Jump to content

  •  

- - - - -

Sovietski TAL-2, 6 inch Newtonian



The TAL-2 comes with many features and accessories, and all deserve mention. Don't let the $649 price fool you!

The telescope arrived in two huge cardboard boxes. Inside each, bubble wrapped, is a large Baltic Birch plywood case. Both cases have a plaque identifying the contents and serial number, and a detailed list inside the lid. The case hardware is mat black, with a bit of a handmade look to it, but functional. Inside various spacers and mounts are made of plywood and long bolts with thumb wheel nuts. Fingers rotate to lock items into place. You will have to remove/rearrange the spacers to use the case for daily storage. The OTA goes in place with the finder on, if you unscrew the eyepiece holder and remove one long case bolt.

The pedestal tube is 100mm ID, accepting the 3 support screws at the bottom and threaded for 3 clamping screws at the top.

The GEM mount slides into the top of the pedestal. The very bottom of the mount is a collar with a groove in the outside to accept the clamping screws. The inside of this collar has some rather massive threads. The GEM mount actually screws into this large collar and is held in place with a set screw, check to see that this screw is tight or the head might rotate by unscrewing from the collar.

Sovietski replaces the original European RA motor with a US made Hurst before shipping. The mount has 2 clutches in the RA train. One provides slippage for the slow motion knobs on the worm gear the other on the 180-tooth ring gear allows the OTA to be moved by nudging it around like you might a DOB.

You may think that the slow motion control is hard to turn at first, and it is, because there are two clutches in the RA drive, and there is no RA lock. This is a great feature to have as it allows you to slew the scope by moving the tube by hand without destroying the position error correction (PEC) calibration if you are using a motor corrector. Both clutches are adjustable through sliding portholes on the motor housing. The actual feel can be made smoother and easier by taking the steps below:

1. Make sure the motor gear is properly aligned with the spur gear on the worm. I had to disassemble the motor clutch and drill the center hole all the way out (it was only partially bored on mine). This is necessary because the Hurst motor has a longer shaft than the original. Line up the outer edges of the two gears by moving the clutch assembly in or out and tightening the set screw. You may not need to do this step.

2. Adjust the tension on the motor clutch (the small one) until the worm just turns when you run the motor, no tighter. Do this with only after you have balanced the mount. I tape an ice cream stick in the slot on the knob to accentuate the rotation. I can see it move better that way.

3. Balance the scope/mount in RA. I do this by simply moving the scope so that the weight arm is almost parallel with the ground, then move the slow motion knob back and forth. If it feels stiff, rough, or harder to turn in one direction than the other, the scope is not balanced.

The RA drive has typical position error (PE), but is a smooth transition from slow to fast. I use a JMI Mototrak V for PEC but I am still learning how to train the combination.

The RA circle is of the typical rotating scale, backwards moving hour type. I believe that about 1/2 of the telescopes are made with this type. It can only be used for relative shifts in RA unless you relabel the hour circle as I did, to allow direct reading of the RA as you slew the scope. The RA must be re-set before leaving each target, however or you won't find the next. I use the setting circles with great results, so I decided not to get digital setting circles.

The weight is held on the weight shaft with a compression nut. The weight & shaft connects to the declination shaft by an identical compression nut that acts as a slip nut. This means the scope breaks down into four pieces. The solid declination shaft is tapered from 1.462 inches down to one inch OD. There is also a 15/16 shoulder, which I use to attach the declination pointer (the scale is fixed to the mount body, the usual, but not the best, arrangement). The weight shaft rotates in declination, allowing use of accessories (a camera) attached to it.

Heavy-duty pre-loaded ball bearings are used everywhere, including the worm. I have used this mount for my Celestron C-9.25 SCT, a much heavier scope.

This mount has a 14-inch tangent arm for tube mounting. This arrangement allows a clamping nut (declination lock) to be used at the top of the declination shaft, while the tangent arm rotates +- 4 degrees with a vernier knob. Each end of the tangent arm has a screw slot and a dado to accept the tube rings. The rings attach by placing their base in the dado and flipping the captive screws down into the slots. The rings are felt lined and have captive screws bridging the split.

Latitude adjustment goes to 70 and has a double lock, a knob on a brace and lever on the axis screw. I doubt if any amount of cold will affect this mount.

