stefano
member
Reged: 04/20/06
Posts: 81
Loc: Arezzo, Tuscany, ITALY
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I just upgraded my AS II from version 3.0d to 4.1i.
As usual the txt file attached to the buildLX file do not explain a lot.
Questions: (1) GPS-UTC offset - why? I put already my observation site time zone, my time, my daylight saving time setting. I belived GPS was working on GMT, so which value must introduce? (2) Dec. guiding - what does it means?
Thank you in advance.
Stefano
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Ciao
************************************
"SPECULA IN SANCTAE MAMAE PAGO LOCATA"
MEADE 12" LX200GPS
Main: CCD Starlightxpress MX7C USB
Guide: Pentax 75 SDHF + Starlightxpress MX5C
MPC Obs. Code B38
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CactusButt
sage
Reged: 01/25/06
Posts: 349
Loc: Deep in the Heart of Texas
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The GPS-UTC offset is used to make up the difference between GMT and GPS time, the latter not taking into account leap seconds. Here is a pretty cool link:
http://www.leapsecond.com/java/gpsclock.htm
Very early Meade scopes had a GPS receiver that needed this number to adjust, but for the vast majority of the scopes out there, a newer Sony(?) receiver already has this built in.
It is beyond me, and several other people, why Meade defaults this to 13 instead of 0, when by far the majority of users want 0. Also, because it is called GPS-UTC Offset, people get it confused with their timezone offset. 
I am not sure which option you mean by "Dec Guiding"?
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Barry
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Meade LX200GPS 10" : Scopey
Orion 80ED : Smokey
Willam Optics ZenithStar 66SD - Patriot Edition : Sammy
Coronado PST - Double Stacked : Sunny
Vixen PortaMount
Denkmeier Standard Binoviewers
Pentax PCF WP II 12x50
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JAT Observatory
Space Freak
Reged: 02/20/05
Posts: 5652
Loc: Eastern PA
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GPS-UTC offset is the zero point correction for leap seconds which UTC accounts for and GPS does not. The GPS zero point was UTC time on Jan 6 1980. There have been 14 leap seconds added to UTC time since then.
It will be come clearer if you view this page:
http://www.leapsecond.com/java/gpsclock.htm
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-Marcus
The problem with free speech is even the stupid have a voice.
http://jatobservatory.org
12" LX200R on a Paramount ME
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JAT Observatory
Space Freak
Reged: 02/20/05
Posts: 5652
Loc: Eastern PA
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You beat me to it CB:)
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-Marcus
The problem with free speech is even the stupid have a voice.
http://jatobservatory.org
12" LX200R on a Paramount ME
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stefano
member
Reged: 04/20/06
Posts: 81
Loc: Arezzo, Tuscany, ITALY
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Sorry Marcus,
I am not so deep in English please could you translate "You beat me to it CB:)"?
Stefano
--------------------
Ciao
************************************
"SPECULA IN SANCTAE MAMAE PAGO LOCATA"
MEADE 12" LX200GPS
Main: CCD Starlightxpress MX7C USB
Guide: Pentax 75 SDHF + Starlightxpress MX5C
MPC Obs. Code B38
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stefano
member
Reged: 04/20/06
Posts: 81
Loc: Arezzo, Tuscany, ITALY
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Dec guiding is a new feature (I should check if it is under SET UP menu or under UTILITIES menu) that can assume the following values:
Not
North-South
North
South
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Ciao
************************************
"SPECULA IN SANCTAE MAMAE PAGO LOCATA"
MEADE 12" LX200GPS
Main: CCD Starlightxpress MX7C USB
Guide: Pentax 75 SDHF + Starlightxpress MX5C
MPC Obs. Code B38
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JAT Observatory
Space Freak
Reged: 02/20/05
Posts: 5652
Loc: Eastern PA
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Stefano,
It is slang for "you did it before me". In this case meaning our posts were similar, but you managed to get yours posted first.
