1691 replies to this topic

[Masvingo]

Out of interest, I’ve been collecting serial numbers and, where reported sale/purchase date and any production date shown on the RA drive motors. The attached table has been built up from postings on CN, a few Astromart ads and a table on the Stargazers Lounge forum. Following suggestions made during discussions on another thread I have started this thread to serve as a registry for the C8s.

There are three formats of SN:

• early tricolours had a simple sequential serial number stamped on a plate attached to the mount base (some OTAs which were sold separately had their own separate SN sequence with the SN stamped on a plate attached to the OTA)
• some time around the 3rd quarter 1972 the SN changed to a QxxxxY format where Q gives the quarter in which the 'scope was produced, xxxx is the sequential number since (probably) start of C8 production and Y is the last digit of the year of production
• around the time of the change from Celestron Pacific to Celestron International (late 1977/early 1978) the SN changed to a new style which, for C8s was 8xxxxx, the 8 signifying a C8 and the rest a sequential number with no production date indication.

There are some anomalies in the list (marked with an exclamation mark in the left hand column):

• The Stargazers Lounge list reported a SN of 4936 (sale date 1973) – this however seems too high to fit into the early SN sequence of just a sequential number and also doesn’t tie in with the first date type SN of 37842 which suggests that the 784th C8 was made in the 3rd qtr of 1972. It may be that the last digit (which gives the year and in some case was spaced apart from the rest of the number) was omitted and the full number should be 49362
• orion61’s sandcast C8 with a SN of 223139 – this doesn’t fit in at all with the SN formats but as that scope may have been built as a ‘special’ for the use of Leo Henzl (Celestron VP Marketing) it may have been given a different style of SN
• SN 1 2563 4 has a sequential number which is out of step with the general sequence – it is hard to be certain from the picture of the SN plate in the thread which gave this number but it is possible that the number is actually 4 2563 4 which may fit better although there is still a bit of a jump to the only reported SN for the following quarter: 1 29845 5?

With regard to the later 8xxxxx series that came in about the time of the change from Celestron Pacific to Celestron International as there is no indication of a production date it is hard to be certain whether the sequential number is a continuous sequence or whether there are breaks in it. The highest number I have seen is 956651 which, if the sequence is continuous, suggests that 156,651 C8s since the change had been made by the time that ‘scope was produced.

With the later 8xxxxx style SNs it helps to have the date code stamped on the RA drive motor(s) – in the few cases where I have found a motor date as well it seems as if some ‘scopes might have sat in stock for a while before being sold – of course it could also be that the motors sat in stock, either at the manufacturer or at Celestron for some time before being used.

Any corrections, clarifications, additions gratefully received!

7 Jan 2013 Edited: revised table with additional information highlighted in blue and column to record corrector SNs where known

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[PiSigma]

Nice work James! I find this kind of information fascinating, which is why I did it for Cave mirrors.

I have always been curious as to when the change from sand cast to die cast forks occurred.

Again, great job!

[Masvingo]

Thanks for your kind words Jon. I did get inspiration from your Cave Registry which is a valuable reference for Cave 'scopes.

Yes, I find it fascinating too. When I get time I want to try and revisit the comments, particularly for the orange tube era, to better record any change in the mount / tube characteistics.

James

[orion61]

Im glad you listened to my suggestion in the other thread!
I TRUE professional grade telescope, and having found the Henzl is a Dream come true!
This thread will be at the top of my favorites!
Way to go, taking the time and doing the work to make a comment (wish) come true!

[Brian Risley]

What is interesting is I came upon my canceled check for getting the scope repaired in 1979, and I noted 253 on the check as the serial #. 458 is the optics number. I lost the serial number plate when I stripped it down back in 1980. I am now not not sure which the unit really was.
if 253, it is 70/71, if 458, it is 71/72. I would be curious if anyone in the lower hundreds has compared serial # with optics # (check edge of corrector or back of primary.) This may give me a clue as to what is correct.
Brian

[tim53]

My optics on Tinky have 135 engraved in them - same as the serial number.

