See Flexible Log Scale
http://www.tushar-
mehta.com/excel/newsgroups/flexible_log_scale/index.html

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Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
Custom MS Office productivity solutions

In article , howie1
@discussions.microsoft.com says...
My chart has y-axis values on a scale from 10 to 100 in increments of 10 per
each tic. When I set the scale to logarithmic, the only two tic values left
appearing on the axis are 10 and 100. How do I get the values 10, 20, 30,
..., 100 all to appear on the axis?