The E2 signal generator has a wide frequency range from 100kHz to 1OOMHz and an accurate attenuator system. It is designed to provide a degree of accuracy sufficient for all practical purposes in the measurement of selectivity and sensitivity in radio receivers. Provision is made for external modulation with low power input up to 10kHz, as well as for 400Hz 30% internal modulation, The frequency range covers the sound broadcasting and band 1 television frequencies on fundamentals.