Standards, synthesizers and frequency comparators

Standard frequencies - high stability frequency source electromagnetic signals (the radio or optical). frequency standards are used as secondary or working standards in metrological measurements as well as the manufacture of high-precision measurement of frequency and time, in navigation, astronomy, and other frequencies sferah.Sintezator - a device for generating electrical harmonic oscillations via line repetition (multiplication, summation , difference) from one or more reference comparator generatorov.Chastotny - means for comparing the frequencies of the two sources of high stability. A particular kind of frequency comparators are phase comparators, there are also comparators-receivers, allowing to compare the frequency verified, calibrated measure of frequency, transmitted via the reference radio.