Quark Chromosphere Blockfilter Mod

[AndiesHandyHandies]

Hi

In my ERF tests with a full 3 pack ERF and a 7nm on a 23C in the shade day the 12.5mm blocker front was 21C. Last summers shade was 14C hotter than that in the UK. Just 2C below standard blocking filter reference temperature of 23C.

The Combo was warmer without a 7nm. It was a few degrees warmer without a KG3 in the ERF stack. Full ERF 27.3C and with no KG3 33.6C. So should I use a 7nm on the Combo?

Been looking at the blocker specifications.

Andover recomend a max of 70C on the filters with a max change of 5C per minute to prevent thermal shock.

I will measure blocking filter teperatures with just a UV-IR as ERF on my 90mm.

The standard operating temperature for the specification is 23C. Maybe Daystar buy customised filters as this can be specified.
Increasing the temperature increases the bandpass as Mark said.
Tilting reduces the bandpass.
The Quark blockers are not tiltable so the only option is to cool, or heat where below 23C, the blocker filter to keep it on the specified centre of the bandwidth.

Cheers. Andrew.

[AndiesHandyHandies]

Hi

I am continuing ERF testing and effects on the blocking filter temperature on my ERF safety testing thread.

Cheers. Andrew.

[Dennis]

One thing i still dont understand about the Quark Chromosphere:
It is safe to use visual, but what is actually reducing the lighttransmission to safe levels? The Andover blockfilter has a transmission of 45% and the Etalon probably in a similar range.. so what else is reducing the light to safe levels?

[FRAZ]

Just my tuppenceworth here on the use of a bf30 which made an appearance earlier in this thread.

In the later versions of this filter, like the one I have. When I used it the image was much darker and it reduced the speed of capture by as much as four or fivefold.

[AndiesHandyHandies]

Hi

Lost a reply.

What I have gleaned.

The safety all comes down to picking out a sliver of the light on offer.

1.

Any ERF only reduces the heat load on the Quark, if done properly internal ones are cheaper and just as effective than a front ERF.
You should put the first dielectric filter near the diagonal so the Suns light only falls on the filter glass even when off axis to observe or image prominences. Advice to put the filters as far up the tube as possible is wrong.

Remember only so many filters go in the coating chamber for each sequence of coatings needed so less coatings on large filters and so a wider bandwidth.

The Quark blocker is just a DERF reducing the bandpass to 10nm and blocking long UV and IR.

2.

The etalon allows a frequency through by constructive inteference where an exact no of waves fit in the gap.

So there is a comb of individual images, but the off-axsis ones are dimmer and less sharply on band as you go more off axis.

And there is leakage of other colours as you go more off axis and they start to constructively intefere but less efficiently.

The central orthogonal one is brightest.

3. A trim filter picks out the one central peak which is on band.

4. A red filter blocks the out of band leakage.

5.

Peter Drew uses a 6" PST Mod2 with no ERF for observing as any heating does not distort or melt the etalon.

Professional telescopes use no ERF, Hironde uses a perforated 45Deg flat to reflect out of image energy into space.
The first filter in the chain is a normal UV-IR blocking filter.

Big earth based ones use special internal liquid cooling of the optics and mounts.


6. The Quark blocking filter is already above the h-alpha at its specified temperature and needs cooling to get down to its specified temperature and as on band as possible.

Cheers. Andrew.

[Dennis]

Thanks for the input Andrew.
At the moment im wondering if i can remove the red itf from the quark blocker, since im not using it visually and also have the front d-erf which blocks ir until 1300nm.. you think that can work?

[AndiesHandyHandies]

Hi

I would not remove bits of the Quark assembly for your own safety.

But if you removed the red filter the off band light coming through would swamp the CCD and reduce contrast, A lot I would think.

Cheers. Andrew.

[Dennis]

Hi

I would not remove bits of the Quark assembly for your own safety.

