Vixen Sphinx-anyone using one?

hotspur (Chris) · #1 10-12-2009, 03:18 PM

I have to purchase a new goto mount,was thinking of getting one of these.

I recently sold my EQ 6,it was very good performance,but rather heavy,
took up lots of room im my observatory,and was IMO an ugly looking thing.also i only use a 4 inch scope,so was a bit of an overkill.

I have two options get a second hand Vixen sky sensor for my Vixen GP,problem is its old and not supported any more,which is ashame its very,very good

or get a Sphinx (i will stick with Jap stuff),YES i know the sphinx has had

issues,but i heard Firmware updates have fixed it ,also the newer ones shouldnt have problems of first issue ones,also there is a 'deluxe'
model(it has black writting on it) its a lot dearer than blue one,i know
little about them so if anyone got any helpfull advice,

cheers Chris

Ross G · #2 10-12-2009, 09:50 PM

Hi Chris,

I have the Vixen Spinx Sxw (the blue one).
It looks good and it is very portable. However it's tracking is not very good. Unguided, I am lucky to get decent 30 second exposures. I also have a Skywatcher HEQ5 Pro with which I can get good 2 minute unguided exposures.
The Vixen also has very bad DEC backlash. You have to set the DEC backlash compensation to 80% or even 100%.
Vixen Japan has told me that this is normal!
However, on the plus side, when I autoguide I get perfect 10 minute exposures and I'm sure I could extend this to 20 minutes without a problem. This is much better than the HEQ5 Pro.

Good luck.

Ross

CometGuy · #3 10-12-2009, 10:13 PM

Hi Chris,

I have had an excellent experience with the Sphinx. It's certainly a lot lighter and smaller that the EQ6 Pro, although naturally the EQ6 has a higher payload.

Tracking is pretty smooth and predictable, so I would imagine autoguiding would work pretty well (provided you set the mount up to correct only in one direction in DEC due to the backlash problem). The Dec backlash problem is a well known problem but can be worked around (i.e ensure the mount corrects in one direction if autoguiding). At 2000mm Focal length on a C8 I can do 45second exposures unguided, with about a 80% keeper rate. At 1400mm with a focal reducer this improves to 60+ seconds. Handles the C8 with ease actually.

There is a freely available ASCOM driver available for the sphinx that works really well. One of my projects at the moment is to do PE correction via the ASCOM driver.

Terry

marki · #4 10-12-2009, 10:24 PM

Terry, does your's have the PEC function in the starbook? If so have you tried that?

Mark

CometGuy · #5 10-12-2009, 10:40 PM

I tried it..but without much success.

What I did was map out the error from a sequence of short exposures and put them into a PE table stored on a PC. The challenge is now how do I synchronise the sequence.

Terry

marki · #6 10-12-2009, 10:44 PM

I got mine last tuesday so am a new user and have a bit to learn about them. Have you tried pempro and transferring the curves to the starbook?

Mark

CometGuy · #7 10-12-2009, 11:14 PM

Not yet. But I don't think the Starbook has the capability uploading PE data - I tried to find it (if there is it doesn't appear to be documented). Also, I'm not sure if the mount has the ability to return absolute positions of the axis's which I imagine would be required for effective PE.

I haven't spent too much time on this though as the main application for this mount is comet hunting and I limit exposures to 20-60 second exposures and slew to another position. BTW the mount has been doing this for 2 years and I would estimate close to 10000 GOTO's - without a single problem!

Terry