NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2015 Jun 25, 14:24 -0700
Marty, you wrote:
"The calibration table in the box lists all zeros for every 15 deg. Not sure if it is believable."
I would say that it is not believable. It was mostly a marketing gimmick at that point in time.
And:
"I won't call this my knock-about sextant, but it does let me keep my nice 1953 C. Plath in the closet."
Well, then, here you've got a way of testing this hypothesis. Set up your artificial horizon, leveled as best as possible, and then try shooting a dozen sights with the Tamaya-like followed immediately by a dozen with the C. Plath. Repeat a couple of times as the Sun's altitude changes, maybe once every 90 minutes. If you're showing a systematic offset with both instruments, then you can look for a common cause, probably the tilt of the A.H. But if the Plath is more or less dead-on while the Tamaya shows a systematic offset that varies with altitude, then you've got some confirmation that the residual error is "arc error".
Frank Reed
