NavList:

Hi Jim

So tempting to get a Kollsman but without a decent mount alas bit wasted.

The Orion had a Kollsman and these were wonderful to use but very narrow field of view if I remember correctly, so relatively useless to find a dim nav star.

However, there was a great advantage. You calculated your 3 star fix and set the direction from true north as mount allowed exact setting. Set in dec and no matter how dim there was the star. But if it wasn't it was cloudy.

However, when I acquired my HP41CV and wrote a 3 star fix program I could calculate in 30 secs a now bearing and dec for any nav star set it and decide if this particular star would be it useful for a fix.

Often we had cloud above us even at 30k ft that was enough to obscure the weaker stars so you often had to pick and match.

The kollsman was brilliant for that. 

The beauty of a standard hand held view through an astrodome was if you knew your stars, which we did it was easy to just pick 3 approx 120 deg apart and shoot them then calculate after.

The HP 41CV made that brilliantly easy.

Howard H

-------- Original message --------

From: Jim Rives <NoReply_JimRives@fer3.com>

Date: 1/4/22 10:47 (GMT+10:00)

To: Howard George <HHG@raptorbusinessservices.com.au>

Subject: [NavList] Re: Kollsman Periscopic Sextant for sale