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Captain Magenta

SW 300p secondary mirror size

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If anyone has one of these, the solid tube Sky-Watcher 305mm f/4.9 Newtonian as pictured below, could you perhaps kindly let me know what the size of the secondary is please? Minor axis.

My 300p is in Ireland and I’m not there until Christmas so I can’t measure it myself...

Thanks in advance...

Magnus

 

71E6A59E-BB94-419E-B901-9C9A7BBA97EE.jpeg

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Thanks both. I’ve seen SW’s current Dob specs at 70mm, but there’s nothing “out there” that definitively states the dimensions for their solid tube any more. But the GSO also at 70mm strengthens the case...

 

Edited by Captain Magenta

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7 hours ago, Captain Magenta said:

Thanks both. I’ve seen SW’s current Dob specs at 70mm, but there’s nothing “out there” that definitively states the dimensions for their solid tube any more. But the GSO also at 70mm strengthens the case...

 

Hi Magnus,

I've just been out and measured my SW 305mm F/4.9 Flextube Dob secondary and it is 70mm wide.

Not a solid tube I know, but the specs are identical to yours, so must surely be the same.

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5 hours ago, Geoff Barnes said:

Not a solid tube I know, but the specs are identical to yours, so must surely be the same.

Thanks. I’d be surprised if it were different from 70mm, would just be nice to have it confirmed by someone with the identical scope...

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Telesope Express gives these specs for the 300pds so I’d be surprised if your secondary is different.

Aperture: 12” - 305mm
Focal length: 1500 mm
Focal ratio: f/4.9
Mirror: Parabolic primary mirror - substrate is Pyrex
Secondary mirror: Diameter 70 mm minor axis
Edited by johninderby
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