Equipment information

General Radio Company 760-B Analyzer
Manufacturer:
Model:
760-B
Date:
1953
Category:
Group:
Description:
Sound Analyzer

Information

The Type 760-B Sound Analyzer is intended primarily for use with the Type 1551-A or Type 759-B Sound-Level Meter to separate complex sounds and noises into their various frequency components. It is also useful as a general-purpose laboratory harmonic analyzer, and can be used as a frequency- selective bridge detector for audio frequencies. The band width of the Analyzer is a constant percentage of the frequency to which the Analyzer is tuned. Frequency Range: Calibrated directly in cycles per second from 25 to 7500. This total range is covered in five complete turns of the tuning knob, the ranges on the various dial rotations being 25 to 75, 75, to 250, 250 to 750, 750 to 2500, and 2500 to 7500 cycles. A push-button switch allows immediate change of the main control to any one of these ranges. Frequency Calibration: The accuracy of frequency calibration is +1-1/2% of the frequency to which the dial is set or +1-1/2 cycles per second, whichever is the larger. Voltage Range: The Analyzer will give usable indications on input voltages ranging from 1 millivolt to 10 volts. The meter scale is calibrated for reading directly component tones down to 1% of the sound pressure (or voltage) of the fundamental or loudest component. Accordingly, to make full use of this feature, the input voltage at the loudest component or fundamental should be 0.1 volt or higher. Input Impedance: The input impedance is between 20,000 and 30,000 ohms, depending upon the setting of the sensitivity control. A blocking capacitor is in series with the input. Frequency Response: The response is flat within +2 db over the entire range. At points where two ranges overlap, the sensitivity is the same on either range, within +1 db. BandWidth: The average selectivity is such that the relative attenuation is 3 db at 1% off the peak to which the Analyzer is tuned. Temperature and Humidity Effects: Under very severe conditions of temperature and humidity only slight, and generally negligible, shifts in calibration, sensitivity, and band width will occur. Meter: The indicating meter is calibrated in two ranges. The nominal ranges are 0 to - 30 db and -14 to -40 db. For convenience in use the meter scale is calibrated with the nominal range located 2 db below full scale on the meter, so that actual meter scales are +2 to -30 db and -12 to -40 db. Auxiliary percentage ranges of 0 to 120% and 0 to 24% are provided. Headphones: A jack is provided on the panel for plugging in a pair of head telephones, in order to listen to the actual component of the sound to which the instrument is tuned. This is also useful when the Analyzer is used as a bridge-balance indicator. Tubes: Three 1L4 and one 1U4 tubes are used together with a neon pilot light (NE-51). All are supplied. Batteries: The batteries required are four Burgess No. 2FBP 1.5-volt batteries, or the equivalent, and three Burgess No. Z30NX 45-volt batteries, or the equivalent. A compartment is provided in the case of the Analyzer for holding all batteries, and connections are automatically made to the batteries when the cover of this compartment is closed. A set of batteries is included in the price of the instrument. Accessories Supplied: A shielded cable-and-plug assembly for connecting the Analyzer to the sound-level meter. Case: The Analyzer is built into a shielded carrying case of airplane-luggage construction. Dimensions: (Length) 18 x (width) 10 x (height) 11-1/2 inches, overall. Net Weight: 36-1/2 pounds, with batteries; 29-3/4 pounds, without batteries.

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Service and User Manual
Manual Type:
Service and User Manual
Pages:
16
Size:
6.80 Mbytes (7125928 Bytes)
Language:
english
Revision:
Manual-ID:
695-D
Date:
1953 01 01
Quality:
Scanned document, all readable.
Upload date:
2016 12 30
MD5:
897fcd1f5527a3697c1d76073094498d
Downloads:
432