Re: Calibrating the secondary dew heater
I wish I knew, it is powered by a 9VDC battery, has a red LED and a sensor that hangs out from the secondary.? I will try to look for a name brand when I disassemble again.
Bob
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Re: Calibrating the secondary dew heater
I apologize if I missed this. What brand?
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On Nov 7, 2021, at 5:47 PM, bob414 via groups.io <bob414@...> wrote:
?From what I see from the manual is that it only describes installation, no calibration instructions.
Bob
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Re: Calibrating the secondary dew heater
From what I see from the manual is that it only describes installation, no calibration instructions.
Bob
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Re: Calibrating the secondary dew heater
Isn't there a manufacturers instruction sheet?
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On Nov 7, 2021, at 5:21 PM, bob414 via groups.io <bob414@...> wrote:
?Our secondary quickly fogs up even a fresh 9VDC battery installed.?
When the dew heater sensor is warmed between two fingers, the red LED lights to show power is applied and the secondary try's to clear up.?
Does anybody know how to calibrate the secondary dew heater on the 18 inch classic.? We have disassembled the secondary to get to the Dew heater, and see there is a potentiator on the circuit board.? So I believe? calibration should be possible.? Is there a
procedure to do this?
Bob
|
Calibrating the secondary dew heater
Our secondary quickly fogs up even a fresh 9VDC battery installed.?
When the dew heater sensor is warmed between two fingers, the red LED lights to show power is applied and the secondary try's to clear up.?
Does anybody know how to calibrate the secondary dew heater on the 18 inch classic.? We have disassembled the secondary to get to the Dew heater, and see there is a potentiator on the circuit board.? So I believe? calibration should be possible.? Is there a procedure to do this?
Bob
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Anyone have suggestions for what to use to remount my secondary heater once it and my primary come back from re-coating ??
I have a circuit board looking dew heater that has 6 little elements that touch the secondary mirror and it appeared to have some kind of blue stretchy stuff directly between the element and the mirror ?? I thought it might be a Blue RTV Silicone ?? But someone said that that was not conductive to heat ??
Any ideas what I should make sure I use between the elements and the mirror to hold it in place?
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Re: Sling adjustment on obsession classic 18"
A wiffle tree mod would require an entirely new mirror cell…Aurora Precision mirror cells offer custom versions. I recently upgraded to the Glatter Sling- well worth it.
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Hello 贵谤é诲é谤颈肠 ? Thanks for the feedback. Good idea for the etalon. I’ve heard of the Howie Glatter sling as well as of whiffletree. Something to consider if it makes a significant difference. My mirror is 50mm thick and I heard they are more important for thinner mirrors.? ? The etalon to centre the mirror is a great idea, I’ll do that!. Thanks? ? ? Hi Olivier,?
I own a classic 15 and UC22. All the indications are highly relevant but I add a few things from my own experience.
As the mirror will be out for a while you might consider replacing the original kevlar sling by a Howie Glatter sling (google it). It is a real master piece of mechanics that guarantees that the mirror is always suspended with the cable sling strictly parallel to the main surface of the mirror. If you consider it there are several sites giving you the right place to put the cable at the center of gravity of the mirror according to the f ratio and diameter.??
To center the mirror and repeat it precisely each time I move my scopes, I use cardboard "etalon" that I tuned in width after centering the mirror precisely once (according to the initial setup sequence proposed by Dave). When I setup I use these "etalon" to recenter the mirror, the etalon being inserted between the mirror box wall and the edge of the mirror on each side. Doing so I consistently reproduce the same collimation parameters (primary at the same place, tubes numbered and put at the same place, etc) leading to a fastest and consistent collimation achievement.
Hope this helps,
贵谤é诲é谤颈肠?
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--
Mark Bungart
15" Obsession #643 / Swayze mirror
Grove City, Ohio
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Re: Sling adjustment on obsession classic 18"
Thanks Jesse, good tips, will use them. ?