The OTA is 48" long, continuously baffled aluminum 1/10 inch thick. An aluminum cell holds the 150mm spherical mirror at three points. It uses the standard 4-screw adjustment arrangement and all screws are satin finished stainless steel (as they are everywhere). The mirror is easy to remove and clean.

There is a 4-vane spider holding the secondary. The secondary itself rotates freely if the screws are loosened all the way; there is no centering detent. This is the same screw and vane arrangement used in many other newts though and provides minimum blockage by the vanes.

The rack and pinion focuser and the eyepiece holder are two separate parts, held together on the old Universal (Pentax) camera lens mount threads. You just have to unscrew the eyepiece holder and screw on the camera body and you are at prime focus. So all you need is the camera. Plus, you use a standard set of Pentax extension tubes to extend the scope for close ups! (Otherwise close focus is 400 meters). Focus tension is adjusted by holding one of the two knobs and turning the other. The holder itself uses a compression ring to retain the eyepiece after the Russian fashion.

The OTA weighs in at 16.5 lbs.; the weight & shaft 14, the GEM and the pedestal are each 21 lbs. There is no need to remove the weight from the weight shaft since it unscrews from the declination shaft itself.

The manual states that the focal length is 1200mm, focal ratio is f8. The scope comes with 42 and 15mm Kellners and a terrific 25mm Plössl. A 4x barlow is included yielding magnifications of 28, 48, 80, 112, 190, 312x at fields of view of 1°12', 1°10', 37', 14', 13' and 10'. I have found the 4x Barlow to compare well optically with my Celestron Ultima SV 2x. A set of 6 color filters is provided including two Neutral Densities for the sun and moon respectively. These are of the slip-on type, which is either good or bad depending on how you use filters. I like to "try" a lot of eyepieces and filters, an operation which would take forever if I had to screw and unscrew each filter on each eyepiece. They are astronomy not photographic filters and have the proper tints for astronomical use.

I do not recommend viewing the sun through the ND filter. A projection screen is provided, as is an off-axis stop. Tube caps are provided for both ends of the main tube but not for the finder.

The 25mm Plössl includes a pre-focused cross hair that screws into the eyepiece barrel. In a pinch, this can be used for collimation or guiding/training. It will not work with other eyepieces because the cross hair itself extends into the barrel to reach the focus point.

The finder is a fine small wide-angle telescope in its own right. It is a bright 8x50 with a 7-degree fov. The eyepiece is the same 25mm Plössl supplied with the main scope and is focusable. The reticule is of the type using 4 crosshairs such that the very center is blank. The hairlines are the size of fine hair and can be hard to see in very dark skies. The holder is of the 6-screw type and attaches to the tube via a dovetail. Plastic rings circle the finder tube and are grooved to accept the screw ends and holding the tube in place while the screws are adjusted, no tube dents here. When you swing your head down to look through this finder it's just like someone turned on a television set. The view is that bright! I have a Scopetronix red-dot 1x finder piggybacked on the 8x50.

Collimation is easy, with standard collimation screw arrangements. It took me a while to master the operation, I used an Orion Cheshire Collimator (http://www.telescope.com).

I have been told, and agree, that this is a perfect optic of its type. With a spherical mirror at f8 it is right at the edge of being diffraction limited. I know that it shows me everything that a 6" Newt should show and more. I later compared this to an Intes MN61 Maksutov Newtonian and, although the stars were smaller in the MN. The TAL had brighter images.

Sovietski sells 9 different Plössl eyepieces for their scopes, the mount, mirror; rings, finder and other components are available only on their web site. They also sell other sized Newts, a 100mm refractor and a 200mm Klevzov Cassegrain.

The pocket-sized manual is very good considering it is translated from the Russian. It is both clear and detailed, giving all specifications. The section on the drift method of polar alignment refers to whether the upper end of the scope moves up or down, rather than the standard indications of east and west. Up and down I can do, but I can never figure out which is east or west with a GEM mount. There is a section on cleaning (the correct way) the optics. Like all my Russian optics a certification of slushing is included in the back. Now, if anyone can tell me what slushing is...? Mine is serial number 2223 manufactured 6-99.

This is an extremely satisfying scope to own and use and the mount by itself is worth twice the price of the TAL-2. I can recommend this scope to anyone who wants old-fashioned quality regardless of price. It is a great bargain, especially at the prices Sovietski is charging! This is also the best "starter" scope I have ever seen.



0 Comments



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics