of insulating tape around the scope and dovetail. Could not want for a more stable fixing (titter titter). Then it dawns on me that the 12v supply i used for the meade has the wrong type of connector on it and i have to butcher the EQ-6 battery pack to get the plug off and temporarily bodge it onto the exsisting 12v supply.
Right ready for action, all be it with a rather unfullfilling scope.
Having only ever seen other people set up their equatorial mounts i didnt really have a clue what i was doing so i turned to my old pal google and did a few searches on polar alignment in general and also EQ-6 polar alignment. Found a couple of PDFs the Manual and polar scope setup/alignment. Oh how many hours did i spend trying to setup the polar scope correctly, then more hours actually aligning the scope RA axis to polaris then more hours off setting the RA axis by the correct amount. At last we are ready. Having used the scope for nearly a year, optically i knew what to expect. What i did not expect was an notable optical improvment simply becuase of the greater level of stability introduced by the massivley engineered mount. I must confess that following the polar alignment procedures in the above mentioned PDF seemed to give worse alignment than simply pointing the Xhairs of the alignment scope at polaris, then perfoming a 180 degree rotaion of the RA axis and re-aligning the Xhairs to polaris untill the 180 rotations saw polaris remaining on the Xhairs.
This session lasted about 2 hours with most observation carried out between gaps in the clouds. I did not detect any bad tracking visually (using the above non pdf alignment procedure) and the first object i centered (Jupiter and Co) would have remained in the FOV almost indefinitely. I aligned M57 (my favourite) smack in the middle of the FOV @ 100X then went to make coffee and toast. 45 minutes later i returned, refreshed and re-awakened only to find M57 in exactly the same place as it was when i left. I appreciate that this does not mean the tracking is good enough to do long exposures at prime but, i see no reason that this level of accuracy would not be sufficient for 15 minute exposures through a 200mm slr lens. To date i have not tried any long FL exposures with the EQ-6 (2003-06-13).
I can honestly say, although i only have probably 30 hours of experience with this mount that the only problems i can find are listed below.
I intend to do some tests of my own devise to see just how well the scope tracks. I have already take some 15 second exposures through the eyepiece with a digital camera although these images where very rough and not really good enough to publish they did show that the mount tracks accuratley enough for a full 15 seconds at 50X. I will also get round to doing some long FL piggyback photography. I have tried some 28mm lens pictures and will post the results here when i get them back from the lab.
Bear in mind that my experience with the eq6 is currently limited to only about 30 hours i dont think you could invest in a better mount for the price(£705). Tracking is excellent out of the box, setup is relativley painless, if your fit and strong. This mount is emmensely stable and would easily handle a huge scope (25kg aparently). If you are looking for a mount in the 700 quid range then this is the one.
I have, over the last few weeks since writing the top half of this page been trying different polar alignment methods. I have not enough patience for the drift method so i only gave that one a bash a couple of times. I have also tried the once described in the pdf doc above. This method seems relativley accurate but even with a 200mm piggyback camera lens the tracking was not good enough to give pinpoint stars accross the entire photographic field. The one method i have been trying to most success is this one (local copy) by Fr. Lucian J Kemble, OFM and Dr. Peter Bergbusch. Although it was first used in 1975 it seems to be (for me anyway) a very accurate and quick way of polar aligning a equatorial mount for my needs (visual and upto 300mm FL piggyback). All the alignment procedures in the world dont make up for the fact that the power cord can silently falls out of the mount ruining hours of open shutter, do somthing else for 30 mins, close shutter astrophotography.
I had to sell the original EQ-6 in order to pay for more pressing requirements(potatoes, milk and bread to feed the sprogs) and have recently had a vast improvement of my financial situation(no longer have to worry about feeding the sprogs ;)and could afford to buy a new EQ-6. This paragraph is about the differences between the first and second versions of the mount. The first thing i noticed was the polar illuminator, yes, the newer mount has one built in and it even has a potentiometer to vary the intensity of the red illuminator LED. Second is a small bubble level built into the bottom of the mount. Pity its not build into the tripod, at least then leveling the thing would not be such a back breaking job. The hand controller also has axsis reversing switches for both RA and DEC. Please, if someone knows the point in these little chaps can they let me know because i can not fathom it out.
All together although very subtle these modifications pretty much deal with the list of nags that i had for the original mount. I have yet to be honored with clear skies such that i can test the tracking and noise levels of the new mount. For those of you thinking of moving to the south east of england, more accurately Kent, 21 days without a single clear night should be enought to change your mind!!!
Having always noticed a bind in the DEC axis since the first use. A problem that my original EQ-6 also suffered. And also having decided to invest in an AWR GOTO system i have finaly got round to finding the source of the bind. I have stripped and re-assembled the DEC axis removing a highspot from the collar on which the axis lock presses. I used this doc as a reference. The AWR system was a sinch to install although i must confess i have yet to get much use out of it. I have only used it 3 times and have other mechanical issues to deal with(RA backlash). At last though, these problems are all gone and i am now expecting a long period of shite weather to spoil my new toy excitement :(
A small gap in the could cover afforded me the chance to test the mount for backlash last night. The backlash is non exsitant, im not sure if there is suposed to be a tad of backlash but the RA axis does not have any so im guessing that DEC axis does not need any either.
I read a few docs from the yahoo eq-6 group and decied that most where being a bit over careful with their equipment. People spoke of grubscrews(one top, one bottom) and the four bolts on top of the DEC axis. I looked and decided to loosen the 4 cap head bolts then jiggle the top half of the DEC cover until the join was even all round. It worked fine and i shall be off to test it on the next decent clear night...