525 replies to this topic

[NinePlanets]

There was a time in the 1970's that a batch of C5/C8's were released with slightly off-spec threads. From time to time folks still run into one that won't quite take a standard visual back or T-adapter. I don't know where we got them from, whether Celestron, or another, but at Star Tracker we kept a box of spare rings for visual backs that had the internal threads opened up a bit to fit those few C5/C8's with problems. When someone came in complaining of the issue we just handed them one, no charge.

[Joe Cepleur]

My new-to-me Black Tube C5 displays the serial number "503384" on the secondary holder, but also displays the number "NT 602133" engraved into the base with what appears to have been a hand-held, powered engraving tool. Both motors have "51535-11" stamped on them. There are also all sorts of letters and numbers engraved on their sides, but the motors are recessed so tightly into the telescope's base that I can not read them.

 

The original paperwork was included, although regrettably not with the sales slip. The Celestron Optical Certification certificate says that the installed optics were number 681. Also included is a full-color poster advertising the wonders of seeing Halley's Comet with "Celestron precision optics!" 

 

The original owner, an American who accepted a job in Australia, related the telescope's history. Knowing he would be there for some years, he purchased a C11 and this C5 with Southern Hemisphere motors. Upon his return to the United States, he shipped both telescopes back to Celestron for reconditioning and the substitution of Northern Hemisphere motors. (My club also received the C11 in his donation.) 

 

Putting all of this together – please correct me if I may be wrong! – I suspect that this telescope was made in 1985 or 1986, and that the motors were switched in 2011 (taking the "11" from both the approximate time of the man's return to the United States and the "11" in "51535-11.") I have to wonder whether, upon reconditioning, the "NT 602133" was engraved into the base, with the "NT" standing for, "New Telescope," or some such code. 

 

Condition is excellent, except for fogging of the corrector plate. I have heard that this occurs from off-gassing of greases over many years, so that will need to be cleaned. Will the fog also be on the mirrors, and if so, is it worth the effort to clean them? Also, the finder bracket is not original. It is a grayish one from an Orange Tube C8, so it does not quite fit, and is held on with only one screw. 

 

The original tripod, wedge, and footlocker are included. 

 

Best of all, the optics test well! I have heard that during the Halley's Comet craze, Celestron rushed production of many terrible optics, but this telescope is good! 

Edited by Joe Cepleur, 10 August 2024 - 02:57 PM.

[Bob Hayes]

So it was real!!   Nice score.   Such a lovely scope.  

In the original listing, it looked like it was missing the R.A. slow motion know but in your photos everything looks present.   Did you need to do any little bit of touch-up maintenance once you got the scope?   Did you have to go on a road trip to get it or did you get extra lucky and have it appear nearby?

I thought the knob was missing when I got it home. I found it in a bag he gave me with it that contained the eyepieces. I was missing the original power cord but I have since found one.

[RSX11M+]

... are modern Celestron SCT accessories suppose work on these older C5 scopes?  I've got a Celestron visual back and a Celestron focal reducer and nether will completely screw onto the threads of the scope.

 

 

Yes, but there's a caveat.

 

All Celestron's SCTs [and other manufacturers] eventually standardized on the same optical back which became known as "SCT Thread". [please note that a C90 is a MAK not an SCT]

 

But... early Celestron scopes and accessories had a slightly "off" thread. When Celestron later changed to correct this, their own newer accessories became slightly incompatible with their early scopes.

 

The dividing line seems to have been around the 1977 date. All my Tri-Color scopes are cross-compatible, as are the sand cast models and accesories. Some time in the Diecast era, seems to be the change.

 

This incompatibility is likely what you are experiencing if the accessory thread ring seems to screw on partway, then stops prior to the mating flanges meeting. It leaves the "adapter" loose and not fully seated against the back of the scope.

 

It's a minor headache we often forget about.

 

More details are available here.

 

 

I would gladly have continued as a DEC OEM, but they decided to pursue the Mainframe market instead, proclaiming at one point: "We would rather have 2% of IBM's Business than all the customers we have now."

