Skip to Main Content
A description is given of a direct-reading frequency-measuring equipment which enables precise frequency measurements between 30 cps and 30 mc to be carried out in one second. The measuring device itself consists of an electronic counter ranging from 30 cps + 1 mc, an instrument giving multiples of 1 mc in the range from 1 + 29 mc and a combining part. The whole has only one knob, namely, that for choosing the desired multiple of 1 mc. The result of a measurement is indicated on the electronic counter and on the knob. When taking a series of measurements, the results are printed on a normal page printer, one measurement every two seconds. If desired, a continuous recording instrument may be used for the registration of every two out of the six figures of electronic counter. The accuracy when making a measurement in one second equals the precision of the second impulse derived from the frequency standard (10-7 to 10-8) plus or minus 1 cps. To enable measurements on far-off telephone or telegraph transmitters to be made, the equipment is completed with a receiver, ranging from 5÷30 mc. In this case the accuracy is somewhat less. The maximum deviation is, however, always below plur or minus 5 cps.