Agilent 1956-02 free download

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HEWLETT - PACKARD JOURNAL TECHNICAL INFORMATION FROM THE -dp- LABORATORIES Vol. 7 No. 6 BLISHED BY THE HEWLETT-PACKARD COMPANY, 275 PAGE MILL ROAD, PALO ALTO, CALIFORNIA FEBRUARY, 1956 Three New -hp- Audio Oscillators YEAR after year the simple, reliable -hp- ing of the frequency dials. Rotary switches use R-C audio oscillator remains one of the bar type knobs for ease of switching. work horses of the electronics laboratory. The /. HIGH-OUTPUT HIGH-QUALITY AUDIO Hewlett-Packard Company has always taken TEST OSCILLATOR (20 CPS-20 KC) special pride in the R-C oscilla The new Model 20 1C oscillator at the left in tor and has always striven to Fig. 1 is designed for testing higher-quality see that suitable R-C oscillators audio systems. The instrument operates over are provided for every purpose. the range from 20 cps to 20 kc and provides a The three oscillators shown in Fig. 1 are evi maximum of 3 watts into a 600-ohm load. Dis dence of this program. These oscillators are re tortion in the output is less than 0.5% at levels designs which have been made of three popular below 1 watt and less than 1% at levels up to -hp- instruments to incorporate in these instru 3 watts. ments the latest electrical and mechanical fea The output circuit is designed so that the tures of the -hp- line of oscillators. Electrical instrument can be operated either as a low features are described in detail below. Mechani source-impedance device or a 600-ohm source- cally, the instruments are lighter in weight than impedance device. Fig. 2 shows the output cir their predecessors and are housed in new, cuit arrangement. The output transformer smaller, more attractive cabinets. The fre feeds through a precision bridged-T attenuator quency dials are all provided with high-ratio to the output terminals. To permit the instru