Levenhuk Ra 200N Reflectors Dobson telescope User Manual

: June 5, 2024
: levenhuk

Table of Contents

Telescope assembly
Operating the telescope
Specifications
Batteries safety instructions
Care and maintenance
Levenhuk International Lifetime Warranty
Documents / Resources

Reflectors OTA
Levenhuk Ra 200N F5 OTA
User Manual
Levenhuk Ra 200N Reflectors Dobson telescope
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Levenhuk Ra Reflectors OTA
Congratulations on your purchase of a high-quality Levenhuk telescope! These instructions will help you set up, properly use, and care for your telescope. Please read them thoroughly before getting started.
CAUTION! Never look directly at the Sun — even for an instant — through your telescope or finderscope without a professionally made solar filter that completely covers the front of the instrument, or permanent eye damage may result. To avoid damage to the internal parts of your telescope, make sure the front end of the finderscope is covered with aluminum foil or another non- transparent material. Children should use the telescope under adult supervision only. All parts of the telescope will arrive in one box. Be careful when unpacking it. We recommend keeping the original shipping containers. In the event that the telescope needs to be shipped to another location, having the proper shipping containers will help ensure that your telescope survives the journey intact. Make sure all the parts are present in the packaging. Be sure to check the box carefully, as some parts are small. No tools are needed other than those provided. All screws should be tightened securely to eliminate flexing and wobbling, but be careful not to overtighten them, as that may strip the threads. During assembly (and anytime, for that matter), do not touch the surfaces of the optical elements with your fingers. The optical surfaces have delicate coatings on them that can easily be damaged if touched. Never remove mirrors from their housing, or the product warranty will be null and void.

Telescope assembly

Attaching the OTA to a mount
Your OTA comes with a pair of hinged tube rings that may be used to attach the optical tube to a mount or a guide scope to the OTA.
Once you have attached your optical tube to a mount, you might have to balance the assembly. Loosen the ring clamps and slide the optical tube forward or backward within the tube rings to balance it. Do not forget to retighten the ring clamps afterward.
Finderscope assembly
A finderscope is a small wide-field telescope used to help locate and center objects in the field of view of the optical tube.
To install the finderscope follow these simple steps:

Locate the finderscope bracket and remove the rubber ring from it.
Slide the rubber ring into the groove at the center of the finderscope tube.
Slide the finderscope bracket into the mount on the optical tube and tighten the screw to hold the bracket in place.
Loosen two adjustment thumbscrews on the bracket and pull the spring pin 1 .
Slide the finderscope tube into the bracket until the rubber ring sits in the bracket.
Release the spring pin and retighten the thumbscrews.

Aligning the finderscope
The finderscope and the main telescope have to be aligned so that they point to the same spot in the sky. Alignment is best done outdoors during the day, when it is easier to locate objects. Note that you will have to use the 35-mm extension adapter to reach focus with most eyepieces. First, insert an eyepiece (an eyepiece with a reticle is recommended) into the 35-mm extension adapter and insert the adapter into the focuser. Point the telescope at an object at least 500 yards (450 meters) away. Adjust the telescope so that the target object appears in the center of the field of view in the eyepiece. Check the finderscope to see if the object is also centered there. If it is not centered, use the adjustment thumbscrews to center the object in the field of view.
It is recommended to check the alignment before every stargazing or astrophotography session. Alignment can be done at night, as well. Choose any bright star or a planet, center the object in the telescope eyepiece, and then use the adjustment thumbscrews until the star or the planet is also centered in the finderscope.
Focusing the finderscope
If the image in the finderscope appears out of focus, you will have to refocus it. First, loosen the locking ring located behind the objective lens cell on the finderscope body2. Then, focus your view by rotating the objective lens cell in either direction. Once the image appears sharp, retighten the locking ring behind the objective lens cell.
Eyepiece assembly
An eyepiece magnifies the image produced by the OTA. The eyepiece is installed into the focuser. Eyepieces are commonly referred to by their focal length and barrel diameter. The focal length of each eyepiece is printed on the eyepiece shell. The longer the focal length, the lower the eyepiece magnification, and vice versa. The total power of the telescope setup may be calculated with the following formula: Magnification = Focal Length of Telescope (mm) / Focal Length of Eyepiece (mm)

To install an optional eyepiece:

Loosen the screw on the focuser.
Slide the eyepiece into the focuser.
Retighten the screw to secure the eyepiece in place.