But if you removed the red filter the off band light coming through would swamp the CCD and reduce contrast, A lot I would think.

Cheers. Andrew.

Hm.. i think i will be safe if only for imaging. But will the Andover blockfilter not block all out of band light? I understand that the ITF is only for visual safety.

This is still one big question im still looking the answer for.. is the ITF IR blocking needed for imaging?

[AndiesHandyHandies]

Hi

How do you know there is a ITF in the Quark?

And is there a 'Trim' filter to pick out the central comb?

Do you have a diagram with each filters specification?

ITFs are a silver layer protected by coatings to provide far IR blocking.
Another solution is KG3 glass.

The front 'blocker' on the quark blocks UV and IR to OD5, but that may be limited to near the H-alpha as its is for other filters.

It is too wide to be a trim filter to pick out the one on axis central comb out of the Quark etalon. It looks like.

I use a UV-IR, Red CCD, and Baader 7nm in my internal DERF at the moment on the Quark. Gradually reflects back energy outside of H-alpha region.
The 7nm does not block long IR as far out as the 35nm, but the 35nm seems poor optically for solar for some reason.

With the Quark front blocker you do not need extra far UV or IR blocking. Mark Thias says using a KG3 as well would just dim the image.

Mark Townley says far IR affects his CCD images. I tried a KG3 on the original PST and I felt it was a bit better visually.

Cheers. Andrew.

[Dennis]

Hi

How do you know there is a ITF in the Quark?

And is there a 'Trim' filter to pick out the central comb?

Do you have a diagram with each filters specification?

ITFs are a silver layer protected by coatings to provide far IR blocking.
Another solution is KG3 glass.

The front 'blocker' on the quark blocks UV and IR to OD5, but that may be limited to near the H-alpha as its is for other filters.

It is too wide to be a trim filter to pick out the one on axis central comb out of the Quark etalon. It looks like.

I use a UV-IR, Red CCD, and Baader 7nm in my internal DERF at the moment on the Quark. Gradually reflects back energy outside of H-alpha region.
The 7nm does not block long IR as far out as the 35nm, but the 35nm seems poor optically for solar for some reason.

With the Quark front blocker you do not need extra far UV or IR blocking. Mark Thias says using a KG3 as well would just dim the image.

Mark Townley says far IR affects his CCD images. I tried a KG3 on the original PST and I felt it was a bit better visually.

Cheers. Andrew.

Hi Andrew,
i just took the blockfilter out of the Quark and had a quick look. It is in fact not a single filter but a filter sandwich. The ITF is on the back (red glass filter) and on the front there is the visible silver filter. So i assume the silver one is the blockfilter and the red one on the back is the IR blocker. I didnt feel much like taking this apart since i plan to replace the whole unit with something better.

[pupak]

I think it's the other way around. The silver one is ERF and the red one is blocking. They can be separated from each other, but it is difficult and requires good tools and skillful hands. I was separating the 25mm from the Combo because the DERF was causing flare and the TZ3. That case is hard aluminum. It can be dissected with a scalpel and then carefully separated, They are connected only by a film on the surface. Removing the ERF made the glare disappear and the blocker works. It must be taken into account that it must not be subject to excessive thermal stress.
If you were selling the blocker, I would be interested. I fried one here and would like to replace it.

[Dennis]

I think it's the other way around. The silver one is ERF and the red one is blocking. They can be separated from each other, but it is difficult and requires good tools and skillful hands. I was separating the 25mm from the Combo because the DERF was causing flare and the TZ3. That case is hard aluminum. It can be dissected with a scalpel and then carefully separated, They are connected only by a film on the surface. Removing the ERF made the glare disappear and the blocker works. It must be taken into account that it must not be subject to excessive thermal stress.
If you were selling the blocker, I would be interested. I fried one here and would like to replace it.

Thanks for sharing your experience Petr. Yes, would make sense if the ERF is first and afterwards the blocker.
About the Blocker i sent you a PM, i hope my replacement will be sucessful.

