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Takahashi TSA-120 or TOA-130

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#51 Scott99

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Posted 22 August 2014 - 10:43 AM

>>>Remember seriously, these forums tend to over blow "EVERYTHING" out of proportion. This whole issue of cool down to a sweet triplet refractor is completely ridiculous, at any level. Anyone that tells you otherwise is just bored and needs to go out and use their gear instead of talk about it out here.

 

good point, totally agree about cooling concerns being overblown!  Some folks even advise choosing oil-spaced apo over air-spaced because of cooling.  I've never seen any difference between the two.   Bigger heavier OTA's take longer to cool, but it's never been a problem for me, even in winter temps.

 

In fact, one of the biggest reasons to buy these expensive apos is because they handle thermal issues better than other designs!  Every one I've used gives good images after 15 minutes in the cold air.  You'll never look into the eyepiece and see heat plumes and thermal problems like other scope designs with mirrors stuck in the middle of the light path.

 

The Tak TOA is heavy because it's "built like a tank".  The old FCT150 was 50 pounds!  A lot of people like the robust construction.  It's hard to see these under-30 pound apos taking criticism for being heavy, all the various 10-inch and up dobs have several components that are heavier than a 6-inch apo OTA.   Many club members I know have to buy vans or pickup trucks to move their dobs and SCT's around.


Edited by Scott99, 22 August 2014 - 10:46 AM.


#52 AustinAstronomer

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Posted 22 August 2014 - 11:42 AM

>>>Remember seriously, these forums tend to over blow "EVERYTHING" out of proportion. This whole issue of cool down to a sweet triplet refractor is completely ridiculous, at any level. Anyone that tells you otherwise is just bored and needs to go out and use their gear instead of talk about it out here.

 

good point, totally agree about cooling concerns being overblown!  Some folks even advise choosing oil-spaced apo over air-spaced because of cooling.  I've never seen any difference between the two.   Bigger heavier OTA's take longer to cool, but it's never been a problem for me, even in winter temps.

 

In fact, one of the biggest reasons to buy these expensive apos is because they handle thermal issues better than other designs!  Every one I've used gives good images after 15 minutes in the cold air.  You'll never look into the eyepiece and see heat plumes and thermal problems like other scope designs with mirrors stuck in the middle of the light path.

 

The Tak TOA is heavy because it's "built like a tank".  The old FCT150 was 50 pounds!  A lot of people like the robust construction.  It's hard to see these under-30 pound apos taking criticism for being heavy, all the various 10-inch and up dobs have several components that are heavier than a 6-inch apo OTA.   Many club members I know have to buy vans or pickup trucks to move their dobs and SCT's around.

 

My TOA-130NS weighs 23 pounds (with awesome mechanics).  Is that truly "heavy"?  The Celestron C9.25 weighs 21 pounds, and yet I've never heard anyone complain that it was "heavy."

 

AA


Edited by AustinAstronomer, 23 August 2014 - 10:25 PM.


#53 thomqos

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Posted 23 August 2014 - 03:30 AM

Thanks guys for all your opinions.

I decided to go with the TSA-120... Am waiting on the invoice to come through. Lead time of a few weeks. Have ordered rings for it from Joe at Parallax.
It was a very tough decision for me. Could have gone either way. Am sure I would have been thrilled to the back teeth with the TOA, but in the end, my decision came down to just the following:-
 

a). Cost. The money I saved will pay to rebuild my 10" f6 so I can use it on the G-11 (rotating rings, moonlight focuser, etc.). My wife has been very supportive of my going through this process, so I need to reciprocate that support by showing at least some restraint in my spending; I've just purchased a TSA-120, G-11, AP Maxbright, rings, etc. I also need a hard case still & I plan to get a 41mm panoptic for the TSA, as well as a high power nagler/delos, so I think I've had a fair go at spending money! Additionally, I have kids to educate, mortgage to pay, etc.. So I decided to draw the line at the TSA-120.
 

b). Portability. I wanted a scope which will be happy on a lightweight mounting one day if needed.  The TSA-120 looks to be a pretty portable scope for an almost 5" refractor.

