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{"id":523,"date":"2015-11-01T21:43:33","date_gmt":"2015-11-01T21:43:33","guid":{"rendered":"http:\/\/desertstars.info\/wp\/?p=523"},"modified":"2016-01-06T05:53:44","modified_gmt":"2016-01-06T05:53:44","slug":"gear-celestron-compustar-11-number-4-of-50","status":"publish","type":"post","link":"https:\/\/desertstars.info\/wp\/2015\/11\/01\/gear-celestron-compustar-11-number-4-of-50\/","title":{"rendered":"GEAR: Celestron Compustar 11 – Number 4 of 50"},"content":{"rendered":"

With over one year into using this rig (new to me in 6\/2014), I figure it is time to give some details about the C11 used here at Desert Stars Observatory. \u00a0 \u00a0It is a fairly rare Celestron C11 featuring the Ahead of its time Compustar GOTO system. \u00a0 \u00a0This was the first system of its kind for small telescopes, really defined the direction all of them would go in years to come. \u00a0 \u00a0There is very little documentation about the Compustars, \u00a0and experts say the C11 was the least made of the three flavors, C8, C11, and C14. \u00a0 There are no records available for serial number\/build sequence that I know of, but I do know they were all hand built as Celestron shipped them to a 3rd party to be converted to Compustars. \u00a0 \u00a0Mine is likely to be #4 of ether all C11’s built or #4 of the Compustar line as the Forks, motors and different parts have a matching #4 on them. \u00a0 \u00a0RA Motor with #4 and an alignment mark:<\/p>\n

$\"20151224_123022\"$ <\/p>\n

The Compustar has the coolest computer system made for telescopes! \u00a0 It is unfortunate that modern versions don’t offer this kind of functionality.<\/p>\n

Compustar control box<\/figcaption><\/figure>\n
$\"IMG_3119\"$ <\/p>\n
This, like several other early GOTO telescopes were hit with the “Y2K” bug. \u00a0 Its computer was only programmed to handle 2 digit dates… a common practice in the 1980’s when memory was expensive. \u00a0Every character that could be saved usually was. \u00a0 \u00a0I ran it with the Y2K bug by just entering the 1995 date and time, and everything was fairly close. \u00a0 One other thing is that the database of positions was based on 1950 data, since 2000 had yet to come. \u00a0 This year I updated the brains of the control system with a Y2K update chip. \u00a0This not only fixed the Y2K bug allowing dates well into the 2100’s, \u00a0but also updated the star database from 1950 to year 2000 data.<\/p>\n
Opening up the control\u00a0box showed that it had a birthday just the day before I did the upgrade! \u00a0The CNGC catalog EPROMS have a hand written date of 10\/31\/1987. \u00a0 I was doing the upgrade 11\/1\/2015!<\/p>\n
$\"Born$
Born on 10\/31\/1987<\/figcaption><\/figure>\n
It is also a very fast and quiet GOTO system. \u00a0It has a high tech whine when slewing, unlike the coffee grinder noise that the LX200 and ASGT have. \u00a0 Unfortunately the speed does effect GOTO positioning occasionally. \u00a0 It goes full speed until target, which most of the time is still near the center of FOV, \u00a0but occasionally it overshoots and the target is on the edge or slightly off. \u00a0 Tracking is accurate, but I am currently trying to resolve a harmonic vibration when tracking at\u00a0sidereal\u00a0speeds. \u00a0 It is keeping me from\u00a0having perfect round stars on exposures over 90 seconds. \u00a0The tracking over time is spot on, \u00a0the target will stay centered all night. \u00a0 But there is a very tiny 5 second oscillation noticed at very high magnifications.<\/p>\n
C8 looks and feels TINY next to the massive displacement of the C11. \u00a0The wedge for the C11 is bigger\/heavier than the whole C8 setup!<\/p>\n
$\"C11$
C11 top – C8 bottom<\/figcaption><\/figure>\n
Even the 90 degree diagonals are huge on the C11 compared to the C8 of the same era! \u00a0I think the C11 cast diagonal may actually weigh more than the OTA of the C8.. \u00a0It is a serious piece of metal and glass.<\/p>\n
$\"Standard$
Standard C8 on left, C11 on right,<\/figcaption><\/figure>\n
<\/p>\n
Some other bits about the C11 as I have taken it apart for service and inspection:
\n7″ RA Gear:<\/p>\n
$\"Compustar$
Compustar C11 Dec stepper motor<\/figcaption><\/figure>\n
$\"C11$
C11 RA<\/figcaption><\/figure>\n
$\"PCB$
PCB is copyright 1985…<\/figcaption><\/figure>\n
$\"20151214_122200\"$ <\/p>\n
$\"IMG_3114\"$ <\/p>\n
<\/p>\n
I remember getting home… could not wait to see “first light” with it. \u00a0 A quick look said it was amazingly sharp even though it had been sitting for years, and traveled 1000’s miles before it reached my driveway.<\/p>\n
$\"C11,$
C11, Logitech webcam and Saturn.<\/figcaption><\/figure>\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
With over one year into using this rig (new to me in 6\/2014), I figure it is time to give some details about the C11 used here at Desert Stars Observatory. \u00a0 \u00a0It is a fairly rare Celestron C11 featuring the Ahead of its time Compustar GOTO system. \u00a0 \u00a0This was the first system of its kind for small telescopes, really defined the direction all of them would go in years to come. \u00a0 \u00a0There is very little documentation about the Compustars, \u00a0and experts say the C11 was the least made of the three flavors, C8, C11, and C14. \u00a0 There are no records available for serial number\/build sequence that I know of, but I do know they were all hand built as Celestron shipped them to a 3rd party to be converted to Compustars. \u00a0 \u00a0Mine is likely to be #4 of ether all C11’s built or #4 of the Compustar line as the Forks, motors and different parts have a matching #4 on them. \u00a0 \u00a0RA Motor with #4 and an alignment mark: The Compustar has the coolest computer system made for telescopes! \u00a0 It is unfortunate that modern versions don’t offer this kind of functionality. This, like […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[2],"tags":[13,70],"class_list":["post-523","post","type-post","status-publish","format-standard","hentry","category-gear","tag-c11","tag-gear"],"acf":[],"_links":{"self":[{"href":"https:\/\/desertstars.info\/wp\/wp-json\/wp\/v2\/posts\/523","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/desertstars.info\/wp\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/desertstars.info\/wp\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/desertstars.info\/wp\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/desertstars.info\/wp\/wp-json\/wp\/v2\/comments?post=523"}],"version-history":[{"count":5,"href":"https:\/\/desertstars.info\/wp\/wp-json\/wp\/v2\/posts\/523\/revisions"}],"predecessor-version":[{"id":540,"href":"https:\/\/desertstars.info\/wp\/wp-json\/wp\/v2\/posts\/523\/revisions\/540"}],"wp:attachment":[{"href":"https:\/\/desertstars.info\/wp\/wp-json\/wp\/v2\/media?parent=523"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/desertstars.info\/wp\/wp-json\/wp\/v2\/categories?post=523"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/desertstars.info\/wp\/wp-json\/wp\/v2\/tags?post=523"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}