Coronado SolarMax II 60 - getting it double stacked

[goober]

I'm thinking of dropping some cash to get my SolarMax II 60 double stacked, but I'm a bit confused by what I need to do.

The manual says to pick up part SME60 - that's the easy bit.
I got the impression it simply screws over the front objective - there is a thread there.

My question is I see some sites declaring I need a Coronado mount adapter ring to make this work? Is this true? It doesn't simply screw onto the front of the scope? I do need an adapter to put a Coronado product on a Coronado scope?

Any advice much appreciated.

[Merlin66]

Doug,
I had one of the original SM60 and added the front double stack filter.
It's a standard SM60 etalon but needed the T-Max tilt adjuster to give optimum tuning. This plate is usually part of the filter assembly, but you could double check with the supplier.
Hope this helps.

[goober]

Thanks Ken - the SME60 part is the Tmax / second etalon combined, that sits over the front of the scope.

Just not sure if it simply screws onto the scope, or I need an adapter ring. I've read both and thought someone here may have been through the procedure :)

[Merlin66]

Doug,
Mine just screwed onto the front of the objective.
I can't think of any good reason why they would change the thread size.

[goober]

Great, that is what I would have hoped :)

[yoda776]

Please let me know how you go as I have a Colorado Solarmax II 60 and was looking at it being double stacked.

[goober]

I haven't pulled the trigger yet, as I can't get a definite answer from any supplier. I popped something on Cloudy Nights, but nobody has responded to that either.

I don't want to order it without being certain it will slip right onto the scope.

Seems crazy that it won't simply screw onto a SolarMax scope - but I'm firmly in the TeleVue world where everything works perfectly. :)

[barx1963]

This could be wrong, but I was told that Coronado would only do a Double Stack filter if the scope was returned to them and they would fit it. The reason was that it needed to be tuned to match the specific scope.

Malcolm

[GUS.K]

You can ask Bintel,as they sell the Coronado scopes, they would know if you need an adapter or not. (Try Michael at the Sydney store).

[Hans Tucker]

If it is anything like the SM40 you will need an adapter plate. For the SM60 I think it is the AP186

[N1]

I thought this all sounded familiar...;)

I have a front-mounted SM60 II filter (so this may be different to your situation if you have the scope) and have been looking at double stacking this the "traditional way". Some searching and corresponding with Agena Astro about a year ago resulted in the following:

1. You need the SM60 double stacking etalon with RichView tuning (the one that's not suitable for single stack use (Meade has confirmed this)

2. You need adaptor plate AP186 (Hans is correct and Meade has confirmed this also)

3. At the time, Meade would have been able to supply the etalon but not the adaptor plate. And no-one knew when it would be available (a common problem resellers have with Meade - they are notoriously unreliable with items they don't have in stock at a given moment). Note that the adaptor plate is not rocket science. I've had a similar adaptor made by the guy I bought my FS60 from in Europe. This was needed to attach the SM60 to the FS60.

4. Is factory matching required? Not necessarily, but remember you are mating two elements both of which are subject to normal variation in production. Individually, that may not be a problem, but by combining them you may be compounding 2 initially unproblematic errors to make one that's beyond the tuning system's ability to compensate. I imagine this would happen if both elements were to deviate from the norm in the "same direction" if that makes sense. But I'm not an engineer. Suffice to say it is a slightly risky approach.

This may or may not be of help, but I thought I'd share it here.

Ken & others, I have another idea for a DS solution, which I'd likle to run past you some time & ask your opinion.

$0.02 - YMMV

[goober]

Okay, so it sounds as if there a few generations of product out there, hence the confusion?

Some replied on Cloudy Nights to say the SME-60 double stack unit screws directly onto the front of the SolarMax II 60 - so I'm almost convinced ;)

[Merlin66]

Mirko, et al,
The original SM60 scope was fitted with a front external etalon.
The later SM II versions changed to a smaller internal etalon.
My experience has been with the original SM60 arrangement.
The threads on the front of the etalons are different from the rear threads hence the need for an adaptor ring if two are to be mounted together.
There is no need to have the etalons "factory tuned".
It's a bit of a fiddle to achieve good double stacked performance, but can certainly be done.
I use an SM60 as a front double stack filter on a TS102 PST mod and the results are impressive!!
If you have some other ideas for double stacking just drop me a PM for discussions.

[goober]

Well, a happy ending. My SME-60 double stack turned up today, and it threads straight onto the SolarMax II 60's front cell. No adaptor needed.

[barx1963]

Doug
Where did you end up getting the DS unit from?

Malcolm

[goober]

Malcolm - I sourced it from OPT Telescopes in California - expensive, but very professional to deal with.

I tried a few local outlets, and the responses ranged from "we've had them on order since February" to no responses at all.

[yoda776]

Hi Doug / Malcolm,

After grabbing the Colorado Solarmax II 60 from you (Malcolm) I got lucky and there was a double stack unit on IceInSpace, so bought that. Just arrived yesterday. Actually grabbed mine from John Wilkinson.

I agree Doug, mine went straight on just attach to the front of the Solarmax II. Now for that elusive sunny day ... :P

Can't wait to try mine out. We might have to compare notes Doug. :)
Cheers,
Matt

[yoda776]

I certainly have heard the same which is why I bought the secondhand one here on IceInSpace. Meade have had a history with supply issues previously, which prompted my purchase when I had a chance!

[goober]

I spent about 30 minutes with mine today - literally the first time Melbourne's seen the Sun in a week. Immediately impressed with the improved contrast on the solar disk - features were much more evident and interesting. I had read that prominences were fainter in a double stack, but I didn't find that at all.

Now, I'm not an experienced solar observer (at all - just beginning) and need to do some reading on Halpha observing to understand the features I'm viewing, but the double stack showed a lot more detail. I didn't have to do a lot of tuning - it more or less popped right out.

I dialed up the Learmonth image on http://halpha.nso.edu (Gong) and compared the view in the eyepiece - I could see almost every feature on the Gong image.

I imagine the views getting better when the sun is higher in the sky during the warmer months? Quite addictive, and just SO easy to set up and observe during the daytime :)

[yoda776]

I hear you on the sun finally coming out. We had a couple of good days in Adelaide. I noticed the immediate and impressive look of the sun's surface. The contrast was excellent. I did not have to tune much either and the double-stack did not really cause any faintness of image.

I am just beginning myself and been told it takes a while to get used to viewing. I have been told that viewing in completely clear days are best. I can imagine if we are lucky during winter and get a clear day after rain, the pollutants in the sky may have cleared more to get the optimum view.