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Can't tune my Coronado Solar Max II 60mm for prominences anymore

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#1 Zebra24601

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Posted 18 March 2019 - 01:55 PM

So, at the risk of looking like an idiot, any reason why this might happen?

 

I bought this back in 2012, prior to the annular eclipse.  I used it for many solar outreach events over the years, and always had at least some prominences to show folks.  Then I didn't use it for a while, then brought it out again for several events in 2017 and 2018.  But now I couldn't find any prominences to tune.  I just get an orange disc, although I can see some the "orange peel" effect on the surface.

 

Last year, someone pointed out that you could tune beyond the range it came with by moving the screw that rotates the tuning knob.  But he didn't find any prominences, either.  Since then, I've tried numerous times, rotating in each direction, repeatedly pulling out and reinstalling the screw to tune far in each direction, but have not had any luck in seeing any prominences.  I mean, NONE!  I am able to focus and tune and still see the "orange peel" granulation on the disc, but no prominences.

 

So the question is, is there any part of a Coronado Solar Max II that can fail over time in a way that would make tuning for prominences impossible, but still be able to tune for "surface" detail?  Have I just been picking days when there weren't any prominences to see?  Have my eyes loss sensitivity at the H-alpha wavelength as I have aged (now 55)?  Any ideas?

 

Zebra24601



#2 George Bailey

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Posted 18 March 2019 - 02:17 PM

Here is what is there now:

 

http://halpha.nso.ed...318095030Lh.jpg

 

Some, but small and faint.

 

Try to zero in on known ones with your scope.

 

Good luck!


Edited by George Bailey, 18 March 2019 - 02:17 PM.


#3 ChrisGTS

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Posted 18 March 2019 - 02:45 PM

+1 to what George said.  Take a look at the current NSO/GONG images and you will know what you are looking for.  My experience with my SM2 is that I can see the larger, brighter ones visible in the NSO/GONG images, but not the really faint ones.  If you see a big bright one on the online image and can't get it in your telescope, then perhaps you have an equipment problem (rusted ITF maybe?).  But in general the sun is not all that active right now.



#4 TimK

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Posted 18 March 2019 - 03:41 PM

If this is a double stacked unit remove the second filter temporarily as it reduces brightness considerably.

Most solar telescopes still seem to have a sweet spot (at least for me). Zoom in a little and place the solar limb in the center of the view.
Then sweep around the perimeter.

I have also noticed that most scopes, when tuned for surface detail (orange peel) do not show prominences well. Readjust the tuning slowly and run through the focus as you go. A very minor focus adjustment can make prominences completely disappear.

#5 Zebra24601

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Posted 18 March 2019 - 03:47 PM

Thanks for the answers to date.

 

It is a single stack.

 

I'll keep monitoring the sun and see if I can do better the next time I've got some free time, a clear sky, and daylight.

 

The point of frustration is that it used to be so much easier!



#6 vincentv

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Posted 18 March 2019 - 05:18 PM

Check your ITF. One of the symptoms is a darker image. It can be good enough to show some surface texture but hide the fainter proms. On the LS60 I can see all the proms from gong even though some require averted vision.



#7 dscarpa

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Posted 19 March 2019 - 03:01 PM

 When my BF went bad in my Lunt 60 proms weren't visible. David



#8 Zebra24601

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Posted 19 March 2019 - 05:29 PM

 When my BF went bad in my Lunt 60 proms weren't visible. David

I was wondering if there might be a possible mechanical reason, something that could break or wear out.

 

I've e-mailed Meade twice to ask about an RMA number for non-warranty service, but they have not responded to my e-mails.  So rather than wait on telephone hold indefinitely, I thought I'd ask about possible user error issues.  Also, I'm not even sure if they offer non-warranty service.



#9 Zebra24601

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Posted 19 March 2019 - 05:31 PM

Check your ITF. One of the symptoms is a darker image. It can be good enough to show some surface texture but hide the fainter proms. On the LS60 I can see all the proms from gong even though some require averted vision.

What is "ITF"? 



#10 vincentv

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Posted 19 March 2019 - 08:43 PM

What is "ITF"? 

It's the first filter the light encounters in the diagonal. If you search for "rusted itf" you'll get a bunch of hits. Your diagonal uses the same ITF as the PST (personal solar telescope). There's a couple of vendors who manufacture replacements and both are better than the original.



#11 johnpd

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Posted 20 March 2019 - 04:32 AM

I brought my 60mm Ha filter up to Lunt last week as the tuning wheel was stuck. They found I had moved it to one end and it was a little tough to get it unstuck from that side. While I was there, they cleaned the filter and BF but noticed that one of the glass elements in the BF had started to cloud-over a little, so they replaced it. Over time it probably would have gotten worse and affected what I was able to see.

 

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#12 TimK

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Posted 20 March 2019 - 08:51 AM

I have experienced some humidity actually inside the diagonal.
I removed the one filter element to let it clear out.
After reassembling the images were much improved.
Now I store the telescope with some desiccant packs.

Edited by TimK, 20 March 2019 - 08:52 AM.


#13 ChrisGTS

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Posted 20 March 2019 - 09:52 AM

I store mine with dessicant packs too, and I also put a UV/IR cut filter in front of the diagonal in case that might help extend the life of the ITF.