[AndiesHandyHandies]

Hi

Looking back a Marks post on my Quark etalon safety threads he says the blocker is the ( 10nm is )1nm Andover filter and then a Combination of a silver ITF I presume for long IR and a Red filter I presume for Etalon leakage at other wavelengths. There may be other components.

Yesterday I had the 90mm F6.7 out with Qark Combo Chromo and DS PST Etalon.

I have added a Baader 7nm to the diagonal. So less heat load on the 1nm Andover blocker.

Observing with barlow and etalons stack in the Sun the blocker was at 25.8C, 2.8C above its specification temperature.

I added about an inch worth of 1.25" extensions to the front of the Quark so that the nosepiece with the blocker in was in free air.
I Put two layers of white linen cloth over the stack with free space under.

The Blocker measured at 21.7C 1.3C under its spec temp.

I am going to use some aluminium gun black on the Quark nose piece and try again. Hopefully be cooler as more heat radiating away.

Cheers. Andrew.

[Dennis]

Hi

Looking back a Marks post on my Quark etalon safety threads he says the blocker is the 10nm Andover and then a Combination of a silver ITF I presume for long IR and a Red filter I presume for Etalon leakage at other wavelengths. There may be other components.

Yesterday I had the 90mm F6.7 out with Qark Combo Chromo and DS PST Etalon.

I have added a Baader 7nm to the diagonal. So less heat load on the 10nm Andover blocker.

Observing with barlow and etalons stack in the Sun the blocker was at 25.8C, 2.8C above its specification temperature.

I added about an inch worth of 1.25" extensions to the front of the Quark so that the nosepiece with the blocker in was in free air.
I Put two layers of white linen cloth over the stack with free space under.

The Blocker measured at 21.7C 1.3C under its spec temp.

I am going to use some aluminium gun black on the Quark nose piece and try again. Hopefully be cooler as more heat radiating away.

Cheers. Andrew.

Thanks Andrew,
yes it is a filter stack with different filters with lower transmission.

My silver Quark ITF is getting around 40°C after a longer imaging session and the triband front d-erf and no problems what so ever. Same goes for the antlia 393nm filter in ca-k mode. Measured with the infrared meat thermometer.

[AndiesHandyHandies]

Hi

Sorry I meant the 1nm above for my Combo Quark.

Andover
656FS02-25
656.3nm Bandpass Filter, HBW 1nm, 25mm dia.

file:///C:/Users/User/Downloads/The%20effects%20of%20temperature%20on%20a%20standard%20blocker%20A1-3.pdf

At 40C the passband of the Quark 1nm blocker has gone up by 0.18A x 20(C) = 3.6A.
So transmission at H-Alpha is very low.

http://astrosurf.com/viladrich/astro/in ... spaced.jpg

Cheers. Andrew.

[Dennis]

Hi

Sorry I meant the 1nm above for my Combo Quark.

Andover
656FS02-25
656.3nm Bandpass Filter, HBW 1nm, 25mm dia.

file:///C:/Users/User/Downloads/The%20effects%20of%20temperature%20on%20a%20standard%20blocker%20A1-3.pdf

At 40C the passband of the Quark 1nm blocker has gone up by 0.18A x 20(C) = 3.6A.
So transmission at H-Alpha is very low.

http://astrosurf.com/viladrich/astro/in ... spaced.jpg

Cheers. Andrew.

Hi Andrew,
the 1nm blocker in the Quark filter stack will not get the 40°C because the silver ITF will keep the heat away from it i suppose.

[AndiesHandyHandies]

Hi

I thought the ITF and red glass combination went after the Andover silver filter?

Also Daystar can order a batch of filters to be on band at a specified temperature. Do they do that?

When people buy individual filters are Andover allowed to supply them set to the same temperature as Daystar ordered ones?

