|For Sale -Dealer Ad |
|Status: Active Ad Category: Telescope-Reflector Ad # 40610|
|LAST one at this price! |
New 20" Dobsonian Telescope
Interferometer test report included
(Please visit my website SkyObserving.ca and click on Mirrors And Telescopes to see my latest models - both lightweight 20" and 24' Dobsonian telescopes)
This 20" one will be last at this price.
Primary mirror - 20" F/4.4 with FL = 2240 mm with 0.85 Strehl.
Mirror is made by me and tested by me with interferometer, coatings with 90-91% reflectivity coated at Fullum's shop, mirror material is Schott low-expansion Supremax33 glass 1.25" thick fine-annealed. Centre circle for easy collimation.
New 3.5" secondary mirror 1/20 surface error from Astrosystems, enhanced aluminum coatings 95-96% reflectivity. Interferometer test report included.
New secondary holder (with required off-set) and heavy duty spider are also from Astrosystems.
New top of the line Feathertouch the best in the world dual focuser 10:1 low-profile newest model FTF2015BCR, only 1.5 inches travel.
Secondary dew heater - Kendrick new secondary heater with wiring out with RCA jack ready to connect to controller.
Cooling fan 12V ready to connect to power via cigarette plug.
1" diameter aluminum trusses, connected at top in pairs for easier set up.
Baltic birch cabinet grade hardwood stained and varnished several times in light cherry finish.
Lightweight aluminum handles with 6" wheels for easy moving the whole scope.
Light shroud from high quality stretchable material.
Wooden box for storing and protecting the mirror when not in use.
The scope holds the collimation without any problems all night - once you collimate the scope - it is collimated till the end of obseving. Also as I mentioned the scope is mechanically very strong.
Mirror cell is 27 point supporting without problems the 1.25" thin mirror which cools fast in comparison with thicker ones which are not capable to follow the temperature drop during the night. The mirror is held by steel cable sling with adjustable length - very easy to place the sling around the mirror and also very easy to center the mirror inside the cell simply with adjusting the length of the cable sling. Collimation is also very easy with the fine 24 TPI collimation rods and big 2" diameter collimation knobs. Sling can be also adjusted in height to fit the mirror properly if you lift or lower the mirror via lifting or lowering the mirror cell. All work in the mirror box: centering, adjusting, tightening, attaching and adjusting the sling, positioning and tightening od the mirror pins and clips and whatever else can be done by hand and very easy without effort and frustration, no tools required. Everything is with knobs. Once you collimate the scope there is no need to check and do it again, it is collimated till the end of the observing. Also collimation of F/4 scope is not at all more difficult than F/5 or F/6 scope, it is equally easy.
The telescope has big bearings which give very smooth and precise movement of the scope. They are detachable, which allows the scope when disassembled to fit in a car, to transport it to the dark place you want ( rocker box only 6" tall, mirror box only 7" tall )
The scope comes with two counterweights 3 Kg each you can attach at the back of the mirror box if you decide to use Naglers, Ethoses eyepieces plus Paracorr2.
Standard 1-year warranty applies on EVERY single part of the scope, even those I do not manufacture, like the focuser, secondary dew heater and mirror coatings. 30-days return to seller in original shape if not satisfied.
Price is only 4,000 CAD and NO TAX for Canadian buyers, buyer pays shipping, local pick-up ok. Compare with 15,000 CAD you will need to pay to buy classic 20" Dobsonian from US with 2" thick mirror, inferior secondary mirror, inferior focuser, with F/5 focal length and more.
Do not miss the chance. I am offering this scope only at this price just to promote my business.
First come first serve
Thanks for viewing
Posted on: 2017-05-15 23:10:44
Last Updated on: 2017-05-15 23:35:19
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