#14 Zebra24601

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Posted 20 March 2019 - 12:33 PM

It's the first filter the light encounters in the diagonal. If you search for "rusted itf" you'll get a bunch of hits. Your diagonal uses the same ITF as the PST (personal solar telescope). There's a couple of vendors who manufacture replacements and both are better than the original.

Huh.  Thanks, Vincentv!

 

I'll take a look.  I googled ITF yesterday, and got a bunch of tennis hits.  Adding "rusted" made all the difference!



#15 gnowellsct

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Posted 21 March 2019 - 12:05 PM

Well it's a different system but your description of the sun sounds a lot like a Quark that hasn't heated up, FWIW.  But listen to the owners here they know more than I.

 

Yesterday visually I had two large prominence groups to play with and a sunspot dipole.  The fringe of spicules on the solar limb shows with remarkable detail on this scope, I don't know whether I never noticed them before (in my other scope) or whether that scope didn't show them.

 

Greg N



#16 Zebra24601

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Posted 21 March 2019 - 12:26 PM

Between work and weather, I haven't had time to actually check the ITF.  But given when I have found on the various fora, and the age of the Coronado, I'm betting that's the problem.  So I did have time to check the website of the company that made the drop-in replacement, but the item is listed as out of stock.  I fired off an e-mail yesterday, and have not yet heard back.

 

I didn't realize when I bought this that the operating lifespan without potentially significant reinvestment was so short.  If I can't get the drop-in ITF, I'd have to buy the whole blocking filter assembly, which is $500!

 

I was tempted to get the 90mm SolarMax II, which is being cleared out by various vendors.  I looked through one back when they had the PATS telescope shows in Pasadena, 8-10 years ago, and it knocked my socks off.  Clearance prices are tempting.  But if I'm only going to get 6-8 years of use before needing to buy another blocking filter, the appeal is severely tempered. 



#17 gnowellsct

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Posted 21 March 2019 - 12:33 PM

 

I was tempted to get the 90mm SolarMax II, which is being cleared out by various vendors.  I looked through one back when they had the PATS telescope shows in Pasadena, 8-10 years ago, and it knocked my socks off.  Clearance prices are tempting.  But if I'm only going to get 6-8 years of use before needing to buy another blocking filter, the appeal is severely tempered. 

That was one of the things that tilted me to a quark.  If the etalon fails I'll still have my apo and a couple of power mates.  I have no idea how long these systems last.  $1200 bucks though.  If it dies after 5 years that will be a disappointment to say the least.  

 

On the other hand, the views of the sun are entrancing.  Few people ever get to see stuff like that.  Except on line.

 

Greg N



#18 vincentv

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Posted 21 March 2019 - 01:43 PM

So I did have time to check the website of the company that made the drop-in replacement, but the item is listed as out of stock.  I fired off an e-mail yesterday, and have not yet heard back.

There's two manufacturers: Maier photonics and beloptik.de

 

But if I'm only going to get 6-8 years of use before needing to buy another blocking filter, the appeal is severely tempered.

Only the ITF has a limited life. The rest of components will last much longer. The Maier is an ITF but better sealed than the coronado, I haven't read any reports about a failed maier. 

The beloptik is supposed to last indefinitely. Either way you get a filter that will last a long time and is cheaper to replace than the whole blocking filter assembly.



#19 Zebra24601

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Posted 21 March 2019 - 02:19 PM

The Maier is attractively priced, but, as noted, out of stock, and they have not yet responded to my inquiry.

 

The German company is priced about $100 higher, plus what ever shipping would be.  I have requested a quote from them, in the event that Maier Photonics does not get back to me or can not supply the filter.

 

Thanks!

 

 

There's two manufacturers: Maier photonics and beloptik.de

 

Only the ITF has a limited life. The rest of components will last much longer. The Maier is an ITF but better sealed than the coronado, I haven't read any reports about a failed maier. 

The beloptik is supposed to last indefinitely. Either way you get a filter that will last a long time and is cheaper to replace than the whole blocking filter assembly.



#20 Zebra24601

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Posted 07 April 2019 - 01:30 PM

<p>So, here's what happened: Presumably because of the age and never having disassembled the blocking filter diagonal, I could not unscrew the silver-colored barrel (objective side). With some effort, i was able to unscrew the black tube (eyepiece) side.</p>
<p>&nbsp;</p>
<p>Once that was off, I could see what should be the &quot;red&quot; side of the ITF. It was mostly green (rusted), but still slightly reddish, near the center.</p>
<p>&nbsp;</p>
<p>Having confirmed the rust, I tried to use a spanner wrench to remove the retaining ring that holds the ITF to the mirrored end of the diagonal. But I couldn't get a good grip with the spanner wrench. Ended up pushing the filter holder right out if the barrel. Turns out it's glued to the end of the barrel.</p>
<p>&nbsp;</p>
<p>So now I REALLY needed to separate the silver barrel from the diagonal. Ended up taking the blocking filter diagonal to work, where a vise grip and a REALLY tight grip with an adjustable wrench eventually managed to loosen the silver tube from the diagonal.&nbsp; That freed the filter assembly.</p>
<p>&nbsp;</p>
<p>Once out, it was out, it was only moderately difficult to loosen the retaining ring and switch out the ITF.</p>
<p>&nbsp;</p>
<p>All that's left now is to glue the filter assembly back on to the mirror-end of the silver barrel, and I'll be back in business.</p>


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