 

Our response was "We hope DEC and all their new customers are very happy. Goodbye-"

 

Sadly, they succeeded. Just another case of "Snatching Defeat from the Jaws of Victory". In the end they would have no one and be swallowed up by Compaq who broke them up, trading off units to Microsoft and HP, among others, before being absorbed themselves.

 

Dave Cutler of RSX fame, went on to write NT and later Windows OS kernels.

 

It was a fun time, though heartbreaking in the end. Were it not for the Open Source movement rescuing UNIX from obscurity, the world would be very different today. Enjoy the fact that you have an historic perspective many do not.

[RSX11M+]

My new-to-me Black Tube C5 displays the serial number "503384" on the secondary holder, but also displays the number "NT 602133" engraved into the base with what appears to have been a hand-held, powered engraving tool. Both motors have "51535-11" stamped on them. There are also all sorts of letters and numbers engraved on their sides, but the motors are recessed so tightly into the telescope's base that I can not read them.

 

The original paperwork was included, although regrettably not with the sales slip. The Celestron Optical Certification certificate says that the installed optics were number 681. Also included is a full-color poster advertising the wonders of seeing Halley's Comet with "Celestron precision optics!" 

 

The original owner, an American who accepted a job in Australia, related the telescope's history. Knowing he would be there for some years, he purchased a C11 and this C5 with Southern Hemisphere motors. Upon his return to the United States, he shipped both telescopes back to Celestron for reconditioning and the substitution of Northern Hemisphere motors. (My club also received the C11 in his donation.) 

 

Putting all of this together – please correct me if I may be wrong! – I suspect that this telescope was made in 1985 or 1986, and that the motors were switched in 2011 (taking the "11" from both the approximate time of the man's return to the United States and the "11" in "51535-11.") I have to wonder whether, upon reconditioning, the "NT 602133" was engraved into the base, with the "NT" standing for, "New Telescope," or some such code. 

 

Condition is excellent, except for fogging of the corrector plate. I have heard that this occurs from off-gassing of greases over many years, so that will need to be cleaned. Will the fog also be on the mirrors, and if so, is it worth the effort to clean them? Also, the finder bracket is not original. It is a grayish one from an Orange Tube C8, so it does not quite fit, and is held on with only one screw. 

 

The original tripod, wedge, and footlocker are included. 

 

Best of all, the optics test well! I have heard that during the Halley's Comet craze, Celestron rushed production of many terrible optics, but this telescope is good! 

Hello Joe, and thanks for registering your C5.

 

I am not personally as familiar with C5 history, but I can give you some details from other registry entries and the knowledge I do have.

 

Your serial number dates to the the end of production, which seems to be in late 1982. After 1982 there was a ten year hiatus. When reintroduced the mount had changed from the two fork-arm type to a single arm mount, and registry notes say "White OTA" instead of the previous Orange or Black.

 

503384 would make your scope second to last in the registry prior to the hiatus.

 

Curiously, 503352 is noted as a 240v scope. This makes it likely a southern hemisphere candidate as well.

 

Knowing that your scope was returned and converted back to Northern Hemisphere by Celestron is a bit of history easily lost. Your entry will be so noted.

 

Since motor dates can not be used to support your scope's original manufacture, I will direct you to this earlier registry post and image of the then motor's date suffix. It may aid you in understanding your replacement motor's epoch, if you are ever able to read them. [I keep a dental mirror for such occasions]

 

 Finally, the hand etched "NT 602133" readable outside the base is not a traditional Celestron service practice I am aware of. Occasionally, internal markings are suspected to be of service department origin. External marks are most often Inventory Tags added by an owning institution or other holder. [evidence tag?]

 

Well, that's the best I can offer. Others, perhaps more knowledgable, frequent this thread and will be all too happy to add to, or correct, my information.

 

If you post photos, it may help support or correct this profile.

 

Thank you again for registering.

[Kasmos]

Your serial number dates to the the end of production, which seems to be in late 1982. After 1982 there was a ten year hiatus. When reintroduced the mount had changed from the two fork-arm type to a single arm mount, and registry notes say "White OTA" instead of the previous Orange or Black.

 

503384 would make your scope second to last in the registry prior to the hiatus.

 

 

His C5 is most likely from mid (edit, '83 to late 1985)

 

The Orange C5 is still shown in the 1983 Catalog (below)

and I'm fairly sure they used the same catalog in '84.

