Lunt LS60 users - advice please

[jonathan]

I may be imagining things, but I've used my solar scope so little in the past three years that I've forgotten what it's supposed to look like, I'm sure I remember things being much sharper, clearer, and with greater contrast when we had all the solar activity before the minimum.

Presently when I view the sun through the scope I get quite a light red background in the eyepiece, almost like when there's a full moon, the proms are barely visible against it and I don't seem to be getting much granularity or filaments (feels like the contrast is missing).  Is there something I need to check on the scope?  I appear to have misplaced the instruction manual, perhaps there's something I'm not doing right during setup but I really can't think what.

I've tried different eyepieces so I don't think that will be the problem.  Check my signature for the precise model.

[AdeKing]

If you've not used it for a while, then you could check the blue ITF filter on the eyepiece side of the blocking filter diagonal, these have a habit of going cloudy.

If it's gone cloudy, you can either order a replacement from Bresser Europe or if you're happy to carefully remove it by unthreading the retaining ring then you could spray it with some Viakal limescale remover leave it to do its job for a while then rinse it off and gently clean it with Baader Wonderfluid.  

See thread here.

Is it single or double stacked. If it's double stacked, check you are looking at the image of the sun and not one of the reflex images caused by the double stack. I made that mistake myself recently when I wasn't paying attention.

https://luntsolarsystems.com/wp-content/uploads/2018/08/Double-stack_manual1.pdf&ved=2ahUKEwisj8Pn7vnoAhUytHEKHb05CrwQFjAAegQIAhAC&usg=AOvVaw1qqBlvIffrJob6vaCBl6Q1

Hope I've been of some help.

Ade

Edited April 21, 2020 by AdeKing

[Owmuchonomy]

Is your pressure tuner working correctly. Can you hear it ‘pop’ when you release the pressure. Does it then recharge ok? It could be the sealing ring has degraded in that time?

[Peter Drew]

The Sun is currently lacking in all visual departments due to the point in the solar cycle.  No comparison with the appearance a few years ago.  Things will improve!     😀

[Davey-T]

As mentioned the pressure tuner may need regreasing, mine stopped working after being unused for a while.

Dave

[jonathan]

25 minutes ago, Davey-T said:

As mentioned the pressure tuner may need regreasing, mine stopped working after being unused for a while.

Dave

Hmm, I can definitely hear a brief hiss when I release the pressure tuner all the way (I don't remove it, but it comes to the end of the thread), perhaps it could do with a bit more grease though - will any normal car grease do? 

I'm hesitant to remove the PT completely, is it safe to remove and inspect?  It does appear to work still (gets stiffer as I tune inwards), difficult to tell how well though with the contrast problem.

[jonathan]

1 hour ago, AdeKing said:

If you've not used it for a while, then you could check the blue ITF filter on the eyepiece side of the blocking filter diagonal, these have a habit of going cloudy.

If it's gone cloudy, you can either order a replacement from Bresser Europe or if you're happy to carefully remove it by unthreading the retaining ring then you could spray it with some Viakal limescale remover leave it to do its job for a while then rinse it off and gently clean it with Baader Wonderfluid.  

See thread here.

That sounds like an avenue worth investigating!  So long as I can't damage the filter by using chemicals...  I might email Bresser Europe first to see if they're able to send out a replacement lens (after I confirm if that is the problem).

Thank you all for your replies!

[Davey-T]

3 minutes ago, jonathan said:

Hmm, I can definitely hear a brief hiss when I release the pressure tuner all the way (I don't remove it, but it comes to the end of the thread), perhaps it could do with a bit more grease though - will any normal car grease do? 

I'm hesitant to remove the PT completely, is it safe to remove and inspect?  It does appear to work still (gets stiffer as I tune inwards), difficult to tell how well though with the contrast problem.

You can unscrew it completely and check grease and O ring / rings, needs to be the right grease which I can't remember ATM.

Dave

[jonathan]

OK, I checked and it's the blue lens at the front end of the B1200 blocking filter diagonal that has clouded up with residue / deposits of some kind.  Email sent to Lunt so we'll see if they get back to me in the next day or so, otherwise I might as well go ahead and try the cleaning suggestions from that other thread, they don't sound too hard to do.

Edited April 21, 2020 by jonathan

[richard ashbee]

Is the clouding of the Blocking Filter a common problem? anything you can do to stop this happening?

[AdeKing]

9 hours ago, richard ashbee said:

Is the clouding of the Blocking Filter a common problem? anything you can do to stop this happening?