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Van: [email protected] <[email protected]> Namens Jesse Godsey
Verzonden: zondag 31 oktober 2021 13:49
Aan: [email protected]
Onderwerp: Re: [ObsessionUsers] Sling adjustment on obsession classic 18"? Here is the other item.? You might find getting the mirror back in is going to be a little bit of a chore with that sling getting in the way.? I have found that if you pick one bolt at the top where the sling wraps around and loosen it so that you can take some slack out on the strap, you can much more easily get it back into position and then retighten it back up.? You can not reuse the velcro and make sure you take it all off before shipping it.? Get all the sticky stuff off of the side of the mirror as well.? I have found just using your fingers and keep pushing and rolling against the sticky stuff will get it removed.? You will need a short handled wrench for the inside nut under the mirror to get it tightened back up while turning the bolt from underneath. As far as center of gravity.? That fabric strap is pretty wide and I would think your biggest concern is just to make sure it is all around the edges of the mirror well.? Also, if you use the loosen one bolt method, don't over tighten it.? You don't want it pressed tightly against the top support bolt but just a gap between it and the mirror present.? And yes, try to get it as centered left to right as you can.? It should allow you to adjust a little?even when the sling is on anyway. ? Hello Linton, ? Thanks a lot for your informative reply – I’ll check those triangular mirror supports too. And I still have the original box in which the mirror was shipped. I’ll probably bring the mirror myself to the coater close to Paris. ? Thanks again ? Olivier ? ? Olivier, ? It’s much less of a problem than you may think. Slide the mirror away from the sling to give a little room to release the double sided tape from between the sling and the mirror edge (you may need a thin knife). Let the sling drop off the mirror turn the three mirror clips well out if the way (you may need a spanner to loosen them). If you can get someone to help you lift the mirror out you may feel more confident, but an 18” is fine for one person. There’s enough room to get your fingers under the mirror while keeping your palms away from the reflective coating. Lift out carefully and place it in a box. I made one from wood with carpet on the bottom to support the mirror. When you come to replace it any double sided tape will do, it only has to stop the sling from falling off. Attach about 4cm of the tape to the edge of the mirror, but leave the top tape coating on until you have the mirror in place. Now remove the top coating and with the mirror pressed away from the sling to give yourself some room, slip the sling up and onto the tape ( this can be a bit of a fiddle as there’s not much room.? Don’t forget to turn the mirror clips back into position! The mirror should hang free of any of the black acytl supports so that all the weight is on the sling when the scope is tipped right down. Whenever I collimate my obsession I always press the mirror from the back first to check it is still swinging free.
My fabric sling is pretty much the full size of the mirror edge, one day I will get round to buying one of the Glatter metal slings that ride up and down with the mirror when collimating etc. These sound a great idea, but to be honest I have not had a problem with my fabric sling. I only once had an astigmatism problem and I traced this to one of the triangular mirror supports which had got stuck and was not supporting the mirror properly (this was not an obsession scope) once I released it the mirror settled back into shape and the problem disappeared, it’s amazing what glass can do! I hope it all goes well for you, I just had my Obsession 20” recoated here in England for the first time. The original USA coating from 2006 lasted very well and the firm here had real problems dissolving it off! ? ?Hello
I have since years (2008) a classic 18" Obsession and I just love it. But it's time to recoat the mirror and this makes me a bit scared to move the mirror in and out of the mirror box (although I've done it myself in 2008 but now I feel less confident about it).
So here is the question:? is there besides the instruction in the manual a video available on how to install the mirror in the mirror cell and on adjusting the sling? Or a post with pictures??
Also, in the manual it's recommended? to put double sided tape. Will I be able to reuse the curent one ? If not how do I get a good one (I live in Europe, Belgium)?
What's the optimum position of the sling? I mean, where should the centre (of the width) of the sling be positionned? In the middle of the mirror edge? Or a bit more to the bottom because that's the direction of the Centre of Gravity?
I guess it's also important to install the mirror in the centre of the mirror cell to make sure the supports are placed on the right positions on the mirror. How critical is this to avoid astigmatism?
Thanks for the feedback
Olivier
??
This message has been sent through the Bedford School email Server, and is intended for the addressee(s) only. If you have received this message in error, please contact the sender, or administrator@..., and delete the email. The views expressed are the views of the sender, and not necessarily the views of the School. The information in this message may be confidential and should not be read, copied, or otherwise distributed unless permission is given. Bedford School is part of The Harpur Trust: a company limited by guarantee. Registered in England: Company No. 3475202. Registered Office: Pilgrim Centre, Brickhill Drive, Bedford, MK41 7PZ. Registered Charity No. 1066861 ?