 

Once and awhile you'll see C5s from '85 and they are usually black.

Keep in mind that Celestron didn't make a black C5 or C8 until about mid '85. (edit, wrong more like mid '83)

Also, according to Uncle Rod's Guide the C5 was dropped from the line up in 1986.

 

Here's a invoice for a C5 sold in '82 showing the date and serial number

 

'And here's another C5 that's very likely from '85 (edit, late '83-85)

 

Just last night I saw the Celestron ad annoucing Black as a new color option.

IIRC, it was the Aug. 85 issue of Sky & Telescope. (edit, Aug. '83)

I'll try to find it and post it when I do.

Edited by Kasmos, 14 August 2024 - 03:57 AM.

[RSX11M+]

His C5 is most likely from mid to late 1985.

 

The Orange C5 is still shown in the 1983 Catalog (below)

and I'm fairly sure they used the same catalog in '84.

C5-83.jpg

 

Once and awhile you'll see C5s from '85 and they are usually black.

Keep in mind that Celestron didn't make a black C5 or C8 until about mid '85.

Also, according to Uncle Rod's Guide the C5 was dropped from the line up in 1986.

 

Here's a invoice for a C5 sold in '82 showing the date and serial number

C5-82-Invoice.jpg

 

And here's another C5 that's very likely from '85

C5-Black.jpg

C5-Black-Number.jpg

 

Just last night I saw the Celestron ad annoucing Black as a new color option.

IIRC, it was the Aug. 85 issue of Sky & Telescope.

I'll try to find it and post it when I do.

Well Joe, take your pick. Kasmos and I often go-round on the difference between Manufacture date and Sale date. How would you view a scope sitting in a shop window for two years "new" being sold for the first time?

 

While date serialization was used, motor dates were seen to  preceded manufacture dates by up to two years. At the end of Date Serialization, the differential had fallen to nil. But Sales Receipt dates could lag well behind the serialized date.

 

Perhaps inventory aging was a motive for Celestron to de-serialize.

 

With the change to 5xxxxx numbering, motor dates commenced in early 1979. On average they stepped in batches of about 400 serial numbers per 9 motor-months. Until in March of 81, units with 11/79 motors were being reportedly sold. This represents a year's delay between parts ordering and actual Sale.

 

Once again, I can only defend manufacture dates, and even at that with a range.

 

 

Masvingo placed the note "C5 relaunched in December 1992 with a single arm fork mount and white OTA and uses a new SN sequence" after C5 504107 [orange tube] and before 50100 [new numbering system]

 

I do not know what reference he used for that citation.

This leads me to ask:

* Did Celestron manufacture a stock of C5 scopes, and sell them in the manufacturing hiatus?

* Did Tuthill do the same - stock a limited supply to live from?

 

With Kasmos information, I would guess that in 1986 the existing stock ran out. We might know more if one of the motor dates from a 1985-6 sale turned up.

 

 

On Black Tube vs Orange - The registry also has 502749 as an Orange tube, 503230 as black and 504107 as Orange. So black OTA units are bracketed by Orange in the same era.

 

The Registry shows 503352 and prior have motor dates 1982 and prior, with no motor date after.

 

The registry contains 502534, only 48 units from the one on Kasmos' receipt - but noted between motors 10/80 and 4/81. This is consistent with another year-ish delay.

 

 

So Joe, wasn't that fun?

 

 

Thank you again Kasmos.

[Kasmos]

I was wrong. The more I thought about it, '85 was too late for the first black scopes. It was also too late to check my magazines so before bed I looked at Sky &Telescope on the Internet Archive and the first Black Super C8 shown was Aug. '83. and the first mention of it (coming in July), was the month before but it was covered by a black cloth in the ad. Before that I don't think they ever showed or sold a Black C8 let alone a C5 (not counting the telephoto versions). Edit: Now that I think of it I could have found the same info on those ads from Uncle Rod.

 

IMO, It's probably safe to assume that like the C8 you could still get a orange C5 up until they stopped making them for the 7 years that Uncle Rod claims they were no longer offered. If I read the stuff on serial numbers right, it sounds like that was the case so we can assume that a Black one would have had to be made in the mid '83 to '85 time frame.

