L A B O R A T O R Y I N S T R U M E N T S OF S P E E D A N D A C C U R A C Y
Standard -hp- instruments shown here are adaptable for making nearly every electronic measurement in the electronic field. Following is a brief description of a few o these instruf ments. Complete technical information will be sent- without obligation - on request. In addition, -hp- engineers are at your service to help solve special problems.
VACUUM TUBE VOLTMETER
-hp- Model 400A Vacuum Tube Voltmeter sets a MW standard of performance for voltage measurements in the audio, supersonic. and lower radio frequency region. Measurements up to 1 megacycle with this instrument are as simple as measurements with the usual multi-range meter a t d-c. Nine ranges give full-scale sensitivities from ,030t o 300 volts. Ordinarily no p r e cautions whatsoever are required: turn-over effect and waveform errors are minimized: there are no adjustments to make during operation: a large overload will not damage the instrument. The input impedance is I megohm so that most circuits will not be disturbed when their voltage is measured.
WIDE-BAND AMPLIFIER
-hp- 490A Amplifier is a new, versatile. wide-band amplifier designed for general laboratory or production use. I t provides exceptional stability a t 40 or 20 d b gain. and gives new freedom from spurious responses. ow phase shift is assured by a straight forward. reresistance-cou led amplifier design, together with inverse feed back. Frequency response is flat within 'z d b / between IO and 1,000,000 cps. Varying tube voltages or aging tubes have no appreciable effect o n the gain or other characteristics. When used in conjunction with -hp- 400A Vacuum Tube Voltmeter. i t increases voltmeter sensitivity 100 times.
AUDIO SIGNAL GENERATORS H-F VACUUM TUBE VOLTMETER
-hp- 410A. High Frequency Vacuum Tube Voltmeter combines in one instrument a n ac voltmeter covering frequencies from 20 cps to 700 mc. a dc voltmeter with 100 megohms input impedance. and an ohmeter capable of measuring resistances from .2 ohms to 500 megohms. The special probe places a capacity of 1.3 uufd acrose the circuit under test. Input resistance for ac measurements is 6 megohms. Six voltage ranges provide fullscale sensitivities from I to 300 volts.
-hp- Audio Signal Generators are designed for timesaving performance. They are excellent for laboratory applications because they supply a voltage as well as a known frequency a t the commonly used impedance levels. They are particularly suitable f o r gain measurements because no auxiliary a paratus
is required. They provide an excellent source of for distortion measurements because their waveform distortion is very small.
voltage
HARMONIC WAVE ANALYZER RESISTANCE-TUNED AUDIO OSCILLATORS
-hp- Resistance-Tuned Oscillators are suitable for almost every type of work. Their low distortion makes them particularlyvaluable in making distortion measurements on audio amplifiers. broadcast transmitters and other equipment. They provide a n excellent source of voltage for accurate bridge measurements. The output is suffcient to drive signal generators and other e q u i p ment requiring considerable power, Their wide frequency range also makes them suitable for work in the supersonic region. -hp- Model 300A Harmonic Wave Analyzer is a n excellent where accurate and laboratory and production work instrument for both rapid measurement of individual components of a complex wave is required. The maximum selectivity is sufficient for measurement of harmonics of frequencies as low as 30 cycles and i t can be varied 'over a wide range. With this variable selectivity feature. measurements a t higher frequencies can be made more rapidly. yet with no sacrifice in accuracy.
DISTORTION ANALYZER
This Model 330B Distortion Analyzer is -hp-'s newest. finest distortion measuring instrument. I t is capable of measuring distortion a t any frequency between 20 cps and 20,000 cps. It will make noise measurements of voltages as small as 100 microvolts. A linear r-f detector makes it possible to measure these characteristics directly from a modulated r-f carrier. The hi h sensitivity. ,stable accuracy and compactness of 330B ma e it extremely valuable for broadcast, laboratory and production measurements.