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Re: Sling adjustment on obsession classic 18"
Hello 贵谤é诲é谤颈肠 ? Thanks for the feedback. Good idea for the etalon. I’ve heard of the Howie Glatter sling as well as of whiffletree. Something to consider if it makes a significant difference. My mirror is 50mm thick and I heard they are more important for thinner mirrors. ? The etalon to centre the mirror is a great idea, I’ll do that!. Thanks ?
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Van: [email protected] <[email protected]> Namens 贵谤é诲é谤颈肠 Ruciak
Verzonden: maandag 1 november 2021 9:31
Aan: [email protected]
Onderwerp: Re: [ObsessionUsers] Sling adjustment on obsession classic 18"? Hi Olivier,?
I own a classic 15 and UC22. All the indications are highly relevant but I add a few things from my own experience.
As the mirror will be out for a while you might consider replacing the original kevlar sling by a Howie Glatter sling (google it). It is a real master piece of mechanics that guarantees that the mirror is always suspended with the cable sling strictly parallel to the main surface of the mirror. If you consider it there are several sites giving you the right place to put the cable at the center of gravity of the mirror according to the f ratio and diameter.??
To center the mirror and repeat it precisely each time I move my scopes, I use cardboard "etalon" that I tuned in width after centering the mirror precisely once (according to the initial setup sequence proposed by Dave). When I setup I use these "etalon" to recenter the mirror, the etalon being inserted between the mirror box wall and the edge of the mirror on each side. Doing so I consistently reproduce the same collimation parameters (primary at the same place, tubes numbered and put at the same place, etc) leading to a fastest and consistent collimation achievement.
Hope this helps,
贵谤é诲é谤颈肠
|
|
Dit e-mailbericht is gecontroleerd op virussen met Avast antivirussoftware.
|
|
Re: Sling adjustment on obsession classic 18"
Hi Olivier,?
I own a classic 15 and UC22. All the indications are highly relevant but I add a few things from my own experience.
As the mirror will be out for a while you might consider replacing the original kevlar sling by a Howie Glatter sling (google it). It is a real master piece of mechanics that guarantees that the mirror is always suspended with the cable sling strictly parallel to the main surface of the mirror. If you consider it there are several sites giving you the right place to put the cable at the center of gravity of the mirror according to the f ratio and diameter.??
To center the mirror and repeat it precisely each time I move my scopes, I use cardboard "etalon" that I tuned in width after centering the mirror precisely once (according to the initial setup sequence proposed by Dave). When I setup I use these "etalon" to recenter the mirror, the etalon being inserted between the mirror box wall and the edge of the mirror on each side. Doing so I consistently reproduce the same collimation parameters (primary at the same place, tubes numbered and put at the same place, etc) leading to a fastest and consistent collimation achievement.
Hope this helps,
贵谤é诲é谤颈肠
|
Re: Sling adjustment on obsession classic 18"
Here is the other item.? You might find getting the mirror back in is going to be a little bit of a chore with that sling getting in the way.? I have found that if you pick one bolt at the top where the sling wraps around and loosen it so that you can take some slack out on the strap, you can much more easily get it back into position and then retighten it back up.? You can not reuse the velcro and make sure you take it all off before shipping it.? Get all the sticky stuff off of the side of the mirror as well.? I have found just using your fingers and keep pushing and rolling against the sticky stuff will get it removed.? You will need a short handled wrench for the inside nut under the mirror to get it tightened back up while turning the bolt from underneath.
As far as center of gravity.? That fabric strap is pretty wide and I would think your biggest concern is just to make sure it is all around the edges of the mirror well.? Also, if you use the loosen one bolt method, don't over tighten it.? You don't want it pressed tightly against the top support bolt but just a gap between it and the mirror present.? And yes, try to get it as centered left to right as you can.? It should allow you to adjust a little?even when the sling is on anyway.
