WO 2" Diagonal & Meade LX90

[dwc]

I recently purchased a WO 2" Diagonal for use with an LX90 SCT, using the supplied SCT adaptor to connect it. It works beautifully, except, it is too long and snags the mount when approaching vertical.

I assume there is nothing I can do about this, I can only think of finding a smaller adaptor for fitting to the back of the scope.

The other thing I'm not sure about is whether I can program the handset to prevent it from reaching the snag point, like a maximum elevation.

Am I likely to encounter this with any 2" diagonal, or am I just unlucky settling for the WO?

Paying the price for inadequate research before purchasing !!

[John]

Are you using a "push fit" SCT adapter Dave ?

These can project further from the back of the scope than using an SCT fitting diagonal which screws straight onto the port at the back of the tube.

[alan potts]

DWC,

I have a Meade SC 2 inch back that I did use with the Meade diagonal, and I don't recall this happening. The Meade back is a two part affair as it can have the reducer in the mix without making it longer. You can even use it shorter if you wish. I don't believe the diagonal will be at fault. I no longer use the SC back so if you PM we can talk if you wish to have it, that's if I can find it, it's a long time since I used it as I have had a crayford of one type or another fitted ever since.

Alan.

[dwc]

Thanks both.

The fitting supplied with the WO came in a separate box. It screws into one end of the diagonal just as if it was a filter. The other end screws directly onto the back of the LX90 in place of the original. I'll try to upload a photo later.

I guess my next step shouLd be to contact the supplier to see if they have different fittings. It wasn't clear if WO actually supply the fitting or if the supplier bundles a 3rd party fitting.

Dave.

[dwc]

Her's a rough picture of the WO plus supplied fitting. I'm assuming that is a visual back. It has threads at both ends, one attaches directly to the back of the LX90, the other to the filter thread on the diagonal.

Researching some forums I guess I should look to see if there is a shorter VB available. I'll do some measurements later to see exactly what the tolerances are.

Also, it does seem you can limit the elevation in the S/W.

Dave

[John]

I think there are lower profile fitting diagonals than that available for SCT's.

Look at this one for example:

http://www.scopesnsk...dielectric.html

Telescope House sell the above as well.

[alan potts]

I can see the situation here. The fitting Meade make screws to the back of the scope and the diagonal slides inside it. I have never seen this type of fitting before but it would appear that you end up with a greater distance. Sadly and I know it's stating the obvious but you should have used a Meade dealer. You need the correct 2 inch back as far as I can see.

To the best of my knowldge you cannot limit the elevation.

Alan

[dwc]

Here are the dimensions:

The total length of the WO when fitted is 140mm.

The available gap is 120mm.

In contrast the original Meade 1.25" diagonal is 85mm fitted.

I've emailed the supplier for advice.

And yes, having read the manual, there is no way to limit the movement apart from common sense and paying attention!

[alan potts]

DWC,

I thought there was some way to limit something but it is when it crosses the meridian that can be limited.

I have just measured my 2inch back now I have found it, and the Meade 2 inch diagonal and it comes to 145mm at it's full length so the sleeve would have to be un-screwed to use just the one part. This done it comes to 113mm, so on your scope there is not much in the way of room.

I have 195mm on mine but it's a bigger scope..

The WO is a nice diagonal I bet you are somewhat miffed, I know I would be.

If I can help more let me know.

Alan

[John]

If it's any consolation, there is little or nothing to choose optically between the Revelation, William Optics or Meade dielectric diagonals. So if you have to move to another type the performance will not suffer at least.

[alan potts]

John,

Even with the correct fitting which I have here in front of me it don't give you a lot of room. The WO diagonal is the same as any other it will just slide into the SC 2 inch back and be heald in place by the two thumb screws. I have to say the Meade back is not the best divice I have ever seen but it works and I cant say it has marked my diagonals, but it has only ever had light use before I moved to a focuser.

Alan

[dwc]

Well, having got a response from the supplier, it turns out it was all User Error!

I didn't realise the supplied SCT Adaptor was to REPLACE the standard barrel on the diagonal!

As they has matching screws I just fitted the adaptor onto the barrel, and hence the unusable overall length.

Now I have removed the barrel and fitted the adaptor instead, it is a perfect length.

[John]

Oh gosh ! - we have all been there Dave !

I'm glad it's sorted now. Having a 2" diagonal gives you all sorts of interesting eyepiece options

[alan potts]

I am pleased to see it is OK now, I have never seen that fitting before, as John said we have all made mistakes and I am sure I have not finished yet.

Alan.