31 replies to this topic

[Jay Lawson]

Does anyone know if there is a pattern to the early orange Celestron serial numbers?  Do they match the C8 serial number pattern where first digit is the quarter, four digits for sequence in production, and the last digit was the year?

 

I am working on one right now that is  SN 110376 and it appears to be from the 1970's.  Could it be from the first quarter of 1976?

 

I was thinking if they did the C8's this way they might do the same for C11's.

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[J A VOLK]

I believe the C11 production started around 1980

[lee14]

That is indeed a beautiful scope, you're fortunate to have it. There does not seem to be any record of C11's prior to 1980, when the model was introduced to replace the C10. Maybe they thought half the diameter of the venerable C22 was a selling point...

 

Lee

[CHASLX200]

Around 1981 is when they started selling.

[lee14]

On top of that, Celestron does not maintain a database linking serial numbers to the date of production.

 

Lee

[Jay Lawson]

So I guess a quick internet check would have told me this.  http://www.company7....tron/index.html

 

"By 1980 the Celestron product line added the C-11 telescope to the product line replacing the long discontinued C-10. While the telescopes were offered as optical tubes or on 120 volt powered fork mounts, the C-14 included a DC powered Declination motor necessitating a Drive Corrector with matching output. The C-11 and C-14 (50 lb. OTA with 58 lb. fork) shared the same massive 26 lb. equatorial wedge and 33 lb. locked angle Field Tripod."

 

They were not kidding about the weight.  My OTA and forks come in right about 65 lbs.  Almost too much for me to manage getting on the tripod.

 

So if they started in 1980 and switched to black in 1986, I guess there wouldn't be many of the orange C11's out there?

[CHASLX200]

So I guess a quick internet check would have told me this.  http://www.company7....tron/index.html

 

"By 1980 the Celestron product line added the C-11 telescope to the product line replacing the long discontinued C-10. While the telescopes were offered as optical tubes or on 120 volt powered fork mounts, the C-14 included a DC powered Declination motor necessitating a Drive Corrector with matching output. The C-11 and C-14 (50 lb. OTA with 58 lb. fork) shared the same massive 26 lb. equatorial wedge and 33 lb. locked angle Field Tripod."

 

They were not kidding about the weight.  My OTA and forks come in right about 65 lbs.  Almost too much for me to manage getting on the tripod.

 

So if they started in 1980 and switched to black in 1986, I guess there wouldn't be many of the orange C11's out there?

Not sure how many they are out there. Friend bought a mint 1982 C11 with the worst optics i ever saw in a SCT.  I know they all  vary from bad to very sharp. If you have a sharp one then keep it.  I would love to find a super sharp C11.  The U11 was under mounted .  

[ccwemyss]

They started with a sequential numbering system. The first two digits are the model (C11) and the next four are the sequence number. The school where I teach has S/N 4, which was donated by a family with kids in the school. Their uncle knew someone at Celestron, and got one of the press loaners after they were done with them. It has phenomenal optics. 

 

 

They came out around the time that I was working in the scope shop, and it was known then that they were somewhat variable in quality, so we didn't carry them. 

 

The donation of this one began with the dad asking me if I the school could use a large telescope. Knowing that people often describe a 60mm f15 refractor as large, I asked, "How big around is it?" He held up his hands to about 15" in diameter. So the next question was, "What color is it?" to which he replied "Orange." So I said, yes, we could probably use it (with visions of students looking through a C14). A while later I walked into the lobby and found the filthiest, most neglected C11 I had ever seen. Since I knew the orange ones were iffy, I thought, "What have I gotten myself into with this?" But then I turned it around and saw the serial number, and my jaw dropped. After many hours of cleaning, re-greasing, etc., it went into service. 

 

It is incredibly heavy, and quite a challenge to lift onto the wedge. The family actually donated an Exploradome (when they first came out, they had a very deep discount for schools) to house it, since it was too much to regularly use otherwise. Like the Orange C14, it actually works better to loosen the forks, remove the OTA, put the mount onto the wedge, and then re-mount the OTA. 

 

A few years later I had a similar experience - someone had found a large blue telescope on Freecycle and offered it to the school. I told them to bring it in and I'd look at it. Again, an absolutely filthy, run-down, scope. This one, an 8", in a crude ATM sonotube and plywood mount. "Oh no, what have I gotten myself into?" Then turn it around and there's this:

 

 

Chip W. 

[davidmcgo]

The C11 OTA separates from the forks very easily.  There are slots inside the trunnion plates and extra screws in the rear cell with their heads sticking out as guide pins.  So you set up the fork, aim it as if the scope was pointing straight up, make sure it is clamped.  Then you slide the OTA down into it, it rests on the guide pins in the slots.  They insert the 4 screws to hold everything together.  You do not need to handle all 65 pounds at once.

 

Just be super careful on screw length.  The guide pins are 1/4x20 by 0.25 socket head screw.  The screws to fix the OTA to the trunnions are 1/4x20 x 5/8” socket head.  Any longer on either can hit the primary or jam the focusing.

 

I really like the slow motion on the very earliest models with the knob sticking out the side.  That is the same as the old C10 and allows really fine movement with the RA clamp engaged.  It does affect the setting circle reading though since it is moving the RA gear directly through a clutched coupling.

 

Dave

[davidmcgo]

The manual here shows how to set these up:

 

http://www.physics.m.../c14-manual.pdf

 

Dave

[The Planetman]

Back in the late '90's, I had 110773.  It had the best SCT optics I've ever had.  Wish I hadn't let that one go.  I named it The Orange Blossom Special.  It definitely was special.....