 

If I didn't already have a 10", I would have gone for the TOA.

 

I just hope the scope lives up to my expectations... though people overwhelmingly talk glowingly of it, I've nonetheless read some stories about scopes having to go back to Takahashi in Japan several times to fix problems.  It's a little unnerving spending such a large amount of money on something you've never actually seen up close or touched... or indeed looked through.

 

As Ralph has remarked, we really are so lucky to live in an age where ordinary people have access to such great equipment.

 

An there's a saying - "Want what you have, rather than have what you want".

 

PS: Can the average joe fit the feathertouch focuser upgrade easily?

 

I'll post back after first light...

 

Russ



#54 Erik Bakker

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Posted 23 August 2014 - 04:20 AM

Congratulations Russ!

 

And rest assured: the TSA 120 will live up to your expectations. Great set you put together. Look forward to your first light report in a few weeks.



#55 bobhen

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Posted 23 August 2014 - 08:44 AM

Congratulations. The TSA 120 will absolutely thrill! Mine never disappoints.

One suggestion: Think about forgoing a high-end eyepiece and spending the money on a quick to set-up alt/az mount. I use my 120 on a CG5 but also on a Universal Astronomics Macrostar alt/az mount. The 120 rides very solidly on both for visual. For quick sessions or a 30-minute look at the moon, a quick to set-up mount will take advantage of the TSA 120’s portability and usefulness.

Bob



#56 JimP

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Posted 23 August 2014 - 09:06 AM

I have owned two and they were as good or better optically than any apo I have owned which includes multiple from AP, TMB, TEC and Takahashi. Portable and very lightweight. I agree with you that the TOA 130, which I have also owned, is a wonderful scope. You were in a win/win situation. I believe you will be very pleased with the TSA 120.



#57 BillP

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Posted 23 August 2014 - 11:17 AM

PS: Can the average joe fit the feathertouch focuser upgrade easily?

 

 

Definitely yes.  Simple operation.



#58 t.r.

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Posted 27 August 2014 - 11:04 AM

You may question your decision...until the 120 arrives and you put first light to it. Then, I think any doubt will simply vanish! I wanted the TSA-120 the moment I saw one in person...still do! And I haven't even looked through one.



#59 thesubwaypusher

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Posted 31 August 2014 - 11:00 PM

 

It's very front heavy.

 

 

I found this to be very annoying on my 130 when I had it. It means that you have to have the majority of the tube below the cradle point for balance, so you have to be sitting on the ground to observe. Heavy is one thing, but heavy in one place is quite another.



#60 Lew Chilton

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Posted 02 September 2014 - 02:26 AM

Due to my advancing age and aching back, I recently traded in my TOA-130 for a TSA-120.  I loved the 130, but couldn't handle the weight, especially when combined with its equally heavy Scopeguard case. Now, having taken the 120 to three star parties in the last three months, I have begun to form an impression of it. Despite its fine optics, the 120 doesn't deliver as bright a view of Saturn and deep sky stuff as the 130 did. There is a noticeable difference, although I shouldn't be surprised given the aperture difference.  I don't like the 120's Micro-Edge focuser, either. I thought the one on the 130 was more solid and smoother.

 

The 120 is very well matched to my EM-200 mount and handles almost as well on my GM-8. The EM-200 is quicker to set up because it has few parts and cables than the GM-8.

 

I consider the 120 a compromise. I'm still getting used to it, and maybe in time I'll come to love it. But I do miss the 130.

 

If anyone knows of a TSA-120 clamshell that's for sale at a reasonable price, please let me know.  I need a second one. Thanks a lot,

 

Lew Chilton

Attached Files


Edited by Lew Chilton, 02 September 2014 - 02:38 AM.


#61 Allan Wade

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Posted 02 September 2014 - 03:48 AM

That's still a very nice looking setup you have there Lew, and thanks for the insight into the TSA v TOA debate. That sort of information from owners of both is gold.



#62 NHRob

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Posted 02 September 2014 - 05:43 AM

I once owned a TOA-130 and loved a lot of things about it. I loved the optics and views.  I also loved the look and feel and quality of construction.

