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Gettting a good Meade 7" ED?

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#1 CHASLX200

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Posted 11 May 2019 - 06:37 AM

What are the chances of finding a good used Meade 7" ED?  I would like to find one that comes to me collimated and has the cell fix.  I remember the foucser was pretty sad on mine and it would be replaced with a Moonlite.



#2 t.r.

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Posted 11 May 2019 - 07:27 AM

There are a few out there...put a wanted ad out willing to pay what the seller has in it! You will get a response.

Edited by t.r., 11 May 2019 - 07:28 AM.


#3 Eddgie

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Posted 11 May 2019 - 08:10 AM

By "good", if you mean diffraction limited, I would say chances are very high.  If by "good" you mean something at the higher end of the quality range, I would put the chances at low.  I had the 6" and it was "good" by the first definition. I have seen two tests on Meade EDs and both showed optics consistent with the one I owned, which is to say OK, but nothing special.

 

And even the 6" was a handful to mount.  Better plan on having a big mount.  The LXD 750 that the scopes came with is actually a good mount for them because the legs are very big (about 2.5" or 3" as I recall) so that when the legs are fully extended (which is what is necessary to be able to view at higher angles) there is enough stability to make powers more than 150x useful.  


Edited by Eddgie, 11 May 2019 - 08:13 AM.


#4 CHASLX200

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Posted 11 May 2019 - 08:39 AM

By "good", if you mean diffraction limited, I would say chances are very high.  If by "good" you mean something at the higher end of the quality range, I would put the chances at low.  I had the 6" and it was "good" by the first definition. I have seen two tests on Meade EDs and both showed optics consistent with the one I owned, which is to say OK, but nothing special.

 

And even the 6" was a handful to mount.  Better plan on having a big mount.  The LXD 750 that the scopes came with is actually a good mount for them because the legs are very big (about 2.5" or 3" as I recall) so that when the legs are fully extended (which is what is necessary to be able to view at higher angles) there is enough stability to make powers more than 150x useful.  

I don't mean AP good or Tak good. Just so the lens stays in center and no collimatin problems. I was cheated with my 7" ED back 1999 and i want another chance.  I will pay top $ if the buyer offers a refund if i am not happy.  If it is collimated it should be fine for my needs. I have a AP 800 so it is plenty and much better than than that LXD750 mount i had. But the monster tripod was nice.


Edited by CHASLX200, 11 May 2019 - 08:41 AM.


#5 tony_spina

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Posted 11 May 2019 - 09:45 AM

Now there is a shootout I would like to see Meade 7” ED vs SW 150 ED



#6 starman876

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Posted 11 May 2019 - 09:49 AM

I might sell my Meade 7" ED in the future.   If I had a permanent set up I would never sell it.  However, it rests in the corner like a lot of my scopes that are too large to use everyday.



#7 skyward_eyes

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Posted 11 May 2019 - 10:02 AM

Now there is a shootout I would like to see Meade 7” ED vs SW 150 ED

I did this last August with some friends of mine and their astronomy group out here in AZ.

We set up the 178ED, SW Esprit 150EDT, Evostar 150ED, Celestron C6-R as well as an Esprit 120EDT. We placed similar magnification in each scope, about 130x I believe, and moved each scope to the same object.

The newer 150mm apos provided the cleanest images out of the collection. The 178ED held up but you can see where optical advancements have been made over the last 20 years. Polishing techniques, glass, optical matching and coatings have come a long way from when the big Meades shipped out. While the Meade helps it’s ground the newer scope snapped into focuser and provided overall better images.

I ended up selling the 178ED last year to help finish funding for my 28” dob. I really loved the 178 and it’s an extremely impressive instrument when placed on the right mount. The big issue with these scopes is that they are huge. You need a good mount for these, mine road on my Paramount MX with three 8” extension. I upgrade the rings to Parallax and the focuser to a 2.5” Moonlite.

The collimation on my sample wasn’t a huge problem but did need adjustment every few months, just slightly however. I used mine for outreach so it was all over the place getting used.

I would say anyone looking at one should consider the tube size first and foremost. I would recommend nothing less than a CGE Pro for it as it’s nearly 6’ long and 8” in diameter. Also, if you can, try your sample before you buy it. The 178 samples vary from scope to scope. I’ve found the 152s and smaller are generally very good across the board. The 178s are a different class of refractor however.

