A few newbie questions...

[Leebert]

Hi all,

I picked up a new scope the other day and had a go at balancing it and generally getting to grips with it. I have a few questions though as I'm not 100% sure about a few bits.

It's a Skywatcher 200p (blue tube) with 9x50 finder. The focuser has been upgraded to a Revelation dual speed crayford one.

The mount is a white HEQ5 Synscan.

Here we go...

Firstly, I cant quite get the scope to balance in RA. With the OTA on and balanced in Declination, I put the eye piece in and, even with the weights right out, it won't quite balance. It is very close though (possibly needs another Kg or 2). Is this to be expected?

Secondly, the view through the polarscope is difficult to see. I'm guessing this would become clearer when actually pointing at the stars in question? (I'm assuming it isn't illuminated?)

Third and final question, I can't get a focus on stars with the Revelation focuser. To do so, I have to pull the eyepiece almost all the way out and then it will only focus when it's wound all the way out. Do Revelation focusers have an eyepiece extender that I may be missing?

Thanks in advance.

Regards,

Lee

[x6gas]

WRT balancing in RA, it is better if you can achieve balance but this is more important with motorised mounts to put less strain on motors and gears, but if the mount is only slightly out of balance then you should be ok for visual use.

Polar scopes can be difficult to get used to. I'd suggest unscrewing the polar scope and making sure that the optics are clean. Then take a look at astrobaby's setup guide as the manufacturers for some reason have all failed to come up with good instructions... My advice would then be to check the polar scope out in daylight to get used to it and the reticule markings (some polar scopes do have illuminated reticles but I don't think yours does...)

Can't really help with the focusser other than to state the obvious; something's not right! Double check that there is not an extendible draw tube, but the back focus on newts tends to be quite short so I'm surprised you're having trouble...

Ian

[Stephen]

1) It should balance?! Have you pulled the counterweight bar all the way out? If you are struggling, you could get an extended counterweight bar (as I do due to imaging weight) rather than add more weight to the mount.

2) Yes, it's not illuminated. IIRC there is a focus adjuster on the end? I might be imaging that. Get it under the stars and see if it's better then.

3) I also have the same focuser and it's perfectly expected. You will need a 35mm extension tube (get a 2" fitment one) minimum to get most eyepieces to focus. I also need a 50mm to get my 2" eyepieces to focus. The good part of this is you will have no problems focusing DSLR/CCDs and you get the nice dual focus speeds and compression ring fitments.

[hemihaggis]

hi , im assuming as the scope is second hand , as has been modded with focuser ect , you could always ask the seller for some advice ? , and as above the draw tube can be adjusted on some focusers .

yep polarscopes are a PITA till you get used to them . i use a compass to point tripod north then set the adjuster to 56degress or however far north you are . this way you will be at least in the right ball park when you look for polaris . #

and i have heard of people dangling bottles of water off the weight bar ..............

[Jiggy 67]

Polar scopes are notoriuos to make head nor tale of in the dark. Consider this to make life a bit easier

[Leebert]

Thanks for the replies.

The scope is secondhand and the focuser has been upgraded.

My intention which I had discussed with the seller was to take prime focus photography as well as normal viewing. We talked about the photograhy side a fair bit so I guess it didn't come up that a focuser with more inward travel would need an extension for aneyepiece. Although, it make perfectly reasonable sense that it would now that I think about it.

WRT to balancing, the weights are as far out as they can go and the bar is as well - unless the barcomes out a bit further with a 'click' to hold it in position but it didn't seem to. As I intend to fit a DSLR on there as well, I was considering another 5kg weight. The longer bar is about the same money so I guess that would be the best bet as it keeps the overall weight down for the mount?

Thanks for the back up on the polarscope. I think daylight fiddling to make sure it's in focus and then some practising at night.

Many thanks for your help