It's a gorgeous scope.  However, given it's relative bulk and weight I realized that for the effort I would always pick my bigger dob.

I finally decided that for me, I wanted a refractor that was little more svelte, even if I had to give up on aperture.

Getting older, bad back, bad hip, etc...

 

My TSA120 has wonderful build quality.  Haven't been able to evaluate the optics well yet but, I am not worried. I expect to get a lot of use out of it.

Happy with my decision.

 

Rob



#63 thomqos

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Posted 05 September 2014 - 07:20 AM

Still waiting for my gear to turn up....!



#64 samovu

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Posted 05 September 2014 - 09:04 PM

Due to my advancing age and aching back, I recently traded in my TOA-130 for a TSA-120.  I loved the 130, but couldn't handle the weight, especially when combined with its equally heavy Scopeguard case. Now, having taken the 120 to three star parties in the last three months, I have begun to form an impression of it. Despite its fine optics, the 120 doesn't deliver as bright a view of Saturn and deep sky stuff as the 130 did. There is a noticeable difference, although I shouldn't be surprised given the aperture difference.  I don't like the 120's Micro-Edge focuser, either. I thought the one on the 130 was more solid and smoother.

 

The 120 is very well matched to my EM-200 mount and handles almost as well on my GM-8. The EM-200 is quicker to set up because it has few parts and cables than the GM-8.

 

I consider the 120 a compromise. I'm still getting used to it, and maybe in time I'll come to love it. But I do miss the 130.

 

If anyone knows of a TSA-120 clamshell that's for sale at a reasonable price, please let me know.  I need a second one. Thanks a lot,

 

Lew Chilton

 

Lew, I agree with Allan, that is a beautiful set up! And your honesty in describing your thoughts about the move from one to the other is much appreciated. I came close to doing what you did recently. 

 

About a month ago I placed an ad on AM wanting to trade my TOA130F for a TSA120. I took it down a few hours later as I lost my nerve. I was looking for something a little lighter and easier to set up even though I'm still able to mount the TOA as well as a heavier 6" triplet. But I was afraid that I'd regret it later and am glad I didn't go through with it. 

 

Eventually I will not be able to safely lift any of these heavier scopes and will happily use my smaller ones. 

 

Clear views to all,

John



#65 jinmay

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Posted 22 September 2014 - 07:30 AM

Due to my advancing age and aching back, I recently traded in my TOA-130 for a TSA-120.  I loved the 130, but couldn't handle the weight, especially when combined with its equally heavy Scopeguard case. Now, having taken the 120 to three star parties in the last three months, I have begun to form an impression of it. Despite its fine optics, the 120 doesn't deliver as bright a view of Saturn and deep sky stuff as the 130 did. There is a noticeable difference, although I shouldn't be surprised given the aperture difference.  I don't like the 120's Micro-Edge focuser, either. I thought the one on the 130 was more solid and smoother.

 

The 120 is very well matched to my EM-200 mount and handles almost as well on my GM-8. The EM-200 is quicker to set up because it has few parts and cables than the GM-8.

 

I consider the 120 a compromise. I'm still getting used to it, and maybe in time I'll come to love it. But I do miss the 130.

 

If anyone knows of a TSA-120 clamshell that's for sale at a reasonable price, please let me know.  I need a second one. Thanks a lot,

 

Lew Chilton

Hey, sorry to derail the main topic, but I have an urgent (for me obv :D) question regarding tsa-120 and gm8: do I need any additional dovetail (have 7'' ADM dovetail for gm8) or maybe even different tube rings to setup losmandy mount and tak scope, for now I've used it solely with EM200 mount (same setup as shown in your picture), but soon Ill be going overseas where I only have gm8 mount..

Best regards,

Paul


Edited by jinmay, 22 September 2014 - 07:37 AM.


#66 dawziecat

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Posted 22 September 2014 - 11:38 AM

More about replacing TAK focusers . . .

 

I have two Taks, both with 4" focusers. One the original Tak 4", the other the new "B" version.
 
