More work on the system

Tonight there’s a full moon.  Normally that’s not a great time for star gazing but it doesn’t matter so much when you use a camera.  I’m out at my observatory in northwest Arizona and the weather is fantastic (as usual).  The goal for tonight was to setup the entire system and get an inventory of cables or gear that is need to make the systems complete.  I also picked up a few ideas for how to better run our systems along with a few lessons learned.

The DVR is going to be a tricky beast to keep under control.  It seems that when it’s first turned it immediately begins recording.  A nuisance as long as you know about it.  There’s also a configuration setting relating to recording length.  What this really means is that if you set it for 5 minutes, then after 5 minutes of recording, it will stop recording, save the file and then immediately start another recording.  No matter what, you still have to tell it to stop recording.  Another issue that’s going to take more study is power.  Our DVR has a built-in battery but I haven’t figured how long it’s good for.  If we need to power the unit we’ll need some type of power converter.  The simplest thing is a DC-AC converter.  But, if the battery has a USB connector we might be able to power it from that.

Setting up the camera and IOTA-VTI box does require a few cables, some of which came with the equipment and some not.  We’ll need one BNC to RCA video adapter, a couple of DC power cables, and a power splitter cable.

I also had a bit more practice with the telescope.  For now I’m using the stock finder but I really don’t like it.  I see that it definitely affects the balance of the telescope, making it more tail heavy.  Tonight I used the default “Sky Align” option on the telescope.  I was able to do this while it was quite bright out, in fact, this is the perfect time to do so since you will certainly get the brightest stars that are needed for the alignment procedure.  I did a little bit of testing of the telescope’s ability to find objects.  It worked reasonably well but perhaps not as good as what I’m used to on my old telescope.  Perhaps that’s just because I know the old one better.

I did look at the power connector issue a bit as well.  I got a great suggestion from Dean at Starizona and I tried it out tonight.  He said to take the power cord and tie it around one of the forks and then plug it into the base.  This way, as the telescope moves, the fork pulls the cable around and it avoids putting stress on the power connector.  For me this worked just fine, at least this night.

At the end of my testing I’ve got some video data saved that I can dig into to learn about data quality and timing information.  I want to get reasonably good values for the field of view with and without the focal reducer as well as some idea of how faint this camera can get.

2 thoughts on “More work on the system

  1. Reading Marc’s blog regarding using the new Celestron scope, Just thought I would pass a few things along.

    Even though my older Celestron CPC 1100 doesn’t have the power cord problem I still wrap the cord around the handle attached to the fork and tie a loose overhand knot. This helps hold it in and seems to hold better than wrapping around the fork.

    I agree the stock finder is not very useful. I only use it if I forgot the Telrad or the battery went dead. I have attached a Telrad and actually placed it toward the front of my scope. I did this not because of weight but because of everything else on my scope this was the only place to fit everything. However putting a Telrad toward the front of the scope should help balance the scope.

    I agree dusk is a great time to align the scope. A few years ago I was at Great Basin National Park which is a dark sky area. All the stars appear bright through the stock finder and I kept picking the wrong stars. If I had a telrad them I probably could have worked it out.

    One tip for a faster alignment if you haven’t figured it out yet. On the first bright star you go to with the scope just loosen the clutches and manually push the scope the star. You then fine tune it with the hand controller. Be sure to tighten the clutches (I have forgotten to do this numerous times.) This can save a few seconds aligning the scope. I also find picking 3 stars as far away from each other as possible helps for a better alignment. Also, lower seems to be better for a good alignment. Stay away from anything close to zenith. After you have aligned the scope you can also pick a few other stars to fine tune the alignment through the hand controller.


  2. Well, during last night’s observing I had what must have been my first power glitch, thanks to the goofy power plug. I find that I’m quite often bumping the connector with my gloved hand as I work. It’s really hard to avoid. Well, after one such bump the sound of the telescope drive changed. I thought I’d reset it for sure but when I looked at the control paddle it looked like everything was fine. A few minutes later I noticed that the telescope was tracking very poorly. Eventually I figured out that its coordinates were completely screwed up. I had to start all over on the telescope setup. By then it was quite dark and it took a couple of times to get an alignment to work since I kept picking stars the telescope doesn’t know for alignment. One of the best suggestions I have heard so far is to replace the stock plug with a low-profile right-angle plug. Oh yes, I really miss the Telrad. I don’t have the new one for this telescope yet (it’s sitting back home on my desk).

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