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It would be an interesting adventure (to have someone else take).  I have
used and gotten reasonable results with a Davis MK 25.  BUT - I usually
took multiple measurements and averaged - you may not have time to do that
for LD or else the calculations (LD at different times) would become
complex (not sure if averaging is applicable here)

Several precautions:
1) Allow the MK25 to come to ambient temperature
2) Be aware that the MK25 has a large backlash and tends to bind depending
on temperature.
3) ALWAYS measure the LD and IE from UPscale to DOWNscale - otherwise
backlash will make your measurements very inaccurate.
4) If you go passed the coincident point - do NOT reverse direction
without going back at least an arc-minute or so to eliminate problems
related to backlash.

Good luck


On Wed, February 20, 2019 10:31, Herman Dekker wrote:
> After reading about Lunars. I am interested in this subject, but the
> available instruments are doubtfull. I am surrounded here with mountains.
> If I want to do a lunar the objects must be above 12°.
> From Franks easy Lunars info I understood minium height is 15°so thats no
> problem. For the heights I can use the A-12 bubble sextant, but for the LD
> only the Davis MKIII is available. That sextant has a scale division of
> 2', with a magnifier glass, you can read and interpolate to 1'.
> Is that possible for a Lunar if you have lost accurate time, or is it a
> useless excercise. Regards,
> HermanD

   

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