Jump to content


Photo

Konus 90mm f/11 refractor - should I buy used?

  • Please log in to reply
6 replies to this topic

#1 cpsTN

cpsTN

    Mercury-Atlas

  • ****-
  • Posts: 2501
  • Joined: 26 Apr 2007
  • Loc: Rutherford Co, TN

Posted 26 May 2011 - 09:10 PM

Not far from the house is a Konus 90mm f/11 refractor on a GEM with motor drive. Saw this scope in person and everything seems to be in line EXCEPT the focuser tube.

The focuser tube is plastic and seems to be stripped about an inch from being racked all the way in. It is this way reguardless of how loose or tight the retaining screw is. You can push it in while turning the knob and it will continue. The owner knows close to nothing about scopes. He is asking $125 for it. Would it be possible to replace this focuser without a larger expense? What type of offer should I make in light of this defect or should I buy it at all?

#2 watcher

watcher

    Vanguard

  • *****
  • Posts: 2120
  • Joined: 21 Nov 2007
  • Loc: St. Louis, MO

Posted 27 May 2011 - 04:20 AM

Tough call Charles. The optics are probably good enough, but I would think the mount is a little weak for an F/11 90mm. The focuser could be replaced with an Antares R&P for about 50 bucks, or a nice Crawmach crayford for a bit more. I think that scope/mount sold for around 250 new, so you can have a bargain even after replaceing the focuser. I would get it, sell the mount, or use it for your short 70mm, and get a CG-4 for the scope. Would be pretty nice then.

#3 eric_zeiner

eric_zeiner

    Phoenix's Dad

  • *****
  • Posts: 8040
  • Joined: 09 Dec 2006
  • Loc: Georgia USA 34 31'57.18N 83 53'26.30W

Posted 27 May 2011 - 04:28 AM

Given the situation, I think $125.00 is too much. Especially with a bum focuser. A little over a year ago, I bought my daughter a BNIB SW 90/910 for $150.00 delivered. My guess is that like the SW the Konus is a Synta scope and the optics should be fine. My daughters scope came with an all metal 1.25" R&P focuser. I would see if the owner would be willing to take something in the area of $75.00 for it. As Joe stated it is also probably under mounted too, so that is an issue that will need to addressed. The OTA will be in the area of 40" long and a decent mount is almost a requirement.

#4 scott m

scott m

    Ranger 4

  • *****
  • Posts: 395
  • Joined: 06 Dec 2007
  • Loc: Hatfield Pa

Posted 27 May 2011 - 05:09 AM

It sounds like it's the same thing as the Meade DS-90 which I have. The focuser is the worst part of the scope. I replaced it with a metal R&P from Meridian. The optics are great very little CA.

#5 cpsTN

cpsTN

    Mercury-Atlas

  • ****-
  • Posts: 2501
  • Joined: 26 Apr 2007
  • Loc: Rutherford Co, TN

Posted 27 May 2011 - 07:40 AM

Before I met with him, I asked if we would part with the OTA and not the mount, which seems to be an EQ3 size. He said he wouldn't because he wouldn't need the mount without the OTA. He also said he bought in recently on Craigslist (which is where I found it) and is trying to get his money back. I am afraid he won't be doing that if he paid $125 or similar.

I wouldn't mind the scope but I too think it is undermounted but not to a great deal. The focuser WOULD need replacing - not right away necessarily, but in the near future. I will talk to him and let everyone know what's going on. Thanks everyone so far.

#6 scott m

scott m

    Ranger 4

  • *****
  • Posts: 395
  • Joined: 06 Dec 2007
  • Loc: Hatfield Pa

Posted 27 May 2011 - 02:21 PM

Just saw that Owl Astronomy has a brand new one for 179.95

#7 KWB

KWB

    Hubble

  • *****
  • Posts: 16312
  • Joined: 30 Sep 2006
  • Loc: Westminster,Co Elev.5400 feet

Posted 27 May 2011 - 02:52 PM

Just saw that Owl Astronomy has a brand new one for 179.95

Yep,with a warranty. Add a wooden tripod and the setup is useable.






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics