There are two sets of knobs which can influence the sharpness of the image seen through our Meade LX200 GPS telescope. The first set is the collimation screws at the front. They are for aligning the secondary mirror so that it is perfectly planar to the larger primary mirror. When the two mirrors are perfectly aligned, the stars should appear as a sharp point. The other knob affecting the quality of the image is the primary mirror focus knob. The job of this focus knob is to carefully move the large primary mirror in the back closer or farther from the secondary mirror in the front so objects can come into focus when viewed in the eyepiece.
As with most equipment, refinements can be make to the original. The two items listed above may be upgraded with minimal cost and effort to enhance the LX200 GPS scope’s ease of use. A company called Bob’s Knobs sells a set of replacement screws to make quick work of the secondary mirror calibration task. Another company called Starlight Instruments make a replacement focus knob which, when installed, will enable the user to make ultra-fine adjustments of the mirror unattainable with the OEM knob.
The FeatherTouch knob has two controllers to replace the single one on the Meade scope. The black inner knob is a 1:1 focusing knob. The smaller gold one is a 10:1 fine focusing knob. Note the presences of the deep ridges on both of the knobs of FeatherTouch as compared the OEM one. The ridges are so they could work with a motorized controller for completely hands-free remote control of the focusing operation. We’ll save that for another day.
We are going to do the installation and post the write-ups of both the collimation screws and main focus knob replacements by the end of April. If you are looking for a few final Winter projects for your telescope, consider these upgrades. Dollar for dollar, these focus- related upgrades will probably have more impact on your viewing experience than anything else you can do for your scope. Starlight Instrument’s FeatherTouch (FM-MEA8) Micro Focuser is a direct replacement for the knob of our 10″ Meade LX200 GPS scope. Starlight makes them to fit all of the popular SCTs. Check their site for info regarding your specific model.