Sky Watcher EQ-6 with Sky Scan



By anand; Published 03 Mar 2009

I recently got chance to test a Sky Watcher EQ-6 mount.


DETAILS:


• Positioning Accuracy up to 1 arc minute. Accuracy enhanced by software collimation error (mount mechanical error) compensation.

• Stepper motors with 1.8° step angle and 64 micro steps driven.

• Slewing speed up to 3.4°/sec (800X).

• Auto Guider Interface for astro-photography.

• Guiding speed selectable from 0.25X, 0.50X, 0.75X, or 1X.

• Object database containing complete Messier, NGC, and IC catalogues.

• Minimal vibration for steady long-exposure photography.

• Periodic Error Correction.

• PC compatibility.

• Upgradeable hand control via internet download.


Tripod: Stainless Steel Legs

Counterweight Shaft Diameter: 1.8cm

Counterweight Shaft Length: 28.5cm

Mount Weight (without counterweight): 16Kgs

Mount Height: 41cm

Total weight: 23.5kgs (without counterweights)

Motor Type: Microstep driven 1.8 degree stepper motors

Motor Resolution: 0.144 arc sec (or 9.024,000 steps/rev.)

Power Supply: 11 to 15 V DC 2Amp (Tip positive)

Gear Ratio: 705

*13" Dovetail Bar

SynScan Hand Control


Setting up the mount is easy although it is heavy it took me around 10 minutes to set up.The tripod looks very sturdy at first sight for this mount.The leg spreader has five 1.25" holes and two 2" ones, so it can be used to park up to eight eyepieces. On the mounting plate there's a "nail" protruding which serves for azimuth fine tuning: it's interesting to note that it can be screwed on two different positions, so you can choose between having the "central" leg aiming South (the default, which allows for more conformable observation) or North (which allows for more comfortable use of the polar finder).Motion is very smooth even with the heavy OTA, because of four bearing mounted on two axes worm assembly is also mounted on two ball bearing on each.

The electronics is mostly located under the connector plate, which has only a LED, a 12 V DC input connector and a RJ-type one for the handpad (much better than my LXD75 mount) .


USING EQ-6:

I usually don’t do accurate polar alignment, however the polar finder (same as LXD75) but It is not illuminated, but it presents large sharp reticule markings that will be easily visible under typical (light polluted sky) lighting conditions.

Electronic setup seemed straight forward but at the same time, it was less than that. First, you need your latitude and longitude. Be sure to have it, or the initial seek to your alignment stars will be way off. It takes 3 alignment stars, so alignment can be a bit time consuming.

Be sure that you know your alignment stars! There isn’t even a map in the manual, and some of the alignment stars in the menu are less prominent. My observing site has many trees and obstructions, and I wasn’t familiar with some of the guide stars. Also, the scrolling seems to take a long time. I “THINK” that the mount tries to filter out stars that might be too close to zenith so that you don’t have an OTA/tripod collision, because I noticed that after I selected the first alignment star, I got other stars that were not given in the initial choice menu. Also, it takes a while for the controller to respond to the arrow keys to scroll though the choices. I imagine that this is because of the filtering that I mentioned above. The Meade Autostar is excellent about warning you when you could encounter an orientation that would result in an OTA/Tripod collision, but I have never received such a warning from the SkyScan, so beware… I get the feeling that this is a possibility with the SkyScan.


The alignment process takes more button presses than with the Meade mounts. With Meade Autostar mounts, you simply press a number key to change slew rates, so if the alignment star is pretty far away, you simply press a number button to change to a higher rate, then press a number button again to get back to a slow rate.The SkySkan makes you press a “RATE” button, then select a number button, and then there is a slight delay until it accepts the change. I realize that this seems trivial, but trust me on this, you will want to do enough rate changing that it becomes an annoyance to press extra buttons. The Meade is the best in this respect. The SkyScan falls at the back here.


The good news is that once you have centered all three alignment stars, this thing will usually home in on a target with VERY high precision. I did an alignment on stars to the west, then slewed half-way across the sky to a eastern target several times, and the mount nailed the targets perfectly, placing them in essence directly into the center of the field. Did I mention how quite the motors sound when they are slewing? This thing makes less than half of the noise that my LXD 75 makes when it is set to the SLOW alignment slew speed (which is a menu option on the LXD75).


Speaking of the hand controller, there are not very many options or functions. The Meade allow for brightness control, the SkyScan does not. In fact, the handcontroller on the SkyScan is much harder to read at night than the Meade controllers.


The single most glaring omission in my version of the hand controller is a SYNC function… As good as pointing in this mount is, there were times when it would get out of alignment, or miss a target after a long slew… Worse, occasionally, I will bump a mount leg and shift the mount ever so slightly. With Meade hand controllers, once you locate an object, you can sync the computer to that object so that slews to nearby objects get more accurate. Even if your initial setup was not precise, or if your alignment stars were not far enough apart to result in a super-good alignment, the Sync function can allow you to work a piece of sky with good accurately. The SkyScan controller I have does not have this provision, and again, this is a clear miss. The Meade offers a “Spiral Search” function that has allowed me to recover from a miss too, which again sets you up for the Re-Sync. The SkyScan misses here on both points.


The Meade LXD75 has a red LED light built into the controller. I use it all the time to read eyepieces. I wish the SkyScan had this feature.

The Meade offer more advanced utilities. Now in defence of the EQ6 SkyScan, there was NO play in the gear-train, so maybe the mount doesn’t need all of the calibration options that the Meade provides.


The double-star catalogs in the SkyScan controller themselves appear to be screwed up as well. I did a double-star catalog search and it was wacky. It showed mag 20 stars and had IC and NGC numbers. I don’t think it was a double-star catalog at all. I consider this a quality defect, and when the manufacturer introduces a better controller, I will request one.


In all, the controller software was clearly well behind the Meade.


Mount:

Now for the part about the mount being a heavy-duty mount.Well, no, not quite.Touching the focuser of LXD75 Sn-10 will cause the tube to enter into a long-period oscillation. Slewing then stopping at all but the SLOWEST speeds will cause the view in the eyepiece to oscillate. Dampening is poor.Now the culprit here is totally the tripod. The head itself is actually very robust. I truly believe that it is capable of carrying the weight that the manufacturer specifies.But the tripod, with the legs fully extended, has too much flex in the legs.As an experiment, I would flick one of the legs with my finger, and then feel it, and I could feel the leg vibrating for a couple of seconds.


Now that being said, I mentioned that I am primarily a visual observer, and in the end, I consider the EQ6 SkyScan to be suitable for my needs and while my gripes are indeed serious, I will also say that I am actually overall rather satisfied. As lacking as the hand-controller software is, it is enough for my needs, (Go-To for common objects, RA and DEC readout for double stars). The general quality is quite high and the design is a very modern one.


In summary, the EQ6 mount head itself is indeed a heavy duty head, but it is handicapped by a less than rigid tripod, and this is too bad.