Shure VR300 specifications General, Operation

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		2 2 2 HARTREY AVE , EVANSTON, IL, 6		0 2 0 4 U.S.A.
	-.-...-	AREA CODE 3 121866-2200 CABLE: SHUREMICRO
.M.IOTII..O--LI		TWX: 9 10 - 231- 0 0 4 8	TELEX. 72 -	4381

DATA SHEET

MODEL VR300

M I C R O P H O N E S AND E L E C T R O N I C COMPONENTS

I

A

UNIDIRECTIONAL DYNAMIC MICROPHONE

m- +I0

-Z

U1W

:0

3

W

$ -10

W

20	50	100	1,000	l0,OOO 20,000
		FREOUENCY	IN HERTZ

*Distance from lips to microphone grille

TYPICAL FREQUENCY RESPONSE

FIGURE 1

Impedance

170 ohms actual

Output Level

Open Circuit Voltage* . . . . . . . . . . . -41.0 dB (8.9 mV) Power Level** . . . . . . . . . . . . . . . . . -59.5dB

*O dB = 1V1100 @bar

** 0 dB = 1 mWI10 ybar

Phasing

GENERAL

This microphone is designed especially for use in com- puter voice recognition applications. It is also suitable for other uses such as paging, talkback, and other communication-type applications where excellent voice fidelity and reduction of background noises are needed.

The frequency response is tailored to produce an essen- tially constant output voltage over the voice spectrum when used close to the sound source. The transducer is

alow-impedance, moving coil type with integral hum- bucking coil.

The microphone case is aluminum with a black enam- eled finish. It has a standard 5/a"-27 thread suitable for mounting on a flexible gooseneck, fixed pipe, or micro- phone stand. The unit is supplied with an attached two-conductor shielded cable with a built-in strain relief.

SPECIFICATIONS

Type

--Dynamic, Unidirectional (cardioid), Close-Talking

Frequency Response

100 to 7,000 Hz (see Figure 1)

Copyr~ght1982, Shure Brothers Inc

27A8048 (BL)

Positive pressure on diaphragm produces positive voltage on white conductor with respect to black conductor (see Figure 2)

VOICE	HUMBUCKING		CABLE
COIL	COIL ,-,---------
	-[,r	;BLACK	Ti;
	-I	WHITE	I

:-SHIELD =,

- - - - - ---

INTERNAL CONNECTIONS

FIGURE 2

Hum Pickup

Maximum 15 dB equivalent SPL in 1 mOe field

Cable

1.2m (4 ft) two-conductor shielded

Case

Aluminum with black enameled finish; stainless steel screen

Dimensions

See Figure 3

Net Weight

128 grams (4.5 oz)

OPERATION

To obtain the best performance with the VR300, the microphone must be used in a close-talking manner. The lips should be as close to the microphone grille as comfort permits, with a distance of 1 to 5 cm (0.4 to 2 in.) providing the greatest discrimination between voice and background noise.

P r ~ n t e dIn U.S.A.