TM 9-6695-274-14
Figure 1-15. Hewlett-Packard, Model 8640B, VHF Signal Generator.
Hewlett-Packard, Model 8640B, Signal Generator (fig. 1-15) covers the frequency range from 500 kHz to 512 MHz (450
kHz to 550 MHz with band overlap) and can be extended to 1100 MHz with an external doubler, Hewlett-Packard, Model
11690A. This solid state generator has an output level range of +19 to -145 dBm (2 V to 0.013 microvolts) and is
calibrated, metered, and leveled across the full frequency range of the instrument.
Figure 1-16. Hewlett-Packard, Model 11690A, Frequency Doubler.
Hewlett-Packard, Model I 1690A, Frequency Doubler (fig. 1-16) extends the frequency range of all Hewlett-Packard, Model
8640 Series Signal Generators by doubling the 256-512 MHz frequency band up to 1024 MHz. All model 8640's indicate
the correct doubled output frequency on a dial or counter when the 512-1024 MHz range is selected. The Model 11690A
will also perform well with any source meeting the input requirements of 200-550 MHz at +10 to +19 dBm.
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