Agilent 1957-04 free download

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HEWLETT-PACKARD JOURNAL TECHNICAL INFORMATION FROM THE -dp- LABORATORIES Vol. 8, No. 8 H.ISHED BY THE HEWLETT-PACKARD COMPANY, 275 PAGE MILL ROAD, PALO ALTO, CALIFORNIA APRIL, 1957 A 250 CPS-100 KG Oscillator For High Stability Applications THE general family of -hp- audio oscilla will be seen that during this time the output tors has always been known for stability, frequency remained within a band about 5 but included in this family is one oscillator cps in width. The instrument was operating to which extra measures have been applied from an unregulated power line which did, to obtain added stability for specialized work however, remain within a few volts of its such as telemetry. This instrument is rated average value. as being stable with At other frequencies within the instru SEE ALSO: How 200F stability was in 20 cps per hour at ment's range the percentage stability is often plotted automatically, p. 3 Increased low-frequency 1 00 kc after warmup even higher. Fig. 3, for example, shows the accuracy for counters, p. 4 and, of course, is gen stability at 10 kc. Note that the scale has been erally noticeably better in a typical case. As changed in this curve and that the frequency a result, the instrument is especially suited remained within a band only 0.2 cps or to high-selectivity work such as checking 0.002% in width. the response of narrow-band filters and test The key to the use of the Model 200T is ing selective amplifiers. provided by the curve shown in Fig. 4. This Fig. 2 shows a typical stability character is a typical warmup characteristic for the istic for the instrument when operating at instrument when operating at 100 kc at its highest frequency of 1 00 kc at room tem room temperature. In the first hour of warm- perature after warmup. This curve encom up the output frequency changed about 118 passes a half-hour's operating ti