 

As for sales dates vs manufacturing, I agree there can be a very long delay between the two, but personally I'm more interested in the details of how they were made during each model year. Also, from the appearance of his ads, I believe Roger Tuthill was a fairly good seller of Celestrons, so I would think his inventory didn't sit around too long making an invoice from him a pretty good indicator of how a scope was made for that year.

 

BTW, is there a current link to a jpg. or png. of the registry?

Edited by Kasmos, 14 August 2024 - 11:48 PM.

[Joe Cepleur]

RSX11M+ and Kasmos,

Thank you both for your detailed answers. Sorry not to have responded until now. I have been meaning to post a separate thread about the scope with pictures, when other chaos subsides to leave me time to do that.

Halley's comet appeared last in 1986. My C5 includes an advertising poster touting the wonder of seeing the comet with Celestron precision optics. Did Celestron include those posters with the paperwork as early as 1982?! Seems unlikely, but does anyone know? Perhaps the original owner bought the scope in (or shortly after) 1982, but then slipped a Celestron marketing piece into his paperwork years later, but that also seems unlikely.

Could the scope have been manufactured in 1982 but not sold until 1985 or 1986, at which time the poster could have been added to the paperwork? Or, does the presence of the poster strongly point to a later date of manufacturer?

I especially like this scope, because I have been considering de-forking a C5 for use as a lightweight grab-and-go on an alt/az mount, but it felt sacrilegious to do that to a classic. Then, I noticed that this scope attaches to its fork mount differently from how my Orange Tube C5 attaches. Loosen four screws and it's free of the forks, and would be equally easily replaced (or so it appears). I don't want to do any harm in using the scope differently from how it was intended to be used, but a C5 on a lightweight mount would be the perfect flyweight star cruiser. Weighs almost nothing, but begins to see the dim stuff.

[CHASLX200]

The rare all black C5 was one i never got. They stopping making the C5 after 1985 until the one arm deal came out.

[Joe Cepleur]

My C5 is all black! I had no idea it was rare. Makes me like it even more!

How rare it is? Is there an estimate of how many were made?

Edited by Joe Cepleur, 14 August 2024 - 07:40 PM.

[CHASLX200]

My C5 is all black! I had no idea it was rare. Makes me like it even more!

How rare it is? Is there an estimate of how many were made?

Not sure but once they started making them Celestron stopping making the C5's.

[Kasmos]

RSX11M+ and Kasmos,

Thank you both for your detailed answers. Sorry not to have responded until now. I have been meaning to post a separate thread about the scope with pictures, when other chaos subsides to leave me time to do that.

Halley's comet appeared last in 1986. My C5 includes an advertising poster touting the wonder of seeing the comet with Celestron precision optics. Did Celestron include those posters with the paperwork as early as 1982?! Seems unlikely, but does anyone know? Perhaps the original owner bought the scope in (or shortly after) 1982, but then slipped a Celestron marketing piece into his paperwork years later, but that also seems unlikely.

Could the scope have been manufactured in 1982 but not sold until 1985 or 1986, at which time the poster could have been added to the paperwork? Or, does the presence of the poster strongly point to a later date of manufacturer?

I especially like this scope, because I have been considering de-forking a C5 for use as a lightweight grab-and-go on an alt/az mount, but it felt sacrilegious to do that to a classic. Then, I noticed that this scope attaches to its fork mount differently from how my Orange Tube C5 attaches. Loosen four screws and it's free of the forks, and would be equally easily replaced (or so it appears). I don't want to do any harm in using the scope differently from how it was intended to be used, but a C5 on a lightweight mount would be the perfect flyweight star cruiser. Weighs almost nothing, but begins to see the dim stuff.

In your scopes's case it's not possible since they didn't make them Black in '82.

[RSX11M+]

This is to self-register a Starbright-XLT C5 serial number S143511, purchased as part of a NexStarSE outfit.

 

 

 

There were a number of pleasant surprises to this used item. Most of all was the Fastar style removable secondary, perhaps more so because there does not seem to be any Hyperstar or other accessory available for it.