Hello Linton, ? Thanks a lot for your informative reply – I’ll check those triangular mirror supports too. And I still have the original box in which the mirror was shipped. I’ll probably bring the mirror myself to the coater close to Paris. ? Thanks again ? Olivier ? ? Olivier, ? It’s much less of a problem than you may think. Slide the mirror away from the sling to give a little room to release the double sided tape from between the sling and the mirror edge (you may need a thin knife). Let the sling drop off the mirror turn the three mirror clips well out if the way (you may need a spanner to loosen them). If you can get someone to help you lift the mirror out you may feel more confident, but an 18” is fine for one person. There’s enough room to get your fingers under the mirror while keeping your palms away from the reflective coating. Lift out carefully and place it in a box. I made one from wood with carpet on the bottom to support the mirror. When you come to replace it any double sided tape will do, it only has to stop the sling from falling off. Attach about 4cm of the tape to the edge of the mirror, but leave the top tape coating on until you have the mirror in place. Now remove the top coating and with the mirror pressed away from the sling to give yourself some room, slip the sling up and onto the tape ( this can be a bit of a fiddle as there’s not much room.? Don’t forget to turn the mirror clips back into position! The mirror should hang free of any of the black acytl supports so that all the weight is on the sling when the scope is tipped right down. Whenever I collimate my obsession I always press the mirror from the back first to check it is still swinging free.
My fabric sling is pretty much the full size of the mirror edge, one day I will get round to buying one of the Glatter metal slings that ride up and down with the mirror when collimating etc. These sound a great idea, but to be honest I have not had a problem with my fabric sling. I only once had an astigmatism problem and I traced this to one of the triangular mirror supports which had got stuck and was not supporting the mirror properly (this was not an obsession scope) once I released it the mirror settled back into shape and the problem disappeared, it’s amazing what glass can do! I hope it all goes well for you, I just had my Obsession 20” recoated here in England for the first time. The original USA coating from 2006 lasted very well and the firm here had real problems dissolving it off! ? ?Hello
I have since years (2008) a classic 18" Obsession and I just love it. But it's time to recoat the mirror and this makes me a bit scared to move the mirror in and out of the mirror box (although I've done it myself in 2008 but now I feel less confident about it).
So here is the question:? is there besides the instruction in the manual a video available on how to install the mirror in the mirror cell and on adjusting the sling? Or a post with pictures??
Also, in the manual it's recommended? to put double sided tape. Will I be able to reuse the curent one ? If not how do I get a good one (I live in Europe, Belgium)?
What's the optimum position of the sling? I mean, where should the centre (of the width) of the sling be positionned? In the middle of the mirror edge? Or a bit more to the bottom because that's the direction of the Centre of Gravity?
I guess it's also important to install the mirror in the centre of the mirror cell to make sure the supports are placed on the right positions on the mirror. How critical is this to avoid astigmatism?
Thanks for the feedback
Olivier
??
This message has been sent through the Bedford School email Server, and is intended for the addressee(s) only. If you have received this message in error, please contact the sender, or administrator@..., and delete the email. The views expressed are the views of the sender, and not necessarily the views of the School. The information in this message may be confidential and should not be read, copied, or otherwise distributed unless permission is given. Bedford School is part of The Harpur Trust: a company limited by guarantee. Registered in England: Company No. 3475202. Registered Office: Pilgrim Centre, Brickhill Drive, Bedford, MK41 7PZ. Registered Charity No. 1066861
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Re: Sling adjustment on obsession classic 18"
Hello Linton, ? Thanks a lot for your informative reply – I’ll check those triangular mirror supports too. And I still have the original box in which the mirror was shipped. I’ll probably bring the mirror myself to the coater close to Paris. ? Thanks again ? Olivier ?
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Van: [email protected] <[email protected]> Namens Linton Guise
Verzonden: zaterdag 30 oktober 2021 11:59
Aan: [email protected]
Onderwerp: Re: [ObsessionUsers] Sling adjustment on obsession classis 18"? Olivier, ? It’s much less of a problem than you may think. Slide the mirror away from the sling to give a little room to release the double sided tape from between the sling and the mirror edge (you may need a thin knife). Let the sling drop off the mirror turn the three mirror clips well out if the way (you may need a spanner to loosen them). If you can get someone to help you lift the mirror out you may feel more confident, but an 18” is fine for one person. There’s enough room to get your fingers under the mirror while keeping your palms away from the reflective coating. Lift out carefully and place it in a box. I made one from wood with carpet on the bottom to support the mirror. When you come to replace it any double sided tape will do, it only has to stop the sling from falling off. Attach about 4cm of the tape to the edge of the mirror, but leave the top tape coating on until you have the mirror in place. Now remove the top coating and with the mirror pressed away from the sling to give yourself some room, slip the sling up and onto the tape ( this can be a bit of a fiddle as there’s not much room.? Don’t forget to turn the mirror clips back into position! The mirror should hang free of any of the black acytl supports so that all the weight is on the sling when the scope is tipped right down. Whenever I collimate my obsession I always press the mirror from the back first to check it is still swinging free.
