Konus EM10 Equatorial Mount

3.0 CG-5 (EQ-4) Clone for a Good Price

Inexpensive, rugged, and reasonably well made.
Dual drives.

Typical Chinese construction with thick sticky grease.

I purchased a Konus EM-10 GEM mount off of eBay. In my case, I paid $189 for the mount + shipping. This seems to be a fair going price for this particular mount, with a typical price spread from about $175 to $200. Many people apparently purchase the larger Konus scopes such as the 150mm Mak/Cass or the 6" refractor because of a good price, and opt to put these scopes on a better mount. They then sell the Konus EM-10 mount still new, in the original packaging.

The EM-10 is a clone of the "2nd generation" CG5 mount. It comes with dual motor drives, a hand controller, and a polar alignment scope. The tripod is the "older" version with 1 1/2" steel legs. Most newer CG-5 and EQ-4 type mounts now come with 2" legs for increased stability. However, depending on your use of the mount,the smaller legs may be fine. The mount also came with two counterweights, dual setting circles, manual slow motion controls, an eyepiece/accessory tray, and a mount head that accepts standard "dove tail" rails from many manufacturers (Celestron, Orion, Vixen, etc.)

The EM-10 is a standard Chinese made mount of "average" quality and has the normal problems that seem to be inherent in these mounts. Number one is the use of the thick, sticky grease common to most Chinese mounts that thickens and hardens at colder temperatures. I wasted no time, and immediately dismantled the RA and Dec assemblies, cleaned out the old grease, buffed and polished the machined surfaces, and relubricated everything with a good synthetic white lithium grease. After reassembling and doing minor adjustments on both the RA and Dec drives to reduce backlash, the mount performs remarkably well. Complete instructions for overhauling the mount is available by going to "yahoogroups.com" and joining the "konustelescopes" group. Detailed instructions are located in the files section.

After reassembly, I mounted an Orion 100mm f/6 achromatic refractor with rings on an 8" rail, leveled the tripod, and performed a rough polar alignment. Both axes now had reasonably smooth motions for manual pointing. For my first test, I went to M42, centered the nebula in a 10mm MA eyepiece (60x), turned the drives on and tracked for 2 full hours with not one correction necessary with the controller. Not bad for a first try. Next I moved to Saturn, started with a 22mm MA eyepiece (27x), and then worked my way up to 200x with a 6mm Ortho Eyepiece and a "shorty" 2x barlow. I tracked Saturn for about 40 minutes and noted only minor drifting motion, back and forth, in the center of the eyepiece field. Apparently I have a small amount of periodic error in the RA drive. But never once did it drift even near the field edge at 200x! I call that excellent for a $189 drive!

What more can be said? For the price paid, the mount is an excellent deal. Yes, there are a few problems that must be overcome, but I was aware of them when I made the purchase. If you don't mind putting in a little effort, I don't think you will find a better deal on a mount at this price!