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Home > Classifieds > Astromart Classifieds > Telescope - Reflectors > Classified #286230

For Sale: 12.5" F/4.8 Portaball with Strehl=.991

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12.5” f4.8 Aluminum Sphere Portaball with a superb Zambuto mirror

Some information on the optics:
My wife fell in love with this scope at a star party in 2001 and we bought it. The mirror coatings had some imperfections from poor cleaning and we asked Carl Zambuto if he would check and refigure if needed. The re-figured mirror he created has an astonishing figure with a Strehl ratio of .991 and a Wavefront RMS is 1/68th wave. The secondary2.6” also nearly perfect, both mirros with center dots.

The overall condition of this scope is excellent. But of greatest importance, this Portaball has outperformed every 12.5” telescope any of us here in Flagstaff have ever looked through, period, and there are some professionals here in Flagstaff that know their business.

There are no electrics added to this scope. Cooling is apparently not a problem, judging by the 20 people usually standing in line to view the planets through this scope. We have had many scopes, including a couple of observatory models. The relationship with a Portaball is very different than with any other scope. It’s the most convenient and “happy” scope we’ve ever used. It becomes a part of you when observing and is so comfortable to use, you feel nearly a part of it, much different than a dobsonian or newtonian. It just wouldn’t be the same with electrics all over it.

In the photo note:
8x50 University right angle finder with helical focuser (Required rebalancing the sphere weights).
• Celestron red dot pointer
• NGF focuser
• Light shield
• The papers attached to the scope are a table of magnifications, and filter data for looking at the planets

Not visible in the photo are the following:
• Light shroud
• Space age silver scope cover
• 2 mirror covers, a heavier “storage” one and a very light one for star parties
• Pole container

The Portaball will shipped in the carton that we use to take it to star-parties, a U-Haul 24”x24”x24” with 1” of foam all around inside, but I’ll double box it for shipment to keep it safe. We have all the manuals and letters from Peter Smitka, and some articles on the scope.

Lastly, why are we selling it? Those who have already bought some of our things know my wife has macular degeneration. She cannot use this scope anymore. There are others things we will enjoy doing together.

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