The Hewlett-Packard Model 608C VHF Signal Generator is a general purpose test instrument which furnishes accurately adjustable r-f signals from 0.1 microvolt to 1 volt over the frequency range from 10 to 480 megacycles. The output signal may be amplitude modulated by internally generated sine waves or by externally applied sine waves or pulses. The output signal level is adjustable by an attenuator calibrated in both volts and dbm and can be read directly to an accuracy of ±1 db over the full frequency and attenuation range without the use of external pads, monitoring devices, or charts. The 608C features a very wide frequency range, high output, and straightforward operation through the use of reliable, direct-reading controls and meters. The Model 608C Signal Generator is designed for general applications in the 10- to 480-megacycle frequency range, such as testing, calibrating, and trouble shooting VHF radio equipment and circuits. In conjunction with other test equipment, the 608C is useful for measuring standing wave ratios, antenna and transmission line characteristics, receiver sensitivity, etc. To obtain best accuracy in these applications, care has been taken to hold spurious modulation from the generator to a very low value.