We need someone to test a few Quarks 4.2x and Combo to see at what temperature the blocking filter is on band.

Need someone with a spectrum analyser to compare a standard Quark blocker with a user ordered replacement.

Cheers. Andrew.

[Dennis]

Hi

I thought the ITF and red glass combination went after the Andover silver filter?

Also Daystar can order a batch of filters to be on band at a specified temperature. Do they do that?

When people buy individual filters are Andover allowed to supply them set to the same temperature as Daystar ordered ones?

We need someone to test a few Quarks 4.2x and Combo to see at what temperature the blocking filter is on band.

Need someone with a spectrum analyser to compare a standard Quark blocker with a user ordered replacement.

Cheers. Andrew.

Tbh i dont know exactly, but would make sense to have the blocker after the silver filter.
Most Quark users will get "heat" on the silver element, with or without d-erf. So i assume that either the blockfilter is relatively robust for tempereture changes or it doesnt get the heat. Otherwise there would be much more awareness about it and complaints or? This doesnt seem to be a popular issue.

[AndiesHandyHandies]

Hi

Sorry for confusion.

The front Andover filter just looks 'silver' because it reflects most of the white light on it when you look directly at it.

The ITF is actually a layer of silver metal coated with protective layers. For long IR blocking.

Cheers. Andrew.

[AndiesHandyHandies]

Hi Dennis,

download/file.php?id=53670

This Andover curve was taken at 23C.

viewtopic.php?t=31697

On CVs comparison graph you can see its peak is already higher than h-alpha by a bit.

file:///C:/Users/User/Downloads/The%20effects%20of%20temperature%20on%20a%20standard%20blocker%20A1-3.pdf

Running the Blocker filter at 40C increases the central wavelength by 0.18A x 17 = 3.06A.

Which looking at CVs comparison drops the transmission to about 25%, 1.5 squares over to right.

So you need to temperature control the Quark Blocker.

I used Baader DERF equivalent internal filters and an additional Baader 7nm on the diagonal and insulated the tele-centric and filter stack and exposed the blocker holder to free air under the insulation to get to 21.5C.

In hot countries you would need to actively cool the blocker.

I will go through Daystars woolly recomendations for 'ERF's to see what the blocker temperature is for me in England.

Cheers. Andrew.

[AndiesHandyHandies]

Hi

In old posts people were removing the Quark blocker Andover filter, including ITF and red glass?, to get more light through when imaging. Not to be used for visual if no ITF and red glass.

Removed this reference as not checked out, and the blocking filter should not be removed. Adding a 7nm would be OK BUT not replacing the blocking filter.

Cheers. Andrew.

[Dennis]

Hi

In old posts people were removing the Quark blocker Andover filter, including ITF and red glass?, to get more light through when imaging. Not to be used for visual if no ITF and red glass.

Removed this reference as not checked out, and the blocking filter should not be removed. Adding a 7nm would be OK BUT not replacing the blocking filter.

Cheers. Andrew.

I already replaced the blocking filter and all that was in the andover unit (ITF etc.). Using now the mentioned Alluxa 1nm filter as replacement, of course only for imaging. So far it works fine and gives at least 100% more light (will do more measurements). I will experiment with adding a Baader 20nm h-alpha filter in front to keep the Alluxa cool. You are right, these 1nm blockers need to stay cool for to not have the cwl drift too much.

[AndiesHandyHandies]

Hi

Good you can afford the Alluxa.

Cheers. Andrew.

[AndiesHandyHandies]

Hi

Any etalon or dielectric filter will drift to longer on-band wavelength if heated. And vice-versa.

Cheers. Andrew.

[Dennis]

Hi

Any etalon or dielectric filter will drift to longer on-band wavelength if heated. And vice-versa.

Cheers. Andrew.

Thats true, but especially if its as narrow as 1nm i better want to make sure its not getting too warm. Testing out more on the upcoming days and will see more how it behaves.