From: "Tim" <tjp314@pacbell.net>

Date: June 29, 2008 11:52:20 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: Cables, adapters, and stuff

Milton:

I like the serial port hub idea.  Last night was the first time I

really put the focuser control option of Equinox Image through it's

paces instead of just running the robofocus software on the PC, and I

was rather impressed with it.  

I also think you're right about the mirror flop in SCTs.  Since I'm

guiding with the 9.25", I have this problem around the zenith - which

is unfortunately where the least atmosphere is getting in my way. 

Last night, I took two image sequences.  The first was of M13.  The

whole sequence was over before it crossed the meridian, though, and I

had no noticeable flexure or mirror movement (but I haven't processed

the images yet and they were only 5 minute exposures IIRC).  But for

the Dumbell, I shot 20 minute exposures, and when I was shooting the

green frame, the scope was crossing the meridian (around 2am, I think

- I used my cell phone as an alarm to take naps while imaging).  The

clear and red frames are very nice and sharp, but the first green

frame was trailed.  I started a 2nd green and took another nap, and

found it had trailed again, but with a jump, and so a gap showed in

all the trails.  By then, it was 3am and I had a headache from so many

catnaps, so I buttoned everything up and stared at my eyelids for the

rest of the night.

If the 9.25" was easy to take out of its forks (it might be, I've just

never done it), I'd make a cradle to support my 6" f/5 Jaegers and 5"

f/5 Jaegers together (the latter needing a new OTA), and use one for

imaging and the other for guiding. But I'd want to be able to go back

to the 9.25" for planetary imaging.

Or...   ...hm.  If I made a folded refractor out of that 6" f/15 lens

I have, with 2 folds, that might fit nicely in place of the 9.25".

But probably I should just rig up a mirror locking setup for the

9.25".  That would require disassembling the OTA, though, to drill

holes in the backplate for lock screws.

Finally, the other way of getting around the mirror flop problem would

be to use another fixed-optic scope as the guider.  But I've already

got a lot of weight on the 9.25", so I'd have to think about this a bit.

-Tim.

--- In Astro_IIDC@yahoogroups.com, Milton Aupperle <milton@...> wrote:

Hi Tim;

Your best bet is to get a multi serial port device like

USB 4-Port Serial Adapter

http://www.keyspan.com/products/usa49wg/

That gives you 4 serial ports , which should be enough for Equinox  

with the temp focus controllers, assuming Equinox can use both at the  

same time.

As to Flexure. I've have determined that the lions share of my  

flexure is mirror movement on the C8 scope. Unless I can lock the  

mirror down, a second guide scope simply will not work for me.

HTH..

Milton J. Aupperle

On 28-Jun-08, at 7:09 PM, Tim wrote:

Milton et al.,

I've just about got my rooftop "observatory" doing all the things I

want it to (which is a lot!), but I have some questions.

Here's what I have... get yourself a cup of coffee or a beer, and make

yourself comfy. This is complicated. Actually, you might want to

skip to the last paragraph for the question, and then if you're

curious, read the rest!:

Nexstar 9.25GPS that I control with either Equinox 6 or Voyager 4 on

a Mac Mini or a G4 laptop, or TheSky 6 on an HP laptop. Both the macs

are running 10.4. The HP is running windows xp.

Megrez 80, in Losmandy adjustable guide scope rings on the 9.25.

I've currently got an SBIG ST2000XM mounted on the Megrez. Equinox

Image runs it and the CFW-10 just fine, with the usb cable plugged

into the Belkin hub on the Mini.

On the 9.25", I've got a Meade f/6.3 FR and a Pt Grey Flea2 color

camera that I run using Astro IIDC. This scope is the guider, when

I'm imaging with the SBIG, so I've got a GPUSB plugged into one of the

USB ports on my G4 laptop, and the Flea2 in the Firewire 400 port for

guiding.

Also piggyback on a Losmandy Camera adapter, I have a Pt Grey Flea

color camera with an 11mm c-mount lens on it - makes an awesome

finder. This one runs off Astro IIDC as well, with the firwire 400

cable plugged into a Belkin hub on the Mini.

Now it gets intersesting. I have a Robofocus on the 9.25", and I just

added one to the Megrez. But since I only have one keyspan serial to

usb adapter, I can't have the scope connected to the computer AND run

one of the focusers at the same time, and I'd like to run both.

So, maybe my question is: If I have enough usb ports (between the 2

macs and the Belkin hub, I should, even with my speakers and printer

plugged into a couple), can I simply add a couple more Keyspan

adapters and have everything work happily together?

-Tim.