My fabric sling is pretty much the full size of the mirror edge, one day I will get round to buying one of the Glatter metal slings that ride up and down with the mirror when collimating etc. These sound a great idea, but to be honest I have not had a problem with my fabric sling. I only once had an astigmatism problem and I traced this to one of the triangular mirror supports which had got stuck and was not supporting the mirror properly (this was not an obsession scope) once I released it the mirror settled back into shape and the problem disappeared, it’s amazing what glass can do! I hope it all goes well for you, I just had my Obsession 20” recoated here in England for the first time. The original USA coating from 2006 lasted very well and the firm here had real problems dissolving it off! ?
On 30 Oct 2021, at 09:37, Ovanaelst via groups.io <Ovanaelst@...> wrote:
?Hello
I have since years (2008) a classic 18" Obsession and I just love it. But it's time to recoat the mirror and this makes me a bit scared to move the mirror in and out of the mirror box (although I've done it myself in 2008 but now I feel less confident about it).
So here is the question:? is there besides the instruction in the manual a video available on how to install the mirror in the mirror cell and on adjusting the sling? Or a post with pictures??
Also, in the manual it's recommended? to put double sided tape. Will I be able to reuse the curent one ? If not how do I get a good one (I live in Europe, Belgium)?
What's the optimum position of the sling? I mean, where should the centre (of the width) of the sling be positionned? In the middle of the mirror edge? Or a bit more to the bottom because that's the direction of the Centre of Gravity?
I guess it's also important to install the mirror in the centre of the mirror cell to make sure the supports are placed on the right positions on the mirror. How critical is this to avoid astigmatism?
Thanks for the feedback
Olivier
??
This message has been sent through the Bedford School email Server, and is intended for the addressee(s) only. If you have received this message in error, please contact the sender, or administrator@..., and delete the email. The views expressed are the views of the sender, and not necessarily the views of the School. The information in this message may be confidential and should not be read, copied, or otherwise distributed unless permission is given. Bedford School is part of The Harpur Trust: a company limited by guarantee. Registered in England: Company No. 3475202. Registered Office: Pilgrim Centre, Brickhill Drive, Bedford, MK41 7PZ. Registered Charity No. 1066861
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Re: Sling adjustment on obsession classis 18"
Olivier,
It’s much less of a problem than you may think.
Slide the mirror away from the sling to give a little room to release the double sided tape from between the sling and the mirror edge (you may need a thin knife). Let the sling drop off the mirror turn the three mirror clips well out if the way (you may
need a spanner to loosen them).
If you can get someone to help you lift the mirror out you may feel more confident, but an 18” is fine for one person. There’s enough room to get your fingers under the mirror while keeping your palms away from the reflective coating.
Lift out carefully and place it in a box. I made one from wood with carpet on the bottom to support the mirror.
When you come to replace it any double sided tape will do, it only has to stop the sling from falling off. Attach about 4cm of the tape to the edge of the mirror, but leave the top tape coating on until you have the mirror in place. Now remove the top
coating and with the mirror pressed away from the sling to give yourself some room, slip the sling up and onto the tape ( this can be a bit of a fiddle as there’s not much room.?
Don’t forget to turn the mirror clips back into position!
The mirror should hang free of any of the black acytl supports so that all the weight is on the sling when the scope is tipped right down. Whenever I collimate my obsession I always press the mirror from the back first to check it is still swinging free.
My fabric sling is pretty much the full size of the mirror edge, one day I will get round to buying one of the Glatter metal slings that ride up and down with the mirror when collimating etc. These sound a great idea, but to be honest I have not had a problem
with my fabric sling.
I only once had an astigmatism problem and I traced this to one of the triangular mirror supports which had got stuck and was not supporting the mirror properly (this was not an obsession scope) once I released it the mirror settled back into shape and
the problem disappeared, it’s amazing what glass can do!
I hope it all goes well for you, I just had my Obsession 20” recoated here in England for the first time. The original USA coating from 2006 lasted very well and the firm here had real problems dissolving it off!
Best wishes,
Linton
L.J.Guise
Physics Dept.
