Summer 2016

Summer 2016
Summer in Tsukahara

Spring in Tsukahara

gkimbal's Spring in Tsukahara album on Photobucket

Thursday, June 16, 2016

ScopeDome: Celestron 11 Edge HD

The telescope is a Celestron 11 Edge HD. I won’t bore you with the details, but... I’ll mention that it’s perfect for my current skill level. The Edge optics provide a flat field and is coma free. I can image at a slow f10. With the reducer I can image at f7. The Hyperstar lens will speed things up to f2. It's almost like having three scopes in one which makes the EdgeHD versatile. The mirror can be locked down to minimize mirror flop.

I have a few accessories worth mentioning. The optical train consists of a .7x reducer, Feathertouch focuser/ Microtouch autofocuser, Optec Pyxis LE rotator, QSI 583WSG CCD ( internal 5 position filter wheel), and a Lodestar X2 OAG. I'll be imaging with Astronomik 31mm filters in LRGB, Ha, OIII, and SII. Image processing will be discussed in a later post. 

As far as electronics, I’m using a Gefen USB extender, 2 Digi USB Hubports, and an Edgeport (serial). A couple of RigRunners help keep the 12VDC wiring manageable. It is important that the voltage and signal wire harnesses be separated to prevent any noise. Shielded wires were used whenever possible. Noise is a bad thing when imaging with sensitive equipment. All of the AC wires are kept near the observatory floor and far away from any signal wires. A CPS UX-3 is used to control the AC switching. The mount, camera, and 12VDC power supply are turned on/off remotely using the CPS. Video cameras are used in the ScopeDome to keep an eye on things.

The 12VDC power supply (upper left on the pier) has been relocated to a lower position. As the scope slewed to meridian, I was uncomfortable at how close the CCD camera came to the power supply. 

Power supply wiring is isolated from signal wiring. AC wiring is kept low on the pier.

The bracket I fabricated is a nice platform for the autofocuser, dew heater, USB hub, and one of the RigRunners

The software used to make automation possible include: ACP, CCDAP, MaxIm DL and The SkyX Professional Suite. Other software used to keep things in order include: CCDWare Pempro, CCDInspector, CCD Navigator. A host of other software for focusing, dew control, observatory control, heating, weather monitoring, etc. are incorporated. 

Are we having fun yet? Umm, not quite. I'm still in the wiring and testing stages. This part of the setup will take many months to complete...maybe longer if the weather doesn't cooperate. I'll be ready to balance the rig in the near future so I can finally use the Paramount.

A friend of ours took a look inside the ScopeDome. She said, "Wow! It's a real telescope! I thought it would be a plastic tube thingy. You're really lucky." I replied, "Yes, I'm lucky... to have a wife that will let me do this."         George

Update: The scope is balanced and I have been doing some software tests. I discovered that I often have connection problems. I troubleshot the problem down to the Gefen USB extender. It's not reliable enough for my purposes. I will be replacing the unit with an Icron Ranger 2204. The Gefen was purchased almost 6 years ago. At that time, I was imaging with a Hyperstar and a DSLR. My entire imaging train has been updated and the Gefen is not up to the task. The Icron Ranger will reliably handle all of my equipment for years to come. In the meantime, I have moved the computer into the dome for further extensive software testing. This is going to take some time to get the "bugs" worked out. 

Up next...progress with the exterior of the house


  1. Hello,
    I've seen your photos above of your celestron edge setup.
    I wanted to ask you about your focusers .
    I see you have an external focuser/motor installed after your focal reducer. Does this affect your back focus distance?
    I am assuming you are using this system remotely, is this having some issues with mirror flop at all?

    I have a similar telescope and was hoping for some feed back please .
    Thank you

  2. Thanks for visiting the blog. The main reason I'm using an external focuser is to eliminate mirror flop. I can lock down the mirror after achieving rough focus and use the external focuser to achieve fine focus. FocusMax V4 does a great job with autofocus. No problem with back focus. With the focuser and rotator, I still needed to add a 10mm spacer to get 146mm back focus distance. The QSI(583WSG)camera has an internal OAG so no additional back focus distance is used. No problems with mirror flop or mirror shift. The imaging train has been very far. You might want to check out the Fast Focus System by Optec if you have back focus issues.