Fun day on the deck

[BigBill]

I spent a nice sunny day today plotting some sights I took of Arcturus and Jupiter the other night and then a sun sight today. They all plotted exceptionally tightly for my bubble sextant.
 And since I had nothing better to do and hadn't shot the moon in some time, I dug out some old moon sights from a few years back and re-figured them.
 When I originally shot them, I was at a friend's place in the country and took a quick opportunity to 'get the moon' as I hadn't done that yet. I didn't quite know how to do the moon sight reduction then or the v correction so it was nice to go back and re-do them and brush up all at once. To complicate things more, I had an unknown amount of index error at the time and was trying different numbers to try and get an average. So today I plugged in what I know to be the correct IC and it was good to see all the LOPs move in the right direction and get 'tightish' on the location I had been at when I took the sights. 

Ahhh, fun times, lol.

[LouisC]

BigBill,

What's it like to take a sight through a bubble sextant? Must you hold very still to keep the bubble in the center of the circle?

Lou

[BigBill]

I have a Link A12 made for use in aircraft. It's not too bad but I find it best to be sitting when I take a sight and I do everything slowly otherwise I end up trying to chase the sun, star etc and moving around. If I'm careful, once it's in the bubble things settle down.

[P.Rutherford]

Bigbill,

Do you use the recording drum on the A12? I know there is one but I've never known how they work.

Paul.

[BigBill]

Bigbill,

Do you use the recording drum on the A12?  I know there is one but I've never known how they work.

Paul.

I don't. In fact I remove it since it falls off easily and chips.
The drum was intended to mark multiple sightings of the same body in a short time allowing you to go back later and average them. There is a pencil lead on the sextant that you press to do this. Normally there are 2 or 3 drums so you can take your sightings on different bodies at the same time using a different drum for each. You would have to have the index set at a known start point, later you put the drum back on and rotate it until the pencil lines match up and read each sight off the index.
I just skip the drum and record each sight individually without averaging.

Bill