They are truly beautiful scopes and I’m glad I’ve had the opportunity to own one. A 7” refractor is an amazing scope for all kinds of work and the correction on these big doublets is actually pretty good considering their age.

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Edited by skyward_eyes, 11 May 2019 - 10:17 AM.

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#8 HARRISON SCOPES

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Posted 11 May 2019 - 10:11 AM

I have had two of them, both needed fixing but quite an easy job to tap three holes in the cell, both were nice but by todays standards I think they are falling behind. I found them most impressive as a high contrast deep sky scope, planets had good detail but a tiny bit soft.



#9 CHASLX200

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Posted 11 May 2019 - 10:23 AM

I have had two of them, both needed fixing but quite an easy job to tap three holes in the cell, both were nice but by todays standards I think they are falling behind. I found them most impressive as a high contrast deep sky scope, planets had good detail but a tiny bit soft.

I think for around 3k for a good OTA i would be happy. I have the back and the mount to try one out for kicks.



#10 Jeff B

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Posted 11 May 2019 - 10:29 AM

Chas, my advice is to...

 

RUUUN  

 

away from any such ideas as fast as possible, unless of course you really do want some extra misery in your life.

 

This is based upon my own direct experiences with a sample of it.

 

And if you do get a so called "good" one, please do not upset it in anyway, such as using harsh language around it, or it will take it out on you with coma.

 

Jeff


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#11 CHASLX200

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Posted 11 May 2019 - 10:31 AM

Chas, my advice is to...

 

RUUUN  

 

away from any such ideas as fast as possible, unless of course you really do want some extra misery in your life.

 

This is based upon my own direct experiences with a sample of it.

 

And if you do get a so called "good" one, please do not upset it in anyway, such as using harsh language around it, or it will take it out on you with coma.

 

Jeff

Can't be any worse than the first 7" ed i had.  One member says his is super.  But can it be shipped and stay in collimation?


Edited by CHASLX200, 11 May 2019 - 10:34 AM.


#12 starman876

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Posted 11 May 2019 - 10:31 AM

I did this last August with some friends of mine and their astronomy group out here in AZ.

We set up the 178ED, SW Esprit 150EDT, Evostar 150ED, Celestron C6-R as well as an Esprit 120EDT. We placed similar magnification in each scope, about 130x I believe, and moved each scope to the same object.

The newer 150mm apos provided the cleanest images out of the collection. The 178ED held up but you can see where optical advancements have been made over the last 20 years. Polishing techniques, glass, optical matching and coatings have come a long way from when the big Meades shipped out. While the Meade helps it’s ground the newer scope snapped into focuser and provided overall better images.

I ended up selling the 178ED last year to help finish funding for my 28” dob. I really loved the 178 and it’s an extremely impressive instrument when placed on the right mount. The big issue with these scopes is that they are huge. You need a good mount for these, mine road on my Paramount MX with three 8” extension. I upgrade the rings to Parallax and the focuser to a 2.5” Moonlite.

The collimation on my sample wasn’t a huge problem but did need adjustment every few months, just slightly however. I used mine for outreach so it was all over the place getting used.

I would say anyone looking at one should consider the tube size first and foremost. I would recommend nothing less than a CGE Pro for it as it’s nearly 6’ long and 8” in diameter. Also, if you can, try your sample before you buy it. The 178 samples vary from scope to scope. I’ve found the 152s and smaller are generally very good across the board. The 178s are a different class of refractor however.

They are truly beautiful scopes and I’m glad I’ve had the opportunity to own one. A 7” refractor is an amazing scope for all kinds of work and the correction on these big doublets is actually pretty good considering their age.

I must be lucky with the one I have.  Images are like the are etched in granite.  Very sharp.  I have not had a chance to set up the 178ED and compare it to the APM 152 ED.  I have not even had a chance to set up both the vintage  6" AP and compare it to the 178ED.   Soon I will be done remodeling and will have time for astronomy again.  That and a few other emergencies around here have kept me pretty busy.  



#13 Jeff B

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Posted 11 May 2019 - 11:13 AM

Well Chas, as you found out, they can be a very tweaky instrument when it comes to centering of the elements.