Bedford School.
www.bedfordschool.org.uk/observatory
On 30 Oct 2021, at 09:37, Ovanaelst via groups.io <Ovanaelst@...> wrote:
?Hello
I have since years (2008) a classic 18" Obsession and I just love it. But it's time to recoat the mirror and this makes me a bit scared to move the mirror in and out of the mirror box (although I've done it myself in 2008 but now I feel less confident about
it).
So here is the question:? is there besides the instruction in the manual a video available on how to install the mirror in the mirror cell and on adjusting the sling? Or a post with pictures??
Also, in the manual it's recommended? to put double sided tape. Will I be able to reuse the curent one ? If not how do I get a good one (I live in Europe, Belgium)?
What's the optimum position of the sling? I mean, where should the centre (of the width) of the sling be positionned? In the middle of the mirror edge? Or a bit more to the bottom because that's the direction of the Centre of Gravity?
I guess it's also important to install the mirror in the centre of the mirror cell to make sure the supports are placed on the right positions on the mirror. How critical is this to avoid astigmatism?
Thanks for the feedback
Olivier
??
This message has been sent through the Bedford School email Server, and is intended for the addressee(s) only. If you have received this message in error, please contact the sender, or administrator@..., and delete the email. The views expressed
are the views of the sender, and not necessarily the views of the School. The information in this message may be confidential and should not be read, copied, or otherwise distributed unless permission is given.
Bedford School is part of The Harpur Trust: a company limited by guarantee. Registered in England: Company No. 3475202. Registered Office: Pilgrim Centre, Brickhill Drive, Bedford, MK41 7PZ. Registered Charity No. 1066861
|
Sling adjustment on obsession classis 18"
Hello
I have since years (2008) a classic 18" Obsession and I just love it. But it's time to recoat the mirror and this makes me a bit scared to move the mirror in and out of the mirror box (although I've done it myself in 2008 but now I feel less confident about it).
So here is the question:? is there besides the instruction in the manual a video available on how to install the mirror in the mirror cell and on adjusting the sling? Or a post with pictures??
Also, in the manual it's recommended? to put double sided tape. Will I be able to reuse the curent one ? If not how do I get a good one (I live in Europe, Belgium)?
What's the optimum position of the sling? I mean, where should the centre (of the width) of the sling be positionned? In the middle of the mirror edge? Or a bit more to the bottom because that's the direction of the Centre of Gravity?
I guess it's also important to install the mirror in the centre of the mirror cell to make sure the supports are placed on the right positions on the mirror. How critical is this to avoid astigmatism?
Thanks for the feedback
Olivier
??
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Re: Don't do what I did :)
Yes, my dew heater board lays on the secondary?as well.? I believe people are using Blue RTV Silicone to attach them and letting it cure for 48 hours under some mild heat from the dew controller.? BTW, very nice boards in the link..
On Wed, Oct 27, 2021 at 8:32 AM Al Lamperti < lamperti@...> wrote: I preferred the Kendrik dew heater as it lies flat against the back of the secondary. I wired it so it connects to the UTA that is wired from the ground board through a cable inside one of the truss tubes. I have a dew controller mounted on a dew heater control bracket of the UTA ()
Al
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Re: Don't do what I did :)
I preferred the Kendrik dew heater as it lies flat against the back of the secondary. I wired it so it connects to the UTA that is wired from the ground board through a cable inside one of the truss tubes. I have a dew controller mounted on a dew heater control bracket of the UTA ()
Al
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Re: Don't do what I did :)
Good job! I also added the Glatter Sling?to my 15” ?last summer . Pretty straightforward process, and Rob Teeter ( of Teeter Telescopes and who now makes the sling) was very helpful when I had questions.
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On Oct 26, 2021, at 8:47 PM, Paul Weiler < dc9fxer@...> wrote:
Hi? Yes terry is a great guy , he did my 16” As well? Check astrosystems for dew heaters? Good luck! Paul ? Well guys. ?I sent in the primary and secondary to Ostahowski for recoating the OMI mirror. ?I decided to just get her done !! ?She’s a 2005 and never been done.
Terry there is real nice and very informative.
Also going to be adding the Glatter Cable Sling to her as well with the extension plates.
