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Old February 20th 07, 03:39 PM posted to sci.astro.amateur
David G. Nagel
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Posts: 44
Default GPS problems in a dome

Yo' Momma wrote:
wrote in message
ups.com...
Hello,

I am looking for a solution to my problem: I have a Meade LX200 14"
GPS scope in an Ash Dome. The Dome shields the scopes GPS system from
getting data.
Meade doesn't have an accessory to fix this.
Does anyone out there have a solution to this problem?


Maybe a re-radiating antenna?? This device is mounted in the clear where it
has a good shot at the sky. It receives signals from the satellites then
re-transmits them so a GPS receiver that is screened from the sky receives a
good signal.

http://www.pocketgpsworld.com/reradiating.php

http://www.gpsinformation.org/dale/gpsant.htm

http://www.navtechgps.com/supply/rerad.asp

On the other hand -- my understanding of things is that the GPS system is
used to tell the scope's computer (1) where the scope is located, and, (2)
the precise date and time. Because your scope is mounted in a dome, it's
not moving so you don't worry about the location. Date and time, however,
may be a problem. -- OR -- does this scope require new location, date, and
time info every time it's used? If that's the case, you need to use the
GPS.

If the scope remembers where it is and if it keeps up with the date and time
even with power off, then, it seems as though you would not need the GPS.
Just a thought.




The only problem I have found with time measurement devices, be they
analog or digital, is that they do not keep precise time. Atomic clocks
must be periodically recalibrated usin the average result of many other
clocks. The time period provided by the rotation of the earth must be
adjusted periodically due to the tidal slowing caused by the presence of
the moon.
If a telescope has a continuously running clock, that clock must be
periodically reset due to slight changed in it's operation. This fact of
life gives cause for the atleast periodic running of the GPS system.

Dave Nagel
LX200 GPS SMT SAP UHTC 10" Wireless ALT-AZ