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-Marcus
The problem with free speech is even the stupid have a voice.
http://jatobservatory.org
12" LX200R on a Paramount ME
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stefano
member
Reged: 04/20/06
Posts: 81
Loc: Arezzo, Tuscany, ITALY
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Marcus,thank you for your explanation.
Now I have the complete answer for CB about DEC GUIDING.
Is is a new feature under the SET UP -- TELESCOPE directory.
Waiting, Stefano
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Ciao
************************************
"SPECULA IN SANCTAE MAMAE PAGO LOCATA"
MEADE 12" LX200GPS
Main: CCD Starlightxpress MX7C USB
Guide: Pentax 75 SDHF + Starlightxpress MX5C
MPC Obs. Code B38
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CactusButt
sage
Reged: 01/25/06
Posts: 349
Loc: Deep in the Heart of Texas
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I'm sorry Stefano, I have no clue on the Dec Guiding as I am a visual only observer. Sounds like something for photography to me.
It might help others to know which scope you have. Google turns up very few hits for:
"dec guiding" autostar
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Barry
--------------------
Meade LX200GPS 10" : Scopey
Orion 80ED : Smokey
Willam Optics ZenithStar 66SD - Patriot Edition : Sammy
Coronado PST - Double Stacked : Sunny
Vixen PortaMount
Denkmeier Standard Binoviewers
Pentax PCF WP II 12x50
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Keith Schlottman
member
Reged: 10/02/05
Posts: 49
Loc: Tucson, AZ
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Interesting thread guys...so for an LX200GPS or RCX400 owner, shoud the GPS-UTC offset be set to zero or 14?
Thanks,
Keith Schlottman
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---------------------------------
Wishing you the Clearest of Skies
Xanadu Observatory
http://www.xanaduobservatory.com
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stefano
member
Reged: 04/20/06
Posts: 81
Loc: Arezzo, Tuscany, ITALY
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I expect some Meade's engeneers that after having produced the upgrade should explain to the owners how to use it!!!
Stefano
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Ciao
************************************
"SPECULA IN SANCTAE MAMAE PAGO LOCATA"
MEADE 12" LX200GPS
Main: CCD Starlightxpress MX7C USB
Guide: Pentax 75 SDHF + Starlightxpress MX5C
MPC Obs. Code B38
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JAT Observatory
Space Freak
Reged: 02/20/05
Posts: 5652
Loc: Eastern PA
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The 14 seccond offset is needed for very early GPS scopes that have the Motorola GPS chip.
The Sony chipped GPS units which 99% of the scopes are do not require the offset as it is already accounted for (ie the offset should be zero). It is my understanding the RCX scopes all have the Sony chips (offset should be zero).
--------------------
-Marcus
The problem with free speech is even the stupid have a voice.
http://jatobservatory.org
12" LX200R on a Paramount ME
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stefano
member
Reged: 04/20/06
Posts: 81
Loc: Arezzo, Tuscany, ITALY
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How I can know which is inside my scope?
I bought it in sept. 2003.
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Ciao
************************************
"SPECULA IN SANCTAE MAMAE PAGO LOCATA"
MEADE 12" LX200GPS
Main: CCD Starlightxpress MX7C USB
Guide: Pentax 75 SDHF + Starlightxpress MX5C
MPC Obs. Code B38
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Steve Pearce
member
Reged: 10/05/05
Posts: 19
Loc: Hampshire UK
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Quote:
How I can know which is inside my scope?
I bought it in sept. 2003.
Although I bought my LX200GPS s/h it must have been produced before Sept 2003 (I bought it last year and the guy I bought it off reckoned he'd had it 3 years or so). Over the weekend I did a test, I set the time on my laptop to the correct local time (within a 1/10 second or so). I then started the scope up, after aligment I checked the time on the scope; it was exactly the correct local time too. I have the GPS-UTC offset set to 0 so I it looks like I have a Sony chip.
