The 8643A signal generator has been optimized to provide the performance required for out-of-channel receiver tests while maintaining a low price. Many performance capabilities have been included as standard, such as pulse modulation. Reliability is enhanced by an electronic attenuator on the 1 GHz version. Instead of mechanical relays, the 8643A uses solid state components accurate to within 1.0 dB for setting levels. An advanced internal modulation synthesizer provides coverage to 400 kHz and two-tone capability with the selection of sine, square, triangle, sawtooth, and white Gaussian noise waveforms.