What do you guys recommend for secondary dew heater reattachment ? ?The old stuff was like 6 dots of some blue flexi stuff ? ? Right but what am I looking for ? ?You will see some light right ? ?Try it on yours. ?If it’s light and uniform is that ok or it should have absolutely no light at all come though the back ? ?Also how bright of a light or should it not matter ? On Oct 24, 2021, at 5:53 PM, Mark Bungart <mbungart@...> wrote:
? Well, you can always shine a light from the backside of the mirror and see where the light passes through…any areas without a coating will be obvious. Do it in a darken room of course.
Right but how and when can you tell whether it’s coatings or something else ? On Oct 24, 2021, at 5:16 PM, Mark Bungart <mbungart@...> wrote:
? I agree, difficult to see if they are spots, tree sap, or what on the mirror. I clean mine once a year following Dave’s instructions, using 2 gallons of distilled water. Add one drop of plain old Dawn detergent into one jug , shake and pour on mirror. Never ever rub anything on the mirror. If you need to, get some clean cotton balls and bunch them up wet and while the mirror is wet and soapy, drag the cotton across the mirror, never circular and apply no pressure. Rinse with distilled water. You can lay a cotton towel on the mirror to soak up any water but then just let it air dry.
If the spots are where the coating has flaked off, you need to recoat.
Mark Obsession 15, Swazye mirror
It is hard to tell from the pictures if it is water spots from dew or or general haze.? If a general haze it from the mirror coatingj slowly degrading.? They do that and you just clean your mirror?once a year.? I think the same thing works for water spots but not sure.
Do no rub on the mirror.
Chris
So, quick question.? I have the exact same look on my primary mirror.? Did you wash it a few times and always dry it with a micro-fiber cloth ?? Just wondering the best way to get it off and not scratch or damage the mirror.
Thank you.
-- Mark Bungart 15" Obsession #643 / Swayze mirror Grove City, Ohio
-- Mark Bungart 15" Obsession #643 / Swayze mirror Grove City, Ohio
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Mark Bungart
15" Obsession #643 / Swayze mirror
Grove City, Ohio
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Re: Don't do what I did :)
Hi? Yes terry is a great guy , he did my 16” As well? Check astrosystems for dew heaters? Good luck!
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On Oct 26, 2021, at 8:43 PM, Jesse Godsey <jessegodsey@...> wrote:
? Well guys. ?I sent in the primary and secondary to Ostahowski for recoating the OMI mirror. ?I decided to just get her done !! ?She’s a 2005 and never been done.
Terry there is real nice and very informative.
Also going to be adding the Glatter Cable Sling to her as well with the extension plates.
What do you guys recommend for secondary dew heater reattachment ? ?The old stuff was like 6 dots of some blue flexi stuff ? On Oct 24, 2021, at 6:05 PM, Jesse Godsey via groups.io <jessegodsey@...> wrote:
? Right but what am I looking for ? ?You will see some light right ? ?Try it on yours. ?If it’s light and uniform is that ok or it should have absolutely no light at all come though the back ? ?Also how bright of a light or should it not matter ? On Oct 24, 2021, at 5:53 PM, Mark Bungart <mbungart@...> wrote:
? Well, you can always shine a light from the backside of the mirror and see where the light passes through…any areas without a coating will be obvious. Do it in a darken room of course.
Right but how and when can you tell whether it’s coatings or something else ? On Oct 24, 2021, at 5:16 PM, Mark Bungart <mbungart@...> wrote:
? I agree, difficult to see if they are spots, tree sap, or what on the mirror. I clean mine once a year following Dave’s instructions, using 2 gallons of distilled water. Add one drop of plain old Dawn detergent into one jug , shake and pour on mirror. Never ever rub anything on the mirror. If you need to, get some clean cotton balls and bunch them up wet and while the mirror is wet and soapy, drag the cotton across the mirror, never circular and apply no pressure. Rinse with distilled water. You can lay a cotton towel on the mirror to soak up any water but then just let it air dry.
If the spots are where the coating has flaked off, you need to recoat.
Mark Obsession 15, Swazye mirror
It is hard to tell from the pictures if it is water spots from dew or or general haze.? If a general haze it from the mirror coatingj slowly degrading.? They do that and you just clean your mirror?once a year.? I think the same thing works for water spots but not sure.
Do no rub on the mirror.
