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by Don Urban
The complete configuration arrived in four separate heavy duty cardboard boxes. Each and every individual part was wrapped inside cushioning sheets of bubble wrap to prevent damage during shipment from California.
As I began assembling the unit tripod first - I knew that I had purchased a piece of finely machined work. Although most components are anodized aluminum, there were no sharp edges or burrs. To the contrary, all edges and corners appear to have been intentionally smoothed and rounded, to prevent cuts and snags to clothing. All the tools needed to assemble the GM8 come with the package, except for a 9/16 wrench. Hex wrenches in five sizes make fastening all nuts and bolts a snap.
The GM8 is rated to hold up to 30 pounds, a weight that would certainly include refractors up to 5 inches, as well as 8-inch SCT's and some 6-inch Newtonians. It certainly does an outstanding job for my 11 pound Genesis SDF.
The equatorial head attaches to the tripod in one of three positions, depending on individual preference. The electronic control unit is mounted at the base of the head between the tripod legs and swings up or down so it can be seen from any angle. It has four tracking rates: Sidereal, King, Solar and Lunar. There are 7 different guiding rates in RA and DEC ranging from .3x and .5x (for astrophotography) through fast 16x and 32x speeds for rough adjustments when observing visually. Periodic Error Correction (PEC) is built-in and requires eight minutes of guiding before becoming functional.
Clutches on both axes are tightened or loosened with a turn of a large ring at the base of each axis. When the entire unit is properly balanced it is possible to track with minimum tension on both clutches.
The hand paddle is simple to use and has buttons for the four compass directions. Polar alignment is a piece of cake, thanks in part to two built-in bubble levels, a large knob to adjust for latitude (2 degree increments, from 10 to 60 degrees), and a fine azimuth adjustment with a range of 8 degrees. No more picking up the entire tripod when polar aligning, just to get 4 degrees closer to Polaris! An optional illuminated polar alignment scope slips into the polar axis and shows the Big Dipper and Cassiopeia. By roughly positioning what you see in the finder with what is actually seen overhead, and placing Polaris and one other star in the correct positions, exact alignment is achieved in less than 2 minutes.
Each leg of the tripod is individually adjustable and has a flat 1.25 x 2.5 inch foot covered by a soft rubber cushion which almost totally eliminates vibrations.
It just over 60 pounds and 4 feet long (with the legs folded in), the GM8 lies flat across the back seat of my full size Ford station wagon and is light enough to lift and carry 30 feet from my back yard to the garage. (This is not a mount that you would want to be constantly assembling and breaking down for each observing session.)
Like everything else, it comes with some criticism. The typed directions for assembly could have been helped by the inclusion of illustrated diagrams, which could have saved this dummy (I hate to read directions) more than an hour setting it up for the first time.
Declination setting circles are in 2 degree increments and RA settings are in 6 minute graduations. With a low power eyepiece, this presents no trouble but at higher power, it would have been nice having 1 degree DEC and 5 minute RA markings.
At about $1,395 the GM8 is not inexpensive when compared to other German Equatorial Mounts. But then again, a Lincoln Town Car is expensive when compared with a Ford Escort. Both will get you where you want to go. It's how they do it (the comfort level) that counts. For the money, the GM8 is in a class by itself, and well worth every dollar. An indication of its popularity is a 4 to 6 week wait for delivery from the factory.
The Genesis SDF itself, is another work of art and since there have been countless reviews of it in the past, I will state that I am in complete agreement with what has already been said and written.
