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Two Moonset times in the ...
Forum: General Topics Here
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Old no-plotting method ...
Forum: The Sight Reduction process
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Hello
Forum: The Sight Reduction process
Last Post: PeterB
11-23-2023, 09:39 PM
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Electronic Charts: New Bo...
Forum: Equipment- Wanted or for Sale
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assumed longitude
Forum: General Topics Here
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What Is Your Favorite Wat...
Forum: Equipment- Wanted or for Sale
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Camp Runamuck- TV show
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Help With an Exam Questio...
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USCG Crazy Exam question:...
Forum: General Topics Here
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05-05-2023, 09:48 PM
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How to get LHA and Ap lon...
Forum: General Topics Here
Last Post: Fred_B
04-29-2023, 11:16 AM
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Davis Mark 15 & 25 |
Posted by: BigBill - 03-05-2018, 01:20 AM - Forum: General Topics Here
- Replies (5)
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![](https://thenauticalalmanac.com/Forum/uploads/avatars/avatar_82.jpg?dateline=1489856344) |
I was wondering if the Mark 25 "beam converging" mirror can be retrofitted to the Mark 15.
Davis says the split mirror of the Mark 15 can be fitted to the 25. The dimensions for the replacement parts are similar but not exactly the same. Maybe the reverse is not true. Would anyone happen to know?
I may end up getting a mark 25 anyhow if one pops up on ebay in my price range, in the meantime changing out the mirror might be an economical option.
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AP in the east. |
Posted by: wannathermal - 03-03-2018, 02:51 PM - Forum: The Sight Reduction process
- Replies (17)
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![](https://thenauticalalmanac.com/Forum/images/default_avatar.png) |
I think the instructions for Sight Reductions needs to have something like the following:
* Assumed Position for east longitude use DR longitude integral degree plus 60'-GHA minutes for the minutes, If you are at 35° east and the GHA minutes are 33' then AP is E35° 27' (60'-33'=27')
The instructions work for West.
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Filters |
Posted by: Speicus - 02-17-2018, 03:21 PM - Forum: General Topics Here
- Replies (6)
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![](https://thenauticalalmanac.com/Forum/uploads/avatars/avatar_81.png?dateline=1518902073) |
What do sextant filters filter?
I think this is an important question when looking at the sun. If only visible light is filtered, my pupil widens and lets all ultraviolet through, like with low quality sunglasses. This will harm my eye.
Mine is a second-hand Freiberger sextant - I cannot find any specifications. Does anybody have any information?
Regards
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Just trying to be nice |
Posted by: Rumata - 12-22-2017, 07:14 PM - Forum: General Topics Here
- Replies (3)
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![](https://thenauticalalmanac.com/Forum/images/default_avatar.png) |
Merry Xmas and Happy New Year to all of us. Looks like we're still holding the fort. Good job we're doing.
Toast:
To all of us, members of Celestial Navigation Forum. May we keep sanity in the world which can't live without extra battery. Let's drink!
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A,B, P etc |
Posted by: BigBill - 11-12-2017, 04:35 PM - Forum: General Topics Here
- Replies (5)
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![](https://thenauticalalmanac.com/Forum/uploads/avatars/avatar_82.jpg?dateline=1489856344) |
Does anyone know or have a link that explains what exactly the values for A,B, F, P etc represent in a sight reduction?
I was asked recently and I know anything with H has to do with altitudes and the Zs are azimuths but the rest I don't know with enough certainty to pass on.
Thanks
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Analog or Digital time display |
Posted by: LouisC - 10-21-2017, 01:13 AM - Forum: General Topics Here
- Replies (2)
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![](https://thenauticalalmanac.com/Forum/images/default_avatar.png) |
Do you have a preference for time display?
Which do you like better? Analog or digital?
Do any of you use mechanical watches (not quartz)? Now wouldn't it just be nice to have a Rolex GMT Master?!
In desperation I've searched the web to hear the sound of a Rolex or Piaget ticking but haven't found anything!
Louis
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