It's not the actual blocking filter, it's the blue ITF filter which forms part of the diagonal which houses the blocking filter.

Yes, It's a very common problem.

Its recommended by some to keep the blocking filter diagonal in a sealed container with silica gel when not in use, but I think this just delays the issue rather than solving it completely.

Edited April 22, 2020 by AdeKing

[Merlin66]

Richard,

unfortunately yes. Both the ITF filter in the Coronado and the BG38 in the Lunt are subject to failure. 

These filters form part of the “Blocking filter” assembly, the second element is the “sort/ blocking” filter which is a narrowband filter (usually around 8 to 10 A) to isolate the etalon pass wavelength at the H alpha wavelength.

 

[richard ashbee]

What is the cost of replacing the part? - thanks

[tooth_dr]

1 minute ago, richard ashbee said:

What is the cost of replacing the part? - thanks

I was sent to part free from Germany on behalf of Lunt, but I 'think' it costs around £30 as someone on here bought one.  I bought my scope new in 2017, so I would say that this failure is quite premature in the lifespan of the telescope.

[Merlin66]

Maybe premature but not unusual.....?

[AdeKing]

1 hour ago, richard ashbee said:

What is the cost of replacing the part? - thanks

If you contact Bresser in Germany with photos and the serial number of your Lunt then they have so far been issuing replacements free of charge. 

Can't remember but they might charge for postage, I can't remember.

They also provided me with replacement o-rings and grease for my pressure tuner.

[tooth_dr]

1 hour ago, Merlin66 said:

Maybe premature but not unusual.....?

Is it expected that these filters fail?  I don't know?  Not my field of expertise.  I expect components in anything to fail eventually, but I feel that 2 years is premature.

[tooth_dr]

16 minutes ago, AdeKing said:

If you contact Bresser in Germany with photos and the serial number of your Lunt then they have so far been issuing replacements free of charge. 

Can't remember but they might charge for postage, I can't remember.

They also provided me with replacement o-rings and grease for my pressure tuner.

I didn't pay for postage with my blue glass.

[Davey-T]

I wonder if Telescope House would consider holding a few in stock for the UK market.

Dave

[Carbon Brush]

I got a new 'blue glass' last year free of charge from Bresser Germany.

There are various reports of people successfully cleaning the filters using kitchen/bathroom cleaners.
I know it sounds wrong on optical surfaces, but there are quite a few success stories.

As Peter Drew pointed out, the sun is just a boring disc right now.
I have seen only the odd 'whisker' of prominence this year.
In fact I wondered if my scope was working until I read similar reports from others.
The really good looking images on SGL seem to have come from lots of stacking and image processing.
Not like the 'good old days' when I upraded from white card to a PST, seeing spots every time out.

This is a good site to look at before going to the bother setting up your scope...

https://www.spaceweatherlive.com/en/solar-activity

89 spot free days in 2020!

One day things will change.

David.

[Ibbo!]

I got mine FOC last year.

It did make a difference.

[AdeKing]

3 hours ago, tooth_dr said:

I didn't pay for postage with my blue glass

Thanks for confirming, I didn't think I had, but wasn't 100% sure.

1 hour ago, Carbon Brush said:

I got a new 'blue glass' last year free of charge from Bresser Germany.

Thanks.

 

[richard ashbee]

Are the free ones from those that failed during the warranty period ?

[Ibbo!]

Not sure mine was still in warranty  but it was free.

 

But even if you have to pay they will not break the bank

https://luntsolarsystems.com/shop/solar-products/hydrogen-alpha/lunt-replacement-parts/blue-glass-for-lunt-blocking-filters/

 

[jonathan]

Having contacted Lunt and then Bresser, a new blue glass lens is on it's way to me now.

Lunt mentioned that users have had success using a cleaning solution called CLR, I wonder if anyone in the UK knows of an equivalent?  I have removed my blue glass lens and tried various cleaning products on it but there's still a 'stain' on one side, I tried the strongest thing we have in the house - Harpic toilet cleaner (bleach) with limescale remover, it did nothing.  I'm beginning to think that what I can see is actually etched into the glass.

Another thing to mention - I was told by Bresser (just this morning, while arranging for my replacement blue glass) that the new blue glass has a special coating to prevent the mineral deposit from happening, definitely something to be aware of and try not to damage!  I don't know when this new blue glass with coating was introduced though.

My Lunt LS60 is probably about 9 years old, I think the degredation has been gradual as I've only really noticed it in the past 2-3 years.

Edited April 23, 2020 by jonathan