NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: AN-5851-1 Repair
From: Dave Harwood
Date: 2011 Nov 27, 00:49 +0000
Greg,
I agree, I think I'll just live with the shutter issue if I can otherwise avoid a tear down.
I found the adjustment you described. My concern is that if I make this adjustment it may result in the averaging counter reading off. My logic is that the counter currently outputs precisely what is on the micrometer drum readout after the two minute run. If I change the "reference ring" without a corresponding adjustment to the gear train my counter will no longer agree with my micrometer drum.
If my concern is unfounded, I shall make the adjustment. If it is valid, I think I'll leave well enough alone.
Is there any problem with simply applying the correction as index error? Would such a large value of -17 cause discrepancies in sight reduction?
Thank you for your time and photo's.
Dave Harwood
From: gregrudzinski@yahoo.com
To: NavList@fer3.com
Date: Fri, 25 Nov 2011 09:00:03 -0800
Subject: [NavList] Re: AN-5851-1 Repair
Dave,
I have a Navy MK V and enjoy using it for both bubble and natural horizon observations. I wouldn't worry about the shutter issue. You should know that the averager needs to be fully wound so that the shutter gets retracted from view before an observation is made. On index error first try adjusting the micrometer ring. Loosen set screw then rotate to correct reading. Tighten set screw but not too tight. Be sure the ring is up off the micrometer drum or it will rub and bind during rotation. (see images). Set the ring for your intended use bubble or natural horizon. Synchronizing the bubble and natural horizon requires adjusting the prisms which can be difficult. I don't think the prisms should be fooled with unless you are familiar with how they adjust.
Greg Rudzinski
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From: Dave Harwood
Date: 2011 Nov 27, 00:49 +0000
Greg,
I agree, I think I'll just live with the shutter issue if I can otherwise avoid a tear down.
I found the adjustment you described. My concern is that if I make this adjustment it may result in the averaging counter reading off. My logic is that the counter currently outputs precisely what is on the micrometer drum readout after the two minute run. If I change the "reference ring" without a corresponding adjustment to the gear train my counter will no longer agree with my micrometer drum.
If my concern is unfounded, I shall make the adjustment. If it is valid, I think I'll leave well enough alone.
Is there any problem with simply applying the correction as index error? Would such a large value of -17 cause discrepancies in sight reduction?
Thank you for your time and photo's.
Dave Harwood
From: gregrudzinski@yahoo.com
To: NavList@fer3.com
Date: Fri, 25 Nov 2011 09:00:03 -0800
Subject: [NavList] Re: AN-5851-1 Repair
Dave,
I have a Navy MK V and enjoy using it for both bubble and natural horizon observations. I wouldn't worry about the shutter issue. You should know that the averager needs to be fully wound so that the shutter gets retracted from view before an observation is made. On index error first try adjusting the micrometer ring. Loosen set screw then rotate to correct reading. Tighten set screw but not too tight. Be sure the ring is up off the micrometer drum or it will rub and bind during rotation. (see images). Set the ring for your intended use bubble or natural horizon. Synchronizing the bubble and natural horizon requires adjusting the prisms which can be difficult. I don't think the prisms should be fooled with unless you are familiar with how they adjust.
Greg Rudzinski
----------------------------------------------------------------
NavList message boards and member settings: www.fer3.com/NavList
Members may optionally receive posts by email.
To cancel email delivery, send a message to NoMail[at]fer3.com
----------------------------------------------------------------