Both are fine focusers and I have no idea why anyone would want to consider replacing them for visual. :confused:
 
For AP, I find them totally adequate to carry a heavy imaging train too but, with the following caveat.
You can't side load them!  By that I mean they do not take gracefully to a focus motor that drives the focus shaft through an off-center spur gear. Neither of my TAK focusers would work reliably when side-loaded in this fashion. More often than not, they would not work at all when the spur gear drove the shaft. Occasionally, they would. I had to return an auto-focus set up over this and am still focusing manually until I can get an FLI focuser into action.
 
This characteristic is of absolutely no concern to visual users focusing with their fingers! If you plan on adding a motor to one of these TAK focusers, be aware of the issue.
I think this "replace the focusers" for visual users is little more than a fetish. For Taks anyway. No one should be factoring in the cost and hassle of replacing a stock TAK focuser if they plan on using the instrument visually only and focusing manually. It's just money down a rat hole.



#67 jrbarnett

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Posted 26 September 2014 - 03:22 PM

 

 

It's very front heavy.

 

 

I found this to be very annoying on my 130 when I had it. It means that you have to have the majority of the tube below the cradle point for balance, so you have to be sitting on the ground to observe. Heavy is one thing, but heavy in one place is quite another.

 

Most triplets, not just Taks, are imbalanced in this manner.  Another alternative is to add weight (such as a counterweight ring) to the rear of the OTA, to more evenly distribute the mass.  With my triplets, though, I find that by the time I install the beefy diagonal or turret, finder and a wide field eyepiece, it becomes more balanced.  Now that doesn't help during set-up, but it does help position the OTA more evenly in the rings during observing.  I also sometimes use a nifty Televue bronze 1.25"-to-2" adapter to maintain rear weight when I use lighter eyepieces.

 

Regards,

 

Jim



#68 tomcody

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Posted 28 September 2014 - 01:48 PM

 

 

 

It's very front heavy.

 

 

I found this to be very annoying on my 130 when I had it. It means that you have to have the majority of the tube below the cradle point for balance, so you have to be sitting on the ground to observe. Heavy is one thing, but heavy in one place is quite another.

 

Most triplets, not just Taks, are imbalanced in this manner.  Another alternative is to add weight (such as a counterweight ring) to the rear of the OTA, to more evenly distribute the mass.  With my triplets, though, I find that by the time I install the beefy diagonal or turret, finder and a wide field eyepiece, it becomes more balanced.  Now that doesn't help during set-up, but it does help position the OTA more evenly in the rings during observing.  I also sometimes use a nifty Televue bronze 1.25"-to-2" adapter to maintain rear weight when I use lighter eyepieces.

 

Regards,

 

Jim

 

Jim has a point about using tube counter weights to correct balance and remember the TOA 130 has about 230 mm of back focus so if you put a 2" diagonal, binoviewers and a pair of heavy eyepieces at the focus point only a small inbalance  will remain such that the Tak 2.5 lb tube wieght may correct it all. ( or get the heavier 4" tak focuser or a FT 3.5" focuser, either of which are heavy enough to bring the scope into balance).

I still feel that the 120vs 130 question is one of a simple choice: lightweight scope/mount for portability or larger scope/ mount to get a little more reach and detail, let the buyer choose his preference.

Rex


Edited by tomcody, 28 September 2014 - 01:50 PM.


#69 tomcody

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Posted 28 September 2014 - 02:38 PM

Due to my advancing age and aching back, I recently traded in my TOA-130 for a TSA-120.  I loved the 130, but couldn't handle the weight, especially when combined with its equally heavy Scopeguard case. Now, having taken the 120 to three star parties in the last three months, I have begun to form an impression of it. Despite its fine optics, the 120 doesn't deliver as bright a view of Saturn and deep sky stuff as the 130 did. There is a noticeable difference, although I shouldn't be surprised given the aperture difference.  I don't like the 120's Micro-Edge focuser, either. I thought the one on the 130 was more solid and smoother.

 

The 120 is very well matched to my EM-200 mount and handles almost as well on my GM-8. The EM-200 is quicker to set up because it has few parts and cables than the GM-8.

