Review of the Meade LXD55 6"Refractor by Martin Peston

The Meade LXD55 series is the latest in a new line of GOTO telescopes that have recently appeared on the commercial telescope market. The relatively cheap cost for such sophisticated equipment is very appealing to the amateur astronomer who wants to get the most out of observing.
The 6" refractor is the largest of the LXD refractor range weighing in at around 27lbs for the optical tube assembly.

Optical Tube Assembly
The size of the OTA is impressive and at F8 it produces a focal length of 1200mm. Collimation adjustment screws are set around the 6" primary lens allowing fine collimation of the OTA which not something that is usually seen on smaller refractors. A plastic white dew shield protects the primary lens. The dust cap on the end of the dew shield is a little tight and two hands are required to prise it off without lifting off the dew shield as well.

At the 'business' end the focus mount is very smooth and there is very little lateral movement when racking the focuser tube in and out. A 2" to 1 ¼" eyepiece adaptor and a 1 ¼" star diagonal are supplied. I found the star diagonal, however, to be made of cheap plastic construction and seriously lets down the quality of the optics. I used a 2" mirror diagonal instead to maintain the quality of the optics. A useful feature of the focusing tube is that a screw thread is built in to allow a T-ring camera attachment for astrophotography.

Computerised GOTO Mount
The mount is probably the reason why most astronomers are purchasing these telescopes. It is similar in design to the cheaper Chinese mounts such as the EQ4 and CG5 mounts, however there are improvements, such as no need to re-grease the axes of the mount and a superior paint finish. The mount also comes with an illuminated polar finder reticule eyepiece that I found straightforward to use and made polar alignment setup quick and easy.

Both RA and DEC axes are motorised and have encoders attached to them housed in black plastic boxes. The motors are attached to an #497 Autostar handbox computerised controller via coiled 8pin cables. Autostar operations are straightforward to use and once a thorough read of the operation manual is carried out it doesn't take long for the user to master the telescope's controls. The only downside is that the motors are rather noisy when slewing at maximum speed during a GOTO operation. There is a software upgrade from the Meade site which allows GOTO slewing at a slower speed as all other slew speeds make considerably less noise.

There are no slow motion controls but the telescope can be used manually by loosening the RA and DEC axes clamps and moving the telescope to the desired object. Doing this though forfeits the use of the GOTO operation which is what the mount was intended to be used for.

The tripod that came with the mount can cope with the 6" refractor's weight, however its sturdiness is somewhat lacking and it is advised to use vibration suppression of some kind to improve matters. On the plus side the tripod is strong, light and compact making portability a key factor and once vibration suppression is used it will be more than sufficient for the refractor. A sturdier wooden tripod will be available on the market soon, which will improve the stability of the entire mount system.
As a permanent mount I use a pillar mount instead of the tripod and built an adaptor to fit the LXD mount head to the pillar, which vastly improves stability.

Original Packing and Setup
The telescope came in two large boxes, one for the OTA and one for the mount. Setup was simple as the telescope is made up of four primary parts: OTA, Mount Head, Counterweights and the Tripod. Before observing could start, I performed several setup steps first in order for the telescope to be fully operational. These included training the motors and aligning the polar finderscope with RA axes. These steps did not take long and I carried them out during the day. It is also important to note that you should familiarise themselves with the operation of the telescope during the day before going out at night for the first time.

Observing - First Light
Some practice was needed to accurate polar align as well as entering the exact time in order to get the object central in the eyepiece after a GOTO operation. It took about 15mins for the first time, but once mastered it took no time to set up the telescope ready for a night's observing.

First light on celestial objects produced excellent results. The telescope was pointed at the Moon and several deep sky objects and stars. The objects were viewed through the 26mm eyepiece that was supplied with the telescope.
The Moon was crisp and sharp and there was some false colour which is what one would expect with an F8 Achromatic refractor. Contrast was very good even at high magnification. Stars were very close to pinpoint showing that the collimation was near perfect. Deep sky objects such as M27 the Dumbell Nebula was impressive and the globular cluster M13 revealed myriads of stars surrounding the central bright area.
All this was in a light polluted sky with a limiting magnitude of around 10. The telescope's tracking and GOTO operations performed very well during the night's observing.

Conclusions
In conclusion, the 6" refractor is an excellent telescope with features that would have been unheard of several years ago.

Martin Peston

Click an Image for a LARGER version