NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Freiberger sextant (fwd)
From: Neil
Date: 2001 Nov 05, 3:16 PM
From: Neil
Date: 2001 Nov 05, 3:16 PM
Hello- Just joined the group. My name is Neil and live on Gwynn's Island in Virginia. Own and sail a Nicholson 32. I have 2 sextants, an old Leupold (which I have used off and on for the past 15 years) issued to the MM during wwII and one that I just purchased off of Ebay, a Freiberger made around the mid 70's. I went for a weekend cruise which gave me a chance to try the new sextant. I did an index mirror perpendicularity check. It looked fine, checked for side error and it too looked ok. I did not do a collimation check until I got home, and it was just a rough check. I am concerned that it may be off. I will come back to this in a moment. Saturday in the bay, I checked for index error, then took a morning shot. I only took one. My LOP was .8 nm from my DR so I felt good about the sextant. Sunday I decided to shoot a series of sights and the first 3, my LOP was off between 4 and 12 nm! I took the Leupold out, made a shot, LOP was .5nm from DR, tried again with the Freiberger and it was off again by many miles. Back home, I did the basic collimation and just wonder if the reflection of the telescope should be smack dab in the center of the mirror? I believe it is supposed to be. The reflection I see when the scale is set to zero is centered top to bottom but not side to side, it is over to the left. Could this cause the error I have. Is there an adjustment to correct this without taking it to a professional? I am going to do more testing in the mean time. Thanks- Neil