 

I consider the 120 a compromise. I'm still getting used to it, and maybe in time I'll come to love it. But I do miss the 130.

 

If anyone knows of a TSA-120 clamshell that's for sale at a reasonable price, please let me know.  I need a second one. Thanks a lot,

 

Lew Chilton

Lew regarding your 130 and  120, did they both have the 2.7" Tak focusers? and were the fine focusers both Tak? If yes then they would have the Tak MEF3 focuser and the only difference would be the way they were adjusted. But if the TOA130 had a 4" Tak focuser ? it would have had a MEF4 focuser, which I understand is different than the MEF3 and could feel different.

( although I measure about 7:1 ratio on both my MEF3 and MEF4 but the build on my older MEF4 looks different some how?)

Rex


Edited by tomcody, 28 September 2014 - 02:45 PM.


#70 Lew Chilton

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Posted 03 October 2014 - 02:40 PM

 

Due to my advancing age and aching back, I recently traded in my TOA-130 for a TSA-120.  I loved the 130, but couldn't handle the weight, especially when combined with its equally heavy Scopeguard case. Now, having taken the 120 to three star parties in the last three months, I have begun to form an impression of it. Despite its fine optics, the 120 doesn't deliver as bright a view of Saturn and deep sky stuff as the 130 did. There is a noticeable difference, although I shouldn't be surprised given the aperture difference.  I don't like the 120's Micro-Edge focuser, either. I thought the one on the 130 was more solid and smoother.

 

The 120 is very well matched to my EM-200 mount and handles almost as well on my GM-8. The EM-200 is quicker to set up because it has few parts and cables than the GM-8.

 

I consider the 120 a compromise. I'm still getting used to it, and maybe in time I'll come to love it. But I do miss the 130.

 

If anyone knows of a TSA-120 clamshell that's for sale at a reasonable price, please let me know.  I need a second one. Thanks a lot,

 

Lew Chilton

Hey, sorry to derail the main topic, but I have an urgent (for me obv :D) question regarding tsa-120 and gm8: do I need any additional dovetail (have 7'' ADM dovetail for gm8) or maybe even different tube rings to setup losmandy mount and tak scope, for now I've used it solely with EM200 mount (same setup as shown in your picture), but soon Ill be going overseas where I only have gm8 mount..

Best regards,

Paul

 

Paul, I hope I'm not too late to answer your question before you head overseas.

 

Based on my own experience, you have two ways to mount your TSA-120 on a Losmandy GM-8.

1.  If you already own the Tak clamshell for the TSA-120, then you can buy a "Dr. D" dovetail plate from Woodland Hills Camera & Telescope for about $50. This plate is machined to perfectly mate to the Tak clamshell. (See picture attached below.) This is the cheapest way to go if you already own the Tak clamshell.

 

2.  If you don't already own the Tak clamshell, then you can purchase 2 Parallax tube rings of the appropriate size from Joe Nastasy and attach them to a standard Losmandy or ADM D-size dovetail plate of 7-inch length.  This is the cheapest way to go if you don't own the Tak clamshell.

 

Hope this helps,

Lew


Edited by Lew Chilton, 03 October 2014 - 02:42 PM.


#71 Lew Chilton

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Posted 03 October 2014 - 02:52 PM

Paul,

 

Here's a picture of my TSA-120 mated to my GM-8 via the "Dr. D" dovetail plate. Using this plate allows me to use the Tak clamshell.

Attached Files



#72 Lew Chilton

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Posted 03 October 2014 - 03:24 PM

Paul,

 

Here's a picture of my TSA-120 attached to my GM-8 via the "Dr. D" dovetail plate. Using this plate allows you to use the Tak clamshell.

 

 

Due to my advancing age and aching back, I recently traded in my TOA-130 for a TSA-120.  I loved the 130, but couldn't handle the weight, especially when combined with its equally heavy Scopeguard case. Now, having taken the 120 to three star parties in the last three months, I have begun to form an impression of it. Despite its fine optics, the 120 doesn't deliver as bright a view of Saturn and deep sky stuff as the 130 did. There is a noticeable difference, although I shouldn't be surprised given the aperture difference.  I don't like the 120's Micro-Edge focuser, either. I thought the one on the 130 was more solid and smoother.

