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Tamaya MS-733 manual
From: Doug Royer
Date: 2004 Oct 12, 09:57 -0700
From: Doug Royer
Date: 2004 Oct 12, 09:57 -0700
Alex, I stand corrected on my comments reguarding perp check procedures as stated in the Tamaya owner's manual that I wrote of yesterday. As for stating not moving one's head during the check/adjustment it appears that is one of my procedures.It is NOT stated in the manual. The following is taken directly from the Tamaya manual in reguards to front silvered index mirrors. "FRONT SURFACE MIRRORS If you need to replace your Index mirror with a mirror that is silvered on the front surface,the silvering will be located forward of the axis of rotation of the sextant arm.With this configuration,the normal method of useing the reflected arc will not be adequate.You will notice that as the eye is moved above the sextant,the appearance of the reflected arc changes.The only correct observation point is with the eyes on a level with the sextant frame itself.however,in this position,nothing of the reflected arc can be observed.Thus,the use of calibrating cylinders placed on the sextant arc is required.the eyes can then be positioned level with the top of the calibration cylinders. METHOD OF USE Lay the sextant on its side with the arc scale facing up upon a flat plane.Place the 1st cylinder upright covering the 0* mark on the sextant arc.Place the 2nd cylinder upright on the 110* mark of the sextant arc.Course adjust the index arm to 35* on the sextant scale.With your eye about 1 ft from the sextant,and looking between the horizon and index mirrors,observe the 1st cylinder.Now slowly move your head to the left untill the index mirror starts to obscure the left side of the 1st cylinder.At the same time you will notice the reflected image of the 2nd cylinder begin to appear where the 1st cylinder was.The result is what appears to be an image of 1 cylinder,but is actually a composite of both. To make adjustments for perpendicularity,move your line of sight to be level with the tops of the cylinders.Turn the adjusting screw on the index mirror frame untill the heights of the 2 cylinder images appear equal.You have now removed the error of non-perendicularity between the index mirror and sextant frame" So,I was incorrect in that there is a specified spot to place one's eyes as stated in the manual while doing this procedure.