 

If you're going to tweak that often, might as well upgrade the OTA mechanics of you old Meade 826 newt.  

 

But that's just me.

 

The only reason I would ever get another one is for a project, like getting the cell to work and keep the elements long term centered even after multiple transports. 

 

But I also have an awesome old AP 7" F9 pre-ED triplet with no such issues so I'm really not interested or motivated for such a project.

 

Would it fit in your Vette? grin.gif  

 

Jeff


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#14 HARRISON SCOPES

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Posted 11 May 2019 - 11:29 AM

Agreed I had to use thumbscrews as they needed adjusting so much.

#15 3 i Guy

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Posted 11 May 2019 - 11:36 AM

I think a scope the size of a Scud missile is just what you need, especially considering you just got rid of a TMB 100 became of weight.



#16 starman876

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Posted 11 May 2019 - 11:44 AM

Agreed I had to use thumbscrews as they needed adjusting so much.

I find that interesting.  Mine was shipped from Kansas to Virginia and right out of the box performed well.  Later I adjusted the 178ED on the bench and it needed very little tweaking.  I wonder why some needed tweaking a lot while others did not? Could there have been that much of a difference in the way the elements were made? 


Edited by starman876, 11 May 2019 - 11:44 AM.


#17 Jeff B

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Posted 11 May 2019 - 11:50 AM

I find that interesting.  Mine was shipped from Kansas to Virginia and right out of the box performed well.  Later I adjusted the 178ED on the bench and it needed very little tweaking.  I wonder why some needed tweaking a lot while others did not? Could there have been that much of a difference in the way the elements were made? 

Of course you could take it apart to see why it works so well for you.  grin.gif

 

Have you done any DPAC testing on it?  If you have, I'm curious as to the results.



#18 RogeZ

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Posted 11 May 2019 - 11:56 AM

I think somebody has an acute case of aperture fever....i guess Chas is realizing that a 6” as your biggest planetary scope is a strong compromise :)

I see a 14” Zambuto on Chas’ Christmas list....

#19 CHASLX200

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Posted 11 May 2019 - 02:17 PM

Well Chas, as you found out, they can be a very tweaky instrument when it comes to centering of the elements.

 

If you're going to tweak that often, might as well upgrade the OTA mechanics of you old Meade 826 newt.  

 

But that's just me.

 

The only reason I would ever get another one is for a project, like getting the cell to work and keep the elements long term centered even after multiple transports. 

 

But I also have an awesome old AP 7" F9 pre-ED triplet with no such issues so I'm really not interested or motivated for such a project.

 

Would it fit in your Vette? grin.gif  

 

Jeff

I never leave the house with any scopes. Last Star party marty was in 2003. As long as the lens stays centered i should be fine. But i have never collimated a refractor.  A older AP 7" would be nice, but not paying 20k for one.  As far the 826 goes, i would like to find a light weight made 10" F/6 Newt with no heavy rotating rings to use on the AP800.


Edited by CHASLX200, 11 May 2019 - 02:21 PM.

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#20 CHASLX200

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Posted 11 May 2019 - 02:20 PM

I think a scope the size of a Scud missile is just what you need, especially considering you just got rid of a TMB 100 became of weight.

The only reason i got rid of the TMB 105/650 was it needed a big mount that made the scope way too big to be a grab and go.  Just as well get a 6" as big as that thing was.


Edited by CHASLX200, 11 May 2019 - 02:20 PM.


#21 CHASLX200

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Posted 11 May 2019 - 02:26 PM

I think somebody has an acute case of aperture fever....i guess Chas is realizing that a 6” as your biggest planetary scope is a strong compromise smile.gif

I see a 14” Zambuto on Chas’ Christmas list....

I would need a monster mount for a 14" Newt, Unless a 14.5" Starmaster pops up for sale cheap local..  I always wanted a good Meade 7" since i got cheated out of the one i had. The seller did not tell me the truth when i bought it. He said it was at Meade and Was fixed and still sitting in the box when i traded 6k worth of Televue eyepieces and a nice 10" LX200.  It went back to Meade 3 time when i had it and each time  when i got it back it was bad each time.  This was before the cell fix.

 

So i need to have my second chance with this scope.


Edited by CHASLX200, 11 May 2019 - 02:28 PM.