 

The 120 is very well matched to my EM-200 mount and handles almost as well on my GM-8. The EM-200 is quicker to set up because it has few parts and cables than the GM-8.

 

I consider the 120 a compromise. I'm still getting used to it, and maybe in time I'll come to love it. But I do miss the 130.

 

If anyone knows of a TSA-120 clamshell that's for sale at a reasonable price, please let me know.  I need a second one. Thanks a lot,

 

Lew Chilton

Lew regarding your 130 and  120, did they both have the 2.7" Tak focusers? and were the fine focusers both Tak? If yes then they would have the Tak MEF3 focuser and the only difference would be the way they were adjusted. But if the TOA130 had a 4" Tak focuser ? it would have had a MEF4 focuser, which I understand is different than the MEF3 and could feel different.

( although I measure about 7:1 ratio on both my MEF3 and MEF4 but the build on my older MEF4 looks different some how?)

Rex

 

Rex,

Both my 130 and 120 came equipped with the 2.7" Tak focusers. The 130 came without the Micro-Edge fine focuser, but I added it later. The 120 did come with the Micro-Edge focuser. (By the way, I purchased both OTAs used.)

 

The 120's focuser had a lot of lateral slop when I first used it. This was very noticeable when focusing on a star or planet at high magnifications. I eliminated it by tightening the R&P adjustment. But there's still another minor problem.  I rack the drawtube in all the way so that the scope will fit in its hard case.*

But the next time I set up the scope and rack out the drawtube, the end of it gets hung up inside the focuser housing. I have to jiggle the end of the drawtube slightly while racking it out before it'll come free of the housing.

The adjustment I made to eliminate the slop pushes against the side of the drawtube, and this I believe is the reason why it gets hung up after I rack it in all the way. It's no big deal. I guess I'll just have to live with this minor annoyance.

 

*By the way, the Explore Scientific hard case for its 127 is a perfect fit for the TSA-120.

**  Still looking for a second Tak clamshell!


Edited by Lew Chilton, 03 October 2014 - 03:35 PM.


#73 tomcody

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Posted 03 October 2014 - 04:13 PM

Paul,

 

Here's a picture of my TSA-120 attached to my GM-8 via the "Dr. D" dovetail plate. Using this plate allows you to use the Tak clamshell.

 

 

Due to my advancing age and aching back, I recently traded in my TOA-130 for a TSA-120.  I loved the 130, but couldn't handle the weight, especially when combined with its equally heavy Scopeguard case. Now, having taken the 120 to three star parties in the last three months, I have begun to form an impression of it. Despite its fine optics, the 120 doesn't deliver as bright a view of Saturn and deep sky stuff as the 130 did. There is a noticeable difference, although I shouldn't be surprised given the aperture difference.  I don't like the 120's Micro-Edge focuser, either. I thought the one on the 130 was more solid and smoother.

 

The 120 is very well matched to my EM-200 mount and handles almost as well on my GM-8. The EM-200 is quicker to set up because it has few parts and cables than the GM-8.

 

I consider the 120 a compromise. I'm still getting used to it, and maybe in time I'll come to love it. But I do miss the 130.

 

If anyone knows of a TSA-120 clamshell that's for sale at a reasonable price, please let me know.  I need a second one. Thanks a lot,

 

Lew Chilton

Lew regarding your 130 and  120, did they both have the 2.7" Tak focusers? and were the fine focusers both Tak? If yes then they would have the Tak MEF3 focuser and the only difference would be the way they were adjusted. But if the TOA130 had a 4" Tak focuser ? it would have had a MEF4 focuser, which I understand is different than the MEF3 and could feel different.

( although I measure about 7:1 ratio on both my MEF3 and MEF4 but the build on my older MEF4 looks different some how?)

Rex

 

Rex,

Both my 130 and 120 came equipped with the 2.7" Tak focusers. The 130 came without the Micro-Edge fine focuser, but I added it later. The 120 did come with the Micro-Edge focuser. (By the way, I purchased both OTAs used.)

