I observe via live video from a second floor bedroom. The scope is an 8" f10 LX200 outside the garage, alt-az mounted on a portable tripod. There are two video feeds and four RS232 conductors running from the garage to the second floor bedroom (AKA "the computer room"). The scope carries both a finder camera and a prime focus camera. The finder camera aids in landing small objects on the prime focus camera chip.
With the setup described below, I am able to set up and begin observing via remote video in about five minutes.
The scope is a Meade LX200 8" f10, with a JMI NGF-S focuser driven from the focuser output from the scope front panel.
Supercircuits PC23C, modified to prevent the video gain from rising excessively on small bright objects. The best $80 I have spent in a while. 400 line resolution and very good low light sensitivity. And after modification, no bad habits either.
The finder camera uses a 135mm f2.8 camera lens and results in a reasonably wide view while still allowing objects to be easily and accurately landed on the prime focus chip. I use a 9" B/W monitor for the finder, and a red fine tip felt pen to draw a box with a center dot on the CRT face representing the prime focus chip and its center. Like shooting fish in a barrel!
The RS232 is used to control the scope from either ECU (Earth Centered Universe) or ACP (Astronomer's Control Panel). Total cable run is approximately 50 feet, and works flawlessly.
Images are captured direct to hard drive with an ATI All In Wonder Pro capture card, which so far has produced excellent results.
All DC powered devices are powered from a 12V supply modified to produce 15VDC.
Some time ago, I bought a couple old VHS camera extension cables at a hamfest for just such a use. And now they came in handy! VHS camera cable has four video cables and three plain conductors terminated in good quality 10 pin connectors. I use two video cables as video, and the other two (that have a shared ground) as RS232 conductors. The scope only needs TX, RX and ground, so that works out fine. It also turns out that I bought a short cable and a long one, so I cut the short cable into two pieces and used them as end of line pigtails. One was stripped and the conductors fanned out for use on the scope. The cables snake up from the fork arm through the side handle, through the OTA center handle, and then to the cameras. I also have an un-coiled replacement for the focuser cable that follows the same route and avoids a tangle when the scope slews. The end of the cable is velcro'd to the side of the fork arm and hangs down. The other piece was left longer and also stripped and fanned out. It is the garage end of the affair, and terminates to the power supply, a telephone jack (for the RS232), and the two video cables running upstairs.
Scope control is via Earth Centered Universe, a terrific shareware program that costs about $50 to register. I have used it for years, and have found it to be extremely stable and to do exactly what it is supposed to do. It contains stars down to mag 10 and other objects down to mag 20 or so. Scope control is very good. It will center on any object you click on, has manual slew and focus controls in a movable dialog box that can stay on the screen while you navigate the chart display, and also has a coordinate display that shows the RA and DEC of the current scope position.
And a note to any daytime observers.... ECU is the only easy way to align the LX200 in the daytime using the sun. First level the tripod. Then put on the solar filter, use ECU to slew to the sun (the LX200 will do that if in response to the RS232 port), center the sun and use the SYNC button in the ECU slew panel, and you're aligned. Simple!
Scope control is also via ACP (Astronomer's Control Panel from DC3 Dreams. This program allows full scope control and alignment via RS232. With the finder camera, I can do a two star alignment remotely without having to go to the scope. I also have full control over all scope functions including two star alignments (remember the finder cam?) and tracking speeds (ie., lunar, solar, sidereal, etc.).
Image processing is via Picture Publisher version 8.0. Picture Publisher has many ueful features such as unsharp masking with selectable pixel size and weight, histogram scaling, sharpening, and a powerful macro routine that allows buttons to be created that practiaclly automate making JPEGs and thumbnails of my raw images. In addition, it has a very useful feature that previews the compressed JPEG at any compression depth, allowing compression to be tailored to the individual image.
To set up for an observing run, all I have to do is set the tripod in the desired location, mount the scope, level the base accurately (the built in level is accurate on mine), set the OTA to south and level (by eye), plug in the remote cable, turn the power on, and go inside. From indoors, I use either ECU (daytime) or ACP (night time) to slew to any GOTO object (including the sun if using ECU). I'm usually close enough that I can see it in the finder cam. Center it and sync (you can do that from either ECU or ACP) and I'm aligned and tracking. Essentially a one star alignment. To further refine it at night, I can GOTO the first star in a two star alignment since I'm pretty well aligned anyway. Note that I have found that the scope will not communicate via RS232 if the hand controller is not plugged in.
PC23C video gain modification
Back to the main astronomy page