Explorer 130EM

[hughes70]

Hi, is there anybody who is an expert on the above telescope who could give me an idiots guide through the problems ( prob not set up correctly ) i'm experiencing. When looking through the scope focusing on a star, there is a cross in the middle of it if i zoom in, dont have this problem during the day!

Many Thanks

NH

[brantuk]

Hi NH. I was just showing someone how to set this up before Xmas and have the ota myself. Yes you will see a cross in the ep if you use all the "in focus". You would have to find the focus point by very slowly moving the focuser across it's full range. Go very slow though or you'll miss it. The cross is the spider vanes that hold the secondary in place.

But first - adjust the finder so it is in alignment with the main tube. Do this in daylight on a distant object (eg church spire or pylon tip a good 1-2 miles away).

Then at night you need to align the "mount" with the pole star. Use the two end stars of The Plough to find the pole star - they point directly at it and it lies roughly half way to Cassiopea. It appears as the only star in the neigbourhood there.

To polar align, point the mount due magnetic north and set the altitude scale to your latitude on Earth. With the ota pointing in the same direction as the mount you should be able to see the pole star in the finder. You should see it central in the ep too but if not then adjust the mount using only the az bolts and latitude bolts. Use a 20-25mm ep for this.

Once central in both finder and eyepiece you are polar aligned and ready for observing (imaging requires greater accuracy). now you can loosen both clutches (RA and DEC), spin the tube round to your desired object, lock 'em both back up and engage the motor. Choose the first tracking rate (sidereal) and the object will stay in the eyepiece with only small occasional tweaks in DEC.

Good luck and let me know how you get on

[hughes70]

Many thanks, im going to join a local observatory to help me out, i live in portsmouth and my back garden is south facing, there is a large star at about 1 o'clock which is the only one i can see on its own...thats how basic my star gazing is!!! Looking forward to see saturn etc but wouldn't know where to look at present, i'm led to believe its south east around 6am? This is the 1st scope i've had and have never looked at the stars as you are speaking about them lol. The only motor i have is the one supplied when scope was purchased, think it spins as fast as the earth does but not to sure.

Cheers

Neil