 

The 120's focuser had a lot of lateral slop when I first used it. This was very noticeable when focusing on a star or planet at high magnifications. I eliminated it by tightening the R&P adjustment. But there's still another minor problem.  I rack the drawtube in all the way so that the scope will fit in its hard case.*

But the next time I set up the scope and rack out the drawtube, the end of it gets hung up inside the focuser housing. I have to jiggle the end of the drawtube slightly while racking it out before it'll come free of the housing.

The adjustment I made to eliminate the slop pushes against the side of the drawtube, and this I believe is the reason why it gets hung up after I rack it in all the way. It's no big deal. I guess I'll just have to live with this minor annoyance.

 

*By the way, the Explore Scientific hard case for its 127 is a perfect fit for the TSA-120.

**  Still looking for a second Tak clamshell!

Lew,

That is not the correct way to adjust the focuser, 

You should loosen the two rack screws so there is a lot of play but you can still move the drawtube by turning the rack.

Then 

use acetone, (nail polish remover) to loosen the three allen set screws along the top of the focuser,

a small drop on each screw is usually enough And you may temporarly remove the large drawtube lock to reach the small screws.

Use a 1.5mm allen wrench and adjust the three screws ( middlle screw first) then the two end ones untill you have smooth drawtube movement. Go to full in and out position to check the drawtube.

Then adjust the two rack screws to just eliminate the backlash and you are done.

NOTE

The drawtube adjustment screws press DOWN on the  drawtube, the rack adjustments press UP on the tube so you don't want them to fight each other! 

Rex


Edited by tomcody, 03 October 2014 - 04:15 PM.


#74 Lew Chilton

Lew Chilton

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Posted 03 October 2014 - 07:57 PM

Rex,

The TSA-120's focuser had a lot of lateral slop when I first used it. This was very noticeable when focusing on a star or planet at high magnification. I eliminated it by tightening the two R&P rack screws. But there's still another minor problem.  I rack the drawtube in all the way so that the scope will fit in its hard case.

 

But the next time I set up the scope and racked out the drawtube, the end of it got hung up inside the focuser housing. I had to jiggle the end of the drawtube slightly while racking it out before it came free of the housing.

The adjustment I made to eliminate the slop pushes against the side of the drawtube, and this I believe is the reason why it gets hung up after I rack it in all the way. It's no big deal. I guess I'll just have to live with this minor annoyance.

- Lew

_____________________________________________________________________________________________________________

 

That is not the correct way to adjust the focuser, 

You should loosen the two rack screws so there is a lot of play but you can still move the drawtube by turning the rack.

Then....

use acetone, (nail polish remover) to loosen the three allen set screws along the top of the focuser,

a small drop on each screw is usually enough And you may temporarly remove the large drawtube lock to reach the small screws.

Use a 1.5mm allen wrench and adjust the three screws ( middlle screw first) then the two end ones untill you have smooth drawtube movement. Go to full in and out position to check the drawtube.

Then adjust the two rack screws to just eliminate the backlash and you are done.

NOTE

The drawtube adjustment screws press DOWN on the  drawtube, the rack adjustments press UP on the tube so you don't want them to fight each other! 

Rex

 

Rex, after I get the TSA-120 unpacked from my van, I'll follow your instructions exactly to - hopefully - solve the problem.  I really appreciate your help!

All the best,

Lew


Edited by Lew Chilton, 03 October 2014 - 07:59 PM.


#75 Renae Gage

Renae Gage

    Apollo

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Posted 03 October 2014 - 08:10 PM

I've owned both the TOA-130 and the TSA-120 (current).  The former requires a lot more mount.  You can't go wrong with either for visual.  The best night of viewing I have ever had was under mag ~7 skies at the Nebraska Star Party with the TOA.  Unbelievable.  I'm very happy with the TSA-120 though.  One quibble.  I don't like the feel of the Tak focuser.  Too spongy for me.  Perhaps I didn't have it adjusted well, but I added the FT MPA, which is just the ticket.








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