I have just completed a restoration manual for the A 10 series of bubble sextants. This manual with over 100 pages and 95 labelled photographs, takes you step by step through dismantling and overhaul of this popular World War II sextant series. It goes into particular detail on overhaul of the optical system, giving several methods of restoring the bubble chambers. This is not a re-hash of the official manual but a thoroughly practical overhaul manual. If there is life left in your A 10 or A10 A, this manual will help you get it back into working order.
It is available as a pdf download for US$18.50 or, to order and for an extra $4 to cover production and postage, as a CDROM. Your in-box will need accommodation for 7.16 MB.
I have also revised my very first manual, a restoration manual for the British Mk IX series, and it too is available as a pdf download, for US$17.50. It has 98 pages and 65 labelled colour photographs and diagrams. Your in-box will need space for 4.5 MB. Allow an extra $4 if you want it as a CDROM.
To give you a taste of the manuals, here’s a typical illustration from the A 10 series manual, followed by one from the Mk IX series manual:
Contact me if you wish to buy one or both of these manuals. Alternatively, send the correct sum via PayPal to nzengineernz@gmail.com with a short note of which manual you wish to buy.
The Nautical Sextant 
I’ve always been interested in using sextants, however, I recently came across an A-10A in disrepair that was begging to be given a second chance at life. Not being sextant repair savvy, I purchased the A-10 repair manual. It was the best decision I could have ever made! It’s more than a simple “nuts and bolts” guide to tear down and repair. It is full of the author’s personal tips and tricks that were absolutely instrumental to the successful repair of my seized A-10A. This manual is a must buy!
Dave Harwood
Went through the overhaul process after several reads of the manual. The process stalled when blows could not could budge the main taper bearing. Into the oven with it and it gently gave away with some persuasion from a small arbor press. I would make more special tools the second time around.
It’s interesting to note that most of these A10A sextants were sold by Edmond Scientific in Barrington, NJ, USA, in the late 50 and early 60’s. Some were donated to public schools and sat in the physics department. I saw an ad offering one for sale at $12.50 in an old Popular Mechanics (1959) magazine. Needless to say, folks value them more today.
I took a Sun shot today with my A10A and aside from being uncalibrated, it performed well and brought back memories of using it many years ago as a transport pilot and trained navigator.
The most interesting part of the restoration for me was the bubble chamber. I never really knew how this “thing” worked and it was great to master that after 40 years.
George Anderson, Baltimore, MD