Operating the telescope

Levenhuk Ra reflectors are designed primarily for astrophotography, but they may be used for visual observations as well.
We recommended using high-quality eyepieces for visual observations to achieve exceptional quality of produced views.
Cooling Fan
Your new reflector comes with a cooling fan built into the rear end of the optical tube. This fan reduces the time it takes the primary mirror to adapt to the outside temperature. This eliminates fogging, and your OTA will produce sharper and brighter images as a result. The fan is powered by 6 AA batteries (not included in the kit), or an external 12V battery. Please allow additional time for cooling if there is a substantial difference between the indoor and outside temperatures. Once the telescope has adapted to the outside temperature, you can turn off the cooling fan to reduce the vibration of the optical tube.
Visual observations
To achieve focus, you will likely have to use the included 35-mm extension ring . Just insert it into the focuser and tighten the two thumbscrews to secure the extension ring in place. You can then use either a 2″ eyepiece or a 1.25″ eyepiece (with a 1.25″ adapter).
Focusing
One of the exciting new features of Levenhuk optical tubes is the inclusion of the new dual-speed Crayford focuser. Unlike the traditional Crayford focuser with a spring-loaded shaft to hold the focus tube, the new linear ball-bearing focuser allows you to easily use heavier accessories, such as larger eyepieces, cameras, imagers, guiders, etc. It also reduces image shake and completely eliminates backlash.
During celestial observations, out-of-focus images of dim stars may be very diffuse, making it difficult to focus on such objects. Choose a brighter celestial body (such as the Moon) as your first observation object, and focus your view. With a 10:1 fine focus adjustment (meaning that 10 turns of the fine focus knob equal 1 turn of the coarse focus knob) you can adjust the focus of your view with great precision. Use the coarse focus knob to adjust the view until your object is as close to focus as possible, and
then make fine adjustments with the fine focus knob.
Astrophotography
Levenhuk Ra reflectors have high-quality BK-7 glass optics, which produce bright images and provide for fast exposure. However, fast optics also inherently produce some coma, so to achieve the best possible images, it is recommended to use a coma corrector (not included in the kit). The coma corrector may be attached to the focuser in front of the camera body. Coma correctors eliminate coma and improve the quality of the resulting images across the field of view, so you do not have to crop the images you have taken during your astrophotography sessions.
Camera assembly
Most CCD cameras have a 1.25″ or 2″ barrel, which means that you can attach them directly to the focuser, without an adapter. Simply insert the nosepiece of the CCD camera into the focuser and lock it in place with the two thumbscrews. To attach a DSLR camera, you will need an appropriate T-ring and a camera adapter. Simply attach the T-ring to the camera body and thread the camera adapter onto the T-ring, insert the barrel of the camera adapter into the focuser and secure it in place with the two thumbscrews.

Specifications

| Levenhuk Ra 200N F5 OTA
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Optical design| Newtonian reflector
Optics material| BK-7 glass
Optics coating| aluminum 92-96% coating
Primary mirror shape| paraboloid
Primary mirror diameter (aperture), mm| 200
Focal length, mm| 1000
Focal ratio| f/5
Highest practical power, x| 400
Focuser| 2″ dual-speed Crayford
Eyepiece barrel diameter| 1.25/2″
Tube-mount assembly system| dovetail plate, tube rings
Optical tube material| metal
---|---
Finderscope| optical, 8x5Omm
Cooling fan| +
Batteries (for cooling fan)| 6pcs AA (not included)
Operating temperature range, `C/ °F| -5 … +35 / 23 … 95

The manufacturer reserves the right to make changes to the product range and specifications without prior notice