#22 starman876

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Posted 11 May 2019 - 09:46 PM

Of course you could take it apart to see why it works so well for you.  grin.gif

 

Have you done any DPAC testing on it?  If you have, I'm curious as to the results.

When I have time I will set the lens up and test it again.  Now I think about it the DPAC results reminded me of the APM 152ED I have.  Not perfect straight lines, but nothing horrible either.  Better that 1/4 wave.  In 7" of clear aperture for what the Meade's are going for that is a pretty good bargain if you find a good one.   There are plenty of people who really like their Meade 178ED so I am sure Meade managed to do a good re design.  Of course there also people who claim they have to adjust their scope on a regular basis.  Would be nice if we could figure out why some do not need adjustment and some do.  


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#23 CHASLX200

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Posted 12 May 2019 - 05:55 AM

I think many are floating around with the bad cells. And some are floating around with the cell fix.  I want one soon and will place a ad.

 

Ian Turner and Chuck Pizza from Wolf Cam ended up with my scope after i forced the seller to refund my money.  They did adjust it and said it had a good lens.  But it did end up going to Meade in 2000 for a new cell. The new owner destroyed the scope by placing it on the mount with no counter weight and it slammed into the tripod, not once, but he did it twice. Talk about dumb.

 

I was so happy when i first got the scope, but 20 secs later looking at a star i said, Huston we got a prob. So the 3 times it went back to Meade they fixed it and shipping bumped it out of center each time.  I don't think the end user should have to adjust a scope that cost him over 6k.  I was glad to get rid of it.

 

Now i want a second chance and got the cash ready.



#24 bobhen

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Posted 12 May 2019 - 07:08 AM

When I have time I will set the lens up and test it again.  Now I think about it the DPAC results reminded me of the APM 152ED I have.  Not perfect straight lines, but nothing horrible either.  Better that 1/4 wave.  In 7" of clear aperture for what the Meade's are going for that is a pretty good bargain if you find a good one.   There are plenty of people who really like their Meade 178ED so I am sure Meade managed to do a good re design.  Of course there also people who claim they have to adjust their scope on a regular basis.  Would be nice if we could figure out why some do not need adjustment and some do.  

It’s my understanding that Meade’s answer to the cell problem was not to machine a tighter cell but to take the less expensive road and to add radial “lens element adjustment screws” to the cell. These screws do not collimate the complete cell to the tube but adjust “one of the lens elements” in relation to the other.

 

To get good color correction in a doublet of this size Meade used a lens design with elements that are more steeply curved. Although an exaggeration, think of 2 clear marbles as lens elements and what kind of cell tolerances would be needed to keep them aligned.

 

Send the scope back to Meade and they will adjust it and say it was perfect when it left our factory. Of course in shipping the screws may or may not be enough to keep the elements aligned. Also, if you transport the scope, the same issue may or may not arise. Also, large temperature swings over time may or may not cause an issue. In all of the above you might have to realign the lens elements in respect to each other.

 

If you have a scope with the old cell you will have problems. If you have a new cell with the screws you may or may not have problems depending on shipping and how the scope was used in the past and how and where you intend to use the scope going forward.

 

Bob



#25 CHASLX200

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Posted 12 May 2019 - 08:25 AM

It’s my understanding that Meade’s answer to the cell problem was not to machine a tighter cell but to take the less expensive road and to add radial “lens element adjustment screws” to the cell. These screws do not collimate the complete cell to the tube but adjust “one of the lens elements” in relation to the other.

 

To get good color correction in a doublet of this size Meade used a lens design with elements that are more steeply curved. Although an exaggeration, think of 2 clear marbles as lens elements and what kind of cell tolerances would be needed to keep them aligned.

 

Send the scope back to Meade and they will adjust it and say it was perfect when it left our factory. Of course in shipping the screws may or may not be enough to keep the elements aligned. Also, if you transport the scope, the same issue may or may not arise. Also, large temperature swings over time may or may not cause an issue. In all of the above you might have to realign the lens elements in respect to each other.

 

If you have a scope with the old cell you will have problems. If you have a new cell with the screws you may or may not have problems depending on shipping and how the scope was used in the past and how and where you intend to use the scope going forward.

 

Bob

He says his is good.  So he can send it to me and i can see for myself if there really is a good 7" ED out there.




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