-Tim.

[Masvingo]

Thanks Larry. It's a good exercise for the mind trying to untangle what Celestron did with serial numbers!

James

[Masvingo]

Thanks for the update Brian. Similar to the position with SN #1, having different numbers for the optics compared to the mounts adds a further level of complexity.

Hopefully we can get a few more data points which might make the picture clearer (or muddier)!

James

[Compressorguy]

Thanks Masvingo (and Jon) for compiling this data. I find it all very interesting as well.

How about OTA vs. optics s/n's here's a black tube C8, presumably early 80's, I picked up as an OTA. I believe it was sold/used as a telephoto lens.

OTA s/n 828161

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[Compressorguy]

Primary s/n 5478, note the 81 or 18 number on the masking tape next to the focuser linkage. What is that for??

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[Compressorguy]

and matching corrector #5478. The OTA appears to have never been apart before.

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[Masvingo]

Thanks for the additional SN Scott. I have revised the table attached to my original post to reflect this and the amended SN for Brian's scope and have also added an extra column to record the optics SN where known. I'll try and revisit the original source postings when I have time to see if I can pick up any further optics SNs.

James

[magnus]

James!
Thanks for your great and intressting work!
/Magnus 57N.

[IcecreamLtDan]

Here's mine if you'd like to add it to your registry.

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[johntrob]

I appreciate the work you are putting into this, maybe it will be put up as a sticky so it is easily accesible and can be kept updated.

[starman876]

I have a orange C8 from the early 80's that I was using last night. With the scope collimated and defocused on a bright star I see very nice rings. However, it almost looks like a very thin waterfall slooping down towards the center on one side. Is this an indication the secondary screws are to tight? I have never seen this before in any orange C8 I have had and I have had a few.

[Masvingo]

Thanks IcecreamLtDan, I'll add it in, the more the merrier! Can you see any dates on the drive base motors?

James

[Masvingo]

Tak Magnus.

Thanks John.

My intention is to try and keep the list updated as and when I get additional info so any and all contribution gratefully received and the more info the better, eg motor date, optics SN, purchase date, etc.

James

[Masvingo]

Hi Johann

I'm not sure what would cause the waterfall you're seeing so will leave that for the experts. Does the location reverse when you defocus on the other side of the focus point?

What is the SN of your C8, I'm not sure I've got it on the list? Also, have you got any dates on the motors and do you know the corrector SN?

Thanks

James

[Bill Griffith]

James

Thanks for the work you have done and will do on the C8 registry.
S/N 31 currently has the original optics. These will need to be replaced.

Happy Anniversary to you joining the group, we are fortunate. It's an easy one for me to remember.

Thanks

Bill

[Masvingo]

Thanks Bill. I see what you mean, many happy returns.

I'm sorry to hear about #31's optics, I wish her a speedy recovery.

James

[starman876]

Yes, on other side the watefall flips. I might relax the secondary screws and readjust and see what happens.

[DAVIDG]

I have a orange C8 from the early 80's that I was using last night. With the scope collimated and defocused on a bright star I see very nice rings. However, it almost looks like a very thin waterfall slooping down towards the center on one side. Is this an indication the secondary screws are to tight? I have never seen this before in any orange C8 I have had and I have had a few.

What your seeing is warm air coming out the top of the baffle tube.

- Dave

[starman876]

Thanks Dave. did not even think of that. I did let it cool down to see if it was related , but when I got back out the corrector had dewed over. i will try it again inside with my artificial star and see if I get the same results.

[clamchip]

Hi James.

I was looking over my file and found a few things that may or may not be useful:

#338125
Motor date 6-75
Sandcast fork/mount, sandcast wedge and sandcast tripod.
I no longer own this scope, sold it a few years ago. I wish I hadn't but I did. I have no record of the buyer.

#22908
Motor date 10-77
Diecast fork/mount, diecast wedge and diecast tripod only, NO OTA.
I still own.

Robert