 

 

While I did not expect a tripod at all, based on the ad, one was supplied anyway and is actually nice. It includes a tilt-head that functions as an equatorial wedge. This makes it easy to use the NexStar mount in either Alt-Az or Eq mode as a last second decision.

 

 

 

I am often asked at outreach events what the most affordable starter kit for a beginner would be, and this is certainly a candidate.

 

It was not my intention to use it as a grab-n-go scope, but it may well end up being used just that way.

 

 

Note: No, this does not mean I'm giving up hope of getting a Tricolor C5. nope nope nope-

Edited by RSX11M+, 24 August 2024 - 01:55 AM.

[abe]

Note: No, this does not mean I'm giving up hope of getting a Tricolor C5. nope nope nope-

 

I've been hoping to get a nice sand cast C5 for ages.  

First, there was this one:
​https://www.cloudyni...s-that-got-away

Then, yesterday, I missed out on this one with the compact travel case, due to some technical hiccup while bidding:
https://shopgoodwill.../item/207385864

I guess it's just not meant to be.  

Attached Thumbnails

• 

Edited by abe, 24 August 2024 - 12:28 PM.

[Kasmos]

I've been hoping to get a nice sand cast C5 for ages.  

First, there was this one:
​https://www.cloudyni...s-that-got-away

Then, yesterday, I missed out on this one with the compact travel case, due to some technical hiccup while bidding:
https://shopgoodwill.../item/207385864

I guess it's just not meant to be.  

Somehow I never saw that one (SGW). Looks like the corrector is fogged up and needs cleaning, but a good price for a somewhat early one. It's a brother to my '74 so too bad they didn't include a photo of the badge and serial#. Even among the telescope ignorant, a photo of it's badge seems like it should be a no brainer  

 

Hopefully it's new owner will find the registry and post it.

[Pat Rochford]

For the Registry 

 

Serial Number - 51682      White Tube     CN Pat Rochford

 

Currently under the 'Witness Protection Program'

Attached Thumbnails

• 

Edited by Pat Rochford, 02 September 2024 - 07:04 PM.

[ETXer]

A registry update: C5 serial number 502931 is no longer in my possession, having been (regrettably) sold in 2022 prior to a move in a "downsizing" effort.

 

But after settling in the new place, I realized I couldn't be without one for long, so I recently acquired C5 serial number 501425, presumably dating back to 1981 (?). It has the pebble orange finish, C8-sized drive base, but came with .965-inch accessories.

 

Here it is on a Celestron Wedgepod; I was amazingly able to acquire a vintage Celestron orange 6x30 right-angle finderscope that compliments it brilliantly.

 

 

 

 

Cheers, Allan

[RSX11M+]

I've been hoping to get a nice sand cast C5 for ages...

Never give up, never surrender!

In the meantime, I feel your pain.
 

For the Registry 
 
Serial Number - 51682      White Tube     CN Pat Rochford
 
Currently under the 'Witness Protection Program'

Your scope's manufacture dates between 1992 and 1994, based only on serial number. If this is correct, it most likely has a white OTA tube. Please confirm for our records. [update - I now see white in your description, but it's covered in the photos]
 
It was not previously known to the registry, thanks for including it.

Edited by RSX11M+, 04 September 2024 - 07:12 PM.

[RSX11M+]

A registry update: C5 serial number 502931 is no longer in my possession, having been (regrettably) sold in 2022 prior to a move in a "downsizing" effort.
 
But after settling in the new place, I realized I couldn't be without one for long, so I recently acquired C5 serial number 501425, presumably dating back to 1981 (?). It has the pebble orange finish, C8-sized drive base, but came with .965-inch accessories.
 
Here it is on a Celestron Wedgepod; I was amazingly able to acquire a vintage Celestron orange 6x30 right-angle finderscope that compliments it brilliantly.
 

 
 

 
Cheers, Allan

I recall your earlier scope, and it's optics service. It was already marked as sold by you in the registry.

Your new scope, as I am sure you know, is a slightly earlier serial number. Scopes bracketing serial number 501425 usually have motors dated in late 1979 and claim to have been originally purchased in 1981.

 

If you wouldn't mind, please let us know the motor date-suffix if you can read them. 

 

The RA Finder is indeed a rare and practical upgrade.

