The Sphinx is in!
Posted 24 July 2009 - 10:06 PM
Posted 25 July 2009 - 01:04 PM
Posted 25 July 2009 - 04:31 PM
Posted 26 July 2009 - 03:21 AM
Congratulations on the new mount, hope you enjoy it.
Posted 28 July 2009 - 01:19 PM
A couple of minor issues for your commentary, if able:
1. Counterweighting. It turns out the 4 lb counterweight is TOO heavy for my TV85! To balance things out in RA, I ended up retracting the counterweight bar almost all of the way into the housing then, setting the weight on the 1" protrusion of the bar. It balances ok as near as I can tell (there is a little stiffness to the mount, so things don't freely rotate). Is it OK to use the mount like that, i.e. with the CW shaft mostly retracted?
2. Noise: The GOTO noise level is fine, but there is a steady buzzing during tracking almost like a bee right 1/2" away from the ear. Is this normal? If not, what might be the cause. As I said, I think I'm pretty well balanced at this point, but I was wondering if it could be tracking loudly due to strain.
Please let me know. It looks like a great little mount. I can't wait for clear skies. Hopefully I'll get an opening for the PST this afternoon or the TV-85 tonight. Maybe even guided widefield imaging... Huzzah!
Posted 28 July 2009 - 02:09 PM
Unlike some mounts the weight of the drives is below the RA axis so acts somewhat as a counterweight itself.
Mine sort of emits a low level buzz and a sometimes emits a quiet creak like a door being opened in a dungeon in the distance.
Have fun with the skybook it is soooo cool!
Posted 28 July 2009 - 04:50 PM
You shouldn't have any trouble using the mount with the counterweight shaft retracted if it balances in RA. My SXW makes a little fluttery sound while tracking, which seems to be normal.
Posted 28 July 2009 - 05:11 PM
If I only mount my 80mm scope, I just extend out the CW bar and it balances fine. When tracking I get sort of a ticking sound.
Hope the skies clear up for you, I'm still battling clouds so I haven't been able to take my new Newt out yet.
Posted 28 July 2009 - 07:15 PM
I'm starting to get the impression that no two sphinxes sound alike.
Posted 29 July 2009 - 03:45 AM
You will probably find the lead of the starbook is wrapped around a ferrite tube which sits in a grey plastic housing.
Open the housing, 2 little clips and throw the ferrite away.
This loop often causes the rather thin leads in the cable to break, it happened to me and others. The cable loop is far too tight and stresses the internal very thin wires.
The removal of this ferrite will have NO impact on the working of the starbook, i would keep the ferrite just in case you ever need to return the mount under warranty.
Posted 29 July 2009 - 02:40 PM
I should of mention that when I mount my 80mm by itself on the Sphinx, it uses the scope's Vixen type shoe instead of rings and dovetail.
It's possible that my Sphinx does sound the same as yours, I just may hear it differently.
Posted 29 July 2009 - 03:32 PM
I will give you a full report when I am home from vacation, but first light with the Sphinx/TV85 was wonderful. I don't know if it actually sounded different or if it was just the night air and the stars, but the mount noise was non-obtrusive.
I agree that the Star Book is TDB (too bright), but I love the little thing. Perfect observing system for a geek like me. I had cousins breathing down my neck to get going with the scope, so I never polar aligned beyond eyeballing, but after 4 alignment objects, it was spot on all night. I can't wait to mount a camera. Tomorrow night perhaps?
Posted 29 July 2009 - 03:36 PM
So what does the ferrite clamp do?
It brings the device into compliance with regulations concerning interference with other electronic devices.
Posted 29 July 2009 - 04:06 PM
The ferrite is there so that the starbook computer does not emit tiny amounts of electromagnetic energy when in operation so it can pass EMC (electromagnetic Compatibility) standards.
These are set for the office environment where multiple computers could interfere with each other due to their possible close proximity in an office, eg monitor cables have a ferrite (lump in cable).
Removal of the starbook one will cause no problem to others or yourself and it will eliminate that PITA of an internal cable break.
PS I bought some dark plastic A4 sheet on Ebay and stuck a piece over my starbook screen, in the daytime you can hardly see the screen image it is that dark, but at night it works very well.