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Old 23-10-2009, 21:10   #1
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Challenge: Old School, New Think Sextant

Back in the seventies (I'm an old fart) there was a Time Magazine article abot someone who was going to build a sextant with a chronometer built into the handle. This never came to market, and with GPS, probably will never do so, as well. I'd like to hollow out the handle on one of my sextants and build a pushbutton to "mark" my own sights. Does anyone know of chronometer kits that could do the job?
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Old 23-10-2009, 21:24   #2
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Does anyone know of chronometer kits that could do the job?
Buy a watch with a timer. At a specific time about when you are taking a sighting start the timer. Stop it on the moment of the sighting and do the subtraction. Timers are easy to find. Chronometers are expensive.
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Old 23-10-2009, 21:37   #3
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I just use a stopwatch. Start the clock when you mark the site, then stop it when you are recording the sight. Subract the run time of the stop watch from your chronometer reading.

I think my sports stop watch cost me $20 or so.

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Old 23-10-2009, 21:46   #4
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It's not difficult to manipulate the sextant and a stopwatch at the same time. Note the time and the elapsed time since the sight and you can take a whole string of sights and calculate back to the exact time of each sight at your leisure.
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Old 23-10-2009, 22:48   #5
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I just thought of sewing up an elastic sleeve with loops on it for mounting a digital watch that slips on over the sextant handle.

Position the watch/sleeve so that I can push the chronometer button on the watch to mark the fix with the hand holding the sextant.

This way I don't have to modify the sextant.
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Old 24-10-2009, 00:28   #6
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... a sextant with a chronometer built into the handle. ... and build a pushbutton to "mark" my own sights. Does anyone know of chronometer kits that could do the job?
Put a wireless mic into a ziplock poly bag, under your shirt; start a recording on any kind of device that can pick up the mic; speak the time when convenient; go on deck and start taking sights ~ dictating the information and saying 'Mark' or 'Now' for the time.

Improvements to the system will soon happen as you practice. Within a year you will already have the sight reduced by Excell Macros and voice recognition: as you get back to the chart table.
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Old 24-10-2009, 07:46   #7
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Celestaire sells a mount for a KVH Data Scope that allows one to use that to record both the time of a site and the bearing. With this one can take several sites in close order. For this I use a voice activated tape recorder to record the site and with the KVH I can cycle through the times of each site and the bearings at the chart table. The bearing lines are a good check on the azimuth from my own calculations.

The KVH also has good applications off the Sextant.

See KVH DataScope Handheld Compass and Rangefinder

FWIW...

s/v HyLyte
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Old 24-10-2009, 10:20   #8
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Oop's! Just realized I omitted this from the foregoing post. See KVH Data Scope | Sextant Accessories | Celestaire, Inc.
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Old 24-10-2009, 19:56   #9
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I WANT TO DRILL A HOLE IN THE BASE OF THE SEXTANT HANDLE, DRILL ANOTHER FOR A BUTTON AT THE INDEX FINGER, AND INSTALL SOME OFF-THE-SHELF ELECTRONICS. ANYONE HAVE A SOURCE FOR THIS TYPE OF ELECTRONIC COMPONENT ON THE WEB? I'VE DONE THE TRADITIONAL STUFF. I WANT TO MAKE A ONE-OFF UNIT FOR MY PERSONAL PLEASURE, NOT TO PRODUCE FOR A MICRO-MARKET OF OLD SALTS WITH 21ST CENTURY FANTASIES.
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Old 24-10-2009, 20:00   #10
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I JUST CHECKED OUT THE DATASCOPE. PLEASE ACCEPT MY PROFUSE APOLOGIES. I THINK THIS UNIT WILL FULFILL MY ECCENTRIC PROCLIVITIES. THANK YOU svHyLite!!
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Old 28-03-2010, 02:07   #11
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sv HyLyte, Been looking for a good navigation supply site for ages, what a beauty, they have the supplies I was looking for, Thanks for the heads up
Jeff
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Old 28-03-2010, 06:17   #12
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Is there a stop-watch that can be controlled by voice? Could be the thing to have.

b.
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Old 30-07-2010, 05:44   #13
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Hi,

My brother & myself did a trip from the UK to the West Indies & back 1976-77. We held a 2 inch diameter stopwatch at the back of the sextant handle & the moment the site was right just started the stopwatch. It worked a treat. In the West Indies we used Stars as the Sun was too high & not easy too use. We had a Star finder & would go out & shoot 3 or 4 stars we did not know the name of, use the star finder to identify them & do the calcs & end up with a nice cocked hat, very satisfiying.

All the best,

Brian.
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Old 12-01-2014, 12:00   #14
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Re: Challenge: Old School, New Think Sextant

Watched Celestrial Navigation video by William F Buckley many times (on Netflix) and took copious notes. I have not gotten a real sextant to try it out.

I had tried the sextant app on my iPad several times and it worked fairly well by mapping it close to my location. Look forward to trying it out.
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