Truss Solar Newton T250 for Ha and CaK

[allhoest]

I'm renewing some of my equipment. I bought a camera and FSQ106 and will probably go for a bigger solar scope also.
From my astrogear, the solar newton is for sale.

Truss Solar Newton T250 for Ha and CaK
Works also with the solar continuum
Works also under the G band (430nm)

The truss tube and mirror are made by Martini Optik
The truss tubes and upper cell are stronger than standard models, to cope with the constraints of a Halpha setup.
The mirror is "multilayer" treated, to reflect the red and part of the deep blue wavelength.
Leaks allow imaging with a solar continuum
The spider is a rigid "double" carbon model
The secondary is a Lambda/20 made by Antares; it has a small damage on one end, not affecting the imaging process.
The focuser is a high quality from Starlight Instruments
Remote focusing through USB_Focus and heavy duty motor

Price: 2500Eur
Equipment available from Belgium.
Contact: allhoest@scarlet.be

Images made with this setup:

[marktownley]

Super scope! Good luck with the sale!

[allhoest]

Thank you for the comments.
Some words about the system.
Optically, the design values are: F/D ~7, to be combined later to a telecentric x4 and come to high focal ratio number for imaging with a Halpha etalon.
D is ~250mm; F is about 1700mm.
 
Some words about the system.
The principle is a herschell prism, reflecting 4% of the incoming light flux. There is thus no aluminum coating.
The remaining 96% flux pass through the mirror. The mirror supporting structure is as open as possible, so no heat can build.
It works very well, acting as a giant herschell prism.
 
The open structure minimize (cancel...) the internal "tube" turbulence.
The mirror also is not heating up (less than 2°), to minimize local turbulence.
The open truss concept works well.
 
Above of this, the mirror is multicoated to reflect the red (Ha) and blue (CaK) domains. It becomes a special herschell prism.
It reflects flux in the G band (430nm).
It reflects a leak under the "baader continum 540nm", acting as a regular herschell prism.
 
The multicoating technique is a vaccum deposit of several (many) well calculated oxide layers, to have interferential destruction of some wavelengths. This coating is very resistant it should last for ever.