Batteries safety instructions

Always purchase the correct size and grade of battery most suitable for the intended use.
Always replace the whole set of batteries at one time; taking care not to mix old and new ones, or batteries of different types.
Clean the battery contacts and also those of the device prior to battery installation.
Make sure the batteries are installed correctly with regard to polarity (+ and −).
Remove batteries from equipment that is not to be used for an extended period of time.
Remove used batteries promptly.
Never attempt to recharge primary batteries as this may cause leakage, fire, or explosion.
Never short-circuit batteries as this may lead to high temperatures, leakage, or explosion.
Never heat batteries in order to revive them.
Remember to switch off devices after use.
Keep batteries out of the reach of children, to avoid risk of ingestion, suffocation, or poisoning.
Utilize used batteries as prescribed by your country’s laws.

Care and maintenance

Never, under any circumstances, look directly at the Sun through this device without a special filter, or look at another bright source of light or at a laser, as it may cause PERMANENT RETINAL DAMAGE and may lead to BLINDNESS.
Take the necessary precautions when using the device with children or others who have not read or who do not fully understand these instructions.
Do not try to disassemble the device on your own for any reason. For repairs and cleaning of any kind, please contact your local specialized service center.
Stop using the device if the lens fogs up. Do not wipe the lens! Remove moisture with a hair dryer or point the telescope downward until the moisture naturally evaporates.
Protect the device from sudden impact and excessive mechanical force.
Do not touch the optical surfaces with your fingers. Clean the lens surface with compressed air or a soft lens-cleaning wipe. To clean the device exterior, use only the special cleaning wipes and special tools that are recommended for cleaning the optics.
Store the device in a dry, cool place away from hazardous acids and other chemicals, away from heaters, open fire, and other sources of high temperatures.
Replace the dust cap over the front end of the telescope whenever it is not in use. Always put eyepieces in their protective cases and cover them with their caps. This prevents dust or dirt from settling on the mirror or lens surfaces.
Lubricate the mechanical components with metal and plastic connecting parts. Components to be lubricated:
Optical tube;
Fine mechanics (focuser rail, telescope optical tube micro focuser);
Mounting;
Worm-and-worm pairs, bearings, cogs, threaded mounting gears.
Use all-purpose silicon-based greases with an operating temperature range of −60 … +180°С (−76 … +356°F).
If a part of the device or the battery is swallowed, seek medical attention immediately.
Children should use the device under adult supervision only.

Levenhuk International Lifetime Warranty

All Levenhuk telescopes, microscopes, binoculars, and other optical products, except for accessories, carry a lifetime warranty against defects in materials and workmanship. A lifetime warranty is a guarantee on the lifetime of the product on the market. All Levenhuk accessories are warranted to be free of defects in materials and workmanship for six months from date of retail purchase. The warranty entitles you to free repair or replacement of the Levenhuk product in any country where a Levenhuk office is located if all warranty conditions are met. For further details please visit our website: www.levenhuk.com/warranty If warranty problems arise, or if you need assistance in using your product, contact the local Levenhuk branch.

The original Levenhuk cleaning accessories Levenhuk Ra 200N Reflectors
Dobson telescope - fig 3 Levenhuk Cleaning Pen
LP10 Levenhuk Ra 200N Reflectors Dobson telescope - fig
1

Removes dust with a brush The soft tip is treated with a special cleaning fluid that removes greasy stains Does not damage optical coatings of the lenses Leaves no smudges or stains

levenhuk.com
Levenhuk Inc. (USA): 928 E 124th Ave. Ste D, Tampa, FL 33612, USA, +1 813 468-3001,
contact_us@levenhuk.com
Levenhuk Optics s.r.o. (Europe): V Chotejně 700/7, 102 00 Prague 102, Czech Republic,
+420 737-004-919, sales-info@levenhuk.cz
Levenhuk ® is a registered trademark of Levenhuk, Inc.
© 2006—2021 Levenhuk, Inc. All rights reserved.
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Documents / Resources

| Levenhuk Ra 200N Reflectors Dobson telescope [pdf] User Manual
Ra 200N Reflectors Dobson telescope, Reflectors Dobson telescope, Dobson telescope, F5 OTAD
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