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LX200GPS 10"
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JAT Observatory
Space Freak
Reged: 02/20/05
Posts: 5652
Loc: Eastern PA
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Post deleted by JAT Observatory
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-Marcus
The problem with free speech is even the stupid have a voice.
http://jatobservatory.org
12" LX200R on a Paramount ME
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stefano
member
Reged: 04/20/06
Posts: 81
Loc: Arezzo, Tuscany, ITALY
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Hey guys,
this is what I did last night.
I started up the scope and I compared the time of the scope (I set it some days ago to +14 sec.) with the time of the computer (syncronized with Dimension 4 with the USNO clock)the difference was about 17 sec.
I shut down the scope, I started again and after it got the GPS signal I set the GPS-UTC to 0.
Shut again and restart.
This time the difference was 4 sec.
These values can not be extremely accurate because I need a couple of seconds to go from the handcontroller to the computer, anyway I assume they are good enough.
I hope this can help.
Stefano.
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Ciao
************************************
"SPECULA IN SANCTAE MAMAE PAGO LOCATA"
MEADE 12" LX200GPS
Main: CCD Starlightxpress MX7C USB
Guide: Pentax 75 SDHF + Starlightxpress MX5C
MPC Obs. Code B38
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CactusButt
sage
Reged: 01/25/06
Posts: 349
Loc: Deep in the Heart of Texas
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Quote:
These values can not be extremely accurate because I need a couple of seconds to go from the handcontroller to the computer, anyway I assume they are good enough.
I would think that should be good enough. I have also read that careful centering of the alignment stars is much more important and can more than make up for a few seconds the time may be off.
--------------------
Barry
--------------------
Meade LX200GPS 10" : Scopey
Orion 80ED : Smokey
Willam Optics ZenithStar 66SD - Patriot Edition : Sammy
Coronado PST - Double Stacked : Sunny
Vixen PortaMount
Denkmeier Standard Binoviewers
Pentax PCF WP II 12x50
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stefano
member
Reged: 04/20/06
Posts: 81
Loc: Arezzo, Tuscany, ITALY
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I fully agree with you.
I think few seconds do not make any difference in centering the object.
Cheers, Stefano
--------------------
Ciao
************************************
"SPECULA IN SANCTAE MAMAE PAGO LOCATA"
MEADE 12" LX200GPS
Main: CCD Starlightxpress MX7C USB
Guide: Pentax 75 SDHF + Starlightxpress MX5C
MPC Obs. Code B38
|
JAT Observatory
Space Freak
Reged: 02/20/05
Posts: 5652
Loc: Eastern PA
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I just got done running the test on my GPS scope. The test worked the way Stefano's test did, so I retract my earlier statement about having to load the full catalog. The 2 differences in my test is that there was only a 1 second delta between the time displayed on my PC set back an Atomic internet clock and the display on the autostar. The other difference is that my scope is an older scope so I need the 14 second offset in order for my scope's time to be set correctly. According to the sticker on my scope it was assembled on 10-24-02.
--------------------
-Marcus
The problem with free speech is even the stupid have a voice.
http://jatobservatory.org
12" LX200R on a Paramount ME
|
stefano
member
Reged: 04/20/06
Posts: 81
Loc: Arezzo, Tuscany, ITALY
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Hi, Marcus,
I repeated the test using more sophisticated systems in order to avoid any delay reading the two times (I was watching the computer and my wife the handcontroller).
Well I have also 1 sec of difference, the scope marks 1 sec less than the computer, while it should be 14 sec more.
I tryied to set up this difference on the "GPS-UTC offset" but this accepts only positive values, at least you can set 13 sec instaed.
I check also the other two GPS system I have at home (Garmin eMap and te one that is in the car) and both are running at 0 error.
May be the difference in the scope is due to a delay generated by the electronic circuits in showing the time on the handcontroller while the scope uses the correct time. It is just a supposition.
Cheers, Stefano
--------------------
Ciao
************************************
"SPECULA IN SANCTAE MAMAE PAGO LOCATA"
MEADE 12" LX200GPS
Main: CCD Starlightxpress MX7C USB
Guide: Pentax 75 SDHF + Starlightxpress MX5C
MPC Obs. Code B38
|
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