ETX90 RA tube modified for use of a guidescope with accessories.
-- large adaptor ring (ETX to SCT threads so you can use a standard 1 1/4 visual back or other standard accessories. (new cost at Scopetronix=$25);
-- Screw-on plastic dewshield (Scopetronix new price =$25);
-- Metal screw-on lenscap (Standard on some EXT's, but not on all.); and
-- Aluminum case for storage.
-- Flip mirror adjusting screw -- this enables you to adjust the flip mirror so that things that are centered in the eyepiece are also centered (pretty much) on you guide camera.
-- Stiffened focuser. This is a kind of cowboy attempt to beef up the focuser mechanism to reduce mirror flop. I can go into detail if you wish.
-- And an attempt to devise a mirror lock, which is basically a threaded screw you can run up against the back of the mirror. Didn't really work well, but you might take it to the next step.
- - Some dust on the corrector; a few smudges on the mirror. The smudges won't bother the use of the scope for guiding; probably not for visual either that much, but if you are one who has a deep visceral need for pristine optics, this little scope is not for you.
REASON FOR SELLING:
I finally resigned myself to the idea that my C11 has too much mirror flop and went back to using a self-guided camera. Your mileage may vary.
PRICE: $125 plus actual shipping. If you don't want the case, I'll go $110 plus shipping. Remember, the accessory ring and the dewshield are like new and worth $50 alone.