[davidmcgo]

I have on loan from a friend SN 110748 which doesn’t have the side RA slow motion and came with a blog leg tripod but older style wedge and the 10x40 eyepiece is plastic so probably 1983 or so.  Killer sharp optics with dead on correction..  Coatings all look brand new.

 

Really enjoyable scope to use and will still be just as good in another 20 to 30 years.  That’s why I like the older non go to stuff.  Just simple and reliable.

 

Dave

[starman876]

I had an orange C11 I never should have sold.  Had very good optics.  Most of the SCT's I had that were not messed with by a previous owner and had still all the factory settings was very good.  Any SCT i bought as a special deal were always messed with and severly out of mechanical alignment.   There is a good reason why that bargain SCT was so cheap.  The  person had messed with it and could not get it to give good images anymore.  I am sure most of these SCT's gave the SCT the bad rap you hear so often.

Edited by starman876, 28 November 2020 - 02:37 PM.

[ccwemyss]

Just for the record, it's up for sale on the classifieds - offer pending already at $1750.

 

Chip W. 

[Senex Bibax]

Found this one for sale locally today, serial # 100594..  https://www.kijiji.c...tics/1548681230

[The Planetman]

Found this one for sale locally today, serial # 100594..  https://www.kijiji.c...tics/1548681230

That's an early one for sure.  Her asking price equates to around $2000 US.  If the price is for the scope alone, that's a bit high.  Depending on the accessories that are with it, that could be a decent price. 
Either way, it's all dependent on the condition of the optics and coatings as well.
Still, a good early find. 

[CHASLX200]

I would never touch it unless i could test out the optics. My friend had one and it was the worst SCT i ever looked thru.

[John Higbee]

The C11 OTA separates from the forks very easily.  There are slots inside the trunnion plates and extra screws in the rear cell with their heads sticking out as guide pins.  So you set up the fork, aim it as if the scope was pointing straight up, make sure it is clamped.  Then you slide the OTA down into it, it rests on the guide pins in the slots.  They insert the 4 screws to hold everything together.  You do not need to handle all 65 pounds at once.

 

Just be super careful on screw length.  The guide pins are 1/4x20 by 0.25 socket head screw.  The screws to fix the OTA to the trunnions are 1/4x20 x 5/8” socket head.  Any longer on either can hit the primary or jam the focusing.

 

I really like the slow motion on the very earliest models with the knob sticking out the side.  That is the same as the old C10 and allows really fine movement with the RA clamp engaged.  It does affect the setting circle reading though since it is moving the RA gear directly through a clutched coupling.

 

Dave

Dave - I've got an early C11 Orange tube with the slow motion.  the knob is frozen (won't turn)...any ideas on how to fix this?

 

thanks, John

[davidmcgo]

Hi John,

 

I don’t have any firsthand experience with servicing the C11 setup with that slow motion but on the C10 there is a heavy spring loading on a clutch and the knob is very stiff to turn.  I would suggest taking the worm cover off and seeing what can be stripped down and lubricated.  My C10 was frozen with solidified grease when I got it.

 

Dave

Edited by davidmcgo, 27 June 2021 - 10:00 PM.

[John Higbee]

Dave - will try that today.  By the way, really like your motto/mantra!  John

[Ron Luxemburg]

I have #110333, the forks and base are gone (sold yrs. ago) I purchased it used from a guy in New Mexico. He purchased it from someone in Texas who left it outside year round. According to the New Mexico owner he sent it into Celestron and they replaced the corrector and re-coated the mirrors. Optics are top notch. Mine is now a carbon fiber tube and it rides solidly on either an AP 900 or 1200 mount. The C11 is a great scope.

[jragsdale]

I would never touch it unless i could test out the optics. My friend had one and it was the worst SCT i ever looked thru.

How do you guys quantify the quality of the optics? What if it's just out of collimation, secondary central alignment, focuser tilt, eyepiece placement, corrector spacing/rotation alignment with secondary, thermal equilibrium? If any of those things are way off, the optics will suck. One almost needs to spend hours fine tuning each one before finally deciding if something actually is freaky sharp or not. I bet there a lot of freaky sharp, non-optimized SCTs out there!

[Whurst00]

Hi folks, I am a new owner of an old orange tube, it only took 41 years to get one but I have been dreaming of getting one for years.  Have I read right? Can I send this to Celestron to be checked out and adjusted?

Edited by Whurst00, 28 April 2024 - 11:14 AM.

[CHASLX200]

How do you guys quantify the quality of the optics? What if it's just out of collimation, secondary central alignment, focuser tilt, eyepiece placement, corrector spacing/rotation alignment with secondary, thermal equilibrium? If any of those things are way off, the optics will suck. One almost needs to spend hours fine tuning each one before finally deciding if something actually is freaky sharp or not. I bet there a lot of freaky sharp, non-optimized SCTs out there!

We did every trick in the book . RoTated the corrector and did it all and nothing but cotton balls for stars. I GOTTA  WONDER if that scope is still being sold to other suckers since 1998 when he had it.

[CHASLX200]

Hi folks, I am a new owner of an old orange tube, it only took 41 years to get one but I have been dreaming of getting one for years.  Have I read right? Can I send this to Celestron to be checked out and adjusted?

Not sure if they will touch a older scope like that.