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This Meade
LX200 GPS 10" was the result of failure to keep my wallet closed at
Astrofest 2004! However, I soon found that this scope is a step up from the LX90
which has provided me with much fun and experience.
The scope is mounted on a wedge and pier in my dome.
Several setup items are different on the LX200 from the ETX and LX90 telescopes I had used before. The major initial difference is that the whole scope is setup rotated through 180o on its pier/tripod. In polar alignment the LX200 is trained on a star not a terrestrial object.
I have setup the LX200 with training, including that for PEC and Smart Mount. As my telescope is permanently mounted and 'parked' after each session, I can now just switch on the power and all the start process is automatic thanks to the GPS - I just have to remember to press 'Mode' and I am away. My computers take longer to boot than the telescope does to reach full operation.
I use the remote Autostar keypad, from the Meade Autostar Suite, together with the SkyMap Pro planetarium program on my laptop in the dome to provide ease of operation. With webcam or my Starlight Xpress camera also on the laptop I can work away from the telescope. Telescope focussing and movement are provided through the Autostar software.
Detailed below are several items I have discovered, bought or made for use
with the telescope.
I had tested the scope outside the dome before mounting on the pier and all
systems seemed to operate OK. Inside the dome
the GPS could not get a fix; my dome is made from fibreglass.
I saw on the web that others had experienced similar problems - I wanted the GPS to make for easy setup to provide my wife with 'immediate' viewing when I was out so I installed a re-radiating antenna which has a GPS receiving aerial outside the dome and then re-transmits a signal within the dome. This worked first time. The system was from GPS Central.ca and called Tri-M Mighty Mouse Wide Re-Radiating Antenna. The supplied cables are longer than they appear in the image - each cable exceeds 16ft.
I have the external antenna for the Mighty Mouse mounted on top of a vertical post made of plastic downpipe: the antenna is mounted flat across the top of the pipe with cable routed inside the pipe. The internal re-radiator antenna is mounted at the top of the fixed inside wall of my dome - about 1 - 1.5 metre from the GPS receiver in the Meade arm. The supplied cables are more than adequate for my cable runs which are not the shortest route. I feed it with 12VDC from and old PC power supply which also supplies the telescope - it thus is powered up when I power up the telescope. See Dome.
With the GPS operational I can now Park the telescope between sessions and after a hands-free power-on routine it is immediately available for use.
I have my LX200 GPS mounted in polar mode. I had some problems working out how to train the drive.
The manual says to train the drive by pointing at a terrestrial point in daylight (a technique I had used with ETX and LX90 Meade telescopes). However, I found that the drive 'tracked' whilst I was doing the training (which obviously destroyed the results). I re-read the manual but no help.
I have since found that in Alt/Az mode the manual is correct; but when the the telescope is in polar mode, training should be carried out by pointing at a star. The scrolling message in the Autostar does say this but, until I loaded the remote software version of Autostar from the LPI suite, I found it difficult to read these scrolling messages.
Apparently, early firmware versions of polar training did use terrestrial targets but this was changed somewhere before v1.4 of the telescope firmware.
I
prefer solid dew shields to the flexible variety. I leave my dew shield
permanently mounted to the telescope.
One problem with these, however, is that they are plain cylindrical tubes with constant diameter - I wish that at the front end they were reduced to the original OTA diameter and thus the original dust cap would fit and any additional solar filter or mask would fit onto the dew shield.
So, having added my fixed dew shield to my new telescope, I hunted around for a suitable dust cover.
A trip to my local B&Q (Home Depot equivalent) located a large bucket (£4.98) of the correct diameter at its base. I cut off the base leaving about 2" walls and then inserted foam to provide a reasonable seal.
The aluminium foil on the front of the cover is to reflect sun and reduce heating when I piggyback my Coronado Maxscope 40 Hα Solar Telescope onto the LX200.
One cheap dust cover!
I
had a problem, as described above in the Dust Cap section, fitting my Hartman
Mask over the solid dew
shield I have on my LX200. The solution here was somewhat easier.
I noticed that the outside diameter of both the Hartman Mask and the Dew Shield were the same.
The Hartman Mask had three screws through threaded holes to attach it to the telescope OTA. I used these to secure three small plastic lengths to the outside of the mask which provide a snug push-fit for the mask over the Dew Shield.
If you are worried that the mask might slip off then three pieces of 'Velcro' tape should should fix the problem.
And you are right......... now I have the Hartman Mask problem
solved, I can replace the three plastic inserts into the focussing apertures and
use the mask as a dust cover!
I have made a light box to fit the LX200GPS 10".
Image to the left shows the light box under costruction.
Click the light box image for a page detailing its design and assembly.
Having
had some adventures finding the setup for STAR2000 with my Meade LX90, I hoped
that I would find connecting to the LX200GPS would be quick and easy! I used the
'Standard' connection on the STAR2000 and the RS232 on the telescope - the
lights flashed and all appeared well .... but it did not guide.
The connections that work are STAR2000 'Standard' to LX200GPS 'Autoguider'.
I wish Starlight Xpress would update their manual with this sort of
information. Terry Platt has got this information on 'Tips
on Setting Up STAR2000' within the Canadian Winchester
Electronics website.
The slew rates that I have found to work with the StarMX7C software are
| LX200GPS 10" | RA pixels/sec | Dec pixels/sec |
| f/10 | ||
| f/6.3 | 10 | 4 |
| f/3.3 |
If you are having problems use these values for a start.