Chris
So, quick question.? I have the exact same look on my primary mirror.? Did you wash it a few times and always dry it with a micro-fiber cloth ?? Just wondering the best way to get it off and not scratch or damage the mirror.
Thank you.
-- Mark Bungart 15" Obsession #643 / Swayze mirror Grove City, Ohio
-- Mark Bungart 15" Obsession #643 / Swayze mirror Grove City, Ohio
|
Re: Don't do what I did :)
Well guys. ?I sent in the primary and secondary to Ostahowski for recoating the OMI mirror. ?I decided to just get her done !! ?She’s a 2005 and never been done.
Terry there is real nice and very informative.
Also going to be adding the Glatter Cable Sling to her as well with the extension plates.
What do you guys recommend for secondary dew heater reattachment ? ?The old stuff was like 6 dots of some blue flexi stuff ?
toggle quoted message
Show quoted text
On Oct 24, 2021, at 6:05 PM, Jesse Godsey via groups.io <jessegodsey@...> wrote:
? Right but what am I looking for ? ?You will see some light right ? ?Try it on yours. ?If it’s light and uniform is that ok or it should have absolutely no light at all come though the back ? ?Also how bright of a light or should it not matter ? On Oct 24, 2021, at 5:53 PM, Mark Bungart <mbungart@...> wrote:
? Well, you can always shine a light from the backside of the mirror and see where the light passes through…any areas without a coating will be obvious. Do it in a darken room of course.
Right but how and when can you tell whether it’s coatings or something else ? On Oct 24, 2021, at 5:16 PM, Mark Bungart <mbungart@...> wrote:
? I agree, difficult to see if they are spots, tree sap, or what on the mirror. I clean mine once a year following Dave’s instructions, using 2 gallons of distilled water. Add one drop of plain old Dawn detergent into one jug , shake and pour on mirror. Never ever rub anything on the mirror. If you need to, get some clean cotton balls and bunch them up wet and while the mirror is wet and soapy, drag the cotton across the mirror, never circular and apply no pressure. Rinse with distilled water. You can lay a cotton towel on the mirror to soak up any water but then just let it air dry.
If the spots are where the coating has flaked off, you need to recoat.
Mark Obsession 15, Swazye mirror
It is hard to tell from the pictures if it is water spots from dew or or general haze.? If a general haze it from the mirror coatingj slowly degrading.? They do that and you just clean your mirror?once a year.? I think the same thing works for water spots but not sure.
Do no rub on the mirror.
Chris
So, quick question.? I have the exact same look on my primary mirror.? Did you wash it a few times and always dry it with a micro-fiber cloth ?? Just wondering the best way to get it off and not scratch or damage the mirror.
Thank you.
-- Mark Bungart 15" Obsession #643 / Swayze mirror Grove City, Ohio
-- Mark Bungart 15" Obsession #643 / Swayze mirror Grove City, Ohio
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Re: Mirror recommendation and feedback please
A few years ago we had someone come to our dark sky site looking for help with a 10 inch dob he had bought.? We helped him get set up and working.? He had found the dried remains of a small raccoon on the mirror and had cleaned it off.? You could see the outline of it.? I was very surprised to find that it? did not much affect the views.
Chris?
On Mon, Oct 25, 2021 at 12:12 PM Charlie Starks < cstarks@...> wrote: Even if your coating is flaking, it’s probably only a very small percentage of the area.? Mine is in that category and it still works great.? Eventually I will have it recoated, but there’s no rush.? It was last coated in 2007.? Charlie? ? I am with Frederic.? I would clean and use first.
One of the best pieces of advice I got early in my astronomy life was "If you do not like what you see when you look look at the mirror?with a flashlight don't do that."
Hi Jesse,
When you say I know it is not dust, does it mean that you already cleaned properly the mirror?
If not my first move would be to clean the mirror properly, as described in a lot of videos (Dave Kriege's one) with appropriate water of course.
My own experience was the I had some strange spots after my mirror got dewed one night and dried after.
A good cleaning removed everything.
By the way, looking from the front of the mirror with a light on the back will show you tiny spots of light where the coating is not there but it doesn't mean you have to change it immediately, sometimes the surface of these tiny spots is less than a fraction of a percent.
Hope this helps,
贵谤é诲é谤颈肠
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Jesse Godsey
贵谤é诲é谤颈肠 Ruciak
Al Lamperti
Christine Zeltner