 

The orange tube and diecast base & fork arms are correct for this OTA. The base should have the 3-prong power socket underneath. Also, please confirm if the base plaque SN matches that of the OTA.

 

Thank you for remembering us, your scope will be included the next edition of the registry. [jpg, pdf]

[ETXer]

I recall your earlier scope, and it's optics service. It was already marked as sold by you in the registry.

Your new scope, as I am sure you know, is a slightly earlier serial number. Scopes bracketing serial number 501425 usually have motors dated in late 1979 and claim to have been originally purchased in 1981.

 

If you wouldn't mind, please let us know the motor date-suffix if you can read them. 

 

The RA Finder is indeed a rare and practical upgrade.

 

The orange tube and diecast base & fork arms are correct for this OTA. The base should have the 3-prong power socket underneath. Also, please confirm if the base plaque SN matches that of the OTA.

 

Thank you for remembering us, your scope will be included the next edition of the registry. [jpg, pdf]

I was able to look at one of the motors (the other wasn't in a position to be easily read) and it appears the date was April 1980 (04/80). It does indeed have the 3-prong socket, but there's no placard on the side of the base nor does it look like there's evidence that there ever was one, the only label being the volts/amps sticker. The scope also came with its case/trunk/power cord in great condition. Thanks again!

 

Cheers, Allan

[Kasmos]

I was able to look at one of the motors (the other wasn't in a position to be easily read) and it appears the date was April 1980 (04/80). It does indeed have the 3-prong socket, but there's no placard on the side of the base nor does it look like there's evidence that there ever was one, the only label being the volts/amps sticker. The scope also came with its case/trunk/power cord in great condition. Thanks again!

 

Cheers, Allan

He made a mistake. Ones like yours with the serial# on the plastic secondary never had a base name plaque.

[RSX11M+]

I was able to look at one of the motors (the other wasn't in a position to be easily read) and it appears the date was April 1980 (04/80). It does indeed have the 3-prong socket, but there's no placard on the side of the base nor does it look like there's evidence that there ever was one, the only label being the volts/amps sticker. The scope also came with its case/trunk/power cord in great condition. Thanks again!

 

Cheers, Allan

Ah... 4-80 indicates an early production run, but after the initial batch. I do think it could have been shipped/sold as early as 1980, but more likely after. I had heard that the placard was dropped at some point, but Kasmos is correct in saying I had no idea when this change took place.

 

He made a mistake. Ones like yours with the serial# on the plastic secondary never had a base name plaque.

Is this true for all  scopes with a numbered-plastic secondary holder? I'd like to make a note of this in the registry (s) especially if it's true for all C5 and C8 models.

 

Were any scopes equipped with unnumbered plastic secondary holders, but still had a plaque on their base?

[Kasmos]

Ah... 4-80 indicates an early production run, but after the initial batch. I do think it could have been shipped/sold as early as 1980, but more likely after. I had heard that the placard was dropped at some point, but Kasmos is correct in saying I had no idea when this change took place.

 

Is this true for all  scopes with a numbered-plastic secondary holder? I'd like to make a note of this in the registry (s) especially if it's true for all C5 and C8 models.

 

Were any scopes equipped with unnumbered plastic secondary holders, but still had a plaque on their base?

Every C5 and C8 I've ever seen that had a metal secondary had the name plaque on the base with it's serial number. And I've never seen one with a plastic secondary to have a base plaque. I don't believe there was any transistion models that broke that mold. There has been a few scopes that had a base plaque and another plaque on the OTA but those were OTAs that were sold without a mount and one was added later.

 

This appears to be true on the diecast transistion models which appeared to change to the three prong power cord at the same time.

 

If there are exceptions and someone has evidence of any I'd love to hear about it, or better yet, see one.

[Pat Rochford]

Your scope's manufacture dates between 1992 and 1994, based only on serial number. If this is correct, it most likely has a white OTA tube. Please confirm for our records. [update - I now see white in your description, but it's covered in the photos]

 
It was not previously known to the registry, thanks for including it.

 

Yes ... and my attempt at humor by mentioning it was under the witness protection program (i.e. the Reflectix 'disguise').

 

Thanks for the manufacture date range.   P

Edited by Pat Rochford, 06 September 2024 - 01:00 PM.