The Hewlett-Packard Model 3320A/B Frequency Synthesizer provides accurate and stable frequencies from 0.001 Hz to 12.9999 MHz. Frequency selection is by three controls that provide three digits of resolution plus an overrange digit, and a vernier control that provides two digits of resolution. A range control provides five ranges of 1000 Hz, 10 kHz, 100kHz, 1000 kHz, and 10 MHz. The output frequencies are derived from a precision single frequency source by an indirect synthesis technique. 1-8. In the 3320A, the output amplitude is selected by a 0-13 dBm continuous potentiometer. Maximum output voltage is I V rms into 50 Ω. The 3320B has a range of +26.99 dBm to -{)9.99 dBm with a resolution of 0.01 dB. The output amplitude can be selected in steps of 0.0 I dB, 0.1 dB, 1.0 dB, or 10 dB. Maximwn output voltage of the 3320B is 5 V rms into 50 Ω.