# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

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Re: Tamaya NC-77 Almanac
From: Stan K
Date: 2017 Apr 30, 16:46 -0400
Gary,

Using the suggested fix, I just tried 30 April 2017, 12-00-00 UT.  Here's what I got:
NC-77        USNO
GHA Aries         38º37.2'       38º37.2'
GHA Sun            0º42.0'        0º42.2'
Dec Sun            14º55.0'N    14º54.9'N

So the dec of the Sun is off by 0.2'.

Here are the results for 30 April 2025
NC-77        USNO
GHA Aries         38º41.0'       38º41.1'
GHA Sun            0º42.2'        0º42.4'
Dec Sun            14º56.3'N    14º56.3'N

If the results are typical, then this is a pretty good fix.  However, the NC-77 is still a bit of a pain to use.  And the fix is only good for the Sun; all other bodies require extracting data from the Nautical Almanac.

Stan

-----Original Message-----
To: slk1000 <slk1000@aol.com>
Sent: Sun, Apr 30, 2017 2:37 pm
Subject: [NavList] Re: Tamaya NC-77 Almanac

Tamaya almanac trials every five years after Y2K to 2050 using the year minus 1900 seems to work good. The largest error observed was a 2025 Sun GHA off by 0.3' and GHA Aries and Sun declinations off by no more than 0.1'.
This looks to be the best fix so far for this classic navigation calculator's ailment. The more interesting question would be how this fix works with the almanac function to get very close results ?
Greg Rudzinski
From: Greg Rudzinski
Date: 2017 Apr 28, 10:13 -0700
It was suggested to me just today to try entering the old Y2K impaired Tamaya NC-77 almanac function using the current year minus 1900 to get reasonably good data out of it. I will be trying this on some sights to see how accurate the Sun and Aries values compare to USNO.
I had been using the Kolbe LTA quad values with success to correct the NC-77 years 1996 through 1999 with good success. If this other method holds up then it will revitalize the great vintage Tamaya NC-77 to it's full function.
Greg Rudzinski
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