In “Measuring Radio Frequencies” [Sep 2009, pp 36-39] the description of vernier operation in Improved Measurement Precision was not quite correct. It should have said that the 10 divisions of the vernier scale were equal in length to nine divisions of the main scale, thus allowing the subdivision of each main scale division into tenths. In Figure 3, the correct reading is 60.4. Thanks to Al, NW2M, for picking up the error.